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Sample records for defoliant thidiazuron gossypium

  1. Disruption of the polar auxin transport system in cotton seedlings following treatment with the defoliant thidiazuron. [Gossypium hirsutum L. cv LG102

    SciTech Connect

    Suttle, J.C.

    1988-01-01

    The effect of the defoliant thidiazuron (TDZ) on basipetal auxin transport in petiole segments isolated from cotton (Gossypium hirsutum L. cv LG102) seedlings was examined using the donor/receiver agar block technique. Treatment of intact seedlings with TDZ at concentrations of 1 micromolar or greater resulted in a dose-dependent inhibition of /sup 14/C-IAA transport in petiole segment isolated 1 or 2 days after treatment. Using 100 micromolar TDZ, the inhibition was detectable 19 hours after treatment and was complete by 27 hours. Both leaves and petiole segments exhibited a marked increase in ethylene production following treatment with TDZ at concentrations of 0.1 micromolar or greater. The involvement of ethylene in this TDA response was evaluated by examining the effects of two inhibitors of ethylene action: silver thiosulfate, 2,5-norbornadiene. One day after treatment, both inhibitors effectively antagonized the TDZ-induced inhibition of auxin transport. Two days after TDZ treatment both inhibitors were ineffective. The decrease in IAA transport in TDZ treated tissues was associated with increased metabolism of IAA. The transport of /sup 14/C-2,4-dichlorophenoxyacetic acid was also inhibited by TDZ treatment. This inhibition was not accompanied by increased metabolism. Incorporation of TDZ into the receiver blocks had no effect on auxin transport. The ability of the phytotropin N-1-naphthylphthalamic acid to stimulate IAA uptake from a bathing medium was reduced in TDZ-treated tissues. This reduction is thought to reflect a decline in the auxin efflux system following TDZ treatment.

  2. Involvement of ethylene in the action of the cotton defoliant thidiazuron.

    PubMed

    Suttle, J C

    1985-06-01

    The effect of the defoliant thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5-ylurea) on endogenous ethylene evolution and the role of endogenous ethylene in thidiazuron-mediated leaf abscission were examined in cotton (Gossypium hirsutum L. cv Stoneville 519) seedlings. Treatment of 20- to 30-day-old seedlings with thidiazuron at concentrations equal to or greater than 10 micromolar resulted in leaf abscission. At a treatment concentration of 100 micromolar, nearly total abscission of the youngest leaves was observed. Following treatment, abscission of the younger leaves commenced within 48 hours and was complete by 120 hours. A large increase in ethylene evolution from leaf blades and abscission zone explants was readily detectable within 24 hours of treatment and persisted until leaf fall. Ethylene evolution from treated leaf blades was greatest 1 day posttreatment and reached levels in excess of 600 nanoliters per gram fresh weight per hour (26.7 nanomoles per gram fresh weight per hour). The increase in ethylene evolution occurred in the absence of increased ethane evolution, altered leaf water potential, or decreased chlorophyll levels. Treatment of seedlings with inhibitors of ethylene action (silver thiosulfate, hypobaric pressure) or ethylene synthesis (aminoethoxyvinylglycine) resulted in an inhibition of thidiazuron-induced defoliation. Application of exogenous ethylene or 1-aminocyclopropane-1-carboxylic acid largely restored the thidiazuron response. The results indicate that thidiazuron-induced leaf abscission is mediated, at least in part, by an increase in endogenous ethylene evolution. However, alterations of other phytohormone systems thought to be involved in regulating leaf abscission are not excluded by these studies.

  3. Effect of the defoliant thidiazuron on ethylene evolution from mung bean hypocotyl segments.

    PubMed

    Suttle, J C

    1984-08-01

    The effect of the defoliant thidiazuron (N-phenyl-N'1,2,3-thiadiazol-5-ylurea) on ethylene evolution from etiolated mung bean hypocotyl segments was examined. Treatment of hypocotyl segments with concentrations of thidiazuron equal to or greater than 30 nanomolar stimulated ethylene evolution. Increased rates of ethylene evolution from thidiazuron-treated tissues could be detected within 90 minutes of treatment and persisted up to 30 hours after treatment. Radioactive methionine was readily taken up by thidiazuron-treated tissues and was converted to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) and an acidic conjugate of ACC. Aminoethoxyvinylglycine, aminooxyacetic acid, cobalt chloride, and alpha-aminoisobutyric acid reduced ethylene evolution from treated tissues. An increase in the endogenous content of free ACC coincided with the increase in ethylene evolution following thidiazuron treatment. Uptake and conversion of exogenous ACC to ethylene were not affected by thidiazuron treatment. No increases in the extractable activities of ACC synthase were detected following thidiazuron treatment.

  4. Disruption of the Polar Auxin Transport System in Cotton Seedlings following Treatment with the Defoliant Thidiazuron.

    PubMed

    Suttle, J C

    1988-01-01

    The effect of the defoliant thidiazuron (TDZ) on basipetal auxin transport in petiole segments isolated from cotton (Gossypium hirsutum L. cv LG102) seedlings was examined using the donor/receiver agar block technique. Treatment of intact seedlings with TDZ at concentrations of 1 micromolar or greater resulted in a dose-dependent inhibition of (14)C-IAA transport in petiole segments isolated 1 or 2 days after treatment. Using 100 micromolar TDZ, the inhibition was detectable 19 hours after treatment and was complete by 27 hours. Both leaves and petiole segments exhibited a marked increase in ethylene production following treatment with TDZ at concentrations of 0.1 micromolar or greater. The involvement of ethylene in this TDZ response was evaluated by examining the effects of two inhibitors of ethylene action: silver thiosulfate, 2,5-norbornadiene. One day after treatment, both inhibitors effectively antagonized the TDZ-induced inhibition of auxin transport. Two days after TDZ treatment both inhibitors were ineffective. The decrease in IAA transport in TDZ treated tissues was associated with increased metabolism of IAA. The transport of (14)C-2,4-dichlorophenoxyacetic acid was also inhibited by TDZ treatment. This inhibition was not accompanied by increased metabolism. Incorporation of TDZ into the receiver blocks had no effect on auxin transport. The ability of the phytotropin N-1-naphthylphthalamic acid to stimulate IAA uptake from a bathing medium was reduced in TDZ-treated tissues. This reduction is thought to reflect a decline in the auxin efflux system following TDZ treatment.

  5. Microbial degradation of thidiazuron and its photoproduct.

    PubMed

    Benezet, H J; Knowles, C O

    1982-01-01

    Degradation of the cotton defoliant thidiazuron and its photoproduct photothidiazuron by soil and thirteen species of microorganisms was examined. Aspergillus versicolor, Torula rosea, and Flavobacter sp. were most active in degrading thidiazuron. Unknown water-soluble metabolites and phenylurea were the major products. A. versicolor and Penicillium cyclopium were most active in degrading photothidiazuron. 4-Hydroxyphenylphotothidiazuron was the major organosoluble product formed by A. versicolor; phenylurea and an unidentified metabolite constituted the major organosoluble products from P. cyclopium. Both microbes also formed appreciable water-soluble metabolites. Radioactive carbon dioxide was formed from thidiazuron-aniline-14C by Oscillatoria sp. but not by Chlorella sp., suggesting that the former algal species utilized the defoliant as an energy source.

  6. Cotton defoliant runoff as a function of active ingredient and tillage.

    PubMed

    Potter, Thomas L; Truman, Clint C; Bosch, David D; Bednarz, Craig W

    2003-01-01

    Cotton (Gossypium hirsutum L.) defoliant runoff was recently identified as an ecological risk. However, assessments are not supported by field studies. Runoff potential of three defoliant active ingredients, dimethipin (2,3-dihydro-5,6-dimethyl-1,4-dithiin 1,1,4,4-tetraoxide), thidiazuron (N-phenyl-N-1,2,3-thidiazol-5-yl-urea), and tribufos (S,S,S-tributyl phosphorotrithioate) was investigated by rainfall simulation on strip (ST) and conventionally tilled (CT) cotton in south central Georgia. Simulated rainfall timing relative to defoliant application (1 h after) represented an extreme worst-case scenario; however, weather records indicate that it was not unrealistic for the region. Thidiazuron and tribufos losses were 12 to 15% of applied. Only 2 to 5% of the more water soluble dimethipin was lost. Although ST erosion rates were less, loss of tribufos, a strongly sorbing compound, was not affected. Higher sediment-water partition coefficients (kd) were measured in ST samples. This likely explains why no tillage related differences in loss rates were observed, but it is unknown whether this result can be generalized. The study was conducted in the first year following establishment of tillage treatments at the study site. As soil conditions stabilize, ST impacts may change. Data provide an estimate of the maximum amount of the defoliants that will run off during a single postapplication storm event. Use of these values in place of the default value in runoff simulation models used in pesticide risk assessments will likely improve risk estimate accuracy and enhance evaluation of comparative risk among these active ingredients.

  7. The Phytotoxin Coronatine Induces Abscission-Related Gene Expression and Boll Ripening during Defoliation of Cotton

    PubMed Central

    Tian, Xiaoli; Duan, Liusheng; Zhang, Mingcai; Tan, Weiming; Xu, Dongyong; Li, Zhaohu

    2014-01-01

    Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ. PMID:24845465

  8. The phytotoxin coronatine induces abscission-related gene expression and boll ripening during defoliation of cotton.

    PubMed

    Du, Mingwei; Li, Yi; Tian, Xiaoli; Duan, Liusheng; Zhang, Mingcai; Tan, Weiming; Xu, Dongyong; Li, Zhaohu

    2014-01-01

    Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ.

  9. Thidiazuron uptake, distribution and metabolism in bluegills and channel catfish.

    PubMed

    Knowles, C O; Benezet, H J; Mayer, F L

    1980-01-01

    Bluegills (Lepomis macrochirus) exposed to 0.1 ppm of thidiazuron-14C cotton defoliant for 28 days under continuous flow conditions accumulated relatively low levels of radiocarbon. The maximum detected was 5.4 ppm in fillet tissue after 1 day. During a 14 day depuration period, radioactivity declined to 1.0 ppm or less. Fractionation of offal and fillet tissues from bluegills collected at 28 days indicated that most of the radioactive material was water soluble, although appreciable amounts of organosoluble radioactive material also were present. When bluegills were injected intraperitoneally with thidiazuron-14C, metabolism and elimination were relatively rapid. Organosoluble radioactive material isolated from fish tissue included thidiazuron, its 2-hydroxyphenyl derivative, phenylurea, and several unknowns. Channel catfish (Ictalurus punctatus) exposed under static conditions to a system containing 0.15 ppm of thidiazuron-14C incorporated into soil also accumulated only low concentrations of radiocarbon. The maximum detected was 2.5 ppb in offal tissue at 7 days. In fillet tissue, radioactivity did not exceed 0.5 ppb. There was no evidence from these studies to indicate that thidiazuron would pose a hazard to the aquatic ecosystem.

  10. Effects of selected defoliants in combination with insecticides on sweetpotato whitefly (Hemiptera: Aleyrodidae) and its parasitoids in cotton

    USDA-ARS?s Scientific Manuscript database

    Effects of two defoliants, Def (S, S, Stributylphosphorotrithioate) and Dropp (thidiazuron) alone and in combination with two commonly used insecticides, a pyrethroid, Karate (lambda-cyhalothrin) and an organophosphate, Guthion (azinphosmethyl) on sweetpotato whitefly, Bemisia tabaci Gennadius Bioty...

  11. Molecular mapping and validation of a major QTL conferring resistance to a defoliating isolate of verticillium wilt in cotton (Gossypium hirsutum L.).

    PubMed

    Zhang, Xingju; Yuan, Yanchao; Wei, Ze; Guo, Xian; Guo, Yuping; Zhang, Suqing; Zhao, Junsheng; Zhang, Guihua; Song, Xianliang; Sun, Xuezhen

    2014-01-01

    Verticillium wilt (VW) caused by Verticillium dahliae Kleb is one of the most destructive diseases of cotton. Development and use of a VW resistant variety is the most practical and effective way to manage this disease. Identification of highly resistant genes/QTL and the underlining genetic architecture is a prerequisite for developing a VW resistant variety. A major QTL qVW-c6-1 conferring resistance to the defoliating isolate V991 was identified on chromosome 6 in LHB22×JM11 F2∶3 population inoculated and grown in a greenhouse. This QTL was further validated in the LHB22×NNG F2∶3 population that was evaluated in an artificial disease nursery of V991 for two years and in its subsequent F4 population grown in a field severely infested by V991. The allele conferring resistance within the QTL qVW-c6-1 region originated from parent LHB22 and could explain 23.1-27.1% of phenotypic variation. Another resistance QTL qVW-c21-1 originated from the susceptible parent JM11 was mapped on chromosome 21, explaining 14.44% of phenotypic variation. The resistance QTL reported herein provides a useful tool for breeding a cotton variety with enhanced resistance to VW.

  12. Molecular Mapping and Validation of a Major QTL Conferring Resistance to a Defoliating Isolate of Verticillium Wilt in Cotton (Gossypium hirsutum L.)

    PubMed Central

    Wei, Ze; Guo, Xian; Guo, Yuping; Zhang, Suqing; Zhao, Junsheng; Zhang, Guihua; Song, Xianliang; Sun, Xuezhen

    2014-01-01

    Verticillium wilt (VW) caused by Verticillium dahliae Kleb is one of the most destructive diseases of cotton. Development and use of a VW resistant variety is the most practical and effective way to manage this disease. Identification of highly resistant genes/QTL and the underlining genetic architecture is a prerequisite for developing a VW resistant variety. A major QTL qVW-c6-1 conferring resistance to the defoliating isolate V991 was identified on chromosome 6 in LHB22×JM11 F2∶3 population inoculated and grown in a greenhouse. This QTL was further validated in the LHB22×NNG F2∶3 population that was evaluated in an artificial disease nursery of V991 for two years and in its subsequent F4 population grown in a field severely infested by V991. The allele conferring resistance within the QTL qVW-c6-1 region originated from parent LHB22 and could explain 23.1–27.1% of phenotypic variation. Another resistance QTL qVW-c21-1 originated from the susceptible parent JM11 was mapped on chromosome 21, explaining 14.44% of phenotypic variation. The resistance QTL reported herein provides a useful tool for breeding a cotton variety with enhanced resistance to VW. PMID:24781706

  13. Thermal defoliation

    USDA-ARS?s Scientific Manuscript database

    The negative perception some consumers hold regarding agricultural chemicals has resulted in an increased demand for organic foods and fibers, and in increasing political pressure for the regulation of agricultural production practices. This has revived interest in thermal defoliation of cotton and ...

  14. Employing broadband spectra and cluster analysis to assess thermal defoliation of cotton

    USDA-ARS?s Scientific Manuscript database

    Growers and field scouts need assistance in surveying cotton (Gossypium hirsutum L.) fields subjected to thermal defoliation to reap the benefits provided by this nonchemical defoliation method. A study was conducted to evaluate broadband spectral data and unsupervised classification as tools for s...

  15. Forest insect defoliators

    Treesearch

    Philip T. Marshall

    1989-01-01

    Defoliation is the removal of all or part of the foliage from the tree. Forest insects are the primary agents that can cause defoliation. They produce the widespread, noticeable defoliation that forest landowners, foresters, and the general public can easily recognize.

  16. Efficiency of Tank-Mixing Insecticide with Defoliant Against Adult Boll Weevil (Coleoptera:Curculionidae) Populations as Determined by Late-Season Field Disturbance Trapping

    USDA-ARS?s Scientific Manuscript database

    Large commercial field plots were used to assess the effect of tank-mixing cyfluthrin with a defoliant applied in preparation for cotton, Gossypium hirsutum L., harvest on adult boll weevil, Anthonomus grandis grandis Boheman, populations in south Texas during 2002 and 2003. The defoliant-insectici...

  17. Simple sequence repeat marker associated with a natural leaf defoliation trait in tetraploid cotton.

    PubMed

    Abdurakhmonov, I Y; Abdullaev, A A; Saha, S; Buriev, Z T; Arslanov, D; Kuryazov, Z; Mavlonov, G T; Rizaeva, S M; Reddy, U K; Jenkins, J N; Abdullaev, A; Abdukarimov, A

    2005-01-01

    Cotton (Gossypium hirsutum L.) leaf defoliation has a significant ecological and economical impact on cotton production. Thus the utilization of a natural leaf defoliation trait, which exists in wild diploid cotton species, in the development of tetraploid cultivated cotton will not only be cost effective, but will also facilitate production of very high-grade fiber. The primary goal of our research was to tag loci associated with natural leaf defoliation using microsatellite markers in Upland cotton. The F2 populations developed from reciprocal crosses between the two parental cotton lines--AN-Boyovut-2 (2n = 52), a late leaf defoliating type, and Listopad Beliy (2n = 52), a naturally early leaf defoliating type--demonstrated that the naturally early leaf defoliation trait has heritability values of 0.74 and 0.84 in the reciprocal F2 population. The observed phenotypic segregation difference in reciprocal crosses suggested a minor cytoplasmic effect in the phenotypic expression of the naturally early leaf defoliation trait. Results from the Kruskal-Wallis (KW) nonparametric test revealed that JESPR-13 (KW = 6.17), JESPR-153 (KW = 9.97), and JESPR-178 (KW = 13.45) Simple sequence repeat (SSR) markers are significantly associated with natural leaf defoliation in the mapping population having stable estimates at empirically obtained critical thresholds (P < .05-.0001). JESPR-178 revealed the highest estimates (P < .0001) for association with the natural leaf defoliation trait, exceeding maximum empirical threshold values. JESPR-178 was assigned to the short arm of chromosome 18, suggesting indirectly that genes associated with natural leaf defoliation might be located on this chromosome. This microsatellite marker may have the potential for use to introgress the naturally early leaf defoliation quantitative trait loci (QTL) from the donor line Listopad Beliy to commercial varieties of cotton through marker-assisted selection programs.

  18. Cotton thermal defoliation economics

    USDA-ARS?s Scientific Manuscript database

    Cotton harvest-aid chemical and application expenses are justified by increased quantity and value of harvested fiber, and decreased harvest costs. Chemical use may be restricted in certain production situations. Harvest preparation costs and producer returns were compared for thermal defoliation ...

  19. 40 CFR 180.403 - Thidiazuron; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Thidiazuron; tolerances for residues. 180.403 Section 180.403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... 0.4 Cattle, meat byproducts 0.4 Cotton, gin byproducts 24.0 Cotton, undelinted seed 0.3 Goat, fat 0...

  20. Defoliation potential of gypsy moth

    Treesearch

    David A. Gansner; David A. Drake; Stanford L. Arner; Rachel R. Hershey; Susan L. King; Susan L. King

    1993-01-01

    A model that uses forest stand characteristics to estimate the likelihood of gypsy moth (Lymantria dispar L.) defoliation has been developed. It was applied to recent forest inventory plot data to produce susceptibility ratings and maps showing current defoliation potential in a seven-state area where gypsy moth is an immediate threat.

  1. Historical Gypsy Moth Defoliation Frequency

    EPA Pesticide Factsheets

    Gypsy moth populations may exist for many years at low densities such that it may be difficult to find any life stages. Then, for reasons that are not completely understood, populations may rise to very high densities and substantial defoliation of the canopy may occur. These data shows the historical frequency (1972-2002) pattern of gypsy moth defoliation as it spreads south and west from the New England states. forested areas with repeated annual defoliation become more stressed and are at increased risk of permanent damage. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  2. Sagebrush defoliator outbreak in Northern California

    Treesearch

    Ralph C. Hall

    1965-01-01

    The sagebrush defoliator was responsible for varying degrees of sagebrush defoliation and mortality over a widespread area in southeastern Oregon, northeastern California, and northwestern Nevada in 1963 and 1964. Severe defoliation sometimes killed sagebrush in a single season. Indications are that the outbreak will continue at least another season. A....

  3. A Ve homologous gene from Gossypium barbadense, Gbvdr3, enhances the defense response against Verticillium dahliae.

    PubMed

    Chen, Tianzi; Kan, Jialiang; Yang, Yuwen; Ling, Xitie; Chang, Youhong; Zhang, Baolong

    2016-01-01

    The tomato Ve1 gene and several Ve1 homologues are involved in the resistance to Verticillium dahliae. Here, we report on another Ve homologous gene, Gbvdr3, from a Verticillium wilt-resistant cotton cultivar, Gossypium barbadense Hai7124, which has a 3207-bp region that encodes a predicted receptor-like protein. Transient expression analyses indicated that Gbvdr3 is localized in the plasma membrane, and virus-induced gene silencing of Gbvdr3 compromised the resistance of Hai7124 cotton to a defoliating strain of V. dahliae, V991, but not to a non-defoliating strain, BP2. This resistance pattern was further confirmed by over-expression of Gbvdr3 in transgenic Arabidopsis, which significantly elevated the expression of the ethylene-regulated gene GST2, the ethylene- and jasmonic acid-regulated defense-related genes PR3 and PDF1.2, and the salicylic acid-regulated genes PR1 and PR5, but not the PR2 gene. It also triggered the accumulation of hydrogen peroxide and callose at early time points during infection by the V991 defoliating strain. In contrast, elevated accumulation of hydrogen peroxide or callose in Gbvdr3-expressed Arabidopsis leaves was not apparent under infection by the non-defoliating strain, BP2. These results suggested that Gbvdr3 is involved in the resistance to a unique spectrum of defoliating V. dahliae strains.

  4. Multiresidue analysis of cotton defoliant, herbicide, and insecticide residues in water by solid-phase extraction and GC-NPD, GC-MS, and HPLC-diode array detection.

    PubMed

    Potter, T L; Marti, L; Belflower, S; Truman, C C

    2000-09-01

    A multiresidue procedure was developed for analysis of cotton pesticide and harvest-aid chemicals in water using solid-phase extraction and analysis by GC-NPD, GC-MS, and HPLC-DAD. Target compounds included the defoliants tribufos, dimethipin, thidiazuron; the herbicide diuron; and the insecticide methyl parathion. Three solid-phase extraction (SPE) media, octadecylsilyl (ODS), graphitized carbon black (GCB), and a divinylbenzene-N-vinyl pyrollidine copolymer (DVBVP), were evaluated. On GCB and ODS, recoveries varied depending on compound type. Recoveries were quantitative for all compounds on DVBVP, ranging from 87 to 115% in spiked deionized water and surface runoff. The method detection limit was less than 0.1 microg L(-)(1). SPE with DVBVP was applied to post-defoliation samples of surface runoff and tile drainage from a cotton research plot and surface runoff from a commercial field. The research plot was defoliated with a tank mixture of dimethipin and thidiazuron, and the commercial field, with tribufos. Dimethipin was detected (1.9-9.6 microg L(-)(1)) in all research plot samples. In the commercial field samples, tribufos concentration ranged from 0.1 to 135 microg L(-)(1). An exponentially decreasing concentration trend was observed with each successive storm event.

  5. Mapping the defoliation potential of gypsy moth

    Treesearch

    David A. Gansner; Stanford L. Arner; Rachel Riemann Hershey; Susan L. King

    1993-01-01

    A model that uses forest stand characteristics to estimate the likelihood of gypsy moth (Lymantria dispar) defoliation has been developed. It was applied to recent forest inventory plot data to produce susceptibility ratings and a map showing defoliation potential for counties in Pennsylvania and six adjacent states on new frontiers of infestation.

  6. Effects of defoliation by gypsy moth

    Treesearch

    Mark J. Twery

    1991-01-01

    Defoliation of trees by the gypsy moth (Lymantria dispar L.) has many and varied effects. It causes economic losses through lost forest production and reduced aesthetic qualities of the forest. However, defoliation may improve habitat for many species of wildlife and contribute to increased diversity of eastern forests. Effects on water resources,...

  7. Rating forest stands for gypsy moth defoliation

    Treesearch

    Owen W. Herrick; David A. Gansner; David A. Gansner

    1986-01-01

    The severity of future defoliation can be estimated from the percentages of basal area in oaks (Quercus), black oak (Q. velutina) and chestnut oak (a prinus), and in trees with good crowns, along with the average diameter of the stand. With information on these variables, the defoliation potential of any hardwood forest stand in an approaching gypsy moth (Lymantria...

  8. Thidiazuron promotes high frequency regeneration of peanut (Arachis hypogaea) plants in vitro.

    PubMed

    Kanyand, M; Dessai, A P; Prakash, C S

    1994-11-01

    Multiple shoots were induced on Valenciatype peanut (Arachis hypogaea L.) explants cultured in vitro on a nutrient medium supplemented with thidiazuron. Zygotic embryos excised from mature seeds were germinated on Murashige-Skoog nutrient medium, and the resulting plantlets (8 days-old) were used as a source of explants. When cultured on a nutrient medium with increasing levels of thidiazuron (0.5 to 30 mg/l), expiants from various parts of the peanut plant (except the root) produced multiple shoot primordia which subsequently developed into individual shoots. Hypocotyl and cotyledon explants produced shoots in higher numbers than other explants (20 shoots per hypocotyl explant at all thidiazuron concentrations and 15 shoots per cotyledon explant at 30 mg/l). Shoots rooted normally on a basal Murashige-Skoog medium containing charcoal and developed into healthy and fertile plants when planted in soil.

  9. What causes the patterns of gypsy moth defoliation?

    Treesearch

    Clive G. Jones

    1991-01-01

    Gypsy moth defoliation is typically observed to occur on xeric ridge tops before more mesic, lowland forest, in oak-dominated habitats in the Northeast. In subsequent years defoliation may also occur in mesic forests. What causes this pattern of defoliation? Differences in the degree of defoliation may be due to differences in the density of gypsy moth populations in...

  10. Differentiating pollen from four species of Gossypium

    USDA-ARS?s Scientific Manuscript database

    Cotton, Gossypium (Malvaceae), has been spun, woven, and dyed since prehistoric times. Four cotton species are economically important, Gossypium arboreum (tree cotton), G. barbadense (American pima cotton), G. herbaceum (levant cotton), and G. hirsutum (American upland cotton). Previous research h...

  11. The Pennsylvania defoliation application pilot test

    NASA Technical Reports Server (NTRS)

    Mcleod, R. G.; Zobrist, A. L.; Bryant, N. A.

    1983-01-01

    Satellite imagery for the State of Pennsylvania was digitally mosaicked to provide the seed data base for monitoring defoliation of hardwood trees by the gypsy moth. Two separate mosaics for the state were prepared, one before defoliation and one after defoliation, to determine the extent, direction, and impact of gypsy moth activity in the state. The digital mosaic technology used to construct the data base was transferred to Pennsylvania State University to permit periodic updates to the data base and to assist in planning and abatement activities. Participating agencies or institutions included Goddard Space Flight Center and the Pennsylvania State University Office for Remote Sensing of Earth Resources.

  12. [Determination of eight defoliant residues in cotton by accelerated solvent extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Wu, Gang; Dong, Suozhuai; Pan, Lulu; Zhao, Shanhong; Wang, Lijun; Guo, Fanglong; Li, Dan

    2013-07-01

    A novel method has been developed for the rapid extraction and determination of eight defoliants including thidiazuron, butiphos, methabenzthiazuron, abscisic acid, carfentra-zone-ethyl, diuron, paraquat, and pyrithiobac-sodium in cotton by accelerated solvent extraction (ASE) coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The defoliants in cotton were extracted by ASE and the extracts were dried by a rotavapor, then redissolved in the solvents of acetonitrile and water (1:9, v/v). The chromatographic analysis was performed on an Acquity UPLC HSS T3 column (50 mmx 2. 1 mm, 1. 8 microm) by a gradient elution employing of acetonitrile and 0.05% (v/v) formic acid as mobile phases. The analytes were detected by electrospray ionization (ESI) tandem mass spectrometry with multiple reaction monitoring (MRM) in positive ion mode. Good linearities (r >0.99) were observed between 0. 01 and 0. 3 mg/L for all the compounds. The recoveries and relative standard deviations (RSDs) were obtained by spiking untreated samples with the eight defoliants at 0. 1, 0. 5 and 1.0 mg/kg. The average recoveries of the eight defoliants were from (84. 18 +/- 8.04)% to (95.99 +/- 6.76)%. The precision values expressed as RSDs were from 7. 04% to 10. 60% (n = 6). The limits of detection were 0. 8 - 29 microg/kg and the limits of quantification were 2.5 - 96 1/4g/kg for the analytes. The results ahowed that the method is simple, rapid, sensitive and accurate, and is suitable for the quantitative determination and confirmation of the eight defoliants in cotton.

  13. TREATMENT WITH THIDIAZURON IMPROVES OPENING AND VASE LIFE OF IRIS FLOWERS

    USDA-ARS?s Scientific Manuscript database

    The marketability of Dutch iris (Iris × hollandica) cut flowers is limited by their short display life and frequent failure to open fully. We tested the ability of thidiazuron (TDZ), a phenyl urea compound with cytokinin-like activity, to improve iris flower opening and longevity. A postharvest pu...

  14. Thidiazuron, a non-metablized cytokinin, shows promise in extending the life of potted plants

    USDA-ARS?s Scientific Manuscript database

    Application of low concentrations of thidiazuron (N-phenyl-N’-1,2,3-thiadiazol-5-yl urea, TDZ) has been shown to be a very effective means of delaying leaf yellowing in cut flowers such as alstroemeria, stock, lilies and tulips. We examined the possible use of this compound for delaying leaf yellow...

  15. Future Risk of Gypsy Moth Defoliation

    EPA Pesticide Factsheets

    Data from the suitable habitat combined with forest density, and adjusted by prefered species basal area and the predicited geographic pattern of defoliation can be used to predict future potential for gypsy moth defoliation. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  16. Genetic diversity in Gossypium genus

    USDA-ARS?s Scientific Manuscript database

    The overall objectives of this paper are to report on cotton germplasm resources, morphobiological and agronomic diversity of Gossypium genus and review efforts on molecular genetic diversity of cotton gene pools as well as on the challenges and perspectives of exploiting genetic diversity in cotton...

  17. Gypsy moth egg-mass density and subsequent defoliation

    Treesearch

    Robert W. Campbell

    1966-01-01

    The relationship between insect density and subsequent defoliation is usually important among the many factors involved in deciding if, when, and where to take control action against a defoliator such as the gypsy moth. Unfortunately, the proportion of the foliage that will be removed by a defoliator in any given place and year depends not only upon the number of...

  18. Tree condition and mortality following defoliation by the gypsy moth

    Treesearch

    Robert W. Campbell; Harry T. Valentine; Harry T. Valentine

    1972-01-01

    Relationships between expected defoliation and the subsequent condition and mortality rate among the defoliated trees are almost always important factors in deciding if, when, and where to take control action against a defoliator such as the gypsy moth, Porthetria dispar (L. )

  19. Simulated impacts of insect defoliation on forest carbon dynamics

    Treesearch

    D. Medvigy; K.L. Clark; N.S. Skowronski; K.V.R. Schäfer

    2012-01-01

    Many temperate and boreal forests are subject to insect epidemics. In the eastern US, over 41 million meters squared of tree basal area are thought to be at risk of gypsy moth defoliation. However, the decadal-to-century scale implications of defoliation events for ecosystem carbon dynamics are not well understood. In this study, the effects of defoliation intensity,...

  20. Defoliation and oak mortality in Southern New England

    Treesearch

    Jeffrey S. Ward

    2007-01-01

    Crown class and diameter of 4088 upland oaks have been monitored at 10-year intervals since 1927. Plots had three episodes of moderate to heavy defoliation: 1961-1964, 1971-1972, and 1981. Primary defoliators were gypsy moth, canker worm, and elm spanworm. Mortality peaked during the period of 1957-1967 when there were three years of defoliation. Mortality was higher...

  1. Simulated impacts of insect defoliation on forest carbon dynamics

    NASA Astrophysics Data System (ADS)

    Medvigy, D.; Clark, K. L.; Skowronski, N. S.; Schäfer, K. V. R.

    2012-12-01

    Many temperate and boreal forests are subject to insect epidemics. In the eastern US, over 41 million meters squared of tree basal area are thought to be at risk of gypsy moth defoliation. However, the decadal-to-century scale implications of defoliation events for ecosystem carbon dynamics are not well understood. In this study, the effects of defoliation intensity, periodicity and spatial pattern on the carbon cycle are investigated in a set of idealized model simulations. A mechanistic terrestrial biosphere model, ecosystem demography model 2, is driven with observations from a xeric oak-pine forest located in the New Jersey Pine Barrens. Simulations indicate that net ecosystem productivity (equal to photosynthesis minus respiration) decreases linearly with increasing defoliation intensity. However, because of interactions between defoliation and drought effects, aboveground biomass exhibits a nonlinear decrease with increasing defoliation intensity. The ecosystem responds strongly with both reduced productivity and biomass loss when defoliation periodicity varies from 5 to 15 yr, but exhibits a relatively weak response when defoliation periodicity varies from 15 to 60 yr. Simulations of spatially heterogeneous defoliation resulted in markedly smaller carbon stocks than simulations with spatially homogeneous defoliation. These results show that gypsy moth defoliation has a large effect on oak-pine forest biomass dynamics, functioning and its capacity to act as a carbon sink.

  2. Defoliation effects on pasture photosynthesis and respiration

    USDA-ARS?s Scientific Manuscript database

    Ecosystem C gain or loss from managed grasslands can depend on the type and intensity of management practices that are employed. However, limited information is available at the field scale on how the type of defoliation, specifically grazing vs. cutting, affects gross primary productivity (GPP) an...

  3. Chemical free cotton defoliation and dessication

    USDA-ARS?s Scientific Manuscript database

    Preliminary results are presented for new techniques to achieve chemical free means of cotton defoliation and desiccation. Report will cover test results, for several different methods, as tested on; greenhouse, outdoor grown potted plants, and field grown cotton plants, that were grown under commer...

  4. Predicting tree mortality following gypsy moth defoliation

    Treesearch

    D.E. Fosbroke; R.R. Hicks; K.W. Gottschalk

    1991-01-01

    Appropriate application of gypsy moth control strategies requires an accurate prediction of the distribution and intensity of tree mortality prior to defoliation. This prior information is necessary to better target investments in control activities where they are needed. This poster lays the groundwork for developing hazard-rating systems for forests of the...

  5. Differentiating pollen from four species of Gossypium

    USDA-ARS?s Scientific Manuscript database

    Cotton, Gossypium (Malvaceae) has been spun, woven, and dyed since prehistoric times. Four cotton species are economically important, Gossypium arboreum (tree cotton), G. barbadense (American pima cotton), G. herbaceum (levant cotton), and G. hirsutum (American upland cotton). Some research has be...

  6. Outbreaks of forest defoliating insects in Japan, 1950-2000.

    PubMed

    Kamata, N; Kamata, N

    2002-04-01

    In Japan, several forest-defoliating insects reach outbreak levels and cause serious defoliation. Stand mortality sometimes occurs after severe defoliation. However, in general, tree mortality caused by insect defoliation is low because of the prevailing moist climate in Japan. Evergreen conifers are more susceptible to tree mortality as a result of insect defoliation whereas deciduous broad-leaved trees are seldom killed. Insect defoliation occurs more frequently in man-made environments such as among shade trees, orchards, and plantations than in natural habitats. Outbreaks of some defoliators tend to occur in stands of a particular age: e.g. outbreaks of the pine caterpillar, Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae) occur more frequently in young pine plantations. In contrast, defoliation caused by outbreaks of lepidopterous and hymenopterous pests in larch plantations is more frequent with stand maturation. There is a relationship between outbreaks of some defoliators and altitude above sea level. Most outbreaks of forest defoliators were terminated by insect pathogens that operated in a density-dependent fashion. Since the 1970s, Japan has been prosperous and can afford to buy timber from abroad. More recently, there has been an increasing demand for timber in Japan, that coincides with a huge demand internationally, so that the country will need to produce more timber locally in the future. The increasing pressure on the forestry industry to meet this demand will require more sophisticated methods of pest control coupled with more sustainable methods of silviculture.

  7. Aerial Photography: Use in Detecting Simulated Insect Defoliation in Corn

    NASA Technical Reports Server (NTRS)

    Chiang, H. C.; Latham, R.; Meyer, M. P.

    1973-01-01

    Artificial defoliation in corn was used to explore the usefulness of aerial photography in detecting crop insect infestations. Defoliation on the top of plants was easily detected, while that on the base was less so. Aero infrared film with Wratten 89B filter gave the best results, and morning flights at the scale of 1:15840 are recommended. Row direction, plant growth stage, and time elapse since defoliation were not important factors.

  8. Aerial Photography: Use in Detecting Simulated Insect Defoliation in Corn

    NASA Technical Reports Server (NTRS)

    Chiang, H. C.; Latham, R.; Meyer, M. P.

    1973-01-01

    Artificial defoliation in corn was used to explore the usefulness of aerial photography in detecting crop insect infestations. Defoliation on the top of plants was easily detected, while that on the base was less so. Aero infrared film with Wratten 89B filter gave the best results, and morning flights at the scale of 1:15840 are recommended. Row direction, plant growth stage, and time elapse since defoliation were not important factors.

  9. Wood formation in Abies balsamea seedlings subjected to artificial defoliation.

    PubMed

    Rossi, Sergio; Simard, Sonia; Deslauriers, Annie; Morin, Hubert

    2009-04-01

    We determined the cambial sensitivity and quantified the anatomical differences in xylem of Abies balsamea (L.) Mill. seedlings subjected to artificial defoliation to simulate spruce budworm feeding. Defoliation was performed by removing two-thirds of needles of all current-year shoots for up to four consecutive growth cycles to account for inter- and intra-annual xylem formation. In Experiment 1, xylem development was studied from May to October 2005 in seedlings defoliated at the end of June. In Experiment 2, anatomical features of the xylem were measured along the tree rings formed in 2005 and 2006 during the four cycles of growth and defoliation. Control and defoliated seedlings showed similar patterns of cambial activity and timing of xylem differentiation, although fewer enlarging cells were observed in August to September in defoliated seedlings. Tree-ring widths were similar in control and defoliated seedlings, with thinner rings produced in the greenhouse in winter. No effect of defoliation on cell lumen area was observed, and effects on radial cell diameter and wall thickness were found only occasionally. The results indicate that the A. balsamea seedlings produced all the resources required to maintain stem growth during the four cycles of defoliation.

  10. Impacts of Insect Defoliation in Cottonwood Plantations in Mississippi

    Treesearch

    Theodor D. Leininger; Nathan M. Schiff; Jackie Henne-Kerr

    2004-01-01

    In spring 2001, a notodontid moth, Gluphisia septentrionis Wlkr., defoliated about 2,000 acres of 9- and 10- year-old eastern cottonwood (Populus deltoides Bartr.) trees in west central Mississippi. The farm manager had never seen cottonwood defoliated by that species of moth, because it was not considered a pest in Mississippi....

  11. Status and trends in gypsy moth defoliation hazard in Tennessee

    Treesearch

    Dennis M. May; Bruce W. Kauffman

    1990-01-01

    The gypsy moth, Lymantria dispar (L.), a major defoliator of eastern hardwood forests, has become established in Virginia and is moving towards Tennessee. In preparation for its inevitable arrival, Tennessee’s timberlands are hazard rated to identify those areas most susceptible to gypsy moth defoliation. Tree, stand, and site characteristics...

  12. Susceptibility of regeneration in clearcuts to defoliation by gypsy moth

    Treesearch

    Ray R., Jr. Hicks; Robert M. Fultineer; Barbara S. Ware; Kurt W. Gottschalk

    1993-01-01

    In 1991 and 1992, we observed gypsy moth defoliation of oak regeneration in clearcuts of varying sizes and ages. We established plots in the surrounding mature forests to document ambient gypsy moth population levels and placed subplots within the clearcuts designed to examine the effect of location relative to the clearcut edge. We found that the levels of defoliation...

  13. Role of corticular photosynthesis following defoliation in Eucalyptus globulus.

    PubMed

    Eyles, Alieta; Pinkard, Elizabeth A; O'Grady, Anthony P; Worledge, Dale; Warren, Charles R

    2009-08-01

    Defoliation can reduce net fixation of atmospheric CO(2) by the canopy, but increase the intensity and duration of photosynthetically active radiation on stems. Stem CO(2) flux and leaf gas exchange in young Eucalyptus globulus seedlings were measured to assess the impact of defoliation on these processes and to determine the potential contribution of re-fixation by photosynthetic inner bark in offsetting the effects of defoliation in a woody species. Pot and field trials examined how artificial defoliation of the canopy affected the photosynthetic characteristics of main stems of young Eucalyptus globulus seedlings. Defoliated potted seedlings were characterized by transient increases in foliar photosynthetic rates and concomitant decreases in stem CO(2) fluxes (both in the dark and light). Defoliated field-grown seedlings showed similar stem CO(2) flux responses, but of reduced magnitude. Despite demonstrating increased re-fixation capability, defoliated potted-seedlings had slowed stem growth. The green stem of seedlings exhibited largely shade-adapted characteristics. Defoliation reduced stem chlorophyll a/b ratio and increased carotenoid concentration. An increased capacity to re-fix internally respired CO(2) (up to 96%) suggested that stem re-fixation represents a previously unexplored mechanism to minimize the impact of foliar loss by maximizing the contribution of all photosynthetic tissues, particularly for young seedlings.

  14. Effects of defoliation on growth of certain conifers

    Treesearch

    Thomas W., Jr. Church

    1949-01-01

    In planning forest management of spruce-fir forests in the Northeast, the possibility of recurring epidemics of the spruce budworm (Archips fumiferana) must be considered. Investigations of this insect must take into account not only the effects of defoliation on mortality, but also the growth losses that result from partial defoliation.

  15. Non-defoliating and defoliating strains from cotton correlate with races 1 and 2 of Verticillium dahliae

    USDA-ARS?s Scientific Manuscript database

    Verticillium wilt caused by Verticillium dahliae is an important disease of cotton worldwide. Isolates of V. dahliae can be characterized as race 1 or race 2 based on the responses of differential cultivars of tomato and lettuce or as defoliating or non-defoliating based on symptom expression in cot...

  16. Regeneration in defoliated and thinned hardwood stands of north-central West Virginia

    Treesearch

    R. M. Muzika; M. J. Twery

    1995-01-01

    Overstory species regeneration was examined in 1989, prior to gypsy moth defoliation and thinnings, on 16 stands in the West Virginia University Forest. Three stands were thinned and defoliated while five were thinned only and three were defoliated only. Five stands were neither thinned nor defoliated. Data were collected from these stands for three years subsequent to...

  17. A general Landsat model to predict canopy defoliation in broadleaf deciduous forests

    Treesearch

    Phillip A. Townsend; Aditya Singh; Jane R. Foster; Nathan J. Rehberg; Clayton C. Kindon; Keith N. Eshleman; Steven W. Seagle

    2012-01-01

    Defoliation by insect herbivores can be a persistent disturbance affecting ecosystem functioning. We developed an approach to map canopy defoliation due to gypsy moth based on site differences in Landsat vegetation index values between non-defoliation and defoliation dates. Using field data from two study areas in the U.S. central Appalachians and five different years...

  18. Monitoring Tamarisk Defoliation and Scaling Evapotranspiration Using Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Dennison, P. E.; Hultine, K. R.; Nagler, P. L.; Miura, T.; Glenn, E. P.; Ehleringer, J. R.

    2008-12-01

    Non-native tamarisk (Tamarix spp.) has invaded riparian ecosystems throughout the Western United States. Another non-native species, the saltcedar leaf beetle (Diorhabda elongata), has been released in an attempt to control tamarisk infestations. Most efforts directed towards monitoring tamarisk defoliation by Diorhabda have focused on changes in leaf area or sap flux, but these measurements only give a local view of defoliation impacts. We are assessing the ability of remote sensing data for monitoring tamarisk defoliation and measuring resulting changes in evapotranspiration over space and time. Tamarisk defoliation by Diorhabda has taken place during the past two summers along the Colorado River and its tributaries near Moab, Utah. We are using 15 meter spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and 250 meter spatial resolution Moderate Resolution Imaging Spectrometer (MODIS) data to monitor tamarisk defoliation. An ASTER normalized difference vegetation index (NDVI) time series has revealed large drops in index values associated with loss of leaf area due to defoliation. MODIS data have superior temporal monitoring abilities, but at the sacrifice of much lower spatial resolution. A MODIS enhanced vegetation index time series has revealed that for pixels where the percentage of riparian cover is moderate or high, defoliation is detectable even at 250 meter spatial resolution. We are comparing MODIS vegetation index time series to site measurements of leaf area and sap flux. We are also using an evapotranspiration model to scale potential water savings resulting from the biocontrol of tamarisk.

  19. Forecasting defoliation by the gypsy moth in oak stands

    Treesearch

    Robert W. Campbell; Joseph P. Standaert

    1974-01-01

    A multiple-regression model is presented that reflects statistically significant correlations between defoliation by the gypsy moth, the dependent variable, and a series of biotic and physical independent variables. Both possible uses and shortcomings of this model are discussed.

  20. Ethylene: a factor in defoliation induced by auxins.

    PubMed

    Hallaway, M; Osborne, D J

    1969-03-07

    Aerial sprays of synthetic auxins defoliate many species of tropical trees. Treatment of Euonymus japonica leaves with the n-butyl ester of 2,4-dichlorophenoxyacetic acid causes premature senescence and leaf fall and stimulates ethylene production by the blade 5-to 25-fold. Exposure to ethylene alone similarly accelerates senescence and leaf fall. Evidence indicates that the defoliant action of auxin is mediated through the enhanced amounts of ethylene in the blade.

  1. Gossypium arboreum accessions resistant to Rotylenchulus reniformis

    USDA-ARS?s Scientific Manuscript database

    In the southeastern United States, reniform nematode (Rotylenchulus reniformis) is a serious pest of upland cotton (Gossypium hirsutum), a species which has no naturally-occurring resistance against this nematode. To identify sources of reniform nematode resistance in species closely related to upla...

  2. Introgression of resistance to reniform nematode (Rotylenchulus reniformis) into upland cotton (Gossypium hirsutum) from Gossypium arboreum and a Gossypium hirsutum/Gossypium aridum bridging line

    USDA-ARS?s Scientific Manuscript database

    Gossypium hirsutum is the predominant cotton of commerce and all cultivars of this species are susceptible to the reniform nematode, Rotylenchulus reniformis. To introgress resistance to R. reniformis into the tetraploid 2(AD1) G. hirsutum, a resistant diploid A2-genome G. arboreum accession (A2-19...

  3. Assessing MODIS-based Products and Techniques for Detecting Gypsy Moth Defoliation

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.; Hargrove, William; Smoot, James C.; Prados, Don; McKellip, Rodney; Sader, Steven A.; Gasser, Jerry; May, George

    2008-01-01

    The project showed potential of MODIS and VIIRS time series data for contributing defoliation detection products to the USFS forest threat early warning system. This study yielded the first satellite-based wall-to-wall 2001 gypsy moth defoliation map for the study area. Initial results led to follow-on work to map 2007 gypsy moth defoliation over the eastern United States (in progress). MODIS-based defoliation maps offer promise for aiding aerial sketch maps either in planning surveys and/or adjusting acreage estimates of annual defoliation. More work still needs to be done to assess potential of technology for "now casts"of defoliation.

  4. Growth and mortality of trembling aspen (Populus tremuloides) in response to artificial defoliation

    NASA Astrophysics Data System (ADS)

    Moulinier, Julien; Lorenzetti, François; Bergeron, Yves

    2014-02-01

    To simulate the effects of forest tent caterpillar (FTC) defoliation on trembling aspen growth and mortality, an artificial defoliation experiment was performed over three years in young aspen stands of northwestern Quebec. Defoliation plots of 15 × 15 m were established on three sites, together with associated control stands of pure trembling aspen. In 2007, root collar diameters were measured and positions of all trees were mapped prior defoliation. Severe FTC defoliation was simulated for three successive years (2007-2009) by manually removing all leaves from all but 7-10% of the trees present in the defoliation plots. Yearly surveys of growth and mortality were conducted until 2010 to evaluate defoliation effects on defoliated as well as surrounding undefoliated trees. In absence of other factors, growth and mortality of trembling aspen decreased and increased, respectively, after defoliation. Our study further revealed that small diameter trees died after one year of artificial defoliation, while larger-diameter trees died after repeated defoliations. Distributions of tree mortality tended to be aggregated at small scales (<5 m), corroborating gap patterns observed in mature stands following FTC outbreaks. This experiment revealed that trembling aspen mortality can be directly attributed solely to defoliation. Repeated defoliations during FTC outbreaks have the potential to profoundly modify stand productivity and structure by reducing tree growth and increasing tree mortality in the absence of predisposing factors.

  5. Glycoalkaloid responses of potato to Colorado potato beetle defoliation.

    PubMed

    Pariera Dinkins, Courtney L; Peterson, Robert K D; Gibson, James E; Hu, Qing; Weaver, David K

    2008-08-01

    Two experiments were conducted to measure the glycoalkaloid concentrations of potato tubers in response to Colorado potato beetle and manual defoliation. For plants defoliated by Colorado potato beetles, there was a significantly greater production of glycoalkaloids than in control plants and manually defoliated plants for both skin and inner tissue of tubers in experiment 1. In experiment 1, there was a 58.1% and 48.3% increase in glycoalkaloids in skin and inner tissue of tubers, respectively, from plants defoliated at high levels by Colorado potato beetles compared to control plants. In experiment 2, although a significant difference in glycoalkaloid concentration was not observed among the treatments, the skin and inner tissue of tubers from plants defoliated at high levels by Colorado potato beetles increased glycoalkaloid concentration by 23.4% and 14.5%, respectively, compared to tubers from control plants. In experiment 1, the concentration of tuber extract required to reduce Chinese hamster ovary (CHO) cellular proliferation by 50% was 10-fold less for the skin versus the inner tissue, indicating that skin tissue was more toxic under the in vitro conditions of this assay.

  6. An Experimental Comparison of Two Methods on Photosynthesis Driving Soil Respiration: Girdling and Defoliation.

    PubMed

    Jing, Yanli; Guan, Dexin; Wu, Jiabing; Wang, Anzhi; Jin, Changjie; Yuan, Fenghui

    2015-01-01

    Previous studies with different experimental methods have demonstrated that photosynthesis significantly influences soil respiration (RS). To compare the experimental results of different methods, RS after girdling and defoliation was measured in five-year-old seedlings of Fraxinus mandshurica from June to September. Girdling and defoliation significantly reduced RS by 33% and 25% within 4 days, and 40% and 32% within the entire treatment period, respectively. The differential response of RS to girdling and defoliation was a result of the over-compensation for RS after girdling and redistribution of stored carbon after defoliation. No significant effect on RS was observed between girdling and defoliation treatment, while the soluble sugar content in fine roots was higher in defoliation than in girdling treatment, indicating that defoliation had less compensation effect for RS after interrupting photosynthates supply. We confirm the close coupling of RS with photosynthesis and recommend defoliation for further studies to estimate the effect of photosynthesis on RS.

  7. An Experimental Comparison of Two Methods on Photosynthesis Driving Soil Respiration: Girdling and Defoliation

    PubMed Central

    Jing, Yanli; Guan, Dexin; Wu, Jiabing; Wang, Anzhi; Jin, Changjie; Yuan, Fenghui

    2015-01-01

    Previous studies with different experimental methods have demonstrated that photosynthesis significantly influences soil respiration (RS). To compare the experimental results of different methods, RS after girdling and defoliation was measured in five-year-old seedlings of Fraxinus mandshurica from June to September. Girdling and defoliation significantly reduced RS by 33% and 25% within 4 days, and 40% and 32% within the entire treatment period, respectively. The differential response of RS to girdling and defoliation was a result of the over-compensation for RS after girdling and redistribution of stored carbon after defoliation. No significant effect on RS was observed between girdling and defoliation treatment, while the soluble sugar content in fine roots was higher in defoliation than in girdling treatment, indicating that defoliation had less compensation effect for RS after interrupting photosynthates supply. We confirm the close coupling of RS with photosynthesis and recommend defoliation for further studies to estimate the effect of photosynthesis on RS. PMID:26177498

  8. Defining the temporal window for monitoring forest canopy defoliation using Landsat

    NASA Technical Reports Server (NTRS)

    Nelson, R. F.

    1981-01-01

    An analysis of Landsat imagery of forested areas near Williamsport, Pennsylvania shows that the effects of defoliation by insects can be assessed over a two month period beginning in early June. Within this window heavily defoliated forest can be successfully delineated from moderately defoliated and healthy forest. Consequently, the effects of insect damage can be assessed at times other than peak defoliation, doubling the probability that useful satellite data can be acquired in the Williamsport area.

  9. Development of regeneration following gypsy moth defoliation of Appalachian Plateau and Ridge & Valley hardwood stands

    Treesearch

    D.M. Hix; D.E. Fosbroke; R.R., Jr. Hicks; K.W. Gottschalk

    1991-01-01

    The effects of gypsy moth defoliation and subsequent overstory mortality on regeneration were located in the Appalachian Plateau physiographic province, and the Maryland stands were located in the Ridge & Valley province. Pre-defoliation data (1984-1986) were compared with post-defoliation data (1989) from the same 315 six-foot-radius plots.

  10. Effects of spring defoliation on first-year growth of young loblolly and slash pines

    Treesearch

    David R. Weise; Ragnar W. Johansen; Dale D. Wade

    1987-01-01

    Partial and complete spring defoliation reduced first-year diameter, height, and volume growth of 4-year-old loblolly and slash pines. Early and late growth differed significantly between defoliation levels (P=0.05). However, the number of height growth flushes produced during the 1986 growing season was not affected by defoliation treatments. No mortality occurred...

  11. Effect of defoliation on carbohydrate content of yellow-poplar seedlings

    Treesearch

    Keith F. Jensen; Roberta G. Masters

    1973-01-01

    Sixty yellow-poplar seedlings were divided into two groups. One group was defoliated twice, and the second group served as the control. Three months after the second defoliation there was no difference in carbohydrate content between the defoliated and undefoliated seedlings in either the stems or roots.

  12. Predicting defoliation by the gypsy moth using egg mass counts and a helper variable

    Treesearch

    Michael E. Montgomery

    1991-01-01

    Traditionally, counts of egg masses have been used to predict defoliation by the gypsy moth. Regardless of the method and precision used to obtain the counts, estimates of egg mass density alone often do not provide satisfactory predictions of defoliation. Although defoliation levels greater than 50% are seldom observed if egg mass densities are less than 600 per...

  13. A critique of silvicultural approaches to managing defoliating insects in North America

    Treesearch

    R.M. ​Muzika; A.M. Liebhold

    2000-01-01

    A variety of silvicultural techniques have been suggested for managing forest defoliating insects. The objectives focus on minimizing defoliation or minimizing damage from defoliation. The theoretical foundations of many approaches have been built upon observation and correlation, and very little reliable empirical evidence exists to support the objectives of...

  14. Defoliation and nitrogen effects on photosynthesis and growth of Eucalyptus globulus.

    PubMed

    Pinkard, Elizabeth A; Battaglia, Michael; Mohammed, Caroline L

    2007-07-01

    Plant responses to defoliation are complex. We established a field experiment in a nine-month-old Eucalyptus globulus Labill. plantation to examine the effects of pattern (upper crown versus lower crown removal), frequency (single, double or triple defoliation within a 12-month period) and severity (25 versus 38% of leaf area removed) of defoliation and the effect of soil nitrogen (N) on photosynthetic processes and stem growth. The photosynthetic responses observed following defoliation could be attributed to changes in source:sink ratios. Light-saturated CO(2) uptake (A(max)) increased with increasing severity and frequency of defoliation irrespective of defoliation pattern. Seedlings defoliated in autumn did not exhibit increases in A(max) until the following spring, whereas there was no such delay in photosynthetic responses associated with spring defoliation. Application of N before defoliation allowed trees to compensate for the effect of defoliation on stem diameter growth, which could not be explained simply in terms of increases in A(max). The observed increases in stem diameter increment following N fertilization of defoliated trees suggested increases in leaf area development, and there were changes in the leaf area:leaf dry mass ratio that may have increased light absorption by the crown. Nitrogen fertilization also increased partitioning of dry mass to branches at the expense of main stems, suggesting that N supply was important in rebuilding crowns following a defoliation event.

  15. Genome-wide comparative analysis of NBS-encoding genes in four Gossypium species

    USDA-ARS?s Scientific Manuscript database

    Nucleotide binding site (NBS) genes encode a large family of disease resistance (R) proteins in plants. The availability of genomic data of the two diploid cotton species, Gossypium arboreum and Gossypium raimondii, and the two allotetraploid cotton species, Gossypium hirsutum (TM-1) and Gossypium ...

  16. Comparative Proteomic Analysis of Gossypium thurberi in Response to Verticillium dahliae Inoculation

    PubMed Central

    Fang, Weiping; Xie, Deyi; Zhu, Heqin; Li, Wu; Xu, Zhenzhen; Yang, Lirong; Li, Zhifang; Sun, Li; Wang, Jinxia; Nie, Lihong; Tang, Zhongjie; Lv, Shuping; Zhao, Fu’an; Sun, Yao; Zhao, Yuanming; Hou, Jianan; Yang, Xiaojie

    2015-01-01

    Verticillium wilt is threatening cotton productivity globally. This disease is caused by soil-borne Verticillium dahliae which directly infects cotton roots, and exclusively colonizes and occludes xylem vessels, finally resulting in necrosis, defoliation, and most severely, plant death. For the first time, iTRAQ (isobaric tags for relative and absolute quantification) was applied to screen the differentially expressed proteins of Gossypium thurberi inoculated with V. dahliae. A total of 6533 proteins were identified from the roots of G. thurberi after inoculation with V. dahliae, and 396 showed up- and 279 down-regulated in comparison to a mock-inoculated roots. Of these identified proteins, the main functional groups were those involved in cell wall organization and reinforcement, disease-resistant chemicals of secondary metabolism, phytohormone signaling, pathogenesis-related proteins, and disease-resistant proteins. Physiological and biochemical analysis showed that peroxidase activity, which promotes the biosynthesis and accumulation of lignin, was induced early in the hypocotyl after inoculation with V. dahliae. Similarly, salicylic acid also accumulated significantly in hypocotyl of the seedlings after inoculation. These findings provide an important knowledge of the molecular events and regulatory networks occurring during G. thurberi-V. dahliae interaction, which may provide a foundation for breeding disease-resistance in cotton. PMID:26506344

  17. Gossypolhemiquinone, a dimeric sesquiterpenoid identified in cotton (Gossypium)

    USDA-ARS?s Scientific Manuscript database

    The report that the cotton leaf perforator, Bucculatrix thurberiella, is one of the few insect herbivores to attack Gossypium thurberi prompted an investigation of the terpenoids present in the leaves of this wild species of cotton. Members of Gossypium produce subepidermal pigment glands in their ...

  18. Distribution and Molecular Diversity of Arborescent Gossypium Species.

    USDA-ARS?s Scientific Manuscript database

    Mexico is a center of diversity of Gossypium. As currently circumscribed, arborescent Gossypium species (Section Erioxylum) are widely distributed in dry deciduous forests located from the central state of Sinaloa at the north of its range to the eastern state of Oaxaca in the south. However, extens...

  19. Gypsy moth defoliation assessment: Forest defoliation in detectable from satellite imagery. [New England, New York, Pennsylvania, and New Jersey

    NASA Technical Reports Server (NTRS)

    Moore, H. J. (Principal Investigator); Rohde, W. G.

    1975-01-01

    The author has identified the following significant results. ERTS-1 imagery obtained over eastern Pennsylvania during July 1973, indicates that forest defoliation is detectable from satellite imagery and correlates well with aerial visual survey data. It now appears that two damage classes (heavy and moderate-light) and areas of no visible defoliation can be detected and mapped from properly prepared false composite imagery. In areas where maple is the dominant species or in areas of small woodlots interspersed with agricultural areas, detection and subsequent mapping is more difficult.

  20. Effects of Invasive Winter Moth Defoliation on Tree Radial Growth in Eastern Massachusetts, USA

    PubMed Central

    Simmons, Michael J.; Lee, Thomas D.; Ducey, Mark J.; Elkinton, Joseph S.; Boettner, George H.; Dodds, Kevin J.

    2014-01-01

    Winter moth, Operophtera brumata L. (Lepidoptera: Geometridae), has been defoliating hardwood trees in eastern Massachusetts since the 1990s. Native to Europe, winter moth has also been detected in Rhode Island, Connecticut, eastern Long Island (NY), New Hampshire, and Maine. Individual tree impacts of winter moth defoliation in New England are currently unknown. Using dendroecological techniques, this study related annual radial growth of individual host (Quercus spp. and Acer spp.) trees to detailed defoliation estimates. Winter moth defoliation was associated with up to a 47% reduction in annual radial growth of Quercus trees. Latewood production of Quercus was reduced by up to 67% in the same year as defoliation, while earlywood production was reduced by up to 24% in the year following defoliation. Winter moth defoliation was not a strong predictor of radial growth in Acer species. This study is the first to document impacts of novel invasions of winter moth into New England. PMID:26462685

  1. Characteristics of Stands Susceptible and Resistant to Gypsy Moth Defoliation

    Treesearch

    David R. Houston

    1983-01-01

    Site conditions strongly influence where gypsy moth defohation will occur. In New England, where gypsy moths and foresta have interacted for over a century, some foreats have had a history of repeated defoliation while others have been defo1iated only rarely. The often defohated or susceptible forests characteristically grow on dry sitea such as rocky ridges or...

  2. Oak silviculture, management, and defoliation effects in France and Germany

    Treesearch

    Kurt W. Gottschalk

    1993-01-01

    A study tour of four areas of France and Germany (two in each country) was conducted to examine oak silvicultural and managerial practices and the influence of insect defoliators on the ecology and management of oak forests. The French and German situations may provide useful information for managing oak forests and gypsy moth in the United States, especially the...

  3. Canada thistle (Cirsium arvense) suppession by sudangrass interference and defoliation

    USDA-ARS?s Scientific Manuscript database

    Canada thistle is difficult to manage in farming systems with reduced reliance on herbicides, including organic and low-external input systems. Previous field studies found that defoliation or sudangrass interference suppressed Canada thistle. Our objective was to understand the factors causing supp...

  4. Estimating Defoliation of Hardwoods Using Blade-petiole Relations

    Treesearch

    Harry T. Valentine

    1978-01-01

    Prediction equations for estimating leaf blade area and dry weight from measurements of petiole thickness were used to estimate defoliation of Populus tremuloides, Acer rubrum, Quercus rubra, and Q. alba. On one tree of each species, a sample of leaves was artifically browsed in May and...

  5. Using dendrochronology to measure radial growth of defoliated trees

    Treesearch

    Thomas W. Swetnam; Marna Ares Thompson; Elaine Kennedy. Sutherland

    1985-01-01

    Budworms (Choristoneura spp.) have repeatedly defoliated millions of hectares of conifers throughout North America. The seriousness of the problem is underscored by research findings in eastern Canada and the northern U.S. Rocky Mountains that the extent, severity, and frequency of bud worm outbreaks have increased in the 20th century, primarily as a result of human-...

  6. Differential Effects of Thidiazuron on Production of Anticancer Phenolic Compounds in Callus Cultures of Fagonia indica.

    PubMed

    Khan, Tariq; Abbasi, Bilal Haider; Khan, Mubarak Ali; Shinwari, Zabta Khan

    2016-04-01

    Fagonia indica, a very important anticancer plant, has been less explored for its in vitro potential. This is the first report on thidiazuron (TDZ)-mediated callogenesis and elicitation of commercially important phenolic compounds. Among the five different plant growth regulators tested, TDZ induced comparatively higher fresh biomass, 51.0 g/100 mL and 40.50 g/100 mL for stem and leaf explants, respectively, after 6 weeks of culture time. Maximum total phenolic content (202.8 μg gallic acid equivalent [GAE]/mL for stem-derived callus and 161.3 μg GAE/mL for leaf-derived callus) and total flavonoid content (191.03 μg quercetin equivalent [QE]/mL for stem-derived callus and 164.83 μg QE/mL for leaf-derived callus) were observed in the optimized callus cultures. The high-performance liquid chromatography (HPLC) data indicated higher amounts of commercially important anticancer secondary metabolites such as gallic acid (125.10 ± 5.01 μg/mL), myricetin (32.5 ± 2.05 μg/mL), caffeic acid (12.5 ± 0.52 μg/mL), catechin (9.4 ± 1.2 μg/mL), and apigenin (3.8 ± 0.45 μg/mL). Owing to the greater phenolic content, a better 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (69.45 % for stem explant and 63.68 % for leaf explant) was observed in optimized calluses. The unusually higher biomass and the enhanced amount of phenolic compounds as a result of lower amounts of TDZ highlight the importance of this multipotent hormone as elicitor in callus cultures of F. indica.

  7. Levels and immunolocalization of endogenous cytokinins in thidiazuron-induced shoot organogenesis in carnation.

    PubMed

    Casanova, Eva; Valdés, Ana Elisa; Fernández, Belén; Moysset, Lluïsa; Trillas, Maria Isabel

    2004-01-01

    We evaluated the capacity of the plant growth regulator thidiazuron (TDZ), a substituted phenylurea with high cytokinin-like activity, to promote organogenesis in petals and leaves of several carnation cultivars (Dianthus spp.), combined with 1-naphthaleneacetic acid (NAA). The involvement of the endogenous auxin indole-3-acetic acid (IAA) and purine-type cytokinins was also studied. Shoot differentiation was found to depend on the explant, cultivar and balance of growth regulators. TDZ alone (0.5 and 5.0 micromol/L) as well as synergistically with NAA (0.5 and 5.0 micromol/L) promoted shoot organogenesis in petals, and was more active than N6-benzyladenine. In petals of the White Sim cultivar, TDZ induced cell proliferation in a concentration-dependent manner and, on day 7 of culture, the proportion of meristematic regions in those petals allowed the prediction of shoot regeneration capacity after 30 days of culture. Immunolocalization of CK ribosides, N6-(delta2-isopentenyl)adenosine, zeatin riboside (ZR) and dihydrozeatin riboside (DHZR), in organogenic petals showed them to be highly concentrated in the tips of bud primordia and in the regions with proliferation capacity. All of them may play a role in cell proliferation, and possibly in differentiation, during the organogenic process. After seven days of culture of White Sim petals, NAA may account for the changes found in the levels of IAA and DHZR, whereas TDZ may be responsible for the remarkable increases in N6-(delta2-isopentenyl)adenine (iP) and ZR. ZR is induced by low TDZ concentrations (0.0-0.005 micromol/L), whereas iP, that correlates with massive cell proliferation and the onset of shoot differentiation, is associated with high TDZ levels (0.5 micromol/L). In addition to the changes observed in quantification and in situ localization of endogenous phytohormones during TDZ-induced shoot organogenesis, we propose that TDZ also promotes growth directly, through its own biological activity. To our

  8. Thidiazuron Triggers Morphogenesis in Rosa canina L. Protocorm-Like Bodies by Changing Incipient Cell Fate

    PubMed Central

    Kou, Yaping; Yuan, Cunquan; Zhao, Qingcui; Liu, Guoqin; Nie, Jing; Ma, Zhimin; Cheng, Chenxia; Teixeira da Silva, Jaime A.; Zhao, Liangjun

    2016-01-01

    Thidiazuron (N-phenyl-N′-1,2,3-thiadiazol-5-ylurea; TDZ) is an artificial plant growth regulator that is widely used in plant tissue culture. Protocorm-like bodies (PLBs) induced by TDZ serve as an efficient and rapid in vitro regeneration system in Rosa species. Despite this, the mechanism of PLB induction remains relatively unclear. TDZ, which can affect the level of endogenous auxins and cytokinins, converts the cell fate of rhizoid tips and triggers PLB formation and plantlet regeneration in Rosa canina L. In callus-rhizoids, which are rhizoids that co-develop from callus, auxin and a Z-type cytokinin accumulated after applying TDZ, and transcription of the auxin transporter gene RcPIN1 was repressed. The expression of RcARF4, RcRR1, RcCKX2, RcCKX3, and RcLOG1 increased in callus-rhizoids and rhizoid tips while the transcription of an auxin response factor (RcARF1) and auxin transport proteins (RcPIN2, RcPIN3) decreased in callus-rhizoids but increased in rhizoid tips. In situ hybridization of rhizoids showed that RcWUS and RcSERK1 were highly expressed in columella cells and root stem cells resulting in the conversion of cell fate into shoot apical meristems or embryogenic callus. In addition, transgenic XVE::RcWUS lines showed repressed RcWUS overexpression while RcWUS had no effect on PLB morphogenesis. Furthermore, higher expression of the root stem cell marker RcWOX5 and root stem cell maintenance regulator genes RcPLT1 and RcPLT2 indicated the presence of a dedifferentiation developmental pathway in the stem cell niche of rhizoids. Viewed together, our results indicate that different cells in rhizoid tips acquired regeneration competence after induction by TDZ. A novel developmental pathway containing different cell types during PLB formation was identified by analyzing the endogenous auxin and cytokinin content. This study also provides a deeper understanding of the mechanisms underlying in vitro regeneration in Rosa. PMID:27200031

  9. Artificial defoliation effect on Populus growth, biomass production, and total nonstructural carbohydrate concentration

    SciTech Connect

    Reichenbacker, R.R.; Hart, E.R.; Schultz, R.C.

    1996-06-01

    The impact of artificial defoliation on Populus growth, biomass production, and total nonstructural carbohydrate concentration was examined. Four Populus clones were field planted and artificially defoliated. Assigned defoliation levels (0, 25, 50, or 75%) were applied to leaves of leaf plastochron index 0 through 8 during a 6-d period in a 3-step incremental manner to simulate cottonwood leaf beetle, Chrysomela scripta F., larval feeding patterns. Artificial defoliations were timed to coincide with the outbreaks of natural beetle populations in adjacent areas. After 2 growing seasons, trees were measured for height, diameter, and biomass accumulation. Root samples were collected from 0 and 75% defoliation treatments for each clone. Biomass was reduced an average of 33% as defoliation level increased from 0 to 75%. As defoliation level increased from 0 to 75%, a consistent allocation ratio of biomass to 2/3 above and 1/3 below ground components continued in all clones. An overcompensation response occurred in above ground biomass when a defoliation level of 25% was applied. Between 25 and 75% a strong linear trend of decreasing biomass as defoliation increased was indicated. Vitality of the tree, as indicated by total nonstructural carbohydrate content, was affected only slightly by increasing defoliation. 26 refs., 1 fig., 6 tabs.

  10. Responses of condensed tannins in poplar roots to fertilization and gypsy moth defoliation.

    PubMed

    Kosola, Kevin R; Parry, Dylan; Workmaster, Beth Ann A

    2006-12-01

    We examined the effects of fertilization and gypsy moth defoliation on condensed tannin concentration (%CT) of hybrid poplar (Populus x canadensis cv 'Eugeneii') fine roots in the summers of 1997 and 1998. This factorial experiment included two defoliation treatments (defoliated and a foliated control) and fertilization treatments (100 kg nitrogen (N) ha(-1) and an unfertilized control). Gypsy moth (Lymantria dispar L.) populations were experimentally increased to obtain defoliation in the summers of 1996, 1997 and 1998; fertilization subplots were supplemented with NH4NO3 (100 kg N ha(-1)) in the spring of each year. Despite the severity of defoliation, the effects were small, and significant on only two sampling dates: in May 1997, when fine root %CT was 23% lower in the defoliated trees, and in November 1997, when trees in the defoliated unfertilized plots had 35% higher root %CT than trees in all other plots. Defoliation effects on root %CT did not follow the same seasonal pattern as defoliation effects on root starch content, N uptake capacity or leaf %CT. Regulation of root condensed tannin concentration appeared to be partially uncoupled from these traits. The small transient effects on root defense reflect the resilience of this early successional tree to severe early season defoliation.

  11. Photosynthetic responses of field-grown Pinus radiata trees to artificial and aphid-induced defoliation.

    PubMed

    Eyles, Alieta; Smith, David; Pinkard, Elizabeth A; Smith, Ian; Corkrey, Ross; Elms, Stephen; Beadle, Chris; Mohammed, Caroline

    2011-06-01

    The phloem-feeding aphid Essigella californica represents a potential threat to the productivity of Pinus radiata plantations in south-eastern Australia. Five- and nine-year-old field trials were used to characterize the effects of artificial and natural aphid-induced (E. californica) defoliation, respectively, on shoot photosynthesis and growth. Photosynthetic capacity (A(max)) was significantly greater following a 25% (D25) (13.8 µmol m(-2) s(-1)) and a 50% (D50) (15.9 µmol m(-2) s(-1)) single-event upper-crown artificial defoliation, 3 weeks after defoliation than in undefoliated control trees (12.9 µmol m(-2) s(-1)). This response was consistently observed for up to 11 weeks after the defoliation event; by Week 16, there was no difference in A(max) between control and defoliated trees. In the D50 treatment, this increased A(max) was not sufficient to fully compensate for the foliage loss as evidenced by the reduced diameter increment (by 15%) in defoliated trees 36 weeks after defoliation. In contrast, diameter increment of trees in the D25 treatment was unaffected by defoliation. The A(max) of trees experiencing upper-crown defoliation by natural and repeated E. californica infestations varied, depending on host genotype. Despite clear differences in defoliation levels between resistant and susceptible genotypes (17 vs. 35% of tree crown defoliated, respectively), growth of susceptible genotypes was not significantly different from that of resistant genotypes. The observed increases in A(max) in the lower crown of the canopy following attack suggested that susceptible genotypes were able to partly compensate for the loss of foliage by compensatory photosynthesis. The capacity of P. radiata to regulate photosynthesis in response to natural aphid-induced defoliation provides evidence that the impact of E. californica attack on stem growth will be less than expected, at least for up to 35% defoliation.

  12. Polyploidy and the petal transcriptome of Gossypium

    PubMed Central

    2014-01-01

    Background Genes duplicated by polyploidy (homoeologs) may be differentially expressed in plant tissues. Recent research using DNA microarrays and RNAseq data have described a cacophony of complex expression patterns during development of cotton fibers, petals, and leaves. Because of its highly canalized development, petal tissue has been used as a model tissue for gene expression in cotton. Recent advances in cotton genome annotation and assembly now permit an enhanced analysis of duplicate gene deployment in petals from allopolyploid cotton. Results Homoeologous gene expression levels were quantified in diploid and tetraploid flower petals of Gossypium using the Gossypium raimondii genome sequence as a reference. In the polyploid, most homoeologous genes were expressed at equal levels, though a subset had an expression bias of AT and DT copies. The direction of gene expression bias was conserved in natural and recent polyploids of cotton. Conservation of direction of bias and additional comparisons between the diploids and tetraploids suggested different regulation mechanisms of gene expression. We described three phases in the evolution of cotton genomes that contribute to gene expression in the polyploid nucleus. Conclusions Compared to previous studies, a surprising level of expression homeostasis was observed in the expression patterns of polyploid genomes. Conserved expression bias in polyploid petals may have resulted from cis-acting modifications that occurred prior to polyploidization. Some duplicated genes were intriguing exceptions to general trends. Mechanisms of gene regulation for these and other genes in the cotton genome warrants further investigation. PMID:24393201

  13. Effects of Artificial Defoliation on Growth and Biomass Accumulation in Short-Rotation Sweetgum (Liquidambar styraciflua) in North Carolina

    PubMed Central

    Jetton, Robert M.; Robison, Daniel J.

    2014-01-01

    Sweetgum, Liquidambar styraciflua L. (Hamamelidales: Hamamelidaceae), is a species of interest for short-rotation plantation forestry in the southeastern United States. Despite its high levels of resistance to many native insects and pathogens, the species is susceptible to generalist defoliators during outbreak epidemics. The objective of this field study was to evaluate the potential impact of defoliation on sweetgum growth and productivity within the context of an operational plantation. Over three growing seasons, trees were subjected to artificial defoliation treatments of various intensity (control = 0% defoliation; low intensity = 33% defoliation; moderate intensity = 67% defoliation; high intensity = 99% defoliation) and frequency (not defoliated; defoliated once in April of the first growing season; defoliated twice, once in April of the first growing season and again in April of the second growing season). The responses of stem height, stem diameter, stem volume, crown volume, total biomass accumulation, and branch growth were measured in November of each growing season. At the end of the first growing season, when trees had received single defoliations, significant reductions in all growth traits followed the most severe (99%) defoliation treatment only. After the second and third growing seasons, when trees had received one or two defoliations of varying intensity, stem diameter and volume and total tree biomass were reduced significantly by 67 and 99% defoliation, while reductions in stem height and crown volume followed the 99% treatment only. All growth traits other than crown volume were reduced significantly by two defoliations but not one defoliation. Results indicate that sweetgum is highly resilient to single defoliations of low, moderate, and high intensity. However, during the three-year period of the study, repeated high-intensity defoliation caused significant reductions in growth and productivity that could have lasting impacts on yield

  14. Future impacts of nitrogen deposition and climate change scenarios on forest crown defoliation.

    PubMed

    De Marco, Alessandra; Proietti, Chiara; Cionni, Irene; Fischer, Richard; Screpanti, Augusto; Vitale, Marcello

    2014-11-01

    Defoliation is an indicator for forest health in response to several stressors including air pollutants, and one of the most important parameters monitored in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The study aims to estimate crown defoliation in 2030, under three climate and one nitrogen deposition scenarios, based on evaluation of the most important factors (meteorological, nitrogen deposition and chemical soil parameters) affecting defoliation of twelve European tree species. The combination of favourable climate and nitrogen fertilization in the more adaptive species induces a generalized decrease of defoliation. On the other hand, severe climate change and drought are main causes of increase in defoliation in Quercus ilex and Fagus sylvatica, especially in Mediterranean area. Our results provide information on regional distribution of future defoliation, an important knowledge for identifying policies to counteract negative impacts of climate change and air pollution.

  15. Characterization and development of chloroplast microsatellite markers for Gossypium hirsutum, and cross-species amplification in other Gossypium species.

    PubMed

    Cai, X Y; Liu, F; Zhou, Z L; Wang, X X; Wang, C Y; Wang, Y H; Wang, K B

    2015-10-05

    Cotton is an important economic crop worldwide; its fiber, commonly known as cotton lint, is the main natural source for the textile industry. Sixty chloroplast microsatellites were identified and characterized from the complete sequence of the Gossypium hirsutum chloroplast genome using a bioinformatic approach. Twenty chloroplast microsatellite loci were polymorphic in the 66 Gossypium germplasm accessions. A total of 85 alleles were detected, with allele numbers varying from 2-7 per locus. Polymorphism information content varied from 0.02-0.66, with a mean of 0.48. Additionally, transferability of the 20 polymorphic chloroplast microsatellite primers was evaluated in other 31 Gossypium species. Sixteen markers were successfully amplified across all species tested, while the remaining 4 markers cross-amplified in most species tested. These polymorphic chloroplast microsatellite markers may be useful tool for studies of individual identification, genetic diversity, evolution, conservation genetics, and molecular breeding in Gossypium.

  16. Defoliation reduces soil biota - and modifies stimulating effects of elevated CO2.

    PubMed

    Dam, Marie; Christensen, Søren

    2015-11-01

    To understand the responses to external disturbance such as defoliation and possible feedback mechanisms at global change in terrestrial ecosystems, it is necessary to examine the extent and nature of effects on aboveground-belowground interactions. We studied a temperate heathland system subjected to experimental climate and atmospheric factors based on prognoses for year 2075 and further exposed to defoliation. By defoliating plants, we were able to study how global change modifies the interactions of the plant-soil system. Shoot production, root biomass, microbial biomass, and nematode abundance were assessed in the rhizosphere of manually defoliated patches of Deschampsia flexuosa in June in a full-factorial FACE experiment with the treatments: increased atmospheric CO 2, increased nighttime temperatures, summer droughts, and all of their combinations. We found a negative effect of defoliation on microbial biomass that was not apparently affected by global change. The negative effect of defoliation cascades through to soil nematodes as dependent on CO 2 and drought. At ambient CO 2, drought and defoliation each reduced nematodes. In contrast, at elevated CO 2, a combination of drought and defoliation was needed to reduce nematodes. We found positive effects of CO 2 on root density and microbial biomass. Defoliation affected soil biota negatively, whereas elevated CO 2 stimulated the plant-soil system. This effect seen in June is contrasted by the effects seen in September at the same site. Late season defoliation increased activity and biomass of soil biota and more so at elevated CO 2. Based on soil biota responses, plants defoliated in active growth therefore conserve resources, whereas defoliation after termination of growth results in release of resources. This result challenges the idea that plants via exudation of organic carbon stimulate their rhizosphere biota when in apparent need of nutrients for growth.

  17. Consequences of resource limitation for recovery from repeated defoliation in Eucalyptus globulus Labilladière.

    PubMed

    Barry, Karen M; Quentin, Audrey; Eyles, Alieta; Pinkard, Elizabeth A

    2012-01-01

    Recovery following defoliation can be modified by co-occurring site resource limitations. The growth response of young Eucalyptus globulus saplings to two defoliation events was examined in an experimental plantation with combinations of low (-) or high (+) water (W) and nitrogen (N) resources. Artificial defoliation was applied at 3 and 9 months of age to remove ~40 and 55% of leaf area in the upper crown, respectively. At 18 months of age, height, stem diameter and leaf area were not significantly different between control and defoliated saplings, across all resource treatments. However, stem volume, bark volume and branch number were significantly increased in defoliated saplings, including a significant interaction with resource treatment. Total above-ground biomass of saplings in response to defoliation was significantly higher (almost double) than controls for the low water (N + W-) treatment only. Significantly increased foliar starch content (and a trend for increased soluble sugars) in the upper crown zone was found in the defoliated saplings of the N + W- treatment compared with the upper zone of control saplings. Foliar total non-structural carbohydrates were significantly correlated to stem biomass regardless of resource treatment or defoliation, and we suggest that foliar resources are most important for stem growth in E. globulus rather than stored carbon (C) from other tissues. After repeated defoliation and several months recovery, E. globulus saplings were generally not C limited in this study.

  18. Monitoring the defoliation of hardwood forests in Pennsylvania using LANDSAT. [gypsy moth surveys

    NASA Technical Reports Server (NTRS)

    Dottavio, C. L.; Nelson, R. F.; Williams, D. L. (Principal Investigator)

    1983-01-01

    An automated system for conducting annual gypsy moth defoliation surveys using LANDSAT MSS data and digital processing techniques is described. A two-step preprocessing procedure was developed that uses multitemporal data sets representing forest canopy conditions before and after defoliation to create a digital image in which all nonforest cover types are eliminated or masked out of a LANDSAT image that exhibits insect defoliation. A temporal window for defoliation assessment was identified and a statewide data base was established. A data management system to interface image analysis software with the statewide data base was developed and a cost benefit analysis of this operational system was conducted.

  19. Starch Grain Distribution in Taproots of Defoliated Medicago sativa L.

    PubMed

    Habben, J E; Volenec, J J

    1990-11-01

    Defoliation of alfalfa (Medicago sativa L.) results in a cyclic pattern of starch degradation followed by reaccumulation in taproots. Characterization of changes in anatomical distribution of starch grains in taproots will aid our understanding of biochemical and physiological mechanisms involved in starch metabolism in taproots of this species. Our objectives were to determine the influence of defoliation on starch grain distribution and size variation in taproots of two alfalfa lines selected for contrasting concentrations of taproot starch. In addition, we used electron microscopy to examine the cellular environment of starch grains, and computer-based image optical analysis to determine how cross-sectional area of tissues influenced starch accumulation. Taproots of field-grown plants were sampled at defoliation and weekly thereafter over a 28-day period. Taproot segments were fixed in glutaraldehyde and prepared for either light or electron microscopy. Transverse sections were examined for number and size of starch grains and tissue areas were measured. Starch grains were located throughout bark tissues, but were confined primarily to ray parenchyma cells in wood tissues. During the first week of foliar regrowth after defoliation, starch grains in ray cells near the cambium disappeared first, while degradation of those near the center of the taproot was delayed. During the third and fourth weeks of regrowth, there was a uniform increase in number of starch grains per cell profile across the rays, but by 28 days after defoliation there were more starch grains in ray cells near the cambium than in cells near the center of the taproot (low starch line only). Bark tissues from both lines showed synchronous degradation and synthesis of starch grains that was not influenced greatly by cell location. Diameter of starch grains varied with cell location in medullary rays during rapid starch degradation, but was not influenced by cell position in bark tissues. Therefore

  20. Interactive effects of resource availabilities and defoliation on photosynthesis, growth, and mortality of red oak seedlings

    Treesearch

    James B. McGraw; Kurt W. Gottschalk; Milan C. Vavrek; A.L. Chester

    1990-01-01

    Responses of forest trees to defoliation by insects such as gypsy moth vary greatly from site to site and from individual to individual. To determine whether some of this variation could be explained by variation in other stress factors, red oak (Quercus rubra L.) seedlings were exposed to low and high light, water, mineral nutrient, and defoliation...

  1. Effects of defoliation and drought on root food reserves in sugar maple seedlings

    Treesearch

    Johnson Parker; Johnson Parker

    1970-01-01

    The artificial defoliation of sugar maple (Acer. saccharum Marsh.) can cause a marked decline in root food reserves, especially starch, and an increase in the levels of the reducing sugars, fructose and glucose. Defoliation can also bring on the dieback-decline syndrome in sugar maples (Parker and Houston 1968). Two experiments designed to examine this question were...

  2. Recovery of hemlock in Vermont from defoliation by the spring hemlock looper, Lambdina athasaria (Walker)

    Treesearch

    Barbara S. Burns; Henry, Jr. Trial

    2000-01-01

    Following an outbreak of spring hemlock looper in 1991, ten hemlocks in each of fifteen study plots were monitored annually through 1999. Although some mortality occurred within two years after defoliation, and additional mortality occurred in plots which were subsequently disturbed by logging, most defoliated trees recovered. Twenty-four percent of the trees with 90%...

  3. Responses of an Insect Folivore and Its Parastoids to Multiyear Experimental Defoliation of Aspen

    Treesearch

    Dylan Parry; Daniel A. Herms; William J. Mattson

    2003-01-01

    Foliage quality may decline in deciduous trees following defoliation, thus affecting the insect generation responsible for the herbivory (rapid induced resistance, RIR), or future generations (delayed induced resistance, DIR). During outbreaks, trees often suffer partial or complete defoliation for two or more successive years, yet most studies have examined induced...

  4. Assessment of MODIS NDVI time series data products for detecting forest defoliation by gypsy moth outbreaks

    Treesearch

    Joseph P. Spruce; Steven Sader; Robert E. Ryan; James Smoot; Philip Kuper; al. et.

    2011-01-01

    This paper discusses an assessment of Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data products for detecting forest defoliation from European gypsy moth (Lymantria dispar). This paper describes an effort to aid the United States Department of Agriculture (USDA) Forest Service in developing and assessing MODIS-based gypsy moth defoliation...

  5. Potential defoliation of trees by outbreak populations of gypsy moth in the Chicago area

    Treesearch

    David W. Onstad; David J. Nowak; Michael R. Jeffords

    1997-01-01

    The gypsy moth, Lymantria dispar, will soon become established in much of the Midwest. If an outbreak with extremely high population levels of this serious defoliator is allowed to occur in the Chicago area, what kind of damage can be expected? A model for defoliation, refoliation and mortality was developed based on the number of trees and...

  6. Proceedings: population dynamics, impacts, and integrated management of forest defoliating insects

    Treesearch

    M.L. McManus; A.M., eds. Liebhold

    1998-01-01

    This publication contains 52 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties S7.03.06, "Integrated Management of Forest Defoliating Insects", and S7.03.07, "Population dynamics of forest insects", of the International Union of Forestry...

  7. Prediction of stand susceptibility and gypsy moth defoliation in Coastal Plain mixed pine-hardwoods

    Treesearch

    C.B. Davidson; J.E. Johnson; K.W. Gottschalk; R.L. Amateis

    2001-01-01

    The European gypsy moth (Lymantria dispar L.) is an introduced defoliator that has become endemic in forests of the northeastern United States. During the last five decades, populations have continued to advance into the southeastern United States. Defoliation outbreaks continue to occur along the leading edge of the infestation, and the potential...

  8. Mortality and growth reduction of white fir following defoliation by the Douglas-fir tussock moth

    Treesearch

    Boyd E. Wickman

    1963-01-01

    In 5 years after a 1954-56 outbreak of Hemerocampa pseudotsugata in Calaveras and Tuolumne Counties, California, 20 percent of the merchantable white fir, or 11,071 board feet per acre, died in heavily defoliated stands. Another 1,113 board feet per acre was lost owing to radial growth reductions in partly defoliated trees; 12 percent of these trees...

  9. Growth reduction after defoliation is independent of CO2 supply in deciduous and evergreen young oaks.

    PubMed

    Schmid, Sandra; Palacio, Sara; Hoch, Günter

    2017-02-27

    Reduced productivity of trees after defoliation might be caused by limited carbon (C) availability. We investigated the combined effect of different atmospheric CO2 concentrations (160, 280 and 560 ppm) and early season defoliation on the growth and C reserves (nonstructural carbohydrates (NSC)) of saplings of two oak species with different leaf habits (deciduous Quercus petraea and evergreen Quercus ilex). In both species, higher CO2 supply significantly enhanced growth. Defoliation had a strong negative impact on growth (stronger for Q. ilex), but the relative reduction of growth caused by defoliation within each CO2 treatment was very similar across all three CO2 concentrations. Low CO2 and defoliation led to decreased NSC tissue concentrations mainly in the middle of the growing season in Q. ilex, but not in Q. petraea. However, also in Q. ilex, NSC increased in woody tissues in defoliated and low-CO2 saplings towards the end of the growing season. Although the saplings were C limited under these specific experimental conditions, growth reduction after defoliation was not directly caused by C limitation. Rather, growth of trees followed a strong allometric relationship between total leaf area and conductive woody tissue, which did not change across species, CO2 concentrations and defoliation treatments.

  10. Effects of Fertilization on Shoot Growth of Defoliated and Undefoliated Red Oak Seedlings

    Treesearch

    Johnson Parker

    1978-01-01

    Fertilization of red oak (Quercus rubra L.) seedlings increased their terminal shoot growth. Dry, liquid, and liquid + dry fertilizer was applied to groups of undefoliated, once-defoliated, and twice-defoliated seedlings. Terminal shoot growth was measured after the first and second growing season and compared to that of a similar group of...

  11. Effects of previous stand management on mortality following gypsy moth defoliation: preliminary results

    Treesearch

    Kurt W. Gottschalk

    1989-01-01

    Oak-hickory forest stands were sampled for tree mortality using a series of temporary plots. Stands were classified by gypsy moth defoliation and by thinning treatment timing. Thinning of forest stands does accomplish its goal of reducing mortality in undefoliated stands; however, the effect is not clear when stands are defoliated.

  12. Effects of defoliation, girdling and severing of sugar maple trees on root starch and sugar levels

    Treesearch

    Parker Johnson

    1974-01-01

    Root starch levels of defoliated sugar maple trees, on the average, were lower after 4 weeks in two separate experiments than in girdled, cut off, or girdled and defoliated trees. Root starch levels in all these treatments were lower than in controls. Sucrose levels, but not the levels of fructose and glucose, followed the same trends. It is suggested that...

  13. Defoliation effects on Bromus tectorum seed production: Implications for grazing

    USGS Publications Warehouse

    Hempy-Mayer, K.; Pyke, D.A.

    2008-01-01

    Cheatgrass (Bromus tectorum L.) is an invasive annual grass that creates near-homogenous stands in areas throughout the Intermountain sagebrush steppe and challenges successful native plant restoration in these areas. A clipping experiment carried out at two cheatgrass-dominated sites in eastern Oregon (Lincoln Bench and Succor Creek) evaluated defoliation as a potential control method for cheatgrass and a seeding preparation method for native plant reseeding projects. Treatments involved clipping plants at two heights (tall = 7.6 cm, and short = 2.5 cm), two phenological stages (boot and purple), and two frequencies (once and twice), although purple-stage treatments were clipped only once. Treatments at each site were replicated in a randomized complete block design that included a control with no defoliation. End-of-season seed density (seeds??m-2) was estimated by sampling viable seeds from plants, litter, and soil of each treatment. Undipped control plants produced an average of approximately 13 000 and 20 000 seeds??m-2 at Lincoln Bench and Succor Creek, respectively. Plants clipped short at the boot stage and again 2 wk later had among the lowest mean seed densities at both sites, and were considered the most successful treatments (Lincoln Bench: F 6,45 = 47.07, P < 0.0001; Succor Creek: F6,40 = 19.60, P < 0.0001). The 95% confidence intervals for seed densities were 123-324 seeds??m-2 from the Lincoln Bench treatment, and 769-2256 seeds??m-2 from the Succor Creek treatment. Literature suggests a maximum acceptable cheatgrass seed density of approximately 330 seeds??m-2 for successful native plant restoration through reseeding. Thus, although this study helped pinpoint optimal defoliation parameters for cheatgrass control, it also called into question the potential for livestock grazing to be an effective seed-bed preparation technique in native plant reseeding projects in cheatgrass-dominated areas.

  14. Remote Sensing Plant Stress Using Combined Fluorescence and Reflectance Measurements for Early Detection of Defoliants within the Battlefield Environment

    DTIC Science & Technology

    2012-10-02

    REPORT Remote sensing plant stress using combined fluorescence and reflectance measurements for early detection of defoliants within the battlefied...stress using combined fluorescence and reflectance measurements for early detection of defoliants within the battlefied environment Report Title...combined fluorescence and reflectance measurements for early detection of defoliants within the battlefield environment ARO Proposal # (49364-EV

  15. Response of tomato to defoliation and elevated CO[sub 2]level

    SciTech Connect

    Freidus, D. )

    1993-06-01

    Increased resources are expected to result in increased plant productivity and to increase a plant's ability to replace tissue lost to defoliation. This hypothesis was tested by growing tomato plants (Lycopersicon esculentum) in a phytotron greenhouse at ambient (355 ppm) and elevated (710 ppm) levels of CO[sub 2]. The experiment was fully factorial for CO[sub 2] level and two manual defoliation treatments, the first during vegetative growth and the second during fruiting. Elevated CO[sub 2] level did not alter total biomass, but did alter allocation: total fruit biomass and fruit number decreased. This is contrary to the expected result. Only the first defoliation treatment lowered total vegetative and reproductive biomass produced. There was no interaction between response to defoliation and response to elevated CO[sub 2] level. Thus, both the main effect of elevated CO[sub 2] and the interaction of defoliation and elevated CO[sub 2] were inconsistent with my hypothesis.

  16. Genotypic differences and prior defoliation affect re-growth and phytochemistry after coppicing in Populus tremuloides.

    PubMed

    Stevens, Michael T; Gusse, Adam C; Lindroth, Richard L

    2012-03-01

    Although considerable research has explored how tree growth and defense can be influenced by genotype, the biotic environment, and their interaction, little is known about how genotypic differences, prior defoliation, and their interactive effects persist in trees that re-grow after damage that severs their primary stem. To address these issues, we established a common garden consisting of twelve genotypes of potted aspen (Populus tremuloides) trees, and subjected half of the trees to defoliation in two successive years. At the beginning of the third year, all trees were severed at the soil surface (coppiced) and allowed to regenerate for five months. Afterwards, we counted the number of root and stump sprouts produced and measured the basal diameter (d) and height (h) of the tallest ramet in each pot. We collected leaves one and two years after the second defoliation and assessed levels of phenolic glycosides, condensed tannins, and nitrogen. In terms of re-growth, we found that the total number of sprouts produced varied by 3.6-fold among genotypes, and that prior defoliation decreased total sprout production by 24%. The size (d(2)h) of ramets, however, did not differ significantly among genotypes or defoliation classes. In terms of phytochemistry, we observed genotypic differences in concentrations of all phytochemicals assessed both one and two years after the second defoliation. Two years after defoliation, we observed effects of prior defoliation in a genotype-by-defoliation interaction for condensed tannins. Results from this study demonstrate that genotypic differences and impacts of prior defoliation persist to influence growth and defense traits in trees even after complete removal of above-ground stems, and thus likely influence productivity and plant-herbivore interactions in forests affected by natural disturbances or actively managed through coppicing.

  17. Pre-culturing of nodal explants in thidiazuron supplemented liquid medium improves in vitro shoot multiplication of Cassia angustifolia.

    PubMed

    Siddique, I; Abdullwahab Bukhari, N; Perveen, K; Siddiqui, I; Anis, M

    2013-09-01

    An in vitro propagation system for Cassia angustifolia Vahl. has been developed. Due to the presence of sennosides, the demand of this plant has increased manyfold in global market. Multiple shoots were induced by culturing nodal explants excised from mature plants on a liquid Murashige and Skoog [8] medium supplemented with 5-100 μM of thidiazuron (TDZ) for different treatment duration (4, 8, 12 and 16 d). The optimal level of TDZ supplemented to the culture medium was 75 μM for 12 d induction period followed by subculturing in MS medium devoid of TDZ as it produced maximum regeneration frequency (87%), mean number of shoots (9.6 ± 0.33) and shoot length (4.4 ± 0.46 cm) per explant. A culture period longer than 12 d with TDZ resulted in the formation of fasciated or distorted shoots. Ex vitro rooting was achieved when the basal cut end of regenerated shoots was dipped in 200 μM indole-3-butyric acid (IBA) for half an hour followed by their transplantation in plastic pots filled with sterile soilrite where 85% plantlets grew well and all exhibited normal development. The present findings describe an efficient and rapid plant regeneration protocol that can further be used for genetic transformation studies.

  18. High-Frequency Regeneration of the Drought-Tolerant Tree Melia volkensii Gurke Using Low-Cost Agrochemical Thidiazuron

    PubMed Central

    Mulanda, Eliud Sagwa; Adero, Mark Ochieng; Amugune, Nelson Onzere; Akunda, Elijah; Kinyamario, Jenesio I.

    2012-01-01

    Melia volkensii Gurke is a drought-tolerant tree native to East Africa's arid and semiarid lands (ASALs), with vast but underutilized potential for agroforestry and sustainable livelihoods in the ASALs. Its cultivation is limited by difficulties in propagation via conventional means. Full exploitation of the ability of thidiazuron (TDZ) to elicit regeneration in plant tissue cultures, as sole plant growth regulator (PGR), is hampered by high costs. This study tested the effectiveness of a low-cost agrochemical TDZ for in vitro propagation of M. volkensii. Zygotic embryos from mature seeds were cultured on Gamborg's B5 medium containing 0 to 4 mg/L of agrochemical TDZ from Kingtai Chemicals Co.,Ltd., China. Callus induction frequency was 96.67 to 100%. Significantly large callus fresh mass was produced at 0.05 mg/L TDZ concentration (ANOVA, P < 0.001). The effect of TDZ on embryogenicity was significant over certain ranges of concentrations (Anova, P < 0.001). Multiple somatic embryos developed within 14 days of subculture to hormone-free B5 medium. Somatic embryos developed into microshoots which elongated when transferred to 1/2 MS medium supplemented with 0.1 mg/L 6-benzylaminopurine plus 10% coconut water. The Kingtai-TDZ showed a high potency and suitability for use in M. volkensii tissue culture. PMID:23227344

  19. Correlation of epiphyllous bud differentiation with foliar senescence in crassulacean succulent Kalanchoe pinnata as revealed by thidiazuron and ethrel application.

    PubMed

    Jaiswal, Sarita; Sawhney, Sudhir

    2006-05-01

    Leaves of Kalanchoe pinnata have crenate margins with each notch bearing a dormant bud competent to develop into a healthy plantlet. Leaf detachment is a common signal for inducing two contrastingly different leaf-based processes, i.e. epiphyllous bud development into plantlet and foliar senescence. To investigate differentiation of bud and its correlation, if any, with foliar senescence, thidiazuron (TDZ), having cytokinin activity and ethrel (ETH), an ethylene releasing compound, were employed. The experimental system was comprised of marginal leaf discs, each harbouring an epiphyllous bud. Most of the growth characteristics of plantlet developing from the epiphyllous bud were significantly inhibited by TDZ but promoted by ETH. The two regulators modulated senescence in a manner different for leaf discs and plantlet leaves. Thus, TDZ caused a complete retention whereas ETH a complete loss of chlorophyll in the leaf discs. In contrast, the former resulted in a complete depletion of chlorophyll from the plantlet leaves producing an albino effect, while the latter reduced it by 50% only. In combined dispensation of the two regulators, the effect of TDZ was expressed in majority of responses studied. The results presented in this investigation clearly show that the foliar processes of epiphyllous bud differentiation and senescence are interlinked as TDZ that delayed senescence inhibited epiphyllous bud differentiation and ETH that hastened senescence promoted it. A working hypothesis to interpret responsiveness of the disc-bud composite on lines of a source-sink duo, has been proposed.

  20. Gossypium arboreum Accessions Resistant to Rotylenchulus reniformis

    PubMed Central

    Stetina, Salliana R.; Erpelding, John E.

    2016-01-01

    In the southeastern United States, reniform nematode (Rotylenchulus reniformis) is a serious pest of upland cotton (Gossypium hirsutum), a species which has no naturally occurring resistance against this nematode. To identify sources of reniform nematode resistance in species closely related to upland cotton, 222 G. arboreum accessions from the U.S. germplasm collection were evaluated in repeated growth chamber experiments. In initial screenings, root infection was measured 4 wks after inoculation. The 15 accessions supporting the fewest infections (PI 529992, PI 615755, PI 615766, PI 615788, PI 615848, PI 615856, PI 615950, PI 615977, PI 615991, PI 616008, PI 616016, PI 616062, PI 616126, PI 616159, and A2 553) were evaluated again in confirmation tests lasting 8 wk. The combined totals of nematodes extracted from soil and eggs extracted from roots were analyzed. All 15 accessions tested supported significantly smaller reniform nematode populations than the susceptible controls (G. hirsutum cultivar Deltapine 16 and G. arboreum accession PI 529729). Nine accessions (PI 529992, PI 615755, PI 615766, PI 615788, PI 615856, PI 615950, PI 615991, PI 616008, and PI 616159) supported reniform nematode populations comparable to the resistant control (G. arboreum accession PI 615699), and accession PI 615848 had significantly fewer reniform nematodes than the resistant control. Cotton breeders would benefit from introgressing the newly identified resistance from these accessions into their upland cotton improvement programs. PMID:28154428

  1. Branch growth and leaf numbers of red maple (Acer rubrum L.) and red oak (Quercus rubra L.): response to defoliation.

    PubMed

    Heichel, G H; Turner, Neil C

    1984-04-01

    Branch growth and leaf formation from terminal and from lateral buds of red maple (Acer rubrum L.) and red oak (Quercus rubra L.) were measured in response to simulated insect defoliation. A single large branch representative of the crown of each tree was used for enumeration of growth and of bud numbers throughout three successive years of 0, 50, 75, and 100% leaf removal for the entire tree. Leaf number per tree for both species after the last year of defoliation was reduced in direct proportion to the severity of defoliation, in comparison to the predefoliation status of the trees. Bud number per tree for red maple, but not for red oak, was also reduced in proportion to severity of defoliation.Averaged over all defoliation treatments, defoliation reduced branch growth more than leaf production. Furthermore, the reduction in branch growth and leaf production was greater in red oak than in red maple. Three years of successive defoliation reduced the mean lateral plus terminal branch growth by 40% in red oak and by 23% in red maple, while leaf number was reduced 22% in red oak and remained unchanged in red maple. In red maple, 100% defoliation caused greater branch death than the 50 or 75% defoliation treatments, and the amount of death was greater after each successive year of defoliation. In contrast to red maple, undefoliated red oak incurred a substantial amount of branch death throughout the study which was little affected by defoliation treatment.

  2. Selective defoliation affects plant growth, fruit transcriptional ripening program and flavonoid metabolism in grapevine

    PubMed Central

    2013-01-01

    Background The selective removal of grapevine leaves around berry clusters can improve the quality of ripening fruits by influencing parameters such as the berry sugar and anthocyanin content at harvest. The outcome depends strongly on the timing of defoliation, which influences the source–sink balance and the modified microclimate surrounding the berries. We removed the basal leaves from Vitis vinifera L. cv Sangiovese shoots at the pre-bloom and veraison stages, and investigated responses such as shoot growth, fruit morphology and composition compared to untreated controls. Moreover, we performed a genome-wide expression analysis to explore the impact of these defoliation treatments on berry transcriptome. Results We found that pre-bloom defoliation improved berry quality traits such as sugar and anthocyanin content, whereas defoliation at veraison had a detrimental effect, e.g. less anthocyanin and higher incidence of sunburn damage. Genome-wide expression analysis during berry ripening revealed that defoliation at either stage resulted in major transcriptome reprogramming, which slightly delayed the onset of ripening. However, a closer investigation of individual gene expression profiles identified genes that were specifically modulated by defoliation at each stage, reflecting the uncoupling of metabolic processes such as flavonoid biosynthesis, cell wall and stress metabolism, from the general ripening program. Conclusions The specific transcriptional modifications we observed following defoliation at different time points allow the identification of the developmental or metabolic processes affected in berries thus deepening the knowledge of the mechanisms by which these agronomical practices impact the final berry ripening traits. PMID:23433030

  3. Grass competition surpasses the effect of defoliation on a woody plant invader

    NASA Astrophysics Data System (ADS)

    Aranda, Melina J.; Tognetti, Pedro M.; Mazía, Noemí

    2015-10-01

    Woody encroachment in grasslands represents a global phenomenon with strong consequences on ecosystem functioning. While the causes triggering this process can be multiple, there is consensus on the fact that anthropogenic activities play a central role in woody expansion. In particular, the loss of grass cover increases the chances of woody invasion, whereas the role of defoliation is less known. In this study our objective was to assess the simultaneous effect of competition generated by resident vegetation and woody seedling defoliation on the growth and survival of Gleditsia triacanthos seedlings, a woody invader in Argentina. We established a factorial pot experiment with two main factors: Gleditsia defoliation (2 levels: with and without defoliation) and pasture competition (3 levels: without pasture, clipped pasture and intact pasture). Our results showed that pasture competition reduced Gleditsia survival and tree growth, but that the effect of tree defoliation on tree growth depended on the magnitude of pasture competition. More widely, our results stress the existence of a hierarchy order of factors controlling Gleditsia establishment (survival + growth): grass competition was the main control and tree defoliation became important only in the absence of competition. This evidence suggests that maintaining a competitive grass cover along with a frequency of tree defoliation could diminish tree establishment in herbaceous communities.

  4. Carbon allocation during defoliation: testing a defense-growth trade-off in balsam fir

    PubMed Central

    Deslauriers, Annie; Caron, Laurie; Rossi, Sergio

    2015-01-01

    During repetitive defoliation events, carbon can become limiting for trees. To maintain growth and survival, the resources have to be shared more efficiently, which could result in a trade-off between the different physiological processes of a plant. The objective of this study was to assess the effect of defoliation in carbon allocation of balsam fir [Abies balsamea (L.) Mill.] to test the presence of a trade-off between allocation to growth, carbon storage, and defense. Three defoliation intensities [control (C-trees, 0% defoliation), moderately (M-trees, 41–60%), and heavily (H-trees, 61–80%) defoliated] were selected in order to monitor several variables related to stem growth (wood formation in xylem), carbon storage in stem and needle (non-structural soluble sugars and starch), and defense components in needles (terpenoids compound) from May to October 2011. The concentration of starch was drastically reduced in both wood and leaves of H-trees with a quasi-absence of carbon partitioning to storage in early summer. Fewer kinds of monoterpenes and sesquiterpenes were formed with an increasing level of defoliation indicating a lower carbon allocation for the production of defense. The carbon allocation to wood formation gradually reduced at increasing defoliation intensities, with a lower growth rate and fewer tracheids resulting in a reduced carbon sequestration in cell walls. The hypothesis of a trade-off between the allocations to defense components and to non-structural (NCS) and structural (growth) carbon was rejected as most of the measured variables decreased with increasing defoliation. The starch amount was highly indicative of the tree carbon status at different defoliation intensity and future research should focus on the mechanism of starch utilization for survival and growth following an outbreak. PMID:26029235

  5. Carbon allocation during defoliation: testing a defense-growth trade-off in balsam fir.

    PubMed

    Deslauriers, Annie; Caron, Laurie; Rossi, Sergio

    2015-01-01

    During repetitive defoliation events, carbon can become limiting for trees. To maintain growth and survival, the resources have to be shared more efficiently, which could result in a trade-off between the different physiological processes of a plant. The objective of this study was to assess the effect of defoliation in carbon allocation of balsam fir [Abies balsamea (L.) Mill.] to test the presence of a trade-off between allocation to growth, carbon storage, and defense. Three defoliation intensities [control (C-trees, 0% defoliation), moderately (M-trees, 41-60%), and heavily (H-trees, 61-80%) defoliated] were selected in order to monitor several variables related to stem growth (wood formation in xylem), carbon storage in stem and needle (non-structural soluble sugars and starch), and defense components in needles (terpenoids compound) from May to October 2011. The concentration of starch was drastically reduced in both wood and leaves of H-trees with a quasi-absence of carbon partitioning to storage in early summer. Fewer kinds of monoterpenes and sesquiterpenes were formed with an increasing level of defoliation indicating a lower carbon allocation for the production of defense. The carbon allocation to wood formation gradually reduced at increasing defoliation intensities, with a lower growth rate and fewer tracheids resulting in a reduced carbon sequestration in cell walls. The hypothesis of a trade-off between the allocations to defense components and to non-structural (NCS) and structural (growth) carbon was rejected as most of the measured variables decreased with increasing defoliation. The starch amount was highly indicative of the tree carbon status at different defoliation intensity and future research should focus on the mechanism of starch utilization for survival and growth following an outbreak.

  6. Preference of Gossypium genotypes to Bemisia argentifolii (Homoptera: Aleyrodidae)

    USDA-ARS?s Scientific Manuscript database

    Several Gossypium species and genotypes were evaluated by in field and greehouse tests in the Lower Rio Grande Valley, Texas, for preference to the whitefly. Genotypes with G.hirsutum, G. barabadense, G. herbaceum, and G. arboreum were examined, including commercial and obsolete cultivars,(cultivar...

  7. Molecular confirmation of Gossypium hirsutum chromosome substitution lines

    USDA-ARS?s Scientific Manuscript database

    The primary gene pool for tetraploid cotton species includes G. hirsutum L., as well as the other four 2n=52 species of Gossypium (G. barbadense, G. mustellinum, G. tomentosum and G. darwinii). To help overcome barriers to effective introgression, we have developed a number of alien chromosome subst...

  8. Molecular Diversity of Gossypium herbaceum L. and G. arboreum L.

    USDA-ARS?s Scientific Manuscript database

    The diploid Asiatic cotton species (Gossypium herbaceum L. and G. arboreum L.) are a valuable source of genetic variation in modern cotton improvement. In this study, the genetic diversity of selected G. herbaceum and G. arboreum accessions collected from different regions all around the world accor...

  9. Enhancement and diversity of primitive cotton, Gossypium hirsutum L., accessions

    USDA-ARS?s Scientific Manuscript database

    Cotton, Gossypium hirsutum L., is an important cultivated crop that is grown throughout the world. Improvements in agronomic performance and fiber quality are needed to ensure its economic viability. Primitive accessions of cotton offer a wealth of genetic variability; however, since most of these...

  10. Localization of Allotetraploid Gossypium SNPs Using Physical Mapping Resources

    USDA-ARS?s Scientific Manuscript database

    Recent efforts in Gossypium SNP development have produced thousands of putative SNPs for G. barbadense, G. mustelinum, and G. tomentosum relative to G. hirsutum. Here we report on current efforts to localize putative SNPs using physical mapping resources. Recent advances in physical mapping resour...

  11. Postinfection development of Rotylenchulus reniformis on resistant Gossypium barbadense accessions

    USDA-ARS?s Scientific Manuscript database

    The reniform nematode (Rotylenchulus reniformis) causes significant cotton (Gossypium hirsutum) losses in the midsouthern United States. The research objective was to describe the effects of two resistant G. barbadense lines (cultivar TX 110 and accession GB 713) on development and fecundity of reni...

  12. Portable DNA markers tailored for systematic characterization of Gossypium germplasm

    USDA-ARS?s Scientific Manuscript database

    Many small-scale ad-hoc studies on characterization of Gossypium germplasm have been conducted that use different sets of markers. Coordination with the cotton community is needed to reach a consensus on the appropriate initial set of DNA markers. In consultation with the cotton community, a set o...

  13. Preculturing effect of thidiazuron on in vitro shoot multiplication and micropropagation round in Capparis decidua (Forsk.) an important multipurpose plant.

    PubMed

    Bukhari, Najat A W; Siddique, Iram; Perveen, Kahkashan

    2016-09-01

    An efficient protocol was developed for clonal multiplication of an important shrub: Capparis decidua (Forsk.) Edgew, through in vitro shoot induction and multiplication from nodal explants. Pretreatment of nodal explants in a liquid Murashige and Skoog (MS) medium augmented with various thidiazuron (TDZ) concentrations at relatively high levels (5-100 μM) for different time duration (4, 8, 12 and 16 d), proved a significant approach for in vitro shoot production. After an initial exposure time to TDZ, nodal explants were inoculated onto a MS basal medium devoid of TDZ for further induction and proliferation. The highest regeneration rate (85%), average number of shoots/explant (8.7 ± 0.22) and maximum shoot length (3.9 ± 0.33 cm) were obtained from the nodal explants exposed to 50 μM TDZ for 8 d. The nodal explants excised from the proliferated cultures of TDZ (50 μM) for 8 d were used as explants and showed an enhancement rate after next three round of in vitro propagation. Best results for rooting was obtained by ex vitro treatment of shoots with 200 μM indole-3-butyric acid (IBA) for 20 min. as it produced an average of 5.7 ± 0.41 roots per microshoot with 4.4 ± 0.39 cm root length in 84% shoots. Different planting substrates was tested for maximum survival of hardening off micropropagated plantlets and soilrite proved most effective than others as 97.1 ± 7.21 plantlets survived. All micropropagated plants grew well in natural conditions and showed similar morphology to the mother plant.

  14. Extreme defoliation reduces tree growth but not C and N storage in a winter-deciduous species

    PubMed Central

    Piper, Frida I.; Gundale, Michael J.; Fajardo, Alex

    2015-01-01

    Background and Aims There is a growing concern about how forests will respond to increased herbivory associated with climate change. Carbon (C) and nitrogen (N) limitation are hypothesized to cause decreasing growth after defoliation, and eventually mortality. This study examines the effects of a natural and massive defoliation by an insect on mature trees’ C and N storage, which have rarely been studied together, particularly in winter-deciduous species. Methods Survival, growth rate, carbon [C, as non-structural carbohydrate (NSC) concentration] and nitrogen (N) storage, defences (tannins and total polyphenols), and re-foliation traits were examined in naturally defoliated and non-defoliated adult trees of the winter-deciduous temperate species Nothofagus pumilio 1 and 2 years after a massive and complete defoliation caused by the caterpillar of Ormiscodes amphimone (Saturniidae) during summer 2009 in Patagonia. Key Results Defoliated trees did not die but grew significantly less than non-defoliated trees for at least 2 years after defoliation. One year after defoliation, defoliated trees had similar NSC and N concentrations in woody tissues, higher polyphenol concentrations and lower re-foliation than non-defoliated trees. In the second year, however, NSC concentrations in branches were significantly higher in defoliated trees while differences in polyphenols and re-foliation disappeared and decreased, respectively. Conclusions The significant reduction in growth following defoliation was not caused by insufficient C or N availability, as frequently assumed; instead, it was probably due to growth limitations due to factors other than C or N, or to preventative C allocation to storage. This study shows an integrative approach to evaluating plant growth limitations in response to disturbance, by examining major resources other than C (e.g. N), and other C sinks besides storage and growth (e.g. defences and re-foliation). PMID:25851136

  15. Extreme defoliation reduces tree growth but not C and N storage in a winter-deciduous species.

    PubMed

    Piper, Frida I; Gundale, Michael J; Fajardo, Alex

    2015-06-01

    There is a growing concern about how forests will respond to increased herbivory associated with climate change. Carbon (C) and nitrogen (N) limitation are hypothesized to cause decreasing growth after defoliation, and eventually mortality. This study examines the effects of a natural and massive defoliation by an insect on mature trees' C and N storage, which have rarely been studied together, particularly in winter-deciduous species. Survival, growth rate, carbon [C, as non-structural carbohydrate (NSC) concentration] and nitrogen (N) storage, defences (tannins and total polyphenols), and re-foliation traits were examined in naturally defoliated and non-defoliated adult trees of the winter-deciduous temperate species Nothofagus pumilio 1 and 2 years after a massive and complete defoliation caused by the caterpillar of Ormiscodes amphimone (Saturniidae) during summer 2009 in Patagonia. Defoliated trees did not die but grew significantly less than non-defoliated trees for at least 2 years after defoliation. One year after defoliation, defoliated trees had similar NSC and N concentrations in woody tissues, higher polyphenol concentrations and lower re-foliation than non-defoliated trees. In the second year, however, NSC concentrations in branches were significantly higher in defoliated trees while differences in polyphenols and re-foliation disappeared and decreased, respectively. The significant reduction in growth following defoliation was not caused by insufficient C or N availability, as frequently assumed; instead, it was probably due to growth limitations due to factors other than C or N, or to preventative C allocation to storage. This study shows an integrative approach to evaluating plant growth limitations in response to disturbance, by examining major resources other than C (e.g. N), and other C sinks besides storage and growth (e.g. defences and re-foliation). © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany

  16. cis-3-Chloroacrylic Acid: A New Cotton Defoliant and Crop Desiccant.

    PubMed

    Herrett, R A; Kurtz, A N

    1963-09-20

    cis-3-Chloroacrylic acid is a potent cotton defoliant and a crop desiccant. Relationships between structure and activity indicate a relatively high degree of specificity, since minor modifications in structure result in loss of activity.

  17. Effects of Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) Larval Defoliation, Clone, and Season on Populus Foliar Phagostimulants

    Treesearch

    David R. Coyle; Joel D. McMillin; Richard B. Hall; Elwood R. Hart

    2003-01-01

    Abstract: The cottonwood leaf beetle, Chrysomela scripta F., is a serious defoliator of plantation Populus in the United States. Current control methods include biorational and synthetic chemicals as well as selecting Populus clones resistant or tolerant to C. scripta...

  18. The Virgin River Tamarisk Defoliation by Diorhabda carinulata: It's Effects on Evapotranspiration Rates and Groundwater Consumption

    NASA Astrophysics Data System (ADS)

    Sueki, S.; Healey, J. M.; Acharya, K.

    2013-12-01

    Saltcedar (tamarisk; Tamarix spp) has become the most widespread invasive plant species in the western United States. Waterways and their corridors have evolved into mono-species stands of saltcedar. Chemical and mechanical methods of tamarisk eradication have been partially effective and prove to be expensive and cause irrepressible damage to natural resources. In the late 1960s, biological control program began in order to reduce the risk of damaging native plants. In 2001, Diorhabda elongate (leaf beetles) was released for open field tests followed by other releases in several locations in the western United States. One of the successful releases occurred in St. George, UT along the Virgin River in 2006. The last few years has seen establishment of large scale populations in the lower Virgin River. Eddy covariance (EC) tower including groundwater monitoring well was set up along the Virgin River near Mesquite, NV in 2010 to monitor effects of tamarisk defoliation on evapotranspiration (ET). Initial 2010 data (pre-beetle) established a baseline for characterization of tamarisk ET and groundwater consumption prior to defoliation of tamarisk. The beetles arrived at the site in late 2010 and established a healthy population at the growing season of 2011. 2010 data compared to the episodic herbivore events, observed at the site in 2011 and 2012, clearly show the direct impact of tamarisk defoliation. The results show that the post-defoliation ET values along with magnitude of diurnal fluctuations, found in the water level record, decreased compared to the pre-defoliation values. However, magnitude of the effects of defoliation seemed to be dependent on growth stage of tamarisk at the time of defoliation. Also, the defoliation periods are short lived as tamarisk quickly recovered and establish new growth. In 2012, the defoliation occurred twice since tamarisk re-foliated quickly after the first defoliation by late summer before beetles started overwintering

  19. Defoliation negatively affects plant growth and the ectomycorrhizal community of Pinus pinaster in Spain.

    PubMed

    Pestaña, Montserrat; Santolamazza-Carbone, Serena

    2011-03-01

    In this work, by artificially reproducing severe (75%) and moderate (25%) defoliation on maritime pines Pinus pinaster in NW Spain, we investigated, under natural conditions, the consequences of foliage loss on reproduction, abundance, diversity and richness of the fungal symbionts growing belowground and aboveground. The effect of defoliation on tree growth was also assessed. Mature needles were clipped during April 2007 and 2008. Root samples were collected in June-July 2007 and 2008. Collection of sporocarps was performed weekly from April 2007 to April 2009. Taxonomic identity of ectomycorrhizal fungi was assessed by using the internal transcribed spacer (ITS) regions of rDNA through the polymerase chain reaction (PCR) method, subsequent direct sequencing and BLAST search. Ectomycorrhizal colonization was significantly reduced (from 54 to 42%) in 2008 by 75% defoliation, accompanied with a decline in species richness and diversity. On the other hand, sporocarp abundance, richness and diversity were not affected by foliage loss. Some ECM fungal symbionts, which are assumed to have a higher carbon cost according to the morphotypes structure, were reduced due to severe (75%) defoliation. Furthermore, 75% foliage loss consistently depressed tree growth, which in turn affected the ectomycorrhizal growth pattern. Defoliation impact on ECM symbionts largely depends on the percentage of foliage removal and on the number of defoliation bouts. Severe defoliation (75%) in the short term (2 years) changed the composition of the ECM community likely because root biomass would be adjusted to lower levels in parallel with the depletion of the aboveground plant biomass, which probably promoted the competition among mycorrhizal types for host resources. The persistence of fungal biomass in mycorrhizal roots would be crucial for nutrient up-take and recovery from defoliation stress of the host plants.

  20. The dynamics of recovery and growth: how defoliation affects stored resources.

    PubMed

    Atkinson, R R L; Burrell, M M; Rose, K E; Osborne, C P; Rees, M

    2014-05-22

    Growth rate varies widely among species and the trade-off between growth rate and storage or maintenance traits is a principal axis of variation between species. Many plant species have substantial root stores, but very little is known about how growth rate modifies responses of these stores to defoliation and other stresses. Species with different growth rates are predicted to respond in distinct ways, because of variation in the pre-defoliation allocation to storage. Here, we quantified the dynamics of stored carbohydrates in seven species with varying growth rate, following defoliation in a pot experiment. For faster growing species, there was significant reduction in carbohydrate concentration following defoliation, followed by relatively fast recovery, whereas for slower growing species, carbohydrate concentration levels remained relatively invariant across treatments. Results for total carbohydrates mirrored those for concentration, but were not as significant. Our findings were consistent with the idea that faster growing species respond more rapidly than slower growers to defoliation, through changes in carbohydrate pool concentrations. Growth rate as an indicator of life-history and ecological strategy may therefore be key to understanding post-defoliation recovery and storage strategies.

  1. Modeling forest defoliation using simulated BRDF and assessing its effect on reflectance and sensor reaching radiance

    NASA Astrophysics Data System (ADS)

    Rengarajan, Rajagopalan; Schott, John R.

    2016-09-01

    Remote sensing techniques such as change detection are widely used for mapping and monitoring forest cover to detect the declining health and vigor of forests. These techniques rely on the assumption that the biophysical variation in the forest introduces a corresponding variation in its reflectance. The biophysical variations are assessed by foresters, but these assessment techniques are expensive and cannot be performed frequently to identify a specific level of change in the forest, for example, infection due to gypsy moths that results in forest defoliation. Further, the interaction of atmosphere, sensor characteristics, and phenology that are inherent in the remotely sensed images makes it difficult to separate biophysical changes from observational effects. We have addressed these limitations by developing a method to model the spectral reflectance properties of forests with varying degrees of defoliation using the Digital Image and Remote Sensing Image Generation (DIRSIG) tool. This paper discusses the in-canopy radiative approach and the impact of defoliation on the reflectance and radiance observed by sensors such as Landsat. The results indicate that the relative variation in forest reflectance between a non-defoliated and a 30% defoliated deciduous forest can be as high as 10% in the NIR spectral band. A function can be fit to predict the level of defoliation from the relative variation in radiance. The modeling and analysis techniques can be extended to assess the impact of atmospheric factors and sensor characteristics relative to the biophysical changes as well as for assessing other biophysical variables in forests.

  2. Resource allocation in an annual herb: Effects of light, mycorrhizal fungi, and defoliation

    NASA Astrophysics Data System (ADS)

    Aguilar-Chama, Ana; Guevara, Roger

    2016-02-01

    Concurrent interactions and the availability of resources (e.g., light) affect the cost/benefit balance during mutualistic and antagonistic interactions, as well as plant resource allocation patterns. Mycorrhizal interactions and herbivory concur in most plants, where mycorrhizae can enhance the uptake of soil nutrients by plants as well as consuming a large fraction of the plant's carbon, and defoliation usually reduces light interception and photosynthesis, thereby causing direct losses to the hosts of mycorrhizal fungi. Both types of interactions affect the carbon budget of their host plants and thus we predict that the relative costs of herbivory and mycorrhizal colonization will increase when photosynthesis is reduced, for instance in light limited environments. We conducted a greenhouse experiment using Datura stramonium to investigate the effects of defoliation and mycorrhizal inoculation on the resource allocation patterns in two different light environments. Defoliated plants overcompensated in terms of leaf mass in both light environments, but total seed mass per fruit was negatively affected by defoliation in both light environments. Mycorrhizal inoculation had a positive effect on vegetative growth and the leaf nitrogen content, but defoliation negates the benefit of mycorrhizal interactions in terms of the leaf nitrogen content. In general, D. stramonium compensated for the relative costs of concurrent mycorrhizal interactions and defoliation; plants that lacked both interactions exhibited the same performance as plants with both types of interactions.

  3. Are gas exchange responses to resource limitation and defoliation linked to source:sink relationships?

    PubMed

    Pinkard, E A; Eyles, A; O'Grady, A P

    2011-10-01

    Productivity of trees can be affected by limitations in resources such as water and nutrients, and herbivory. However, there is little understanding of their interactive effects on carbon uptake and growth. We hypothesized that: (1) in the absence of defoliation, photosynthetic rate and leaf respiration would be governed by limiting resource(s) and their impact on sink limitation; (2) photosynthetic responses to defoliation would be a consequence of changing source:sink relationships and increased availability of limiting resources; and (3) photosynthesis and leaf respiration would be adjusted in response to limiting resources and defoliation so that growth could be maintained. We tested these hypotheses by examining how leaf photosynthetic processes, respiration, carbohydrate concentrations and growth rates of Eucalyptus globulus were influenced by high or low water and nitrogen (N) availability, and/or defoliation. Photosynthesis of saplings grown with low water was primarily sink limited, whereas photosynthetic responses of saplings grown with low N were suggestive of source limitation. Defoliation resulted in source limitation. Net photosynthetic responses to defoliation were linked to the degree of resource availability, with the largest responses measured in treatments where saplings were ultimately source rather than sink limited. There was good evidence of acclimation to stress, enabling higher rates of C uptake than might otherwise have occurred.

  4. Impact of defoliation intensities on plant biomass, nutrient uptake and arbuscular mycorrhizal symbiosis in Lotus tenuis growing in a saline-sodic soil.

    PubMed

    García, I; Mendoza, R

    2012-11-01

    The impact of different defoliation intensities on the ability of Lotus tenuis plants to regrowth, mobilise nutrients and to associate with native AM fungi and Rhizobium in a saline-sodic soil was investigated. After 70 days, plants were subjected to 0, 25, 50, 75 and 100% defoliation and shoot regrowth was assessed at the end of subsequent 35 days. Compared to non-defoliated plants, low or moderate defoliation up to 75% did not affect shoot regrowth. However, 100% treatment affected shoot regrowth and the clipped plants were not able to compensate the growth attained by non-defoliated plants. Root growth was more affected by defoliation than shoot growth. P and N concentrations in shoots and roots increased with increasing defoliation while Na(+) concentration in shoots of non-defoliated and moderately defoliated plants was similar. Non-defoliated and moderately defoliated plants prevented increases of Na(+) concentration in shoots through both reducing Na(+) uptake and Na(+) transport to shoots by accumulating Na(+) in roots. At high defoliation, the salinity tolerance mechanism is altered and Na(+) concentration in shoots was higher than in roots. Reduction in the photosynthetic capacity induced by defoliation neither changed the root length colonised by AM fungi nor arbuscular colonisation but decreased the vesicular colonisation. Spore density did not change, but hyphal density and Rhizobium nodules increased with defoliation. The strategy of the AM symbiont consists in investing most of the C resources to preferentially retain arbuscular colonisation as well as inoculum density in the soil.

  5. Genetic diversity and population structure of cottons (Gossypium spp.) of the New World assessed by SSR markers

    USDA-ARS?s Scientific Manuscript database

    A global analysis of cotton (Gossypium spp.) genetic diversity is the first step to understand its geographical distribution, dissemination, genetic relatedness, and population structure. To assess the genetic diversity and population structure in Gossypium species, 111 cotton accessions representin...

  6. Defoliation by pastoralists affects savanna tree seedling dynamics by limiting the facilitative role of canopy cover.

    PubMed

    Bufford, Jennifer L; Gaoue, Orou G

    2015-07-01

    Recurrent tree defoliation by pastoralists, akin to herbivory, can negatively affect plant reproduction and population dynamics. However, our understanding of the indirect role of defoliation in seedling recruitment and tree-grass dynamics in tropical savanna is limited. In West African savanna, Fulani pastoralists frequently defoliate several fodder tree species to feed livestock in the dry season. We investigated the direct and indirect effects of recurrent defoliation of African mahogany (Khaya senegalensis) by Fulani people on seedling (< 2 cm basal diameter) and sapling dynamics in West Africa using four years of demographic data on seedling and sapling density, growth, and survival, coupled with fruit production and microhabitat data over the same time period. Tree canopy cover facilitated seedlings but had negative effects on sapling growth possibly via intraspecific competition with adult plants. Interspecific competition with grasses strongly reduced seedling survival but had a weak effect on sapling growth. Fire reduced seedling survival and weakly reduced growth of seedlings and saplings, but did not affect sapling survival. These results indicate that the effect of fire on seedlings and saplings is distinct, a mechanism suitable for an episodic recruitment of seedlings into the sapling stage and consistent with predictions from the demographic bottleneck model. Defoliation affected seedling density and sapling growth through changes in canopy cover, but had no effect on seedling growth and sapling survival. In the moist region, sapling density was higher in sites with low-intensity defoliation, indicating that defoliation may strengthen the tree recruitment bottleneck. Our study suggests that large-scale defoliation can alter the facilitative role of nurse trees on seedling dynamics and tree-sapling competition. Given that tree defoliation by local people is a widespread activity throughout savanna-forest systems in West Africa, it has the potential to

  7. Combined effects of defoliation and water stress on pine growth and non-structural carbohydrates.

    PubMed

    Jacquet, Jean-Sébastien; Bosc, Alexandre; O'Grady, Anthony; Jactel, Hervé

    2014-04-01

    Climate change is expected to increase both pest insect damage and the occurrence of severe drought. There is therefore a need to better understand the combined effects of biotic and abiotic damage on tree growth in order to predict the multi-factorial effect of climate change on forest ecosystem productivity. Indeed, the effect of stress interactions on tree growth is an increasingly important topic that greatly lacks experiments and data, and it is unlikely that the impact of combined stresses can be extrapolated from the outcomes of studies that focused on a single stress. We developed an original manipulative study under real field conditions where we applied artificial defoliation and induced water stress on 10-year-old (∼10 m high) maritime pine trees (Pinus pinaster Ait.). Tree response to combined stresses was quantitatively assessed following tree secondary growth and carbohydrate pools. Such a design allowed us to address the crucial question of combined stresses on trees under stand conditions, sharing soil supplies with neighboring trees. Our initial hypotheses were that (i) moderate defoliation can limit the impact of water stress on tree growth through reduced transpiration demand by a tree canopy partly defoliated and that (ii) defoliation results in reduced non-structural carbohydrate (NSC) pools, affecting tree tolerance to drought. Our results showed additive effects of defoliation and water stress on tree growth and contradict our initial hypothesis. Indeed, under stand conditions, we found that partial defoliation does not limit the impact of water stress through reduced transpiration. Our study also highlighted that, even if NSC in all organs were affected by defoliation, tree response to water stress was not triggered. We found that stem NSC were maintained or increased during the entire growing season, supporting literature-based hypotheses such as an active maintenance of the hydraulic system or another limiting resource for tree growth

  8. Is growth reduction in defoliated trees a consequence of prioritized carbon allocation to reserves?

    NASA Astrophysics Data System (ADS)

    Hoch, Guenter; Schmid, Sandra; Palacio, Sara

    2015-04-01

    Tissue concentrations of carbon reserve compounds are frequently used as proxies for the carbon balance of trees, but the mechanisms regulating the formation of carbon reserves are still under debate. It is often assumed that carbon storage in trees is largely a consequence of surplus carbon supply (reserve accumulation). In contrast, carbon storage might also occur against prevailing carbon demand from other sink activities, like growth (reserve formation), in which case carbon reserve pools might increase even at carbon limitation, and thus, cannot be used as indicators for a tree's carbon supply status. Such a situation might be severe defoliation by herbivores. Especially in evergreen tree species, it has been shown that natural and experimental defoliation leads to a reduction of growth that is proportional to the lost leaf area. Compared to this strong effect on growth, carbon reserve pools (i.e. sugars, starch and storage lipids) of defoliated trees often exert only a temporary decrease immediately after defoliation, while tissue concentrations of carbon reserves return to those of undefoliated trees by the end of the growing season. Within a recent experiment, we investigated, if the growth decline in trees following early season defoliation is the consequence of prioritized carbon allocation to carbon reserves over growth. To test this hypothesis we grew seedlings of evergreen Quecus ilex and deciduous Quercus petraea trees under low (140 ppm), medium (280 ppm) and high (560 ppm) CO2 concentrations and completely defoliated half of the seedlings in each CO2 treatment at the beginning of the growing season. In undefoliated control trees, CO2 had a significant positive effect on the seasonal growth in both species. Defoliation had a strong negative impact on growth in the evergreen Q. illex, but less in the deciduous Q. petraea. In both species, the growth reduction after defoliation relative to undefoliated controls was very similar at all three CO2

  9. Gossypolhemiquinone, a dimeric sesquiterpenoid identified in cotton (Gossypium).

    PubMed

    Stipanovic, Robert; Puckhaber, Lorraine; Frelichowski, James; Esquivel, Jesus; Westbrook, John; O'Neil, Mike; Bell, Alois; Dowd, Michael; Hake, Kater; Duke, Sara

    2016-02-01

    The report that the cotton leaf perforator, Bucculatrix thurberiella, is one of the few insect herbivores to attack Gossypium thurberi prompted an investigation of the terpenoids present in the leaves of this wild species of cotton. Members of Gossypium produce subepidermal pigment glands in their leaves that contain the dimeric sesquiterpenoid gossypol as well as other biosynthetically related terpenoids. In addition to gossypol, a previously unknown dimeric sesquiterpenoid, gossypolhemiquinone (GHQ), was identified in trace amounts in G. thurberi, a member of the D genome. Other members of the D genome of Gossypium were subsequently found to contain this compound, but GHQ was not detected in commercial cotton cultivars. When fed to Helicoverpa zea in an artificial diet, GHQ delayed days-to-pupation, reduced pupal weights, and survival to adulthood to a lesser or equal extent than gossypol in comparison to the control diet. However, GHQ had a synergistic effect on survival and days-to-pupation when combined with gossypol at the highest dosage tested (0.18%; 15.5:84.5 GHQ:gossypol). Because gossypol exhibits anti-cancer activity, GHQ was also evaluated for its anti-cancer activity against the National Cancer Institute's 60-Human Tumor Cell Line Screen. Significant inhibitory activity against most of these cell lines was not observed, but the results may offer some promise against leukemia cancer cell lines.

  10. Spraying Hydrangea Leaves with Chemical Defoliants, Urea, and GA in the Autumn Alters Defoliation Efficiency and Growth and Flowering Performance of Hydrangea during Forcing.

    USDA-ARS?s Scientific Manuscript database

    In two separate experiments, Hydrangea macrophylla ‘Merritt’s Supreme’ plants were used to study the effects of foliar sprays of Def-6 (Def, 2500, 5000, 7500 and 10000ppm), giberellic acid, (GA, 50ppm), copper-EDTA (CuEDTA, 0.5% and 1.0%), Florel (F, 2000ppm) and urea (U, 3%) on defoliation in the a...

  11. Dissipation of the defoliant tribufos in cotton-producing soils.

    PubMed

    Potter, Thomas L; Reddy, Krishna N; Millhollen, Eddie P; Bednarz, Craig W; Bosch, David D; Truman, Clint C; Strickland, Timothy

    2002-06-19

    Soil dissipation of the cotton defoliant tribufos was measured in laboratory incubations and on 0.2-ha research plots. Computed 50% dissipation time (DT(50)) using nonlinear and linear kinetic models ranged from 1 to 19 days. Data indicated that exchangeable soil aluminum inhibited tribufos-degrading soil organisms. Nevertheless, measured DT(50) values were 40 to 700 times less than the aerobic soil half-life (t(1/2)) values used in recent tribufos risk assessments. DT(50) values suggest that risk estimates were overstated. However, edge-of-field runoff concentrations measured on research plots exceeded invertebrate LOECs, thus some aquatic risk is indicated. Field data also suggested that volatilization may be a significant soil dissipation pathway. From this result, we conclude that volatilization should be included in simulation models used for pesticide registration. This will likely improve the accuracy of model outputs for products such as tribufos. Potential volatilization losses indicate a need to evaluate the atmospheric behavior of tribufos.

  12. Genetic diversity and population structure in the US Upland cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Elite plant breeding programs could likely benefit from the unexploited standing genetic variation of obsolete cultivars without the yield drag typically associated with wild accessions. A set of 381 accessions comprising 378 Upland (Gossypium hirsutum L.) and 3 Gossypium barbadense L. accessions of...

  13. Gossypolone and Gossypolhemiquinone: Biological activity of terpenoids found in cotton (Gossypium)

    USDA-ARS?s Scientific Manuscript database

    The wild cotton plant, Gossypium thurberi grows in the Sonoran Desert in northern Mexico and southern Arizona, and is attacked by few herbivorous insects (Korban, 1999). In general, members of Gossypium produce a rich assortment of sesquiterpenoid and sesterterpenoids in the subepidermal pigment gl...

  14. Canopy Defoliation has More Impact on Carbohydrate Availability than on Hydraulic Function in Declining Scots Pine Populations

    NASA Astrophysics Data System (ADS)

    Poyatos, R.; Aguadé, D.; Gómez, M.; Mencuccini, M.; Martínez-Vilalta, J.

    2013-12-01

    Drought-induced defoliation has recently been associated with depletion of carbohydrate reserves and increased mortality risk in Scots pine (Pinus sylvestris L.) at its dry limit. Are defoliated pines hydraulically impaired compared to non-defoliated pines? Moreover, how do defoliated pines cope with potentially lethal droughts, as compared to non-defoliated pines in the same population? In order to address these questions, we measured the seasonal dynamics of sap flow and needle water potentials (2010-2012), hydraulic function and non-structural carbohydrates (NSC) (2012) in healthy and defoliated pines in the Prades mountains (NE Spain). The summer drought was mild in 2010, intense in 2012 and extremely long in 2011. Defoliated Scots pines showed higher sap flow per unit leaf area during spring, but they were more sensitive to summer drought (Figure 1). This pattern was associated with a steeper decline in soil-to-leaf hydraulic conductance, which could not be explained by differences in branch vulnerability to embolism across defoliation classes. Accordingly, the native loss of xylem conductivity in branches, measured in 2012, remained similar across defoliation classes and reached >65% at the peak of the drought. However, a steeper vulnerability curve was observed for root xylem of defoliated pines. Xylem diameter variations (2011-2012) will be used to further investigate possible differences in the aboveground/belowground partitioning of hydraulic resistance across defoliation classes. NSC levels varied across tree organs (leaves>branches>roots>trunk) and strongly declined with drought. Defoliated pines displayed reduced NSC levels throughout the study period, despite enhanced water transport capacity and increased gas exchange rates during spring. Overall, the defoliated vs. healthy status seems to be more associated to differences in carbohydrate storage and dynamics than to hydraulic differences per se. However, starch conversion to soluble sugars during

  15. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species.

    PubMed

    Guada, Guillermo; Camarero, J Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die.

  16. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species

    PubMed Central

    Guada, Guillermo; Camarero, J. Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M. Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die. PMID:27066053

  17. Interactive effects of water supply and defoliation on photosynthesis, plant water status and growth of Eucalyptus globulus Labill.

    PubMed

    Quentin, A G; O'Grady, A P; Beadle, C L; Mohammed, C; Pinkard, E A

    2012-08-01

    Increased climatic variability, including extended periods of drought stress, may compromise on the health of forest ecosystems. The effects of defoliating pests on plantations may also impact on forest productivity. Interactions between climate signals and pest activity are poorly understood. In this study, we examined the combined effects of reduced water availability and defoliation on maximum photosynthetic rate (A(sat)), stomatal conductance (g(s)), plant water status and growth of Eucalyptus globulus Labill. Field-grown plants were subjected to two water-availability regimes, rain-fed (W-) and irrigated (W+). In the summer of the second year of growth, leaves from 75% of crown length removed from trees in both watering treatments and physiological responses within the canopies were examined. We hypothesized that defoliation would result in improved plant water status providing a mechanistic insight into leaf- and canopy-scale gas-exchange responses. Defoliated trees in the W+ treatment exhibited higher A(sat) and g(s) compared with non-defoliated trees, but these responses were not observed in the W- treatment. In contrast, at the whole-plant scale, maximum rates of transpiration (E(max)) and canopy conductance (G(Cmax)) and soil-to-leaf hydraulic conductance (K(P)) increased in both treatments following defoliation. As a result, plant water status was unaffected by defoliation and trees in the defoliated treatments exhibited homeostasis in this respect. Whole-plant soil-to-leaf hydraulic conductance was strongly correlated with leaf scale g(s) and A(sat) following the defoliation, providing a mechanistic insight into compensatory up-regulation of photosynthesis. Above-ground height and diameter growth were unaffected by defoliation in both water availability treatments, suggesting that plants use a range of responses to compensate for the impacts of defoliation.

  18. Mortality following cotton defoliation: San Joaquin Valley, California, 1970-1990.

    PubMed

    Ames, R G; Gregson, J

    1995-07-01

    A proportional mortality study comparing the cotton-growing areas of the San Joaquin Valley with the rest of the State of California was performed by the Office of Environmental Health Hazard Assessment as a continuation of earlier studies related to mercaptan-releasing pesticides. This mortality study found a pattern of increased proportion of "respiratory causes" mortality (ICD codes 460-519), statistically significant at less than the .05 probability level, for 15 of 21 years between 1970 and 1990, for the time period during and immediately following cotton defoliation. Defoliants which have the potential to produce acute symptoms include DEF and Folex, both of which release odorous butyl mercaptan gas as a degradation product. This paper tests the hypothesis that exposure to cotton defoliant breakdown products may be associated with a disproportionate increase in mortality. Prediction of the mortality proportions by pounds of DEF and Folex used was not statistically significant in the unadjusted models or in models adjusted for air pollution variables. One air pollution adjustment factor, total suspended particulates, was a statistically significant independent mortality proportion predictor. This finding suggests that total suspended particulates, not defoliants, may be related to mortality differentials during defoliation season. Possible confounding by demographic variation of the counties was not controlled in the analysis.

  19. Consequences of Repeated Defoliation on Belowground Bud Banks of Carex brevicuspis (Cyperaceae) in the Dongting Lake Wetlands, China

    PubMed Central

    Chen, Xin-Sheng; Deng, Zheng-Miao; Xie, Yong-Hong; Li, Feng; Hou, Zhi-Yong; Wu, Chao

    2016-01-01

    Despite the predominant role of bud banks in the regeneration of clonal macrophyte populations, few studies have examined the way in which clonal macrophytes adjust the demographic features of bud banks to regulate population dynamics in response to defoliation in wetlands. We investigated the density and composition of bud banks under repeated defoliation in the wetland sedge Carex brevicuspis C. B. Clarke in the Dongting Lake wetlands, China. The density and biomass of rhizome buds and shoots did not decrease significantly in response to repeated defoliation over two consecutive years. The composition of bud banks, which consisted of long and short rhizome buds, also did not change significantly in response to repeated defoliation. Nevertheless, the ramet height and the shoot, root, and rhizome mass of C. brevicuspis declined significantly under repeated defoliation. Our findings suggest that bud banks are a conservative reproductive strategy that enables C. brevicuspis to tolerate a certain amount of defoliation. The maintenance of large bud banks after repeated defoliation may enable C. brevicuspis populations to regenerate and persist in disturbed habitats. However, bud bank density of C. brevicuspis might decline in the long term because the amount of carbon stored in rhizome buds and plants is reduced by frequent defoliation. PMID:27524993

  20. Consequences of Repeated Defoliation on Belowground Bud Banks of Carex brevicuspis (Cyperaceae) in the Dongting Lake Wetlands, China.

    PubMed

    Chen, Xin-Sheng; Deng, Zheng-Miao; Xie, Yong-Hong; Li, Feng; Hou, Zhi-Yong; Wu, Chao

    2016-01-01

    Despite the predominant role of bud banks in the regeneration of clonal macrophyte populations, few studies have examined the way in which clonal macrophytes adjust the demographic features of bud banks to regulate population dynamics in response to defoliation in wetlands. We investigated the density and composition of bud banks under repeated defoliation in the wetland sedge Carex brevicuspis C. B. Clarke in the Dongting Lake wetlands, China. The density and biomass of rhizome buds and shoots did not decrease significantly in response to repeated defoliation over two consecutive years. The composition of bud banks, which consisted of long and short rhizome buds, also did not change significantly in response to repeated defoliation. Nevertheless, the ramet height and the shoot, root, and rhizome mass of C. brevicuspis declined significantly under repeated defoliation. Our findings suggest that bud banks are a conservative reproductive strategy that enables C. brevicuspis to tolerate a certain amount of defoliation. The maintenance of large bud banks after repeated defoliation may enable C. brevicuspis populations to regenerate and persist in disturbed habitats. However, bud bank density of C. brevicuspis might decline in the long term because the amount of carbon stored in rhizome buds and plants is reduced by frequent defoliation.

  1. Tree mortality in mixed pine-hardwood stands defoliated by the European gypsy moth (Lymantria dispar L.)

    Treesearch

    Mark H. Eisenbies; Christopher Davidson; James Johnson; Ralph Amateis; Kurt Gottschalk

    2007-01-01

    Defoliation by the European gypsy moth (Lymantria dispar L.) and subsequent tree mortality have been well documented in the northeastern United States. In this study we evaluate tree mortality after initial defoliation in mixed pine?hardwood stands in the southeastern United States as the range of European gypsy moth expands.

  2. The effects of silvicultural thinning and Lymantria dispar L. defoliation on wood volume growth of Quercus spp.

    Treesearch

    Mary Ann Fajvan; Kurt W. Gottschalk

    2012-01-01

    Pre- and post-defoliation radial growth rates were used to examine the effects of silvicultural thinning and two consecutive years of gypsy moth (Lymantria dispar L.) defoliation on Quercus spp. wood volume production. In the first phase of the study, tree rings from 65 dissected stems, were used to develop polynomial models to...

  3. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (6 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  4. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (5 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  5. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (1 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  6. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (2 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  7. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (4 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  8. Proceedings: Integrated management and dynamics of forest defoliating insects; 1999 August 15-19; Victoria, BC. (3 of 6)

    Treesearch

    A.M. Liebhold; M.L. McManus; I.S. Otvos; S.L.C Fosbroke

    2001-01-01

    This publication contains 18 research papers about the population ecology and management of forest insect defoliators. These papers were presented at a joint meeting of working parties s7.03.06, ?Integrated Management of Forest Defoliating Insectd?, and S7.03.07, ?Population Dynamics of Forest Insects,? of the International Union of Forestry Research Organizations (...

  9. Effect of defoliation prior to a frost on postharvest respiration rate, extractable sucrose, and invert sugar concentration of sugarbeet

    USDA-ARS?s Scientific Manuscript database

    This study investigated the effect of defoliation prior to a frost on postharvest storage properties of sugarbeet (Beta vulgaris L.). Roots of plants with canopies intact until harvest were compared to roots of plants that had been defoliated prior to a frost on multiple harvest dates following a da...

  10. Simulated western spruce budworm defoliation reduces torching and crowning potential: A sensitivity analysis using a physics-based fire model

    Treesearch

    Gregory M. Cohn; Russell A. Parsons; Emily K. Heyerdahl; Daniel G. Gavin; Aquila Flower

    2014-01-01

    The widespread, native defoliator western spruce budworm (Choristoneura occidentalis Freeman) reduces canopy fuels, which might affect the potential for surface fires to torch (ignite the crowns of individual trees) or crown (spread between tree crowns). However, the effects of defoliation on fire behaviour are poorly understood. We used a physics-based fire model to...

  11. Multiple-level defoliation assessment with hyperspectral data: integration of continuum-removed absorptions and red edges

    USDA-ARS?s Scientific Manuscript database

    Hyperspectral data were collected from 40 canopies of saltcedar (Tamarix ramosissima), 10 healthy canopies and 30 canopies defoliated by an introduced biological control agent, the saltcedar leaf beetle (Diorhabda elongata). These data were assessed to detect categories of defoliation in response to...

  12. Effects of insecticide treatments on subsequent defoliation by western spruce budworm in Oregon and Washington: 1982-92.

    Treesearch

    Katharine A. Sheehan

    1996-01-01

    Effects of insecticide treatments conducted in Oregon and Washington from 1982 through 1992 on subsequent defoliation by western spruce budworm (Choristoneura occidentalis Freeman) were evaluated by using aerial sketchmaps and a geographic information system. For each treatment, the extent and severity of defoliation was calculated for the treated...

  13. Tree mortality following defoliation by the European gypsy moth (Lymantria dispar L.) in the United States: a review

    Treesearch

    Christopher B. Davidson; Kurt W. Gottschalk; James E. Johnson

    1999-01-01

    This review presents information related to defoliation by the European gypsy moth (Lymantria dispar L.) and subsequent tree mortality in the eastern United States. The literature describing defoliation-induced tree mortality is extensive, yet questions still remain concerning (1) the association between initial stand composition and subsequent tree...

  14. Interactive effects of defoliation and low resource levels on photosynthesis, growth, and gypsy moth larval response to red oak seedlings

    Treesearch

    James B. McGraw; Kurt W. Gottschalk

    1991-01-01

    The potential for defoliation of oak seedlings by gypsy moth is quite high. We were interested in examining the interactions between various natural stresses and resulting gypsy moth feeding preferences and the results of defoliation stress on the growth and photosynthetic responses of the oak seedlings.

  15. A human dietary risk assessment associated with glycoalkaloid responses of potato to Colorado potato beetle defoliation.

    PubMed

    Dinkins, Courtney L Pariera; Peterson, Robert K D

    2008-08-01

    A quantitative human dietary risk assessment was conducted using the glycoalkaloid concentrations measured from tubers of plants defoliated by Colorado potato beetles and undefoliated (control). There was a significantly greater production of glycoalkaloids for defoliated plants compared to control plants for both skin and inner tissue of tubers. The dietary risk posed to different human subgroups associated with the consumption of potatoes was estimated for the 50th, 95th, and 99.9th percentile US national consumption values. Exposures were compared to a toxic threshold of 1.0mg/kg body weight. Defoliation by Colorado potato beetles increased dietary risk by approximately 48%. Glycoalkaloid concentrations within the inner tissue of tubers, including undefoliated controls, exceeded the toxic threshold for all human subgroups at less than the 99.9th percentile of exposure, but not the 95th percentile.

  16. Thidiazuron-enhanced biosynthesis and antimicrobial efficacy of silver nanoparticles via improving phytochemical reducing potential in callus culture of Linum usitatissimum L.

    PubMed Central

    Anjum, Sumaira; Abbasi, Bilal Haider

    2016-01-01

    Green synthesis of silver nanoparticles (AgNPs) by using plants is an emerging class of nanobiotechnology. It revolutionizes all domains of medical sciences by synthesizing chemical-free AgNPs for various biomedical applications. In this report, AgNPs were successfully synthesized by using whole plant extract (WPE) and thidiazuron-induced callus extract (CE) of Linum usitatissimum. The phytochemical analysis revealed that the total phenolic and flavonoid contents were higher in CE than that in WPE. Ultraviolet-visible spectroscopy of synthesized AgNPs showed a characteristic surface plasmon band in the range of 410–426 nm. Bioreduction of CE-mediated AgNPs was completed in a shorter time than that of WPE-mediated AgNPs. Scanning electron microscopy showed that both types of synthesized AgNPs were spherical in shape, but CE-mediated AgNPs were smaller in size (19–24 nm) and more scattered in distribution than that of WPE-mediated AgNPs (49–54 nm). X-ray diffraction analysis confirmed crystalline nature (face-centered cubic) of both types of AgNPs. Fourier-transform infrared spectroscopy revealed that the polyphenols and flavonoids were mainly responsible for reduction and capping of synthesized AgNPs. Energy dispersive X-ray analysis further confirmed the successful synthesis of AgNPs. Moreover, the synthesized AgNPs were found to be stable over months with no change in the surface plasmon bands. More importantly, CE-mediated AgNPs displayed significantly higher bactericidal activity against multiple drug-resistant human pathogens than WPE-mediated AgNPs. The present work highlighted the potent role of thidiazuron in in vitro-derived cultures for enhanced biosynthesis of chemical-free AgNPs, which can be used as nanomedicines in many biomedical applications. PMID:26955271

  17. Tamarisk (Tamarix spp.) water fluxes before, during and after episodic defoliation by the saltcedar leaf beetle

    USGS Publications Warehouse

    Hultine, K.R.; Nagler, P.L.; Dennison, P.E.; Bush, S.E.; Ehleringer, J.R.

    2009-01-01

    Tamarisk (Tamarix) species are among the most successful and economically costly plant invaders in the western United States, in part due to its potential to remove large amounts of water from shallow aquifers. Accordingly, local, state and federal agencies have released a new biological control - the saltcedar leaf beetle (Diorhabda elongata) along many watersheds in the western United States to reduce the spread of tamarisk. The beetle defoliates tamarisk for much of the growing season resulting in potentially large seasonal declines in productivity, fitness, and water loss from tamarisk stands. We measured sap flux density (Js) using heat dissipation sensors to investigate water use patterns of tamarisk before, during and after a single, six week beetle-induced defoliation event in southeastern, Utah, USA. Granier-style probes were installed on 20 dominant trees from May through September 2008, a period that covers almost the entire growing season. As the beetle emerged from dormancy in mid-June, daytime and nighttime Js measurably increased for approximately two weeks before declining to less than 20% of predicted values (predicted by modeling Js with atmospheric vapor pressure deficit in May and June before defoliation). Tamarisk trees in mid-August produced new leaves and Js returned to pre-defoliation levels. Total Js, summed over the duration of the study was 13% lower than predicted values. These data suggest that defoliation results in only small changes in seasonal water loss from tamarisk stands. Current research is focusing on long-term ecohydrological impacts of tamarisk defoliation over multiple growing seasons.

  18. Vitis vinifera root and leaf metabolic composition during fruit maturation: implications of defoliation.

    PubMed

    Rossouw, Gerhard C; Orchard, Beverley A; Šuklje, Katja; Smith, Jason P; Barril, Celia; Deloire, Alain; Holzapfel, Bruno P

    2017-07-10

    Grapevine (Vitis vinifera) roots and leaves represent major carbohydrate and nitrogen (N) sources, either as recent assimilates, or mobilized from labile or storage pools. This study examined the response of root and leaf primary metabolism following defoliation treatments applied to fruiting vines during ripening. The objective was to link alterations in root and leaf metabolism to carbohydrate and N source functioning under conditions of increased fruit sink demand. Potted grapevine leaf area was adjusted near the start of véraison to 25 primary leaves per vine compared to 100 leaves for the control. An additional group of vines were completely defoliated. Fruit sugar and N content development was assessed, and root and leaf starch and N concentrations determined. An untargeted GC/MS approach was undertaken to evaluate root and leaf primary metabolite concentrations. Partial and full defoliation increased root carbohydrate source contribution towards berry sugar accumulation, evident through starch remobilization. Furthermore, root myo-inositol metabolism played a distinct role during carbohydrate remobilization. Full defoliation induced shikimate pathway derived aromatic amino acid accumulation in roots, while arginine accumulated after full and partial defoliation. Likewise, various leaf amino acids accumulated after partial defoliation. These results suggest elevated root and leaf amino N source activity when leaf N availability is restricted during fruit ripening. Overall, this study provides novel information regarding the impact of leaf source restriction, on metabolic compositions of major carbohydrate and N sources during berry maturation. These results enhance the understanding of source organ carbon and N metabolism during fruit maturation. © 2017 Scandinavian Plant Physiology Society.

  19. The effects of defoliation on carbon allocation: can carbon limitation reduce growth in favour of storage?

    PubMed

    Wiley, Erin; Huepenbecker, Sarah; Casper, Brenda B; Helliker, Brent R

    2013-11-01

    There is no consensus about how stresses such as low water availability and temperature limit tree growth. Sink limitation to growth and survival is often inferred if a given stress does not cause non-structural carbohydrate (NSC) concentrations or levels to decline along with growth. However, trees may actively maintain or increase NSC levels under moderate carbon stress, making the pattern of reduced growth and increased NSCs compatible with carbon limitation. To test this possibility, we used full and half defoliation to impose severe and moderate carbon limitation on 2-year-old Quercus velutina Lam. saplings grown in a common garden. Saplings were harvested at either 3 weeks or 4 months after treatments were applied, representing short- and longer-term effects on woody growth and NSC levels. Both defoliation treatments maintained a lower total leaf area than controls throughout the experiment with no evidence of photosynthetic up-regulation, and resulted in a similar total biomass reduction. While fully defoliated saplings had lower starch levels than controls in the short term, half defoliated saplings maintained control starch levels in both the short and longer term. In the longer term, fully defoliated saplings had the greatest starch concentration increment, allowing them to recover to near-control starch levels. Furthermore, between the two harvest dates, fully and half defoliated saplings allocated a greater proportion of new biomass to starch than did controls. The maintenance of control starch levels in half defoliated saplings indicates that these trees actively store a substantial amount of carbon before growth is carbon saturated. In addition, the allocation shift favouring storage in defoliated saplings is consistent with the hypothesis that, as an adaptation to increasing carbon stress, trees can prioritize carbon reserve formation at the expense of growth. Our results suggest that as carbon limitation increases, reduced growth is not necessarily

  20. Lagged cumulative spruce budworm defoliation affects the risk of fire ignition in Ontario, Canada.

    PubMed

    James, Patrick M A; Robert, Louis-Etienne; Wotton, B Mike; Martell, David L; Fleming, Richard A

    2017-03-01

    Detailed understanding of forest disturbance interactions is needed for effective forecasting, modelling, and management. Insect outbreaks are a significant forest disturbance that alters forest structure as well as the distribution and connectivity of combustible fuels at broad spatial scales. The effect of insect outbreaks on fire activity is an important but contentious issue with significant policy consequences. The eastern spruce budworm (Choristoneura fumiferana) is a native defoliating insect in eastern North America whose periodic outbreaks create large patches of dead fir and spruce trees. Of particular concern to fire and forest managers is whether these patches represent an increased fire risk, if so, for how long, and how the relationship between defoliation and fire risk varies through space and time. Previous work suggests a temporary increase in flammability in budworm-killed forests, but regional and seasonal variability in these relationships has not been examined. Using an extensive database on historical lightning-caused fire ignitions and spruce budworm defoliation between 1963 and 2000, we assess the relative importance of cumulative defoliation and fire weather on the probability of ignition in Ontario, Canada. We modeled fire ignition using a generalized additive logistic regression model that accounts for temporal autocorrelation in fire weather. We compared two ecoregions in eastern Ontario (Abitibi Plains) and western Ontario (Lake of the Woods) that differ in terms of climate, geomorphology, and forest composition. We found that defoliation has the potential to both increase and decrease the probability of ignition depending on the time scale, ecoregion, and season examined. Most importantly, we found that lagged spruce budworm defoliation (8-10 yr) increases the risk of fire ignition whereas recent defoliation (1 yr) can decrease this risk. We also found that historical defoliation has a greater influence on ignition risk during the

  1. Mapping Historic Gypsy Moth Defoliation with MODIS Satellite Data: Implications for Forest Threat Early Warning System

    NASA Technical Reports Server (NTRS)

    Spurce, Joseph P.; Hargrove, William; Ryan, Robert E.; Smooth, James C.; Prados, Don; McKellip, Rodney; Sader, Steven A.; Gasser, Jerry; May, George

    2008-01-01

    This viewgraph presentation reviews a project, the goal of which is to study the potential of MODIS data for monitoring historic gypsy moth defoliation. A NASA/USDA Forest Service (USFS) partnership was formed to perform the study. NASA is helping USFS to implement satellite data products into its emerging Forest Threat Early Warning System. The latter system is being developed by the USFS Eastern and Western Forest Threat Assessment Centers. The USFS Forest Threat Centers want to use MODIS time series data for regional monitoring of forest damage (e.g., defoliation) preferably in near real time. The study's methodology is described, and the results of the study are shown.

  2. Natural hybridization between Gossypium mustelinum and exotic allotetraploid cotton species.

    PubMed

    de Menezes, I P P; da Silva, J O; Malafaia, G; Silveira, R D D; Barroso, P A V

    2015-10-30

    Cotton has been collected in Brazil for decades for its conservation, evaluation, and the use of its genetic resources. Gossypium mustelinum is an allotetraploid cotton species that only occurs in Brazil, and little is known about its genetic potential for improvement. However, the species is threatened by habitat fragmentation and interspecific hybridization with exotic species of cotton. In this study, we investigated the rate of natural hybridization in two populations of G. mustelinum in Bahia, Brazil, with G. hirsutum and G. barbadense using a set of microsatellite markers.

  3. Genetic stability of physiological responses to defoliation in a eucalypt and altered chemical defence in regrowth foliage.

    PubMed

    Borzak, Christina L; Potts, Brad M; Barry, Karen M; Pinkard, Elizabeth A; O'Reilly-Wapstra, Julianne M

    2016-11-22

    Defoliation may initiate physiological recovery and chemical defence mechanisms that allow a plant to improve fitness after damage. Such responses may result in changes in plant resource allocation that influence growth and foliar chemistry. In this study, we investigated the nature and stability of the defoliation response of juvenile plants from three divergent populations of Eucalyptus globulus Labill. A partial defoliation treatment that removed all upper crown leaves and the apical buds was applied to plants sourced from eight families from each of three populations representing contrasting chemical resistance to mammalian herbivory. Growth, photosynthetic rate and chlorophyll content were assessed pre-defoliation and periodically up to 12 weeks post-defoliation. The content of key plant primary and secondary metabolites was assessed pre-defoliation, at 12 weeks post-defoliation in the old foliage (positioned below the point of defoliation) and in the new foliage of the control plants and regrowth (from axillary buds) on the defoliated plants. There were clear treatment impacts on physiological responses, growth and foliar chemical traits, but despite significant constitutive differences in physiology, growth and chemistry the three E. globulus populations did not vary in their response to foliage loss. Distinct physiological responses to defoliation were observed with treatment plants showing significant up-regulation of photosynthetic rate and increased chlorophyll content in the old foliage remaining in the lower crown. There was a significant increase in the concentrations of a number of foliar chemical compounds in the regrowth arising from previously dormant axillary buds compared with new growth derived from apical meristems. There were changes in biomass allocation; defoliated plants had increased branching and leaf biomass, with changes in regrowth morphology to increase light capture. This study argues for multiple responses of E. globulus juveniles

  4. Effect of season and interval of prescribed burn on ponderosa pine butterfly defoliation patterns

    Treesearch

    Becky K. Kerns; Douglas J. Westlind

    2013-01-01

    Current knowledge concerning the interactions between forest disturbances such as fire and insect defoliation is limited. Wildfires and prescribed burns may influence the intensity and severity of insect outbreaks by affecting the vigor of residual trees, altering aspects of stand structure and abundance of preferred hosts, and by changing the physical environment...

  5. Abundance and distribution of rhizomorphs of Armillaria spp. in defoliated mixed oak stands in western Maryland

    Treesearch

    Mark J. Twery; Garland N. Mason; Philip M. Wargo; Kurt W. Gottschalk

    1990-01-01

    The abundance and distribution of rhizomorphs of Armillaria spp. in the soil were quantified in undisturbed stands and in stands defoliated 1 and 5 years previously by insects. Although the species of Armillaria was not determined, similar mixed oak forests in south central Pennsylvania contain North American biological species VII...

  6. Hydrological responses to defoliation and drought of an upland oak/pine forest

    Treesearch

    K.V.R. Schäfer; H.J. Renninger; K.L. Clark; D. Medvigy

    2014-01-01

    Hydrologic variability during 2005-2011 was observed and analyzed at an upland oak/pine forest in the New Jersey Pinelands. The forest experienced defoliation by Gypsy moth (Lymantria dispar L.) in 2007, drought conditions in 2006 and a more severe drought in 2010. By using sap flux and eddy covariance measurements, stream discharge data from USGS,...

  7. Legume ground covers alter defoliation response of black walnut saplings to drought and anthracnose

    Treesearch

    J. W. Van Sambeek

    2003-01-01

    Growth and premature defoliation of black walnut saplings underplanted 5 or 6 years earlier with six different ground covers were quantified in response to a summer drought or anthracnose. Walnut saplings growing with ground covers of hairy vetch, crownvetch, and to a lesser extent sericea lespedeza continued to have more rapid height and diameter growth than saplings...

  8. Interaction between gypsy moth (Lymantria dispar L.) and some competitive defoliators

    Treesearch

    Milka M. Glavendeki& #263; ; Ljubodrag S. Mihajlovi& #263

    2007-01-01

    Insect defoliators liable to frequent or occasional outbreaks can endanger forestry production and disturb the stability of forest ecosystems. There were studied life cycles, parasitoids, predators and population dynamics of leaf rollers, the winter moths, noctuids and gypsy moth, which occur in oak forests.

  9. Interaction of Insect Defoliation, Wildfires and Climate Change on Carbon Dynamics

    NASA Astrophysics Data System (ADS)

    Hom, J.; van Tuyl, S.; Scheller, R.; Pan, Y.; Clark, K.; Cole, J.; Foster, J.; Patterson, M.; Gallagher, M.

    2009-05-01

    We assess and predict the interactive effects of gypsy moth defoliation, fire management, and climate change on carbon uptake, forest productivity, species composition, and tree mortality in the New Jersey Pine Barrens. This effort will combine carbon flux measurements, a forest landscape disturbance model, and field monitoring data. We will determine how interactions among these disturbances affect current management and potential carbon management goals. The LANDIS-II forest landscape simulation model in this study uses three model extensions or modules: the Dynamic Fire System (DFS) extension, the Biomass Succession extension, and an insect defoliation extension. Parameterization of the DFS and the Biomass Succession extension uses new and existing data sources for the study area. This includes flux tower data from three upland forest types, for annual net ecosystem exchange of carbon taken before and after defoliation as well as during prescribed burns. An intensified grid of FIA-type plots around each tower (up to 24 plots per tower) provides additional biometric information. The study conducted a field mortality survey and canopy foliar analysis to understand the process of forest decline with insect defoliation. This project provides a predictive framework for working through landscape to regional management scenarios in areas with multiple, interacting management priorities that can be applied across the US, especially in areas where both insect and fire disturbances occur.

  10. Defoliation Management of Bahiagrass Germplasm Affects Dry Matter Yeild and Herbage Nutritive Value

    USDA-ARS?s Scientific Manuscript database

    Bahiagrass (Paspalum notatum Flügge) cultivars are daylength-sensitive and have minimal cool-season production. A new genotype is less daylength sensitive and more cold tolerant, but its dry matter (DM) yield and nutritive value responses to defoliation treatments are unknown. A 3-yr field experimen...

  11. Short-term effects of gypsy moth defoliation on nongame birds

    Treesearch

    Robert C. Whitmore; Richard D. Greer

    1991-01-01

    The response of a nongame bird community to tree defoliation and mortality caused by gypsy moths was studied during the summers of 1984, 1985, 1987, and 1988 in deciduous forest habitat of eastern West Virginia. Birds and structural vegetation characteristics were sampled on 42 permanent stations. The 1984 and 1985 stations were considered undefoliated because whole...

  12. Area-Wide Analysis of Hardwood Defoliator Effects on Tree Conditions in the Allegheny Plateau

    Treesearch

    Randall S. Morin; Andrew M. Liebhold; Kurt W. Gottschalk

    2004-01-01

    The effects of defoliation caused by three foliage feeding insects, the gypsy moth (Lymantria dispar), the cherry scallopshell moth (Hydria prunivorata), and the elm spanworm (Ennomos subsignarius), on tree mortality and crown conditions were evaluated using data collected from 1984 to 1999 in the Allegheny National Forest located in northwestern Pennsylvania. While...

  13. Differential regulation of two sucrose transporters by defoliation and light conditions in perennial ryegrass.

    PubMed

    Furet, Pierre-Maxime; Berthier, Alexandre; Decau, Marie-Laure; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie; Meuriot, Frédéric

    2012-12-01

    Sucrose transport between source and sink tissues is supposed to be a key-step for an efficient regrowth of perennial rye-grass after defoliation and might be altered by light conditions. We assessed the effect of different light regimes (high vs low light applied before or after defoliation) on growth, fructans and sucrose mobilization, as well as on sucrose transporter expression during 14 days of regrowth. Our results reported that defoliation led to a mobilization of C reserves (first sucrose and then fructans), which was parallel to an induction of LpSUT1 sucrose transporter expression in source and sink tissues (i.e. leaf sheaths and elongating leaf bases, respectively) irrespective to light conditions. Light regime (high or low light) had little effects on regrowth and on C reserves mobilization during the first 48 h of regrowth after defoliation. Thereafter, low light conditions, delaying the recovery of photosynthetic capacities, had a negative effect on C reserves re-accumulation (especially sucrose). Surprisingly, high light did not enhance sucrose transporter expression. Indeed, while light conditions had no effect on LpSUT1 expression, LpSUT2 transcripts levels were enhanced for low light grown plants. These results indicate that two sucrose transporter currently identified in Lolium perenne L. are differentially regulated by light and sucrose.

  14. The effects of thinning and gypsy moth defoliation on wood volume growth in oaks

    Treesearch

    Mary Ann Fajvan; Jim Rentch; Kurt Gottschalk

    2008-01-01

    Stem dissection and dendroecological methods were used to examine the effects of thinning and defoliation by gypsy moth (Lymantria dispar L.) on wood volume increment in oaks (Quercus rubra L., Q. alba L., Q. prinus L.). A model was developed to evaluate radial volume increment growth at three...

  15. Evaluating the impact of red-edge band from Rapideye image for classifying insect defoliation levels

    NASA Astrophysics Data System (ADS)

    Adelabu, Samuel; Mutanga, Onisimo; Adam, Elhadi

    2014-09-01

    The prospect of regular assessments of insect defoliation using remote sensing technologies has increased in recent years through advances in the understanding of the spectral reflectance properties of vegetation. The aim of the present study was to evaluate the ability of the red edge channel of Rapideye imagery to discriminate different levels of insect defoliation in an African savanna by comparing the results of obtained from two classifiers. Random Forest and Support vector machine classification algorithms were applied using different sets of spectral analysis involving the red edge band. Results show that the integration of information from red edge increases classification accuracy of insect defoliation levels in all analysis performed in the study. For instance, when all the 5 bands of Rapideye imagery were used for classification, the overall accuracies increases about 19% and 21% for SVM and RF, respectively, as opposed to when the red edge channel was excluded. We also found out that the normalized difference red-edge index yielded a better accuracy result than normalized difference vegetation index. We conclude that the red-edge channel of relatively affordable and readily available high-resolution multispectral satellite data such as Rapideye has the potential to considerably improve insect defoliation classification especially in sub-Saharan Africa where data availability is limited.

  16. Defoliation effects on growth and mortality of three young southern pine species

    Treesearch

    David R. Weise; Dale D. Wade; Ragnar W. Johansen; Haiganoush K. Preisler; David C. Combs; Edward E. Ach

    2016-01-01

    Foliage from loblolly (Pinus taeda L.), slash (P. elliottii Engelm.), and longleaf (P. palustris Mill.) pines was hand plucked to isolate the effects of level and timing of foliage removal on growth and mortality. Slash and loblolly pine received one of five defoliation treatments during one of four months...

  17. Gypsy Moth Defoliation Potential in the Ouachita/Ozark Highlands Region

    Treesearch

    Andrew M. Liebhold; Kurt W. Gottschalk; James M. Guldin; Rose-Marie Muzika

    2004-01-01

    Abstract - The gypsy moth is expanding its range in North America and is likely to invade the Ouachita/ Ozark Highlands region sometime during this century. A previous analysis indicated that forests in this area are among the most susceptible in North America to defoliation by this insect. We used USDA Forest Service, Forest Inventory and Analysis...

  18. Spread of Gypsy Moth (Lepidoptera: Lymantriidae) and Its Relationship to Defoliation

    Treesearch

    Patrick C. Tobin; Stefanie L. Whitmire

    2005-01-01

    Gypsy moth management is divided into three components: eradication, suppression, and transition zone management. All three components require knowledge of the boundaries that delimit these areas. Additional interest is also placed on the relationship between population spread and defoliation to prepare for the gypsy moth advance in new areas and minimize its impact....

  19. Predictability of gypsy moth defoliation in central hardwoods: a validation study

    Treesearch

    David E. Fosbroke; Ray R., Jr. Hicks

    1993-01-01

    A model for predicting gypsy moth defoliation in central hardwood forests based on stand characteristics was evaluated following a 5-year outbreak in Pennsylvania and Maryland. Study area stand characteristics were similar to those of the areas used to develop the model. Comparisons are made between model predictive capability in two physiographic provinces. The tested...

  20. Assessing cotton defoliation, regrowth control and root rot infection using remote sensing technology

    USDA-ARS?s Scientific Manuscript database

    Cotton defoliation and post-harvest destruction are important cultural practices for cotton production. Cotton root rot is a serious and destructive disease that affects cotton yield and lint quality. This paper presents an overview and summary of the methodologies and results on the use of remote s...

  1. Growth of white firs defoliated by Modoc budworm in northeastern California

    Treesearch

    George T. Ferrell

    1980-01-01

    Open-grown, pole-sized white firs defoliated by Modoc budwonn (Choristoneura viridis) in northeastern California in the years 1959-62 and 1973-75 suffered only minor growth reductions and topkilling compared with the effects that more protracted budworm outbreaks have had elsewhere on their conifer hosts. Growth index analysis indicated that the firs...

  2. Monitoring western spruce budworm with pheromone- baited sticky traps to predict subsequent defoliation

    Treesearch

    Christine G. Niwa; David L. Overhulser

    2015-01-01

    A detailed procedure is described for monitoring western spruce budworm with pheromone-baited sticky traps and interpreting the results to predict defoliation the following year. Information provided includes timing of the survey, how to obtain traps and baits, how many traps are needed, trap assembly, field placement of traps, and how to evaluate the catches.

  3. Responses of African Grasses in the Genus Sporobolus to Defoliation and Sodium Stress: Tradeoffs, Cross-Tolerance, or Independent Responses?

    PubMed Central

    Griffith, Daniel M.; Anderson, T. Michael

    2013-01-01

    In the Serengeti ecosystem of East Africa, grazing ungulates prefer areas with elevated grass Na, suggesting that some grasses tolerate both high soil Na and defoliation. We performed a factorial Na-by-defoliation greenhouse study with five abundant Sporobolus congeners to explore whether Serengeti grasses possess traits which: (i) confer tolerance to both Na and defoliation (cross-tolerance); (ii) display a tradeoff; or (iii) act independently in their tolerances. Our expectation was that related grasses would exhibit cross-tolerance when simultaneously subjected to Na and defoliation. Instead, we found that physiological tolerances and growth responses to Na and defoliation did not correlate but instead acted independently: species characterized by intense grazing in the field showed no growth or photosynthetic compensation for combined Na and defoliation. Additionally, in all but the highest Na dosage, mortality was higher when species were exposed to both Na and defoliation together. Across species, mortality rates were greater in short-statured species which occur on sodic soils in heavily grazed areas. Mortality among species was positively correlated with specific leaf area, specific root length, and relative growth rate, suggesting that rapidly growing species which invest in low cost tissues have higher rates of mortality when exposed to multiple stressors. We speculate that the prevalence of these species in areas of high Na and disturbance is explained by alternative strategies, such as high fecundity, a wide range of germination conditions, or further dispersal, to compensate for the lack of additional tolerance mechanisms. PMID:27137400

  4. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae)

    PubMed Central

    Narbona, Eduardo; Dirzo, Rodolfo

    2010-01-01

    Background and Aims Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Methods Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Key Results Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. Conclusions The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress. PMID:20519239

  5. Genome sequence of the cultivated cotton Gossypium arboreum.

    PubMed

    Li, Fuguang; Fan, Guangyi; Wang, Kunbo; Sun, Fengming; Yuan, Youlu; Song, Guoli; Li, Qin; Ma, Zhiying; Lu, Cairui; Zou, Changsong; Chen, Wenbin; Liang, Xinming; Shang, Haihong; Liu, Weiqing; Shi, Chengcheng; Xiao, Guanghui; Gou, Caiyun; Ye, Wuwei; Xu, Xun; Zhang, Xueyan; Wei, Hengling; Li, Zhifang; Zhang, Guiyin; Wang, Junyi; Liu, Kun; Kohel, Russell J; Percy, Richard G; Yu, John Z; Zhu, Yu-Xian; Wang, Jun; Yu, Shuxun

    2014-06-01

    The complex allotetraploid nature of the cotton genome (AADD; 2n = 52) makes genetic, genomic and functional analyses extremely challenging. Here we sequenced and assembled the Gossypium arboreum (AA; 2n = 26) genome, a putative contributor of the A subgenome. A total of 193.6 Gb of clean sequence covering the genome by 112.6-fold was obtained by paired-end sequencing. We further anchored and oriented 90.4% of the assembly on 13 pseudochromosomes and found that 68.5% of the genome is occupied by repetitive DNA sequences. We predicted 41,330 protein-coding genes in G. arboreum. Two whole-genome duplications were shared by G. arboreum and Gossypium raimondii before speciation. Insertions of long terminal repeats in the past 5 million years are responsible for the twofold difference in the sizes of these genomes. Comparative transcriptome studies showed the key role of the nucleotide binding site (NBS)-encoding gene family in resistance to Verticillium dahliae and the involvement of ethylene in the development of cotton fiber cells.

  6. The draft genome of a diploid cotton Gossypium raimondii.

    PubMed

    Wang, Kunbo; Wang, Zhiwen; Li, Fuguang; Ye, Wuwei; Wang, Junyi; Song, Guoli; Yue, Zhen; Cong, Lin; Shang, Haihong; Zhu, Shilin; Zou, Changsong; Li, Qin; Yuan, Youlu; Lu, Cairui; Wei, Hengling; Gou, Caiyun; Zheng, Zequn; Yin, Ye; Zhang, Xueyan; Liu, Kun; Wang, Bo; Song, Chi; Shi, Nan; Kohel, Russell J; Percy, Richard G; Yu, John Z; Zhu, Yu-Xian; Wang, Jun; Yu, Shuxun

    2012-10-01

    We have sequenced and assembled a draft genome of G. raimondii, whose progenitor is the putative contributor of the D subgenome to the economically important fiber-producing cotton species Gossypium hirsutum and Gossypium barbadense. Over 73% of the assembled sequences were anchored on 13 G. raimondii chromosomes. The genome contains 40,976 protein-coding genes, with 92.2% of these further confirmed by transcriptome data. Evidence of the hexaploidization event shared by the eudicots as well as of a cotton-specific whole-genome duplication approximately 13-20 million years ago was observed. We identified 2,355 syntenic blocks in the G. raimondii genome, and we found that approximately 40% of the paralogous genes were present in more than 1 block, which suggests that this genome has undergone substantial chromosome rearrangement during its evolution. Cotton, and probably Theobroma cacao, are the only sequenced plant species that possess an authentic CDN1 gene family for gossypol biosynthesis, as revealed by phylogenetic analysis.

  7. Remote monitoring of tamarisk defoliation and evapotranspiration following saltcedar leaf beetle attack

    USGS Publications Warehouse

    Dennison, P.E.; Nagler, P.L.; Hultine, K.R.; Glenn, E.P.; Ehleringer, J.R.

    2009-01-01

    Tamarisk (Tamarix spp.) has invaded riparian ecosystems throughout the Western United States, including significant portions of riparian ecosystems within U.S. National Parks and Monuments. Recently, the saltcedar leaf beetle (Diorhabda elongata) was released as a tamarisk biocontrol agent. Although initial releases have been monitored, no comprehensive program is currently in place to monitor the rapid spread of Diorhabda that has resulted from numerous subsequent releases by county and state agencies. Long term monitoring of tamarisk defoliation and its impacts on habitat and water resources is needed. This study examines the potential for using higher spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and lower spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) data for monitoring defoliation caused by Diorhabda and subsequent changes in evapotranspiration (ET). Widespread tamarisk defoliation was observed in an eastern Utah study area during summer 2007. ASTER normalized difference vegetation index (NDVI) showed only minor changes between 2005 and 2006, but a significant drop in NDVI was found within riparian areas between 2006 and 2007. The decrease in NDVI caused by defoliation was apparent despite partial refoliation within the study area. MODIS time series data revealed that absolute decline in EVI varied by site, but that the timing of EVI decline during summer 2007 was early with respect to phenological patterns from 2001 through 2006. Defoliation caused decreases in ET values estimated from both ASTER and MODIS data. MODIS estimated ET declined earlier than in previous years, although annual ET was not significantly different than ET in previous years due to high year-to-year variability. Challenges to detection and monitoring of tamarisk defoliation include spectral mixing of tamarisk and other cover types at subpixel spatial resolution, spatial coregistration of time series images, the

  8. Detection of tamarisk defoliation by the northern tamarisk beetle based on multitemporal Landsat 5 thematic mapper imagery

    USGS Publications Warehouse

    Meng, Ran; Dennison, Philip E.; Jamison, Levi R.; van Riper, Charles; Nager, Pamela; Hultine, Kevin R.; Bean, Dan W.; Dudley, Tom

    2012-01-01

    The spread of tamarisk (Tamarix spp., also known as saltcedar) is a significant ecological disturbance in western North America and has long been targeted for control, leading to the importation of the northern tamarisk beetle (Diorhabda carinulata) as a biological control agent. Following its initial release along the Colorado River near Moab, Utah in 2004, the beetle has successfully established and defoliated tamarisk across much of the upper Colorado River Basin. However, the spatial distribution and seasonal timing of defoliation are complex and difficult to quantify over large areas. To address this challenge, we tested and compared two remote sensing approaches to mapping tamarisk defoliation: Disturbance Index (DI) and a decision tree method called Random Forest (RF). Based on multitemporal Landsat 5 TM imagery for 2006-2010, changes in DI and defoliation probability from RF were calculated to detect tamarisk defoliation along the banks of Green, Colorado, Dolores and San Juan rivers within the Colorado Plateau area. Defoliation mapping accuracy was assessed based on field surveys partitioned into 10 km sections of river and on regions of interest created for continuous riparian vegetation. The DI method detected 3711 ha of defoliated area in 2007, 7350 ha in 2008, 10,457 ha in 2009 and 5898 ha in 2010. The RF method detected much smaller areas of defoliation but proved to have higher accuracy, as demonstrated by accuracy assessment and sensitivity analysis, with 784 ha in 2007, 960 ha in 2008, 934 ha in 2009, and 1008 ha in 2010. Results indicate that remote sensing approaches are likely to be useful for studying spatiotemporal patterns of tamarisk defoliation as the tamarisk leaf beetle spreads throughout the western United States.

  9. Defoliation and below-ground herbivory in the grass Muhlenbergiaquadridentata : Effects on plant performance and on the root-feeder Phyllophaga sp. (Coleoptera, Melolonthidae).

    PubMed

    Morón-Ríos, A; Dirzo, Rodolfo; Jaramillo, V J

    1997-04-01

    In this study we evaluated (1) the combined effects of simulated defoliation and below-ground herbivory (BGH) on the biomass and nitrogen content of tillers and roots of the bunchgrass Muhlenbergia quadridentata and (2) the effect of defoliation on the survival of third-instar root-feeder larvae of Phyllophaga sp. The experiment was performed in a pine forest area at an altitude of 3200 m above sea level. The grass and the root-feeder species were native and dominant in the understory and in the macroarthropod root-feeder communities, respectively. Plants were established in pots in the field and were subjected to the following treatments in a factorial design: simulated defoliation (three levels) and BGH (with or without root-feeder larvae) with ten replicates per treatment. Plants were defoliated three times at 2-month intervals. The interaction between defoliation and root herbivory was significant for all components of plant biomass. In every case, light defoliation with BGH decreased live above-ground, root and total plant biomass, and the number of live tillers by more than 50% with respect to the same defoliation level without root-feeders. Plants apparently did not compensate for the carbon drain by root-feeders when a high proportion of older leaves were not removed by defoliation. Plants under heavy defoliation were not affected by the presence of root-feeders and showed a greater live/dead above-ground biomass ratio than lightly defoliated and control plants. Defoliation and BGH did not change tiller and root N concentrations but root herbivores did decrease live-tiller N content in lightly defoliated plants. Root-feeders but not defoliation decreased the root/shoot ratio by 40% and the live/dead above-ground biomass ratio by 45% through increased tiller mortality. Survivorship and final biomass of Phyllophaga sp. larvae were not affected by defoliation treatments during the 6-month study period.

  10. Rhizosphere interactions, carbon allocation, and nitrogen acquisition of two perennial North American grasses in response to defoliation and elevated atmospheric CO2.

    PubMed

    Augustine, David J; Dijkstra, Feike A; William Hamilton Iii, E; Morgan, Jack A

    2011-03-01

    Carbon allocation and N acquisition by plants following defoliation may be linked through plant-microbe interactions in the rhizosphere. Plant C allocation patterns and rhizosphere interactions can also be affected by rising atmospheric CO(2) concentrations, which in turn could influence plant and microbial responses to defoliation. We studied two widespread perennial grasses native to rangelands of western North America to test whether (1) defoliation-induced enhancement of rhizodeposition would stimulate rhizosphere N availability and plant N uptake, and (2) defoliation-induced enhancement of rhizodeposition, and associated effects on soil N availability, would increase under elevated CO(2). Both species were grown at ambient (400 μL L(-1)) and elevated (780 μL L(-1)) atmospheric [CO(2)] under water-limiting conditions. Plant, soil and microbial responses were measured 1 and 8 days after a defoliation treatment. Contrary to our hypotheses, we found that defoliation and elevated CO(2) both reduced carbon inputs to the rhizosphere of Bouteloua gracilis (C(4)) and Pascopyrum smithii (C(3)). However, both species also increased N allocation to shoots of defoliated versus non-defoliated plants 8 days after treatment. This response was greatest for P. smithii, and was associated with negative defoliation effects on root biomass and N content and reduced allocation of post-defoliation assimilate to roots. In contrast, B. gracilis increased allocation of post-defoliation assimilate to roots, and did not exhibit defoliation-induced reductions in root biomass or N content. Our findings highlight key differences between these species in how post-defoliation C allocation to roots versus shoots is linked to shoot N yield, but indicate that defoliation-induced enhancement of shoot N concentration and N yield is not mediated by increased C allocation to the rhizosphere.

  11. Xylem traits, leaf longevity and growth phenology predict growth and mortality response to defoliation in northern temperate forests.

    PubMed

    Foster, Jane R

    2017-09-01

    Defoliation outbreaks are biological disturbances that alter tree growth and mortality in temperate forests. Trees respond to defoliation in many ways; some recover rapidly, while others decline gradually or die. Functional traits such as xylem anatomy, growth phenology or non-structural carbohydrate (NSC) storage could explain these responses, but idiosyncratic measures used by defoliation studies have frustrated efforts to generalize among species. Here, I test for functional differences with published growth and mortality data from 37 studies, including 24 tree species and 11 defoliators from North America and Eurasia. I synthesized data into standardized variables suitable for numerical models and used linear mixed-effects models to test the hypotheses that responses to defoliation vary among species and functional groups. Standardized data show that defoliation responses vary in shape and degree. Growth decreased linearly or curvilinearly, least in ring-porous Quercus and deciduous conifers (by 10-40% per 100% defoliation), whereas growth of diffuse-porous hardwoods and evergreen conifers declined by 40-100%. Mortality increased exponentially with defoliation, most rapidly for evergreen conifers, then diffuse-porous, then ring-porous species and deciduous conifers (Larix). Goodness-of-fit for functional-group models was strong (R2c = 0.61-0.88), if lower than species-specific mixed-models (R2c = 0.77-0.93), providing useful alternatives when species data are lacking. These responses are consistent with functional differences in leaf longevity, wood growth phenology and NSC storage. When defoliator activity lags behind wood-growth, either because xylem-growth precedes budburst (Quercus) or defoliator activity peaks later (sawflies on Larix), impacts on annual wood-growth will always be lower. Wood-growth phenology of diffuse-porous species and evergreen conifers coincides with defoliation and responds more drastically, and lower axial NSC storage makes them

  12. An integrative analysis of four CESA isoforms specific for fiber cellulose production between Gossypium hirsutum and Gossypium barbadense.

    PubMed

    Li, Ao; Xia, Tao; Xu, Wen; Chen, Tingting; Li, Xianliang; Fan, Jian; Wang, Ruyi; Feng, Shengqiu; Wang, Yanting; Wang, Bingrui; Peng, Liangcai

    2013-06-01

    Cotton fiber is an excellent model system of cellulose biosynthesis; however, it has not been widely studied due to the lack of information about the cellulose synthase (CESA) family of genes in cotton. In this study, we initially identified six full-length CESA genes designated as GhCESA5-GhCESA10. Phylogenetic analysis and gene co-expression profiling revealed that CESA1, CESA2, CESA7, and CESA8 were the major isoforms for secondary cell wall biosynthesis, whereas CESA3, CESA5, CESA6, CESA9, and CESA10 should involve in primary cell wall formation for cotton fiber initiation and elongation. Using integrative analysis of gene expression patterns, CESA protein levels, and cellulose biosynthesis in vivo, we detected that CESA8 could play an enhancing role for rapid and massive cellulose accumulation in Gossypium hirsutum and Gossypium barbadense. We found that CESA2 displayed a major expression in non-fiber tissues and that CESA1, a housekeeping gene like, was predominantly expressed in all tissues. Further, a dynamic alteration was observed in cell wall composition and a significant discrepancy was observed between the cotton species during fiber elongation, suggesting that pectin accumulation and xyloglucan reduction might contribute to cell wall transition. In addition, we discussed that callose synthesis might be regulated in vivo for massive cellulose production during active secondary cell wall biosynthesis in cotton fibers.

  13. Repeated polyploidization of Gossypium genomes and the evolution of spinnable cotton fibres.

    PubMed

    Paterson, Andrew H; Wendel, Jonathan F; Gundlach, Heidrun; Guo, Hui; Jenkins, Jerry; Jin, Dianchuan; Llewellyn, Danny; Showmaker, Kurtis C; Shu, Shengqiang; Udall, Joshua; Yoo, Mi-jeong; Byers, Robert; Chen, Wei; Doron-Faigenboim, Adi; Duke, Mary V; Gong, Lei; Grimwood, Jane; Grover, Corrinne; Grupp, Kara; Hu, Guanjing; Lee, Tae-ho; Li, Jingping; Lin, Lifeng; Liu, Tao; Marler, Barry S; Page, Justin T; Roberts, Alison W; Romanel, Elisson; Sanders, William S; Szadkowski, Emmanuel; Tan, Xu; Tang, Haibao; Xu, Chunming; Wang, Jinpeng; Wang, Zining; Zhang, Dong; Zhang, Lan; Ashrafi, Hamid; Bedon, Frank; Bowers, John E; Brubaker, Curt L; Chee, Peng W; Das, Sayan; Gingle, Alan R; Haigler, Candace H; Harker, David; Hoffmann, Lucia V; Hovav, Ran; Jones, Donald C; Lemke, Cornelia; Mansoor, Shahid; ur Rahman, Mehboob; Rainville, Lisa N; Rambani, Aditi; Reddy, Umesh K; Rong, Jun-kang; Saranga, Yehoshua; Scheffler, Brian E; Scheffler, Jodi A; Stelly, David M; Triplett, Barbara A; Van Deynze, Allen; Vaslin, Maite F S; Waghmare, Vijay N; Walford, Sally A; Wright, Robert J; Zaki, Essam A; Zhang, Tianzhen; Dennis, Elizabeth S; Mayer, Klaus F X; Peterson, Daniel G; Rokhsar, Daniel S; Wang, Xiyin; Schmutz, Jeremy

    2012-12-20

    Polyploidy often confers emergent properties, such as the higher fibre productivity and quality of tetraploid cottons than diploid cottons bred for the same environments. Here we show that an abrupt five- to sixfold ploidy increase approximately 60 million years (Myr) ago, and allopolyploidy reuniting divergent Gossypium genomes approximately 1-2 Myr ago, conferred about 30-36-fold duplication of ancestral angiosperm (flowering plant) genes in elite cottons (Gossypium hirsutum and Gossypium barbadense), genetic complexity equalled only by Brassica among sequenced angiosperms. Nascent fibre evolution, before allopolyploidy, is elucidated by comparison of spinnable-fibred Gossypium herbaceum A and non-spinnable Gossypium longicalyx F genomes to one another and the outgroup D genome of non-spinnable Gossypium raimondii. The sequence of a G. hirsutum A(t)D(t) (in which 't' indicates tetraploid) cultivar reveals many non-reciprocal DNA exchanges between subgenomes that may have contributed to phenotypic innovation and/or other emergent properties such as ecological adaptation by polyploids. Most DNA-level novelty in G. hirsutum recombines alleles from the D-genome progenitor native to its New World habitat and the Old World A-genome progenitor in which spinnable fibre evolved. Coordinated expression changes in proximal groups of functionally distinct genes, including a nuclear mitochondrial DNA block, may account for clusters of cotton-fibre quantitative trait loci affecting diverse traits. Opportunities abound for dissecting emergent properties of other polyploids, particularly angiosperms, by comparison to diploid progenitors and outgroups.

  14. Re-evaluating the phylogeny of allopolyploid Gossypium L.

    PubMed

    Grover, Corrinne E; Gallagher, Joseph P; Jareczek, Josef J; Page, Justin T; Udall, Joshua A; Gore, Michael A; Wendel, Jonathan F

    2015-11-01

    The formation of allopolyploid cotton precipitated a rapid diversification and colonization of dry coastal American tropical and subtropical regions. Previous phylogenetic analyses, combined with molecular divergence analyses, have offered a temporal framework for this radiation, but provide only weak support for some of the resolved branches. Moreover, these earlier analyses did not include the recently recognized sixth polyploid species, G. ekmanianum Wittmack. Here we use targeted sequence capture of multiple loci in conjunction with both concatenated and Bayesian concordance analyses to reevaluate the phylogeny of allopolyploid cotton species. Although phylogenetic resolution afforded by individual genes is often low, sufficient signal was attained both through the concatenated and concordance analyses to provide robust support for the Gossypium polyploid clade, which is reported here.

  15. Comparative transmission genetics of introgressed chromatin in Gossypium (cotton) polyploids.

    PubMed

    Waghmare, Vijay N; Rong, Junkang; Rogers, Carl J; Bowers, John E; Chee, Peng W; Gannaway, John R; Katageri, Ishwarappa; Paterson, Andrew H

    2016-04-01

    Introgression is widely acknowledged as a potential source of valuable genetic variation, and growing effort is being invested in analysis of interspecific crosses conferring transgressive variation. Experimental backcross populations provide an opportunity to study transmission genetics following interspecific hybridization, identifying opportunities and constraints to introgressive crop improvement. The evolutionary consequences of introgression have been addressed at the theoretical level, however, issues related to levels and patterns of introgression among (plant) species remain inadequately explored, including such factors as polyploidization, subgenome interaction inhabiting a common nucleus, and the genomic distribution and linkage relationships of introgressant alleles. We analyze introgression into the polyploid Gossypium hirsutum (upland cotton) from its sister G. tomentosum and compare the level and pattern with that of G. barbadense representing a different clade tracing to the same polyploidization. Across the genome, recurrent backcrossing to Gossypium hirsutum yielded only one-third of the expected average frequency of the G. tomentosum allele, although one unusual region showed preferential introgression. Although a similar rate of introgression is found in the two subgenomes of polyploid (AtDt) G. hirsutum, a preponderance of multilocus interactions were largely within the Dt subgenome. Skewed G. tomentosum chromatin transmission is polymorphic among two elite G. hirsutum genotypes, which suggests that genetic background may profoundly affect introgression of particular chromosomal regions. Only limited correspondence is found between G. hirsutum chromosomal regions that are intolerant to introgression from the two species, G. barbadense and G. tomentosum, concentrated near possible inversion polymorphisms. Complex transmission of introgressed chromatin highlights the challenges to utilization of exotic germplasm in crop improvement. © 2016

  16. Preconditioning of axillary buds in thidiazuron-supplemented liquid media improves in vitro shoot multiplication in Nyctanthes arbor-tristis L.

    PubMed

    Jahan, Anushi A; Anis, M; Aref, Ibrahim M

    2011-04-01

    An efficient tissue culture technology has been designed for mass multiplication of Nyctanthes arbor-tristis L. by preculturing nodal explants in thidiazuron (TDZ)-supplemented liquid Murashige and Skoog (MS) media. Direct inoculation of nodal segments on semi-solid MS medium augmented with various concentrations of TDZ (0.1 to 0.9 μM) produced shoots but with low regeneration response and few shoots per explant. Hence, nodal explants were pretreated with greater concentrations of TDZ (5 to 100 μM) in liquid MS media for different durations (4, 8, 12, and 16 days) with the aim of improving shoot regeneration response from cultured explants. After pretreatment, explants were transferred to agar-solidified hormone-free MS medium. Best response in terms of percent regeneration (94%), number of shoots per explant (20.00 ± 1.15), and greatest shoot length (7.23 ± 0.83 cm) were obtained with nodal segments pretreated in 75 μM TDZ for 8 days. Similarly, root induction was obtained from pulse-treated microshoots for 24 h with 200 μM indole-3-butyric acid (IBA) followed by their transfer to 1/2 MS medium which produced an average of 5.50 ± 0.92 roots per microshoot. The rooted plantlets were transplanted to soil with 80% success rate.

  17. Gibberellin stimulates regrowth after defoliation of sheepgrass (Leymus chinensis) by regulating expression of fructan-related genes.

    PubMed

    Cai, Yueyue; Shao, Linhui; Li, Xiuqing; Liu, Gongshe; Chen, Shuangyan

    2016-09-01

    Gibberellins (GAs) affect forage growth and development; however, it is largely unknown how GAs regulate the metabolism of fructan (an important polysaccharide reserve in many cereals) and the regrowth of forage plants after defoliation. To explore the mechanism of the responses of defoliated sheepgrass [Leymus chinensis (Trin.) Tzvel] to GA, we sprayed defoliated sheepgrass with GA3 and/or paclobutrazol (PAC; an inhibitor of GA biosynthesis) and analyzed the growth characteristics, carbohydrate contents, and transcript levels of genes related to GA metabolism, GA signal transduction, and fructan metabolism. The results showed that spraying exogenous GA3 onto defoliated sheepgrass promoted leaf and internode elongation, while spraying with PAC inhibited leaf and internode elongation, compared with the control. Spraying GA3 onto defoliated sheepgrass also altered the fructan content by extending the period of fructan utilization. At the transcriptional level, exogenous GA3 increased the transcript levels of genes related to GA metabolism in the sheath. Taken together, our results suggest that exogenous GA3 stimulates the regrowth of defoliated sheepgrass regrowth by regulating GA and fructan-related genes, and by promoting endogenous GA synthesis, fructan metabolism, and signaling.

  18. Feast and famine: previous defoliation limiting survival of pine processionary caterpillar Thaumetopoea pityocampa in Scots pine Pinus sylvestris

    NASA Astrophysics Data System (ADS)

    Hódar, José A.; Zamora, Regino; Castro, Jorge; Baraza, Elena

    2004-12-01

    This study analyses the consequences of previous defoliation on the survival of the larvae of the pine processionary moth Thaumetopoea pityocampa (Denis and Schiffermüller) feeding on relict Scots pine Pinus sylvestris (L.) ssp. nevadensis Christ in the Sierra Nevada mountains (SE Spain). Egg batches of the pine processionary moth were placed on four groups of Scots pines that underwent different periods of herbivory. The larval survival was related to the nitrogen content, fibre, phenolics and terpenes in the needles. Larval survival was higher in undefoliated pines, lower in pines defoliated two consecutive years, and intermediate in pines defoliated only one year, suggesting a direct relationship between previous defoliation and larval survival. In contrast, none of the characteristics of the needles showed a clear relationship with larval survival. The resulting reduction in larval number also affects the capacity of the larvae to develop during winter, because it hampered nest warming. Thus, previous defoliation limits, although it does not impede, the possibility of repeated defoliation on Scots pine.

  19. Genome-wide identification of mitogen-activated protein kinase gene family in Gossypium raimondii and the function of their corresponding orthologs in tetraploid cultivated cotton.

    PubMed

    Zhang, Xueying; Wang, Liman; Xu, Xiaoyang; Cai, Caiping; Guo, Wangzhen

    2014-12-10

    Mitogen-activated protein kinase (MAPK) cascades play a crucial role in plant growth and development as well as biotic and abiotic stress responses. Knowledge about the MAPK gene family in cotton is limited, and systematic investigation of MAPK family proteins has not been reported. By performing a bioinformatics homology search, we identified 28 putative MAPK genes in the Gossypium raimondii genome. These MAPK members were anchored onto 11 chromosomes in G. raimondii, with uneven distribution. Phylogenetic analysis showed that the MAPK candidates could be classified into the four known A, B, C and D groups, with more MAPKs containing the TEY phosphorylation site (18 members) than the TDY motif (10 members). Furthermore, 21 cDNA sequences of MAPKs with complete open reading frames (ORFs) were identified in G. hirsutum via PCR-based approaches, including 13 novel MAPKs and eight with homologs reported previously in tetraploid cotton. The expression patterns of 23 MAPK genes reveal their important roles in diverse functions in cotton, in both various developmental stages of vegetative and reproductive growth and in the stress response. Using a reverse genetics approach based on tobacco rattle virus-induced gene silencing (TRV-VIGS), we further verified that MPK9, MPK13 and MPK25 confer resistance to defoliating isolates of Verticillium dahliae in cotton. Silencing of MPK9, MPK13 and MPK25 can significantly enhance cotton susceptibility to this pathogen. This study presents a comprehensive identification of 28 mitogen-activated protein kinase genes in G. raimondii. Their phylogenetic relationships, transcript expression patterns and responses to various stressors were verified. This study provides the first systematic analysis of MAPKs in cotton, improving our understanding of defense responses in general and laying the foundation for future crop improvement using MAPKs.

  20. Cotton fiber cell walls of Gossypium hirsutum and Gossypium barbadense have differences related to loosely-bound xyloglucan.

    PubMed

    Avci, Utku; Pattathil, Sivakumar; Singh, Bir; Brown, Virginia L; Hahn, Michael G; Haigler, Candace H

    2013-01-01

    Cotton fiber is an important natural textile fiber due to its exceptional length and thickness. These properties arise largely through primary and secondary cell wall synthesis. The cotton fiber of commerce is a cellulosic secondary wall surrounded by a thin cuticulated primary wall, but there were only sparse details available about the polysaccharides in the fiber cell wall of any cotton species. In addition, Gossypium hirsutum (Gh) fiber was known to have an adhesive cotton fiber middle lamella (CFML) that joins adjacent fibers into tissue-like bundles, but it was unknown whether a CFML existed in other commercially important cotton fibers. We compared the cell wall chemistry over the time course of fiber development in Gh and Gossypium barbadense (Gb), the two most important commercial cotton species, when plants were grown in parallel in a highly controlled greenhouse. Under these growing conditions, the rate of early fiber elongation and the time of onset of secondary wall deposition were similar in fibers of the two species, but as expected the Gb fiber had a prolonged elongation period and developed higher quality compared to Gh fiber. The Gb fibers had a CFML, but it was not directly required for fiber elongation because Gb fiber continued to elongate rapidly after CFML hydrolysis. For both species, fiber at seven ages was extracted with four increasingly strong solvents, followed by analysis of cell wall matrix polysaccharide epitopes using antibody-based Glycome Profiling. Together with immunohistochemistry of fiber cross-sections, the data show that the CFML of Gb fiber contained lower levels of xyloglucan compared to Gh fiber. Xyloglucan endo-hydrolase activity was also higher in Gb fiber. In general, the data provide a rich picture of the similarities and differences in the cell wall structure of the two most important commercial cotton species.

  1. Low-volatile lipophilic compounds in needles, defoliated twigs, and outer bark of Pinus thunbergii.

    PubMed

    Shpatov, Alexander V; Popov, Sergey A; Salnikova, Olga I; Khokhrina, Ekaterina A; Shmidt, Emma N; Um, Byung Hun

    2013-12-01

    Despite a long history of the use of Pinus thunbergii for technical, medicinal, agricultural, and other purposes, the composition of low-volatile metabolites in the used parts of the plant has been poorly investigated. We report here on the distribution of lipophilic extractive compounds in different parts of the shoot system (needles, defoliated twigs, outer bark) of P. thunbergii studied by GC/MS. The highest and lowest contents of lipophilic substances were found in defoliated twigs and in outer bark correspondingly. Acid compounds in the extract of needles comprised mainly labdane type diterpenoids (trans-communic acid), while in the extracts of defoliated twigs and outer bark the acids were represented predominantly by abietane type compounds (neoabietic, dehydroabietic, abietic, levopimaric and palustric acids). The major neutral components of the extract of needles were 10-nonacosanol, labdanoids (18-hydroxy-1 3-epi-manoyl oxide, trans-communol), and beta-sitosterol. In the case of the extract of defoliated twigs, labdanoids (18-hydroxy-13-epi-manoyl oxide, trans-communol, 13-epi-torulosol), serratane triterpenoids (3beta-methoxyserrat-14-en-21-one), and beta-sitosterol were the main neutral constituents, whereas serratanoids (3beta-methoxyserrat-14-en-21-one) alone dominated among the neutral compounds of the outer bark extract. Most of the neutral components and the labdane type acids were detected for the first time in organs and tissues of P. thunbergii. The distribution of lipophilic metabolites in the studied parts of P. thunbergii shoot system may be applied for chemotaxonomy purposes. Diversified accumulation of extractive substances in different organs of the plant should be taken into account for isolation of specific components from the pine raw material.

  2. Temporal patterns of nitrogen leakage from mid-Appalachian forested watersheds: Role of insect defoliation

    NASA Astrophysics Data System (ADS)

    Eshleman, Keith N.; Morgan, Raymond P.; Webb, James R.; Deviney, Frank A.; Galloway, James N.

    1998-08-01

    Fluxes of dissolved nitrogen (N) as nitrate from forested watersheds in the mid-Appalachian region have important water quality ramifications for small acid-sensitive streams and for downstream receiving waters such as the Chesapeake Bay. Previous studies of N leakage have suggested that annual dissolved N fluxes from small watersheds can vary by several orders of magnitude and may be increasing as second-growth forests gradually become N saturated from the accrual of atmospheric N loadings. In this study, we examined the temporal (intra-annual and interannual) variability in dissolved nitrate fluxes from five small (area < 15 km2) forested watersheds in the mid-Appalachian region from 1988 to 1995. At all sites, nitrate concentrations were observed to increase dramatically during storm flow events, with nitric acid contributing significantly to depressions in pH and acid-neutralizing capacity; annual nitrate fluxes were dominated by high-discharge periods. Interannually, the fluxes at each site varied by 1-2 orders of magnitude, but the patterns of N leakage displayed considerable synchrony with outbreaks of gypsy moth caterpillar defoliation that began in the late 1980s and early 1990s in this region. N leakage from forested watersheds apparently lagged the initial defoliation by several months to perhaps a year or more. Defoliation outbreaks by the gypsy moth caterpillar (or other herbivorous pests) thus provide an alternative explanation of N leakage from forest ecosystems. Poorly documented insect defoliations, rather than premature N saturation of intact forest ecosystems, need to be considered as a possible explanation of N leakage from forested watersheds in the mid-Appalachian region and elsewhere.

  3. [Effects of Litchi chinensis Defoliation on Growth and Photosynthesis of Microcystis aeruginosa].

    PubMed

    Wang, Xiao-xiong; Jiang, Chen-chun; Li, Jin-weiz; Wang, Xiao-ju

    2015-05-01

    The growth and physiology of bloom-forming cyanobacterium Microcystis aeruginosa were determined by the pulse amplitude modulated fluorimetry when exposed to different concentrations of Litchi chinensis defoliation extract for 15 d. The growth, maximal efficiency (Fv/Fm), effective quantum yield (YII) of PSII photochemistry, photosynthesis efficiency (α) , maximum electron transport rate (rETRmax) and light saturation coefficient (Ik) were used to evaluate the growth and photosynthesis in M. aeruginosa. It was found that the extract of L. chinensis defoliation stored for 5 days significantly inhibited the growth of M. aeruginosa in a concentration-dependent way. After a long time of exposure, stimulation effect disappeared gradually. Fv/Fm fluorescence parameters, YII and alpha changed from negative correlation to positive correlation or kept positive correlation with the extract of L. chinensis defoliation, which might affect the photosynthesis of M. aeruginosa at early time or help the cyanobacterium to survive in the stress environment by improving the efficiency of light energy. Ik, rETRmax and the content of algal chlorophyll-a changed from negative to significant negative correlation with the extract. Three-dimensional fluorescence spectra showed that the peak intensities of tryptophan and tyrosine fluorescence were only about one third in 2.0 g · L(-1) extract treatment when compared to the 1.2 g · L(-1) extract treatment on day 15. At the same time, the peak intensity of humic acid fluorescence was weaker than that on day 1. Further study showed that the EC50 of algal growth was smaller than that of the traditional crops straw, which might achieve good effect to control the growth of algae with lower concentration of L. chinensis defoliation extract due to its strong allelopathy.

  4. Effect of defoliant (butiphose) on morpho-physiological properties and enzyme systems of natural membranes.

    PubMed

    Mirakhmedov, A K; Ochilov, K R; Sagatova, G A; Khan, M Z; Khole, V

    1989-03-01

    Butiphose (Tributyltritiophosphate, (C4H9S)3PO) a commonly used defoliant in cotton growing regions of USSR, caused extensive alterations in morphological features of erythrocyte and nuclear membranes and affected the permeability properties of rat liver mitochondrial membrane. It disrupted Ca2+ transport system and other energy dependent processes in mitochondria. A reduction in the activity of cytochrome-c-oxidase and NAD.H-oxidase was also observed.

  5. Effect of nitrogen supply and defoliation on loss of organic compounds from roots of Festuca rubra.

    PubMed

    Paterson, E; Sim, A

    2000-08-01

    The aim of this study was to determine the effects of N-supply and defoliation on rhizodeposition from Festuca rubra, in the context of whole-plant C- partitioning and root morphology. Plants were grown for 36 d in axenic sand microcosms continuously percolated with nutrient solutions of either high or low N concentration (2 mM or 0.01 mM NH(4)NO(3), respectively). The effects of partial defoliation at weekly intervals were determined at high and low N. At low N, dry matter accumulation in roots and shoots was reduced significantly (P<0.001), with proportionately increased partitioning to roots, in comparison with the high N treatment. Root morphology was also affected by N-treatment; at low N, lower biomass production was offset by increased specific root length (P<0.001), reducing the magnitude of the significant (P=0.002) increase in total root length at high N. Cumulative release of organic C from roots of F: rubra over the experimental period was not altered significantly by N-treatment. However, as a proportion of net C-assimilation, rhizodeposition was significantly (P<0.001) greater at low N than at high N. Defoliation transiently (3-5 d) increased the release of soluble organic compounds from roots at each N-supply rate, and increased significantly (P<0.001) cumulative rhizodeposition over the experimental period. These effects of N-supply and defoliation on rhizodeposition are of importance in understanding interactions between plant and microbial productivity in grazed grasslands, and in interpretation of concurrent effects on microbially driven nutrient cycling processes in these systems.

  6. Remarks on the physiological effects of defoliation on sugar maple and some impacts on syrup production

    Treesearch

    Philip M. Wargo

    1991-01-01

    The information I am going to present today is a conglomeration of some of the research on the effects of defoliation that has been done on sugar maple and oak. It involves work done by Drs. David Houston, Johnson Parker, Robert Gregory and me. Dr. Houston, a plant pathologist, and Dr. Parker, a plant physiologist, work with the USDA Forest Service in Hamden, Ct.; Dr....

  7. Effect of Pellet Size of Defoliation and Estimated Kill of Small Stems Treated with Hexazinone

    Treesearch

    J.L. Michael

    1981-01-01

    Hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,2,5-triaine-2,4,(1H,2H)-dione] was tested in the 2, 1, and 0.5 cc size uellet (10% ai) against very small stems [average height, 1.97m; average ground line diameter (GLD), 2 cm] of water oak, Quercus nigra L., at 1.12 and 2.24 kg/ha on a sandy loam soil. First year defoliation of water oak by...

  8. Modeling aspen responses to climatic warming and insect defoliation in western Canada

    Treesearch

    E. H. Ted Hogg

    2001-01-01

    Effects of climate change at three aspen sites in Saskatchewan were explored using a climate-driven model that includes insect defoliation. A simulated warming of 4-5 °C caused complete mortality due to drought at all three sites. A simulated warming of 2-2.5 °C caused complete mortality of aspen at the parkland site, while aspen growth at two boreal sites showed...

  9. Activation of sucrose transport in defoliated Lolium perenne L.: an example of apoplastic phloem loading plasticity.

    PubMed

    Berthier, Alexandre; Desclos, Marie; Amiard, Véronique; Morvan-Bertrand, Annette; Demmig-Adams, Barbara; Adams, William W; Turgeon, Robert; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie

    2009-07-01

    The pathway of carbon phloem loading was examined in leaf tissues of the forage grass Lolium perenne. The effect of defoliation (leaf blade removal) on sucrose transport capacity was assessed in leaf sheaths as the major carbon source for regrowth. The pathway of carbon transport was assessed via a combination of electron microscopy, plasmolysis experiments and plasma membrane vesicles (PMVs) purified by aqueous two-phase partitioning from the microsomal fraction. Results support an apoplastic phloem loading mechanism. Imposition of an artificial proton-motive force to PMVs from leaf sheaths energized an active, transient and saturable uptake of sucrose (Suc). The affinity of Suc carriers for Suc was 580 microM in leaf sheaths of undefoliated plants. Defoliation induced a decrease of K(m) followed by an increase of V(max). A transporter was isolated from stubble (including leaf sheaths) cDNA libraries and functionally expressed in yeast. The level of L.perenne SUcrose Transporter 1 (LpSUT1) expression increased in leaf sheaths in response to defoliation. Taken together, the results indicate that Suc transport capacity increased in leaf sheaths of L. perenne in response to leaf blade removal. This increase might imply de novo synthesis of Suc transporters, including LpSUT1, and may represent one of the mechanisms contributing to rapid refoliation.

  10. Island cotton Gbve1 gene encoding a receptor-like protein confers resistance to both defoliating and non-defoliating isolates of Verticillium dahliae.

    PubMed

    Zhang, Baolong; Yang, Yuwen; Chen, Tianzi; Yu, Wengui; Liu, Tingli; Li, Hongjuan; Fan, Xiaohui; Ren, Yongzhe; Shen, Danyu; Liu, Li; Dou, Daolong; Chang, Youhong

    2012-01-01

    Verticillium wilt caused by soilborne fungus Verticillium dahliae could significantly reduce cotton yield. Here, we cloned a tomato Ve homologous gene, Gbve1, from an island cotton cultivar that is resistant to Verticillium wilt. We found that the Gbve1 gene was induced by V. dahliae and by phytohormones salicylic acid, jasmonic acid, and ethylene, but not by abscisic acid. The induction of Gbve1 in resistant cotton was quicker and stronger than in Verticillium-susceptible upland cotton following V. dahliae inoculation. Gbve1 promoter-driving GUS activity was found exclusively in the vascular bundles of roots and stems of transgenic Arabidopsis. Virus-induced silencing of endogenous genes in resistant cotton via targeting a fragment of the Gbve1 gene compromised cotton resistance to V. dahliae. Furthermore, we transformed the Gbve1 gene into Arabidopsis and upland cotton through Agrobacterium-mediated transformation. Overexpression of the Gbve1 gene endowed transgenic Arabidopsis and upland cotton with resistance to high aggressive defoliating and non-defoliating isolates of V. dahliae. And HR-mimic cell death was observed in the transgenic Arabidopsis. Our results demonstrate that the Gbve1 gene is responsible for resistance to V. dahliae in island cotton and can be used for breeding cotton varieties that are resistant to Verticillium wilt.

  11. Potential of VIIRS Data for Regional Monitoring of Gypsy Moth Defoliation: Implications for Forest Threat Early Warning System

    NASA Astrophysics Data System (ADS)

    Spruce, J. P.; Ryan, R. E.; Smoot, J. C.; Prados, D. L.; McKellip, R. D.; Sader, S. A.; Gasser, G.; May, G.; Hargrove, W.

    2007-12-01

    A NASA RPC (Rapid Prototyping Capability) experiment was conducted to assess the potential of VIIRS (Visible/Infrared Imager/Radiometer Suite) data for monitoring non-native gypsy moth (Lymantria dispar) defoliation of forests. This experiment compares defoliation detection products computed from simulated VIIRS and from MODIS (Moderate Resolution Imaging Spectroradiometer) time series products as potential inputs to a forest threat EWS (Early Warning System) being developed for the USFS (USDA Forest Service). Gypsy moth causes extensive defoliation of broadleaved forests in the United States and is specifically identified in the Healthy Forest Restoration Act (HFRA) of 2003. The HFRA mandates development of a national forest threat EWS. This system is being built by the USFS, and NASA is aiding integration of needed satellite data products into this system, including MODIS products. This RPC experiment enabled the MODIS follow-on, VIIRS, to be evaluated as a data source for EWS forest monitoring products. The experiment included 1) assessment of MODIS-simulated VIIRS NDVI products, and 2) evaluation of gypsy moth defoliation mapping products from MODIS-simulated VIIRS and from MODIS NDVI time series data. This experiment employed MODIS data collected over the approx. 15 million acre mid-Appalachian Highlands during the annual peak defoliation time frame (June 10 through July 27) during 2000-2006. NASA Stennis Application Research Toolbox software was used to produce MODIS-simulated VIIRS data and NASA Stennis Time Series Product Tool software was employed to process MODIS and MODIS-simulated VIIRS time series data scaled to planetary reflectance. MODIS-simulated VIIRS data was assessed through comparison to Hyperion-simulated VIIRS data using data collected during gypsy moth defoliation. Hyperion- simulated MODIS data showed a high correlation with actual MODIS data. MODIS-simulated VIIRS data for the same date showed moderately high correlation with Hyperion

  12. Link between defoliation and light treatments on root vitality of five understory shrubs with different resistance to insect herbivory.

    PubMed

    Karolewski, Piotr; Zadworny, Marcin; Mucha, Joanna; Napierała-Filipiak, Anna; Oleksyn, Jacek

    2010-08-01

    Understory shrubs are frequently attacked by insect herbivores. However, very little is known regarding possible interactions between light condition, defoliation (D) and fine root vitality (% live roots) and metabolic activity, and whether different plant strategies (compensation, trade-off and equilibrium) to defoliation depend on individual species light requirements. To explore the response of roots to such conditions, an experiment was established in which we experimentally removed 50% of leaves in 1-year-old seedlings of Sambucus nigra, Cornus sanguinea, Prunus serotina, Frangula alnus and Corylus avellana grown in 15% and full sunlight. On average, defoliation leads to a 15% reduction in fine root (< 2 mm) vitality (% live roots). However, a statistically significant reduction in root vitality after defoliation was detected only in those species that are less herbivorized in nature (48% in S. nigra and 5% in C. sanguinea). On average, shade conditions (L) resulted in 18% decline in root vitality, and the effects of defoliation were also 22% higher than for plants grown in full light. Root vitality in both treatments (D and L) was significantly correlated with their dry mass, concentration of total phenol (TPh) and carbon to nitrogen ratio, and negatively correlated with nitrogen, soluble carbohydrates, starch and total non-structural carbohydrates (TNC). To a large extent, root vitality and chemistry varied by species. Higher root vitality was related to higher concentrations of phenolics, more than to N and TNC concentrations. Concentrations of phenolics also differed significantly between defoliated plants and controls. However, in defoliated plants, an increase in TPh was observed only in two species, which belong to two different groups in light requirements and susceptibility to insect grazing (C. sanguinea and P. serotina). This study indicated that higher vitality of roots occurred in species that are characterized by higher insect defoliation under

  13. Genome-wide divergence, haplotype distribution and population demographic histories for Gossypium hirsutum and Gossypium barbadense as revealed by genome-anchored SNPs

    USDA-ARS?s Scientific Manuscript database

    Use of 10,129 singleton SNPs of known genomic location in tetraploid cotton provided unique opportunities to characterize genome-wide diversity among 440 Gossypium hirsutum and 219 G. barbadense cultivars and landrace accessions of widespread origin. Using the SNPs distributed genome-wide, we exami...

  14. Comparative analysis of genome-wide divergence, domestication footprints and genome-wide association study of root traits for Gossypium hirsutum and Gossypium barbadense

    USDA-ARS?s Scientific Manuscript database

    Use of 10,129 singleton SNPs of known genomic location in tetraploid cotton provided unique opportunities to characterize genome-wide diversity among 440 Gossypium hirsutum and 219 G. barbadense cultivars and landrace accessions of widespread origin. Using genome-wide distributed SNPs, we examined ...

  15. Analysis of Complete Nucleotide Sequences of 12 Gossypium Chloroplast Genomes: Origin and Evolution of Allotetraploids

    PubMed Central

    Xu, Qin; Xiong, Guanjun; Li, Pengbo; He, Fei; Huang, Yi; Wang, Kunbo; Li, Zhaohu; Hua, Jinping

    2012-01-01

    Background Cotton (Gossypium spp.) is a model system for the analysis of polyploidization. Although ascertaining the donor species of allotetraploid cotton has been intensively studied, sequence comparison of Gossypium chloroplast genomes is still of interest to understand the mechanisms underlining the evolution of Gossypium allotetraploids, while it is generally accepted that the parents were A- and D-genome containing species. Here we performed a comparative analysis of 13 Gossypium chloroplast genomes, twelve of which are presented here for the first time. Methodology/Principal Findings The size of 12 chloroplast genomes under study varied from 159,959 bp to 160,433 bp. The chromosomes were highly similar having >98% sequence identity. They encoded the same set of 112 unique genes which occurred in a uniform order with only slightly different boundary junctions. Divergence due to indels as well as substitutions was examined separately for genome, coding and noncoding sequences. The genome divergence was estimated as 0.374% to 0.583% between allotetraploid species and A-genome, and 0.159% to 0.454% within allotetraploids. Forty protein-coding genes were completely identical at the protein level, and 20 intergenic sequences were completely conserved. The 9 allotetraploids shared 5 insertions and 9 deletions in whole genome, and 7-bp substitutions in protein-coding genes. The phylogenetic tree confirmed a close relationship between allotetraploids and the ancestor of A-genome, and the allotetraploids were divided into four separate groups. Progenitor allotetraploid cotton originated 0.43–0.68 million years ago (MYA). Conclusion Despite high degree of conservation between the Gossypium chloroplast genomes, sequence variations among species could still be detected. Gossypium chloroplast genomes preferred for 5-bp indels and 1–3-bp indels are mainly attributed to the SSR polymorphisms. This study supports that the common ancestor of diploid A-genome species in

  16. Distribution and evolution of cotton fiber development genes in the fibreless Gossypium raimondii genome.

    PubMed

    Xu, Zhanyou; Yu, Jing; Kohel, Russell J; Percy, Richard G; Beavis, William D; Main, Dorrie; Yu, John Z

    2015-07-01

    Cotton fiber represents the largest single cell in plants and they serve as models to study cell development. This study investigated the distribution and evolution of fiber Unigenes anchored to recombination hotspots between tetraploid cotton (Gossypium hirsutum) At and Dt subgenomes, and within a parental diploid cotton (Gossypium raimondii) D genome. Comparative analysis of At vs D and Dt vs D showed that 1) the D genome provides many fiber genes after its merger with another parental diploid cotton (Gossypium arboreum) A genome although the D genome itself does not produce any spinnable fiber; 2) similarity of fiber genes is higher between At vs D than between Dt vs D genomic hotspots. This is the first report that fiber genes have higher similarity between At and D than between Dt and D. The finding provides new insights into cotton genomic regions that would facilitate genetic improvement of natural fiber properties.

  17. Clonal differences and impact of defoliation on Sauvignon blanc (Vitis vinifera L.) wines: a chemical and sensory investigation.

    PubMed

    Šuklje, Katja; Antalick, Guillaume; Buica, Astrid; Langlois, Jennifer; Coetzee, Zelmari A; Gouot, Julia; Schmidtke, Leigh M; Deloire, Alain

    2016-02-01

    The aim of this study, performed on Sauvignon blanc clones SB11 and SB316, grafted on the same rootstock 101-14 Mgt (Vitis riparia × V. ruperstris) and grown at two adjacent vineyards, was two-fold: (1) to study wine chemical and sensory composition of both clones within an unaltered canopy; and (2) to determine the effect of defoliation (e.g. bunch microclimate) on wine chemical and sensory composition. Orthogonal projection to latent structures discriminate analysis (OPLS-DA) was applied to the concentration profiles of volatile compounds derived from gas chromatography-mass spectrometry data. The loadings directions inferred that 3-isobutyl-2-methoxypyrazine (IBMP) discriminated control treatments (shaded fruit zone) of both clones from defoliation treatments (exposed fruit zone), whereas 3-sulfanyl-hexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA), hexanol, hexyl hexanoate and some other esters discriminated defoliated treatments from the controls. The OPLS-DA indicated the importance of IBMP, higher alcohol acetates and phenylethyl esters, for discrimination of clone SB11 from clone SB316 irrespective of the treatment. Defoliation in the fruit zone significantly decreased perceived greenness in clone SB11 and elevated fruitier aromas, whereas in clone SB316 the effect of defoliation on wine sensory perception was less noticeable regardless the decrease in IBMP concentrations. These findings highlight the importance of clone selection and bunch microclimate to diversify produced wine styles. © 2015 Society of Chemical Industry.

  18. Consequences of enriched atmospheric CO{sub 2} and defoliation for foliar chemistry and gypsy moth performance

    SciTech Connect

    Lindroth, R.L.; Kinney, K.K.

    1998-10-01

    Elevated concentrations of atmospheric CO{sub 2} are likely to interact with other factors affecting plant physiology to alter plant chemical profiles and plant-herbivore interactions. The authors evaluated the independent and interactive effects of enriched CO{sub 2} and artificial defoliation on foliar chemistry of quaking aspen (Populus tremuloides) and sugar maple (Acer saccharum), and the consequences of such changes for short-term performance of the gypsy moth (Lymantria dispar). They grew aspen and maple seedlings in ambient and enriched CO{sub 2} environments at the University of wisconsin Biotron. Seven weeks after budbreak, trees in half of the rooms were subjected to 50% defoliation. Afterwards, foliage was collected for chemical analyses, and feeding trials were conducted with fourth-stadium gypsy moths. Enriched CO{sub 2} altered foliar levels of water, nitrogen, carbohydrates, and phenolics, and responses generally differed between the two tree species. Defoliation induced chemical changes only in aspen. They found no significant interactions between CO{sub 2} and defoliation for levels of carbon-based defenses (phenolic glycosides and tannins). CO{sub 2} treatment altered the performance of larvae fed aspen, but not maple, whereas defoliation had little effect on performance on insects. In general, results from this experimental system do not support the hypothesis that induction of carbon-based chemical defenses, and attendant effects on insects, will be stronger in a CO{sub 2}-enriched world.

  19. The effects of defoliation and thinning on the dieback, mortality, and growth of sugar maple in the Tug Hill Region of New York

    Treesearch

    Robert A. Wink; Douglas C. Allen

    1999-01-01

    Some recent literature suggests that thinning should not be conducted immediately prior to, during, or immediately following an outbreak of defoliating insects. Although the individual effects of both defoliation and thinning are well documented in the literature, no study has assessed the combined effect of these two stressors. An outbreak of forest tent caterpillar...

  20. Elevated CO2, not defoliation, enhances N cycling and increases short-term soil N immobilization regardless of N addition in a semiarid grassland

    USDA-ARS?s Scientific Manuscript database

    Elevated CO2 and defoliation effects on nitrogen (N) cycling in rangeland soils remain poorly understood. Here we tested whether effects of elevated CO2 and defoliation (clipping to 2.5 cm height) on N cycling depended on soil N availability (addition of 1 vs. 11 g N/m2) in intact mesocosms extracte...

  1. Defoliating Insect Mass Outbreak Affects Soil N Fluxes and Tree N Nutrition in Scots Pine Forests

    PubMed Central

    Grüning, Maren M.; Simon, Judy; Rennenberg, Heinz; l-M-Arnold, Anne

    2017-01-01

    Biotic stress by mass outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N fluxes and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output fluxes via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of mass insect herbivory on tree N acquisition (i.e., organic and inorganic 15N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine (Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth (Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy. PMID:28638396

  2. Defoliation synchronizes aboveground growth of co-occurring C4 grass species.

    PubMed

    Swemmer, Anthony M; Knapp, Alan K

    2008-10-01

    The aboveground net primary productivity (ANPP) of grass communities in grasslands and savannas is primarily determined by precipitation quantity. Recent research, motivated by predictions of changes in the distribution of rainfall events by global climate change models, indicates that ANPP may be affected by rainfall distribution as much as by annual totals. Grazing and community composition are also known to affect grassland ANPP. The manner in which interactions between rainfall distribution, grazing, and community composition affect the relationship between precipitation and ANPP represents a critical knowledge gap. The effects of community composition and grazing on aboveground growth responses to intraseasonal variation in water availability were investigated at seven grassland sites with a nonselective clipping experiment. The aboveground growth of the dominant C4 species at each site was measured at regular intervals for 2-3 growing seasons in the presence or absence of regular defoliation. In the absence of defoliation, there was a general lack of synchrony of intraseasonal growth among co-occurring species. Variation in growth rates was high and was only partially explained by variation in rainfall. Regular defoliation increased growth synchrony at all sites, but changes in growth responses to rainfall varied between sites. These results suggest that community composition will be important in determining ANPP-precipitation relationships under conditions of altered rainfall distribution. However this effect appears to be a result of species responding differently to soil water or other resources rather than to rainfall per se. Grazing may override the effects of community composition by reducing differences in growth patterns between species and has the potential to weaken precipitation controls on ANPP.

  3. Defoliating Insect Mass Outbreak Affects Soil N Fluxes and Tree N Nutrition in Scots Pine Forests.

    PubMed

    Grüning, Maren M; Simon, Judy; Rennenberg, Heinz; L-M-Arnold, Anne

    2017-01-01

    Biotic stress by mass outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N fluxes and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output fluxes via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of mass insect herbivory on tree N acquisition (i.e., organic and inorganic (15)N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine (Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth (Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy.

  4. Contribution of ambient ozone to Scots pine defoliation and reduced growth in the Central European forests: a Lithuanian case study.

    PubMed

    Augustaitis, Algirdas; Bytnerowicz, Andrzej

    2008-10-01

    The study aimed to explore if changes in crown defoliation and stem growth of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone (O(3)) concentration in central Europe. To meet this objective the study was performed in 3 Lithuanian national parks, close to the ICP integrated monitoring stations from which data on meteorology and pollution were provided. Contribution of peak O(3) concentrations to the integrated impact of acidifying compounds and meteorological parameters on pine stem growth was found to be more significant than its contribution to the integrated impact of acidifying compounds and meteorological parameters on pine defoliation. Findings of the study provide statistical evidence that peak concentrations of ambient O(3) can have a negative impact on pine tree crown defoliation and stem growth reduction under field conditions in central and northeastern Europe where the AOT40 values for forests are commonly below their phytotoxic levels.

  5. Monitoring gypsy moth defoliation by applying change detection techniques to Landsat imagery

    NASA Technical Reports Server (NTRS)

    Williams, D. L.; Stauffer, M. L.

    1978-01-01

    The overall objective of a research effort at NASA's Goddard Space Flight Center is to develop and evaluate digital image processing techniques that will facilitate the assessment of the intensity and spatial distribution of forest insect damage in Northeastern U.S. forests using remotely sensed data from Landsats 1, 2 and C. Automated change detection techniques are presently being investigated as a method of isolating the areas of change in the forest canopy resulting from pest outbreaks. In order to follow the change detection approach, Landsat scene correction and overlay capabilities are utilized to provide multispectral/multitemporal image files of 'defoliation' and 'nondefoliation' forest stand conditions.

  6. Monitoring gypsy moth defoliation by applying change detection techniques to Landsat imagery

    NASA Technical Reports Server (NTRS)

    Williams, D. L.; Stauffer, M. L.

    1978-01-01

    The overall objective of a research effort at NASA's Goddard Space Flight Center is to develop and evaluate digital image processing techniques that will facilitate the assessment of the intensity and spatial distribution of forest insect damage in Northeastern U.S. forests using remotely sensed data from Landsats 1, 2 and C. Automated change detection techniques are presently being investigated as a method of isolating the areas of change in the forest canopy resulting from pest outbreaks. In order to follow the change detection approach, Landsat scene correction and overlay capabilities are utilized to provide multispectral/multitemporal image files of 'defoliation' and 'nondefoliation' forest stand conditions.

  7. Optimising the spatial resolution of WorldView-2 pan-sharpened imagery for predicting levels of Gonipterus scutellatus defoliation in KwaZulu-Natal, South Africa

    NASA Astrophysics Data System (ADS)

    Lottering, Romano; Mutanga, Onisimo

    2016-02-01

    Gonipterus scutellatus Gyllenhal is a leaf feeding weevil that is a major defoliator of the genus Eucalyptus. Understanding the relationship between levels of weevil induced vegetation defoliation and the optimal spatial resolution of satellite images is essential for effective management of plantation resources. The objective of this study was to identify appropriate spatial resolutions for predicting levels of weevil induced defoliation. We resampled the Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) and Enhanced Vegetation Index (EVI) images computed from a WorldView-2 pan-sharpened image, which is characterised with a 0.5 m spatial resolution and 8 spectral bands. Within each plantation compartment 30 × 30 m plots were established, representing different levels of defoliation. From the centre of each plot, the spatial resolution of the original image was progressively resampled from 1.5 to 8.5 m, with 1 m increments. The minimal variance for each level of defoliation was then established and used as an indicator for quantitatively selecting the optimal spatial resolution. Results indicate that an appropriate spatial resolution was established at 1.25, 1.25, 1.75 and 2.25 m for low, medium, high and severe levels of defoliation, respectively. In addition, an Artificial Neural Network was run to determine the relationship between the appropriate spatial resolution and levels of Gonipterus scutellatus induced defoliation. The model yielded an R2 of 0.80, with an RMSE of 1.28 (2.45% of the mean measured defoliation) based on an independent test dataset. We then compared this model to a model developed using the original 0.5 m image spatial resolution. Our results suggest that optimising the spatial resolution of remotely sensed imagery essentially improves the prediction of vegetation defoliation. In essence, this study provides the foundation for multi-scale defoliation mapping using high spatial resolution imagery.

  8. Expression profiles of miRNAs in Gossypium raimondii *

    PubMed Central

    Ma, Jun; Guo, Teng-long; Wang, Qing-lian; Wang, Kun-bo; Sun, Run-run; Zhang, Bao-hong

    2015-01-01

    miRNAs are a class of conserved, small, endogenous, and non-protein-coding RNA molecules with 20–24 nucleotides (nt) in length that function as post-transcriptional modulators of gene expression in eukaryotic cells. Functional studies have demonstrated that plant miRNAs are involved in the regulation of a wide range of plant developmental processes. To date, however, no research has been carried out to study the expression profiles of miRNAs in Gossypium raimondii, a model cotton species. We selected 16 miRNAs to profile their tissue-specific expression patterns in G. raimondii four different tissues, and these miRNAs are reported to play important roles in plant growth and development. Our results showed that the expression levels of these miRNAs varied significantly from one to another in a tissue-dependent manner. Eight miRNAs, including miR-159, miR-162, miR-164, miR-172, miR-390, miR-395, miR-397, and miR-398, exhibited exclusively high expression levels in flower buds, suggesting that these miRNAs may play significant roles in floral development. The expression level of miR-164 was relatively high in shoots beside flower buds, implying that the function of miR-164 is not only limited to floral development but it may also play an important role in shoot development. Certain miRNAs such as miR-166 and miR-160 were extremely highly expressed in all of the four tissues tested compared with other miRNAs investigated, suggesting that they may play regulatory roles at multiple development stages. This study will contribute to future studies on the functional characterization of miRNAs in cotton. PMID:25845363

  9. Isolation and characterization of terpene synthases in cotton (Gossypium hirsutum).

    PubMed

    Yang, Chang-Qing; Wu, Xiu-Ming; Ruan, Ju-Xin; Hu, Wen-Li; Mao, Yin-Bo; Chen, Xiao-Ya; Wang, Ling-Jian

    2013-12-01

    Cotton plants accumulate gossypol and related sesquiterpene aldehydes, which function as phytoalexins against pathogens and feeding deterrents to herbivorous insects. However, to date little is known about the biosynthesis of volatile terpenes in this crop. Herein is reported that 5 monoterpenes and 11 sesquiterpenes from extracts of a glanded cotton cultivar, Gossypium hirsutum cv. CCRI12, were detected by gas chromatography-mass spectrometry (GC-MS). By EST data mining combined with Rapid Amplification of cDNA Ends (RACE), full-length cDNAs of three terpene synthases (TPSs), GhTPS1, GhTPS2 and GhTPS3 were isolated. By in vitro assays of the recombinant proteins, it was found that GhTPS1 and GhTPS2 are sesquiterpene synthases: the former converted farnesyl pyrophosphate (FPP) into β-caryophyllene and α-humulene in a ratio of 2:1, whereas the latter produced several sesquiterpenes with guaia-1(10),11-diene as the major product. By contrast, GhTPS3 is a monoterpene synthase, which produced α-pinene, β-pinene, β-phellandrene and trace amounts of other monoterpenes from geranyl pyrophosphate (GPP). The TPS activities were also supported by Virus Induced Gene Silencing (VIGS) in the cotton plant. GhTPS1 and GhTPS3 were highly expressed in the cotton plant overall, whereas GhTPS2 was expressed only in leaves. When stimulated by mechanical wounding, Verticillium dahliae (Vde) elicitor or methyl jasmonate (MeJA), production of terpenes and expression of the corresponding synthase genes were induced. These data demonstrate that the three genes account for the biosynthesis of volatile terpenes of cotton, at least of this Upland cotton.

  10. Cloning and expression of 1-aminocyclopropane-1-carboxylate oxidase cDNA induced by thidiazuron during somatic embryogenesis of alfalfa (Medicago sativa).

    PubMed

    Feng, Bi-Hong; Wu, Bei; Zhang, Chun-Rong; Huang, Xia; Chen, Yun-Feng; Huang, Xue-Lin

    2012-01-15

    Embryogenic callus (EC) induced from petioles of alfalfa (Medicago sativa L. cv. Jinnan) on B5h medium turned green, compact and non-embryogenic when the kinetin (KN) in the medium was replaced partially or completely by thidiazuron (TDZ). The application of CoCl₂, which is an inhibitor of 1-aminocyclopropane-1-carboxylate oxidase (ACO), counteracted the effect of TDZ. Ethylene has been shown to be involved in the modulation of TDZ-induced morphogenesis responses. However, very little is known about the genes involved in ethylene formation during somatic embryogenesis (SE). To investigate whether ethylene mediated by ACO is involved in the effect of TDZ on inhibition of embryogenic competence of the alfalfa callus. In this study we cloned full-length ACO cDNA from the alfalfa callus, named MsACO, and observed changes in this gene expression during callus formation and induction of SE under treatment with TDZ or TDZ plus CoCl₂. RNA blot analysis showed that during the EC subcultural period, the expression level of MsACO in EC was significantly increased on the 2nd day, rose to the highest level on the 8th day and remained at this high level until the 21st day. However, the ACO expression in the TDZ (0.93 μM)-treated callus was higher than in the EC especially on the 8th day. Moreover the ACO expression level increased with increasing TDZ concentration during the subcultural/maintenance period of the callus. It is worth noting that comparing the treatment with TDZ alone, the treatment with 0.93 μM TDZ plus 50 μM CoCl₂ reduced both of the ACO gene expressions and ACO activity in the treated callus. These results indicate that the effect of TDZ could be counteracted by CoCl₂ either on the ACO gene expression level or ACO activity. Thus, a TDZ inhibitory effect on embryogenic competence of alfalfa callus could be mediated by ACO gene expression.

  11. Constructing a high-density linkage map for Gossypium hirsutum × Gossypium barbadense and identifying QTLs for lint percentage.

    PubMed

    Shi, Yuzhen; Li, Wentan; Li, Aiguo; Ge, Ruihua; Zhang, Baocai; Li, Junzhi; Liu, Guangping; Li, Junwen; Liu, Aiying; Shang, Haihong; Gong, Juwu; Gong, Wankui; Yang, Zemao; Tang, Feiyü; Liu, Zhi; Zhu, Weiping; Jiang, Jianxiong; Yu, Xiaonan; Wang, Tao; Wang, Wei; Chen, Tingting; Wang, Kunbo; Zhang, Zhengsheng; Yuan, Youlu

    2015-05-01

    To introgress the good fiber quality and yield from Gossypium barbadense into a commercial Upland cotton variety, a high-density simple sequence repeat (SSR) genetic linkage map was developed from a BC1 F1 population of Gossypium hirsutum × Gossypium barbadense. The map comprised 2,292 loci and covered 5115.16 centiMorgan (cM) of the cotton AD genome, with an average marker interval of 2.23 cM. Of the marker order for 1,577 common loci on this new map, 90.36% agrees well with the marker order on the D genome sequence genetic map. Compared with five published high-density SSR genetic maps, 53.14% of marker loci were newly discovered in this map. Twenty-six quantitative trait loci (QTLs) for lint percentage (LP) were identified on nine chromosomes. Nine stable or common QTLs could be used for marker-assisted selection. Fifty percent of the QTLs were from G. barbadense and increased LP by 1.07%-2.41%. These results indicated that the map could be used for screening chromosome substitution segments from G. barbadense in the Upland cotton background, identifying QTLs or genes from G. barbadense, and further developing the gene pyramiding effect for improving fiber yield and quality.

  12. Combining ability of ginning rate and net ginning energy requirement in upland cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Combining ability describes the breeding value of parental lines to produce hybrids. The objectives of this study were to detect specific (SCA) and general combining ability (GCA) estimates for ginning rate and net ginning energy requirement in some upland cotton germplasm (Gossypium hirsutum L.). T...

  13. Water use, yield, and fiber quality differences of diverse cotton (gossypium spp.) genotypes

    USDA-ARS?s Scientific Manuscript database

    Declining levels of available water for irrigation use in the Ogallala, TX, San Joaquin Valley, CA, and other aquifers has led to the need to identify and develop cotton (Gossypium spp.) cultivars that can more efficiently use available soil water. Elite upland (G. hirsutum L.) commercial cultivars,...

  14. Breeding implications of boll distribution responses to water stress deficits in Upland cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    To identify the impact of different water stress deficits on the boll distribution of elite Upland cotton (Gossypium hirsutum L.) cultivars in the Texas High Plains, cultivars which represent the diverse gene-pools of the private sector were subjected to three different water deficit regimes. This s...

  15. Measuring diversity in Gossypium hirsutum using the CottonSNP63K Array

    USDA-ARS?s Scientific Manuscript database

    A CottonSNP63K array and accompanying cluster file has been developed and includes 45,104 intra-specific SNPs and 17,954 inter-specific SNPs for automated genotyping of cotton (Gossypium spp.) samples. Development of the cluster file included genotyping of 1,156 samples, a subset of which were iden...

  16. Development of a core set of SSR markers for the characterization of Gossypium germplasm

    USDA-ARS?s Scientific Manuscript database

    Molecular markers such as simple sequence repeats (SSR) are a useful tool for characterizing genetic diversity of Gossypium germplasm collections. Genetic profiles by DNA fingerprinting of cotton accessions can only be compared among different collections if a common set of molecular markers are us...

  17. Lipid metabolites in seeds of diverse Gossypium accessions: Molecular identification of a high oleic mutant allele

    USDA-ARS?s Scientific Manuscript database

    The domestication and breeding of cotton for elite, high-fiber cultivars has led to reduced genetic variation of seed constituents within currently cultivated upland Cotton genotypes. However, a recent screen of the genetically diverse U.S. National Cotton Germplasm Collection identified Gossypium ...

  18. Analyses of Fusarium wilt race 3 resistance in upland cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    In Uzbekistan, the most northern cotton country, as well as in many others worldwide, Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. At least eight genotypes of FOV, called races, have been described. Thes...

  19. RNA interference for functional genomics and improvement of cotton (Gossypium species)

    USDA-ARS?s Scientific Manuscript database

    RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium ssp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function ...

  20. Molecular evolution of the clustered MMIC-3 multigene family of Gossypium species

    USDA-ARS?s Scientific Manuscript database

    Uniqueness, content, localization, and defense-related features of the root-knot nematode resistance-associated MIC-3 supergene cluster in the genus Gossypium are all of interest for molecular evolutionary studies of duplicate supergenes in allopolyploids. Here we report molecular evolutionary rates...

  1. Molecular confirmation of Gossypium hirsutum chromosome substitution lines and interspecific F1 hypoaneuploids

    USDA-ARS?s Scientific Manuscript database

    The tetraploid Gossypium species G. barbadense, G. tomentosum, and G. mustelinum (2n=52) are useful sources of important genes for pest and disease resistance, and for improved agronomic and fiber traits in Upland cotton (G. hirsutum). Cytological analyses of hybrids and comparative linkage mapping...

  2. Molecular Evolution of Clustered MIC-3 (Meloidogyne Induced Cotton -3) Multigene Family of Gossypium Species

    USDA-ARS?s Scientific Manuscript database

    Uniqueness, content, localization, and defense-related features of the root-knot nematode resistance-associated MIC-3 multigene cluster in the genus Gossypium are all of interest for molecular evolutionary studies of duplicate genes in allopolyploids. Here we report molecular evolutionary rates of t...

  3. Molecular evolution of the clustered MIC-3 multigene family of Gossypium species.

    PubMed

    Buriev, Zabardast T; Saha, Sukumar; Shermatov, Shukhrat E; Jenkins, Johnie N; Abdukarimov, Abdusattor; Stelly, David M; Abdurakhmonov, Ibrokhim Y

    2011-12-01

    The Gossypium MIC-3 (Meloidogyne Induced Cotton-3) gene family is of great interest for molecular evolutionary studies because of its uniqueness to Gossypium species, multi-gene content, clustered localization, and root-knot nematode resistance-associated features. Molecular evolution of the MIC-3 gene family was studied in 15 tetraploid and diploid Gossypium genotypes that collectively represent seven phylogenetically distinct genomes. Synonymous (d(S)) and non-synonymous (d(N)) nucleotide substitution rates suggest that the second of the two exons of the MIC-3 genes has been under strong positive selection pressure, while the first exon has been under strong purifying selection to preserve function. Based on nucleotide substitution rates, we conclude that MIC-3 genes are evolving by a birth-and-death process and that a 'gene amplification' mechanism has helped to retain all duplicate copies, which best fits with the "bait and switch" model of R-gene evolution. The data indicate MIC-3 gene duplication events occurred at various rates, once per 1 million years (MY) in the allotetraploids, once per ~2 MY in the A/F genome clade, and once per ~8 MY in the D-genome clade. Variations in the MIC-3 gene family seem to reflect evolutionary selection for increased functional stability, while also expanding the capacity to develop novel "switch" pockets for responding to diverse pests and pathogens. Such evolutionary roles are congruent with the hypothesis that members of this unique resistance gene family provide fitness advantages in Gossypium.

  4. Identification of an Mg2+-independent soluble phosphatidate phosphatase in cottonseed (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Cotton (Gossypium hirsutum L.) provides a major source of oil for food and feed industries, but little was known about the oil biosynthesis pathway in cottonseed. Towards understanding the biochemical pathway of oil accumulation in cottonseed, this study focused on phosphatidic acid phosphatase (PAP...

  5. Virus-induced gene silencing in cultivated cotton (Gossypium spp.) using Tobacco rattle virus

    USDA-ARS?s Scientific Manuscript database

    The study described here has optimized the conditions for virus induced gene silencing (VIGS) in three cultivated cotton species (Gossypium hirsutum, G. arboreum and G. herbaceum) using a Tobacco rattle virus (TRV) vector. The system was used to silence the homolog of the Arabidopsis thaliana chloro...

  6. New DNA Markers for the Use in Cotton (Gossypium spp.) Improvement

    USDA-ARS?s Scientific Manuscript database

    SSR markers, also known as DNA microsatellite markers, are proving to be very useful for saturation of the large and complex upland cotton (Gossypium hirsutum genetic linkage map. Monsanto Company has invested heavily in development of cotton SSRs and has implemented molecular breeding technologies ...

  7. Registration of Four Upland Cotton (Gossypium hirsutum L.) Genetic Stock Mutants with Tolerance to Imazamox

    USDA-ARS?s Scientific Manuscript database

    Few mutants conferring herbicide tolerance in cotton (Gossypium hirsutum L.) have been developed. Imazamox is a broad spectrum imidazolinone herbicide that could give growers a new tool to control many troublesome annual broadleaf and grass weeds. The objective was to identify imazamox tolerance in ...

  8. Performance and combining ability in cotton (Gossypium hirsutum L.) populations with diverse parents

    USDA-ARS?s Scientific Manuscript database

    Improving fiber quality properties of cotton (Gossypium hirsutum L.) is important for increasing the efficiency of manufacturing textiles, including enhancing yarn quality and spinning performance. This study was conducted to determine if we could identify useful cotton cultivars to use as parents ...

  9. Evaluating protective terpenoid aldehyde compounds in cotton (Gossypium hirsutum L.) roots

    USDA-ARS?s Scientific Manuscript database

    Cotton (Gossypium hirsutum L.) has epidermal glands containing terpenoid aldehyde (TA) compounds that help protect the cotton plant from pests and diseases. One terpenoid aldehyde called gossypol, is found predominantly in seed and roots and has two forms, plus (+) and minus (-) present in varying a...

  10. Components of hybrid vigor in upland cotton (Gossypium hirsutum L.) and their relationship with environment

    USDA-ARS?s Scientific Manuscript database

    Upland cotton (Gossypium hirsutum L.) hybrids display commercially useful levels of heterosis for lint yield. Cotton lint yield is primarily a multiplicative product of boll number and lint per boll, both of which can be further dissected into sub-components. Relationships among the yield components...

  11. Genome sequence of cultivated Upland cotton (Gossypium hirsutum TM-1) provides insights into genome evolution

    USDA-ARS?s Scientific Manuscript database

    Genetic and genomic analyses of Upland cotton (Gossypium hirsutum) are difficult because it has a complex allotetraploid (AADD; 2n = 4x = 52) genome. Here we sequenced, assembled and analyzed the world's most important cultivated cotton genome with 246.2 gigabase (Gb) clean data obtained using whol...

  12. The diploid D genome cottons (Gossypium spp.) of the new world

    USDA-ARS?s Scientific Manuscript database

    The diploid D genome cottons (Gossypium spp.) of the New World are part of a great reservoir of important genes for improving fiber quality, pest and disease resistance, and drought and salt tolerance in the modern cultivated Upland/Acala (G. hirsutum) and Pima [also known as Sea Island or Egyptian ...

  13. Repeated polyploidization of Gossypium genomes and the evolution of spinnable cotton fibres

    USDA-ARS?s Scientific Manuscript database

    Emergent phenotypes are common in polyploids relative to their diploid progenitors, a phenomenon exemplified by spinnable cotton fibers. Following 15-18 fold paleopolyploidy, allopolyploidy 1-2 million years ago reunited divergent Gossypium genomes, imparting new combinatorial complexity that might ...

  14. New HPLC methods to quantitate terpenoid aldehydes in foliage of cotton (Gossypium)

    USDA-ARS?s Scientific Manuscript database

    The cotton plant (Gossypium) produces protective terpenoid aldehydes in lysigenous pigment glands. These terpenoids include hemigossypolone, hemigossypolone-6-methyl ether, gossypol, gossypol-6-methyl ether, gossypol-6,6'-dimethyl ether, heliocides H1, H2, H3 and H4, and heliocides B1, B2, B3 and B4...

  15. Assessing Genetic Diversity in Gossypium Arboreum L. Cultivars Using Genomic and EST-Derived Microsatellites.

    USDA-ARS?s Scientific Manuscript database

    The cultivated diploid, Gossypium arboreum L., (A genome) is an invaluable genetic resource for improving modern tetraploid cotton (G. hirsutum L. and G. barbadense L.) cultivars. The objective of this research is to select a set of informative and robust microsatellites for studying genetic relatio...

  16. Molecular diversity among G. hirsutum accessions in the Gossypium Diversity Reference Set

    USDA-ARS?s Scientific Manuscript database

    A core set of 105 SSR markers were employed to develop accession profiles and analyze genetic relationships among 2,254 plant introductions of cotton (Gossypium spp.) including wild species, landraces, and adapted cultivars from around the world as represented in the US National Cotton Germplasm Col...

  17. Genome-wide analysis of the omega-3 fatty acid desaturase gene family in Gossypium

    USDA-ARS?s Scientific Manuscript database

    Background The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid ...

  18. Genetic diversity of the two commercial tetraploid cotton species in the Gossypium Diversity Reference Set

    USDA-ARS?s Scientific Manuscript database

    A diversity reference set has been constructed for the Gossypium accessions in the U.S. National Cotton Germplasm Collection to facilitate more extensive evaluation and utilization of accessions held in the Collection. A set of 105 mapped simple sequence repeat markers were used to study the alleli...

  19. Molecular characterization of the Gossypium diversity reference set of the US National Cotton Germplasm Collection

    USDA-ARS?s Scientific Manuscript database

    An understanding of the genetic diversity of cotton (Gossypium spp.) is essential to develop strategies for collection, conservation, and utilization of these germplasm resources. The US National Cotton Germplasm Collection is one of the largest world collections and includes not only accessions wi...

  20. Four chromosome-specific (Gossypium barbadense chromosome 5sh) Upland cotton RILs with improved elongation

    USDA-ARS?s Scientific Manuscript database

    A chromosome specific recombinant inbred line (CS-B05shRIL) population was created from a cross of TM-1, the genetic standard line of Gossypium hirsutum L. and CS-B05sh, a previously released interspecific chromosome substitution line in which all of the chromosome pairs are genetically similar to T...

  1. Severed stems of Amaranthus palmeri are capable of regrowth and seed production in Gossypium hirsuium

    USDA-ARS?s Scientific Manuscript database

    Field studies were conducted to evaluate the capacity of Amaranthus palmeri to grow and reproduce following incomplete physical control in Gossypium hirsutum fields. Amaranthus palmeri plants that emerged simultaneously with a G. hirsutum crop were selected for use. Treatments included severing the ...

  2. Sequencing of allotetraploid cotton (Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement

    USDA-ARS?s Scientific Manuscript database

    Cotton is the world’s most important natural textile fibre and a significant oilseed crop. Upland cotton (Gossypium hirsutum L.), an allotetraploid derived from A- and D-genome progenitors, accounts for >95% of world production. Here, we sequenced and assembled 88% of the 2.5-gigabase genome of the ...

  3. Potential of VIIRS Data for Regional Monitoring of Gypsy Moth Defoliation: Implications for Forest Threat Early Warning System

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.; Ryan, Robert E.; Smoot, James C.; Prados, Donald; McKellip, Rodney; Sader. Steven A.; Gasser, Jerry; May, George; Hargrove, William

    2007-01-01

    A NASA RPC (Rapid Prototyping Capability) experiment was conducted to assess the potential of VIIRS (Visible/Infrared Imager/Radiometer Suite) data for monitoring non-native gypsy moth (Lymantria dispar) defoliation of forests. This experiment compares defoliation detection products computed from simulated VIIRS and from MODIS (Moderate Resolution Imaging Spectroradiometer) time series products as potential inputs to a forest threat EWS (Early Warning System) being developed for the USFS (USDA Forest Service). Gypsy moth causes extensive defoliation of broadleaved forests in the United States and is specifically identified in the Healthy Forest Restoration Act (HFRA) of 2003. The HFRA mandates development of a national forest threat EWS. This system is being built by the USFS and NASA is aiding integration of needed satellite data products into this system, including MODIS products. This RPC experiment enabled the MODIS follow-on, VIIRS, to be evaluated as a data source for EWS forest monitoring products. The experiment included 1) assessment of MODIS-simulated VIIRS NDVI products, and 2) evaluation of gypsy moth defoliation mapping products from MODIS-simulated VIIRS and from MODIS NDVI time series data. This experiment employed MODIS data collected over the approximately 15 million acre mid-Appalachian Highlands during the annual peak defoliation time frame (approximately June 10 through July 27) during 2000-2006. NASA Stennis Application Research Toolbox software was used to produce MODIS-simulated VIIRS data and NASA Stennis Time Series Product Tool software was employed to process MODIS and MODIS-simulated VIIRS time series data scaled to planetary reflectance. MODIS-simulated VIIRS data was assessed through comparison to Hyperion-simulated VIIRS data using data collected during gypsy moth defoliation. Hyperion-simulated MODIS data showed a high correlation with actual MODIS data (NDVI R2 of 0.877 and RMSE of 0.023). MODIS-simulated VIIRS data for the same

  4. Public tolerance to defoliation and flower distortion in a public horticulture garden.

    PubMed

    Sadof, Clifford S; Sclar, D Casey

    2002-04-01

    Surveys of visitor and grower perception of live potted plant quality were conducted in various locations in a large public display garden. Canna lily, Canna x generalis L.H.Bailey, was used to examine effects of defoliation by Japanese beetle, Popillia japonica Newman, on public perception. Chrysanthemums, Chrysanthemum x morifolium Ramat., were used to identify visitor and grower tolerance to flower distortion caused by western flower thrips, Frankliniella occidentalis (Pergande), on single and multiple flowered plants. On average, the maximum amount of defoliation or flower distortion tolerated by any respondent was low (< or = 10% for canna and < or = 25% for chrysanthemum). The level of acceptable injury was influenced by factors intrinsic to both the respondents and the plants themselves. Tolerance to injury was negatively associated with the risk aversion of the respondents. Visitors were less tolerant of injury on plants they considered for purchase than those that they would view at the garden. Similarly, grower tolerance was lower than that of visitors because producing substandard plants could put their professional reputation at risk. Factors that distracted visitor attention (e.g., presence of flowers and higher levels of background injury) increased their tolerance to plant injury. Visitors tolerated greater levels of flower distortion on multiple flowering chrysanthemum than on those with single flowers. We suggest that tolerance to insect pests can be increased by designing plantings that distract viewers from injured plant parts.

  5. LANDSAT Digital Data Base Preparation for the Pennsylvania Defoliation Application Pilot Test

    NASA Technical Reports Server (NTRS)

    Mcleod, R. G.; Zobrist, A. L.

    1982-01-01

    A LANDSAT digital mosaic data base for the State of Pennsylvania was prepared for use in the development of an automated system to annually estimate the extent and severity of Gypsy Moth defoliation of hardward forests. The techniques for detecting the defoliation and development of a geographic information system (GIS) to assess damage is being developed jointly by NASA/Goddard Space Flight Center and Pennsylvania State University using the JPL prepared mosaic base. The JPL processing involved the use of ground control points from the Master Data Processor for planimetric control, resampling of the LANDSAT data to 57 x 57 meter pixels, realignment to north, and reprojection to the Universal Transverse Mercator (UTM) projection in UTM zones 17 and 18. The completed mosaic for each UTM zone was subdivided into 1 degree of latitude by 2 degrees of longitude quadrangles for easy data handling. Consideration is given to the issues of mapping standards, sensor and spacecraft platform characteristics, and their implication to geographic information systems operation. Methods for obtaining measures of accuracy for LANDSAT mosaics are reviewed.

  6. Using a ceptometer to validate a visual evaluation of the degree of defoliation of holm and cork oak trees

    Treesearch

    Margarida Tome; Maria Vasconcelos

    2000-01-01

    The study presented in this paper is part of a project to monitor the defoliation degree of cork and holm oak trees in stands with signs of "decline," alter application of different amounts of Aliette, a product specific for Phytophotora cinnamonii, one of the possible causes of the "decline". The specific objective was to...

  7. Influence of defoliation date and gin-drying temperature on oven moisture and KFT water within cotton cultivars

    USDA-ARS?s Scientific Manuscript database

    Water measured in lint cotton by Karl Fischer Titration was compared to moisture content measured by standard oven-drying in two cultivars. The cultivars had been defoliated at different times and ginned at two possible temperatures. Ginned lint was further processed to produce mechanically cleaned,...

  8. Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks

    PubMed Central

    Song, Yuan Yuan; Simard, Suzanne W.; Carroll, Allan; Mohn, William W.; Zeng, Ren Sen

    2015-01-01

    Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change. To test whether defoliated IDF can directly transfer resources to ponderosa pine (Pinus ponderosae) regenerating nearby, thus aiding in forest recovery, we examined photosynthetic carbon transfer and defense enzyme response. We grew pairs of ectomycorrhizal IDF ‘donor’ and ponderosa pine ‘receiver’ seedlings in pots and isolated transfer pathways by comparing 35 μm, 0.5 μm and no mesh treatments; we then stressed IDF donors either through manual defoliation or infestation by the budworm. We found that manual defoliation of IDF donors led to transfer of photosynthetic carbon to neighboring receivers through mycorrhizal networks, but not through soil or root pathways. Both manual and insect defoliation of donors led to increased activity of peroxidase, polyphenol oxidase and superoxide dismutase in the ponderosa pine receivers, via a mechanism primarily dependent on the mycorrhizal network. These findings indicate that IDF can transfer resources and stress signals to interspecific neighbors, suggesting ectomycorrhizal networks can serve as agents of interspecific communication facilitating recovery and succession of forests after disturbance. PMID:25683155

  9. Fire and season of post-fire defoliation effects on biomass, composition and cover in mixed-grass prairie

    USDA-ARS?s Scientific Manuscript database

    North American prairies are acknowledged to have evolved with grazing following fire. Given this evolutionary fire-grazing interaction, our objective was to determine whether seasonal timing of defoliation following fire alters subsequent productivity and species composition. Following the April 201...

  10. Development of Screening Trials to Rank Pinus radiata Genotypes for Resistance to Defoliation by Monterey Pine Aphid (Essigella californica)

    Treesearch

    Stephen Elms; Peter Ades; Nick Collet

    2012-01-01

    The Monterey pine aphid (Essigella californica) is a recent arrival in Australia, having first been detected in 1998. It quickly spread throughout the national radiata pine (Pinus radiata D. Don) plantation estate, causing seasonal defoliation and compromising tree growth in many areas. Selection of resistant radiata...

  11. Using slides to test for changes in crown defoliation assessment methods. Part I: Visual assessment of slides.

    PubMed

    Dobbertin, Matthias; Hug, Christian; Mizoue, Nobuya

    2004-11-01

    In this study we used photographs of tree crowns to test whether the assessment methods for tree defoliation in Switzerland have changed over time. We randomly selected 24 series of slides of Norway spruce with field assessments made between 1986 and 1995. The slides were randomly arranged and assessed by three experts without prior knowledge of the year when the slide was taken or the tree number. Defoliation was assessed using the Swiss reference photo guide. Although the correlations between the field assessments and slide assessments were high (Spearman's rank correlation coefficient ranged between 0.79 and 0.83), we found significant differences between field and slide assessments (4.3 to 9% underprediction by the slide assessors) and between the slide assessments. However, no significant trends in field assessment methods could be detected. When the mean differences between field and slide assessments were subtracted, in some years, field assessors consistently underpredicted (1990, 1992) or overpredicted defoliation (1987, 1991). Defoliation tended to be overpredicted in slides taken against the light, and underpredicted for trees with more than 25% crown overlap. We conclude that slide series can be used to detect changes in assessment methods. However, potential observer bias calls for more objective methods of assessment.

  12. Impact of the defoliating moth Hypena opulenta on invasive swallow-worts (Vincetoxicum species) under different light environments

    USDA-ARS?s Scientific Manuscript database

    Black and pale swallow-wort (Vincetoxicum nigrum and V. rossicum, Apocynaceae: Asclepiadoideae) are twining vines from Europe that have become invasive in the northeastern USA and southeastern Canada. Hypena opulenta (Christoph) (Lepidoptera: Erebidae), a defoliating forest moth from the Ukraine, ha...

  13. Effects of Defoliating Insect Resistance QTLs and a crylAc Transgene in Soybean Near-Isogenic Lines

    USDA-ARS?s Scientific Manuscript database

    Additional sources of resistance would be desirable to manage defoliating insect resistance to crystal proteins coded by transgenes from Bacillus thuringiensis (Bt) and to sustain the deployment of Bt crops. The objective of this study was to evaluate the effects and interactions of three soybean (G...

  14. Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks.

    PubMed

    Song, Yuan Yuan; Simard, Suzanne W; Carroll, Allan; Mohn, William W; Zeng, Ren Sen

    2015-02-16

    Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change. To test whether defoliated IDF can directly transfer resources to ponderosa pine (Pinus ponderosae) regenerating nearby, thus aiding in forest recovery, we examined photosynthetic carbon transfer and defense enzyme response. We grew pairs of ectomycorrhizal IDF 'donor' and ponderosa pine 'receiver' seedlings in pots and isolated transfer pathways by comparing 35 μm, 0.5 μm and no mesh treatments; we then stressed IDF donors either through manual defoliation or infestation by the budworm. We found that manual defoliation of IDF donors led to transfer of photosynthetic carbon to neighboring receivers through mycorrhizal networks, but not through soil or root pathways. Both manual and insect defoliation of donors led to increased activity of peroxidase, polyphenol oxidase and superoxide dismutase in the ponderosa pine receivers, via a mechanism primarily dependent on the mycorrhizal network. These findings indicate that IDF can transfer resources and stress signals to interspecific neighbors, suggesting ectomycorrhizal networks can serve as agents of interspecific communication facilitating recovery and succession of forests after disturbance.

  15. Some timber product market and trade implications of an invasive defoliator: the case of Asian lymantria in the United States

    Treesearch

    Jeffrey P. Prestemon; James A. Turner; Joseph Buongiorno; Shushuai Zhu; Ruhong Li

    2008-01-01

    US policy and forest product industry decisionmakers need quantitative information about the magnitude of timber product market impacts from the possible introduction of an exotic and potentially dangerous defoliating forest pest. We applied the Global Forest Products Model to evaluate the effects on the United States of an invasion by the Asian gypsy (...

  16. Impact of insecticide-manipulated defoliation by Japanese beetle (Popillia japonica) on grapevines from vineyard establishment through production.

    PubMed

    Hammons, Derrick L; Kaan Kurtural, S; Potter, Daniel A

    2010-05-01

    Japanese beetle (JB), Popillia japonica Newman, is a severe pest of grapes in the southeastern USA where viticulture is a growing industry. This study evaluated the impact of foliar injury from JB field populations on growth, fruit ripening, berry composition and yield of young vines of six cultivars from vineyard establishment through the first year of production. Three spray regimes, carbaryl applied every 7 or 14 days, or no insecticide, were used to manipulate levels of defoliation by JB. Cultivars varied in susceptibility and response to defoliation by JB. Some (e.g. Norton) showed reduced vine growth and delayed post-veraison increase in total soluble sugars and pH, as well as reduced cluster number and weight, berries per cluster and yield. Others (e.g. Concord) showed little or no measurable impact from JB. Notably, the biweekly spray regime was as effective as weekly sprays in mitigating the impacts of defoliation. Foliar loss from JB feeding can set back establishment and productivity of young grapevines. Nevertheless, many growers can reduce spray frequency without compromising the benefits of JB management. Even susceptible cultivars can tolerate low to moderate (<20%) levels of defoliation, and some are resistant enough to be grown without treating for JB.

  17. Abundance and frequency of the Asiatic oak weevil (Coleoptera: Curculionidae) and defoliation on American, Chinese, and hybrid chestnut ( Castanea )

    Treesearch

    Ashley E. Case; Albert (Bud) Mayfield; Stacy L. Clark; Scott E. Schlarbaum; Barbara C. Reynolds

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (...

  18. Shifts in biomass and resource allocation patterns following defoliation in Eucalyptus globulus growing with varying water and nutrient supplies.

    PubMed

    Eyles, Alieta; Pinkard, Elizabeth A; Mohammed, Caroline

    2009-06-01

    In woody species, potential mechanisms to compensate for tissue loss to herbivory and diseases have been related to post-event shifts in growth, biomass and internal resource allocation patterns, as modulated by external resource limitations. We examined the interactive effects of belowground resource limitations by varying nutrient and water availability, and aboveground carbon limitation imposed by a single defoliation event (40% leaf removal) on stem growth, whole-tree and within-tree resource allocation patterns (total non-structural carbohydrate and nitrogen) and below- and aboveground biomass allocation patterns in 8-month-old, field-grown Eucalyptus globulus Labill. saplings. Two months after treatments were imposed, the direction of the stem growth response to defoliation depended on the abiotic treatment. Five months after defoliation, however, we found little evidence that resource availability constrained the expression of tolerance to defoliation. With the exception of the combined low-nutrient and low-water supply treatment, saplings grown with (1) adequate water and nutrient supplies and even with (2) low-water supply or (3) low-nutrient supply were able to compensate for the 40% foliage loss. The observed compensatory responses were attributed to the activation of several short- and longer-term physiological mechanisms including reduced biomass allocation to coarse roots, mobilization of carbohydrate reserves, robust internal N dynamics and increased ratio of foliage to wood dry mass.

  19. Interactions between elevated atmospheric CO2 and defoliation on North American rangeland plant species at low and high N availability

    USDA-ARS?s Scientific Manuscript database

    Semi-arid rangelands are expected to be highly sensitive to global change, but few studies have explicitly investigated interactions between increased atmospheric CO2 and plant defoliation (such as occurs with animal grazing). This experiment subjected intact plant-soil cylinders from the Wyoming pr...

  20. [The dynamics of phenolic compounds and soluble sugars in the leaves of the silver birch (Betula pendula Roth) after defoliation and their significance in entomological plant resistance].

    PubMed

    Bakhvalov, S A; Martem'ianov, V V; Kukushkina, T A; Vysochina, G I

    2009-01-01

    The dynamics of phenolic compounds, flavonols, catechines, tannins, and soluble sugars in the leaves of the silver birch Betula pendula Roth after strong (75%) and total (100%) artificial defoliation was studied. It was shown that the flavonol content in the leaves did not change after strong and total defoliation, while the amount of tannins did not change during the first 15 days but increased later on 1 and 2 years after 75% and 100% defoliation. The catechine content did not change during the first 15 days and increased later on 1 year after strong and total defoliation; however, it returned to the level of control plants 2 years after both types of defoliations. The amount of soluble sugars in the leaves increased 2 days after 75% defoliation; however, their content conformed to that in control plants after 10 days and it persisted later 1 and 2 years after the damage. The amount of soluble sugars in the leaves also did not change 1 year after 100% defoliation.

  1. Grain amaranths are defoliation tolerant crop species capable of utilizing stem and root carbohydrate reserves to sustain vegetative and reproductive growth after leaf loss.

    PubMed

    Vargas-Ortiz, Erandi; Espitia-Rangel, Eduardo; Tiessen, Axel; Délano-Frier, John Paul

    2013-01-01

    Tolerance to defoliation can be defined as the degree to which productivity is affected by photosynthetic area reduction. This trait was studied in grain amaranth (Amaranthus cruentus and A. hypochondriacus), which are considered to be a highly defoliation-tolerant species. The physiological and biochemical responses to increasing levels of mechanical leaf removal up to total defoliation were quantified. Tolerance appeared to be dependent on various factors: ( i) amount of lost tissue; (ii) mechanics of leaf tissue removal; (iii) environment, and (iv) species tested. Thus, grain amaranth was found to be a highly tolerant species under green-house conditions when leaf tissue loss was performed by gradual perforation. However, tolerance was compromised under similar conditions when defoliation was done by gradual cutting of the leaf. Also tolerance in completely defoliated plants tended to decrease under field conditions, where differences between A. cruentus and A. hypochondriacus were observed. All non-structural carbohydrate (NSC) levels were reduced in stems and roots of totally defoliated amaranths one day after treatment. Such depletion probably provided the carbon (C) resources needed to sustain the early recovery process in the absence of photosynthetic capacity. This was corroborated by shading of intact plants, which produced the same rapid and drastic reduction of NSC levels in these tissues. These results emphasize the role of stored NSCs, particularly starch, in buffering the impact of severe defoliation in amaranth. The fall in sucrose synthase and cell wall invertase activity observed in stems and roots soon after defoliation was consistent with their predicted shift from sink to source tissues. It is concluded that mobilization of C stores in stems and roots, is a physiologically important trait underlying tolerance to defoliation in grain amaranth.

  2. Grain Amaranths Are Defoliation Tolerant Crop Species Capable of Utilizing Stem and Root Carbohydrate Reserves to Sustain Vegetative and Reproductive Growth after Leaf Loss

    PubMed Central

    Vargas-Ortiz, Erandi; Espitia-Rangel, Eduardo; Tiessen, Axel; Délano-Frier, John Paul

    2013-01-01

    Tolerance to defoliation can be defined as the degree to which productivity is affected by photosynthetic area reduction. This trait was studied in grain amaranth (Amaranthus cruentus and A. hypochondriacus), which are considered to be a highly defoliation-tolerant species. The physiological and biochemical responses to increasing levels of mechanical leaf removal up to total defoliation were quantified. Tolerance appeared to be dependent on various factors: ( i) amount of lost tissue; (ii) mechanics of leaf tissue removal; (iii) environment, and (iv) species tested. Thus, grain amaranth was found to be a highly tolerant species under green-house conditions when leaf tissue loss was performed by gradual perforation. However, tolerance was compromised under similar conditions when defoliation was done by gradual cutting of the leaf. Also tolerance in completely defoliated plants tended to decrease under field conditions, where differences between A. cruentus and A. hypochondriacus were observed. All non-structural carbohydrate (NSC) levels were reduced in stems and roots of totally defoliated amaranths one day after treatment. Such depletion probably provided the carbon (C) resources needed to sustain the early recovery process in the absence of photosynthetic capacity. This was corroborated by shading of intact plants, which produced the same rapid and drastic reduction of NSC levels in these tissues. These results emphasize the role of stored NSCs, particularly starch, in buffering the impact of severe defoliation in amaranth. The fall in sucrose synthase and cell wall invertase activity observed in stems and roots soon after defoliation was consistent with their predicted shift from sink to source tissues. It is concluded that mobilization of C stores in stems and roots, is a physiologically important trait underlying tolerance to defoliation in grain amaranth. PMID:23861825

  3. Forest defoliators and climatic change: Potential changes in spatial distribution of outbreaks of western spruce budworm (Lepidoptera: Tortricidae) and gypsy moth (Lepidoptera: Lymantriidae)

    SciTech Connect

    Williams, D.W.; Liebhold, A.M.

    1995-02-01

    Changes in geographical ranges and spatial extent of outbreaks of pest species are likely consequences of climatic change. We investigated potential changes in spatial distribution of outbreaks of western spruce budworm, Choristoneura occidentalis Freeman, and gypsy moth, Lymantria dispar (L.), in Oregon and Pennsylvania, respectively using maps of historial defoliation, climate, and forest type in a geographic information system. Maps of defoliation frequency at a resolution of 2 x 2 km were assembled from historical aerial survey data. Weather maps for mean monthly temperature maxima and minima and precipitation over 30 yr were developed by interpolation. Relationships between defoliation status and environmental variables were estimated using linear discriminant analysis. Five climatic change scenarios were investigated: an increase of 2{degrees}C, a 2{degrees}C increase with a small increase and a small decrease in precipitation, and projections of two general circulation models (GCMs) after 100 yr at doubled carbon dioxide. With an increase in temperature alone, the projected defoliated area decreased relative to ambient conditions for budworm and increased slightly for gypsy moth. With an increase in temperature and precipitation, defoliated area increased for both species. Conversely, defoliated area decreased for both when temperature increased and precipitation decreased. Results for the GCM scenarios contrasted sharply. For one GCM, defoliation by budworm was projected to cover Oregon completely, whereas no defoliation was projected by gypsy moth in Pennsylvania. For the other, defoliation disappeared completely for budworm and slightly exceeded that under ambient conditions for gypsy moth. The results are discussed in terms of current forest composition and its potential changes. 36 refs., 5 figs., 4 tabs.

  4. Variovorax gossypii sp. nov., isolated from Gossypium hirsutum.

    PubMed

    Kämpfer, Peter; Busse, Hans-Jürgen; McInroy, John A; Glaeser, Stefanie P

    2015-12-01

    A beige-pigmented bacterial strain (JM-310T), isolated from the healthy internal root tissue of 4-week-old cotton (Gossypium hirsutum, cultivar 'DES-119') in Tallassee (Macon county), Alabama, USA, was studied taxonomically. The isolate produced small rod-shaped cells, which showed a Gram-negative staining behaviour. A comparison of the 16S rRNA gene sequence of the isolate revealed 99.2, 98.8, 98.7, 98.7, 98.1 and 97.6 % similarity to the 16S rRNA gene sequences of the type strains of Variovorax paradoxus, Variovorax boronicumulans, Variovorax ginsengisoli, Variovorax soli, Variovorax defluvii and Variovorax dokdonensis, respectively. In phylogenetic trees based on 16S rRNA gene sequences, strain JM-301T was placed within the monophyletic cluster of Variovorax species. The fatty acid profile of strain JM-310T consisted mainly of the major fatty acids C16 : 0, C10 : 0 3-OH and summed feature 4 (iso-C15 : 0 2-OH/C16 : 1ω7c/t). The quinone system of strain JM-310T contained predominantly ubiquinone Q-8 and lesser amounts of Q-7 and Q-9. The major polyamine was putrescine and the diagnostic polyamine 2-hydroxyputrescine was detected as well. The polar lipid profile consisted of the major lipids phosphatidylethanolamine, phosphatidylglycerol, diphospatidylglycerol and several unidentified lipids. DNA-DNA hybridization experiments with V. paradoxus LMG 1797T, V. boronicumulans 1.22T, V. soli KACC 11579T and V. ginsengisoli 3165T gave levels of relatedness of < 70 %. These DNA-DNA hybridization results in addition to differential biochemical properties indicate clearly that strain JM-310T is a member of a novel species, for which the name Variovorax gossypii sp. nov. is proposed. The type strain is JM-310T ( = LMG 28869T = CIP 110912T = CCM 8614T).

  5. Nitrate variability in hydrological flow paths for three mid-Appalachian forested watersheds following a large-scale defoliation

    NASA Astrophysics Data System (ADS)

    Riscassi, Ami L.; Scanlon, Todd M.

    2009-06-01

    Nitrate (NO3-) leakage from forested watersheds due to disturbance is a well documented but not well understood process that can contribute to the degradation of receiving waters through eutrophication. Several studies have shown that large-scale defoliation and deforestation events in small forested watersheds in the eastern United States cause immediate and dramatic increases in NO3- flux to steams, with large differences in recovery time. Water quality and discharge data collected from 1992 to 2004 following a large-scale gypsy moth defoliation were used to investigate hydrological controls on long-term NO3- leakage from three forested watersheds in Shenandoah National Park, Virginia. During storm events, a conventional two-component hydrograph separation in conjunction with an inverse solution technique was employed to determine the concentrations of NO3- in groundwater and soil water. Following defoliation, groundwater NO3- concentrations declined exponentially with a distinct seasonal pattern. A rank-order relationship between the rate constants associated with the exponential declines in groundwater NO3- concentrations and groundwater recession constants indicates a hydrological control on long-term watershed recovery for these defoliated systems. Comparisons to deforested systems in Hubbard Brook, New Hampshire, and Coweeta, North Carolina, indicate hydrological controls are similarly present. Biogeochemical differences, however, need to be considered to account for the more attenuated recovery observed in defoliated systems. No long-term trend was found in the model-derived soil water NO3- concentrations, which suggests the presence of some form of rate limitation on the transformation of the nitrogen pool introduced during the disturbance and/or reduced nutrient uptake due to tree mortality.

  6. Contrasting impacts of defoliation on root colonization by arbuscular mycorrhizal and dark septate endophytic fungi of Medicago sativa.

    PubMed

    Saravesi, K; Ruotsalainen, A L; Cahill, J F

    2014-05-01

    Individual plants typically interact with multiple mutualists and enemies simultaneously. Plant roots encounter both arbuscular mycorrhizal (AM) and dark septate endophytic (DSE) fungi, while the leaves are exposed to herbivores. AMF are usually beneficial symbionts, while the functional role of DSE is largely unknown. Leaf herbivory may have a negative effect on root symbiotic fungi due to decreased carbon availability. However, evidence for this is ambiguous and no inoculation-based experiment on joint effects of herbivory on AM and DSE has been done to date. We investigated how artificial defoliation impacts root colonization by AM (Glomus intraradices) and DSE (Phialocephala fortinii) fungi and growth of Medicago sativa host in a factorial laboratory experiment. Defoliation affected fungi differentially, causing a decrease in arbuscular colonization and a slight increase in DSE-type colonization. However, the presence of one fungal species had no effect on colonization by the other or on plant growth. Defoliation reduced plant biomass, with this effect independent of the fungal treatments. Inoculation by either fungal species reduced root/shoot ratios, with this effect independent of the defoliation treatments. These results suggest AM colonization is limited by host carbon availability, while DSE may benefit from root dieback or exudation associated with defoliation. Reductions in root allocation associated with fungal inoculation combined with a lack of effect of fungi on plant biomass suggest DSE and AMF may be functional equivalent to the plant within this study. Combined, our results indicate different controls of colonization, but no apparent functional consequences between AM and DSE association in plant roots in this experimental setup.

  7. The Role of Forest Tent Caterpillar Defoliations and Partial Harvest in the Decline and Death of Sugar Maple

    PubMed Central

    Hartmann, Henrik; Messier, Christian

    2008-01-01

    Background and Aims Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Methods Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Key Results Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Conclusions Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting. PMID:18660493

  8. Whole-plant versus leaf-level regulation of photosynthetic responses after partial defoliation in Eucalyptus globulus saplings

    PubMed Central

    Eyles, Alieta

    2013-01-01

    Increases in photosynthetic capacity (A1500) after defoliation have been attributed to changes in leaf-level biochemistry, water, and/or nutrient status. The hypothesis that transient photosynthetic responses to partial defoliation are regulated by whole-plant (e.g. source–sink relationships or changes in hydraulic conductance) rather than leaf-level mechanisms is tested here. Temporal variation in leaf-level gas exchange, chemistry, whole-plant soil-to-leaf hydraulic conductance (KP), and aboveground biomass partitioning were determined to evaluate mechanisms responsible for increases in A1500 of Eucalyptus globulus L. potted saplings. A1500 increased in response to debudding (B), partial defoliation (D), and combined B&D treatments by up to 36% at 5 weeks after treatment. Changes in leaf-level factors partly explained increases in A1500 of B and B&D treatments but not for D treatment. By week 5, saplings in B, B&D, and D treatments had similar leaf-specific KP to control trees by maintaining lower midday water potentials and higher transpiration rate per leaf area. Whole-plant source:sink ratios correlated strongly with A1500. Further, unlike KP, temporal changes in source:sink ratios tracked well with those observed for A1500. The results indicate that increases in A1500 after partial defoliation treatments were largely driven by an increased demand for assimilate by developing sinks rather than improvements in whole-plant water relations and changes in leaf-level factors. Three carbohydrates, galactional, stachyose, and, to a lesser extent, raffinose, correlated strongly with photosynthetic capacity, indicating that these sugars may function as signalling molecules in the regulation of longer term defoliation-induced gas exchange responses. PMID:23382548

  9. The role of forest tent caterpillar defoliations and partial harvest in the decline and death of sugar maple.

    PubMed

    Hartmann, Henrik; Messier, Christian

    2008-09-01

    Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting.

  10. Whole-plant versus leaf-level regulation of photosynthetic responses after partial defoliation in Eucalyptus globulus saplings.

    PubMed

    Eyles, Alieta; Pinkard, Elizabeth A; Davies, Noel W; Corkrey, Ross; Churchill, Keith; O'Grady, Anthony P; Sands, Peter; Mohammed, Caroline

    2013-04-01

    Increases in photosynthetic capacity (A1500) after defoliation have been attributed to changes in leaf-level biochemistry, water, and/or nutrient status. The hypothesis that transient photosynthetic responses to partial defoliation are regulated by whole-plant (e.g. source-sink relationships or changes in hydraulic conductance) rather than leaf-level mechanisms is tested here. Temporal variation in leaf-level gas exchange, chemistry, whole-plant soil-to-leaf hydraulic conductance (KP), and aboveground biomass partitioning were determined to evaluate mechanisms responsible for increases in A1500 of Eucalyptus globulus L. potted saplings. A1500 increased in response to debudding (B), partial defoliation (D), and combined B&D treatments by up to 36% at 5 weeks after treatment. Changes in leaf-level factors partly explained increases in A1500 of B and B&D treatments but not for D treatment. By week 5, saplings in B, B&D, and D treatments had similar leaf-specific KP to control trees by maintaining lower midday water potentials and higher transpiration rate per leaf area. Whole-plant source:sink ratios correlated strongly with A1500. Further, unlike KP, temporal changes in source:sink ratios tracked well with those observed for A1500. The results indicate that increases in A1500 after partial defoliation treatments were largely driven by an increased demand for assimilate by developing sinks rather than improvements in whole-plant water relations and changes in leaf-level factors. Three carbohydrates, galactional, stachyose, and, to a lesser extent, raffinose, correlated strongly with photosynthetic capacity, indicating that these sugars may function as signalling molecules in the regulation of longer term defoliation-induced gas exchange responses.

  11. Parasitism and Food Web Structure in Defoliating Lepidoptera - Parasitoid Communities on Soybean.

    PubMed

    Avalos, D S; Mangeaud, A; Valladares, G R

    2016-12-01

    Food webs are usually regarded as snapshots of community feeding interactions. Here, we describe the yearly and cumulative structure of parasitoid-caterpillar food webs on soybean in central Argentina, analyzing parasitism rates and their variability in relation to parasitoid diversity and food web vulnerability in the system. Lepidoptera larvae were collected along four seasons from soybean crops and reared in laboratory to obtain and identify adults and parasitoids. Eleven species of defoliating Lepidoptera and ten parasitoid species were recorded. Food web statistics showed rather low annual variability, with most variation coefficients in the order of 0.20 and generality showing the most stable values. Parasitism showed the highest variability, which was independent of parasitoid diversity and food web vulnerability, although parasitism rates were negatively related to parasitoid richness. Our study highlights the need to consider food web structure and variability in order to understand the functioning of ecological communities in general and in extensive agricultural ecosystems in particular.

  12. Employing citizen science to study defoliation impacts on arthropod communities on tamarisk

    NASA Astrophysics Data System (ADS)

    Kruse, Audrey L.

    The invasive tamarisk tree is widespread across the southwestern landscape of the United States and has been dominant in regulated river reaches, outcompeting native vegetation and impacting trophic webs in riparian ecosystems. The changes in riparian habitat and recreation opportunities along southwestern rivers, like the San Juan River in Utah, led to the implementation of a biocontrol program in the form of the tamarisk leaf beetle (Diorhabda spp.). It is unknown what the long term effects on riparian ecosystems are as a result of the beetles' defoliation of tamarisk each summer. This study sought to identify the current arthropod community composition and abundance over one growing season on the San Juan River between Bluff and Mexican Hat, UT and second, to involve the public in this research through a citizen science component. I found that non-native insects, including the tamarisk leaf beetle, dominated the arboreal arthropod communities within the tamarisk and there are relatively few native arthropods residing in tamarisk throughout the summer season. Foliation levels (the quantity of leaves in the canopy of tamarisk) were inconclusive predictors of arthropod abundances but varied by species and by feeding guild. This may indicate that the defoliation of the tamarisk is not necessarily negatively impacting trophic interactions in tamarisk. I incorporated youth participants on educational river rafting trips to assist in data collection of arthropods from tamarisk trees as a way to educate and bring attention to the issue of invasive species in the Southwest. After completing my own citizen science project and after doing a literature review of other, similar citizen science projects, I found that striving for both rigorous scientific data and quality educational programming is challenging for a small scale project that does not target broad spatial, geographic, or temporal data. Citizen science project developers should clearly identify their objectives

  13. Effects of Rag1 on the preference and performance of soybean defoliators.

    PubMed

    Bruner, Robert F; Hodgson, Erin W; Gassmann, Aaron J

    2013-12-01

    The Rag1 gene confers antibiotic resistance to soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and in 2010, varieties expressing Rag1 were released for commercial use in the United States. We do not know how Rag1 varieties will influence the broader community of defoliating insects that inhabit soybean fields. In 2010 and 2011, the preference and performance of pest insects that defoliate soybeans [Glycines max (L.) Merr] were tested using Rag1 and aphid-susceptible varieties. Three coleopterans and four lepidopterans were used: northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae); southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae); bean leaf beetle, Ceratoma trsifurcata Förster (Coleoptera: Chrysomelidae); fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae); corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae); soybean looper, Chrysodeix includens (Walker) (Lepidoptera: Noctuidae); and velvet-bean caterpillar, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae). The preference of insects was evaluated in choice and no-choice tests using Rag1 and susceptible soybeans. Lepidopterans also were evaluated on Rag1 leaves using four nutritional indices: relative growth rate, approximate digestibility, and efficiency of conversion of ingested material. In the majority of preference tests, no effect of Rag1 was detected, and in cases where preferences were found, there was no consistent pattern of preference for Rag1 vs. susceptible leaf tissue. Helicoverpa zea demonstrated a preference for resistant leaf tissue, but this was dependent on the genetic background of the variety. Evaluations of nutritional indices indicated that three species of Lepidoptera, S. frugiperda, H. zea, and A. gemmatalis, displayed reduced conversion efficiency for Rag1 soybeans, suggesting effects of antibiosis.

  14. Effect of defoliation by checkerspot caterpillars (Euphydryas phaeton) and sawfly larvae (Macrophya nigra and Tenthredo grandis) on their host plants (Chelone spp.).

    PubMed

    Stamp, Nancy E

    1984-08-01

    The effect of defoliation by herbivores, checkerspot caterpillars (Euphydryas phaeton) and sawfly larvae (Macrophya nigra and Tenthredo grandis), on the reproductive output of turtlehead (Chelone spp.) was examined. Defoliation prior to development of flower buds reduced the number of reproductive stalks, flower buds, flowers and seed capsules. Severe herbivory, after flower buds appeared, decreased the final number of seed capsules and seeds per capsule. The availability of the host plants to the herbivores was a function of prior defoliation and environmental conditions. Sawfly larvae, by defoliating the plants in midsummer, forced prediapause checkerspot caterpillars to wander in search of food plants. Decimation of these perenials by postdiapause checkerspot caterpillars in a dry spring retarded growth of turtlehead and, consequently, most of the plants were not available for egg-laying by sawflies and checkerspots.

  15. Uniqueness of the Gossypium mustelinum Genome Revealed by GISH and 45S rDNA FISH

    PubMed Central

    Wu, Qiong; Liu, Fang; Li, Shaohui; Song, Guoli; Wang, Chunying; Zhang, Xiangdi; Wang, Yuhong; Stelly, David; Wang, Kunbo

    2013-01-01

    Gossypium mustelinum ((AD)4) is one of five disomic species in Gossypium. Three 45S ribosomal DNA (rDNA) loci were detected in (AD)4 with 45S rDNA as probe, and three pairs of brighter signals were detected with genomic DNA (gDNA) of Gossypium D genome species as probes. The size and the location of these brighter signals were the same as those detected with 45S rDNA as probe, and were named GISH-NOR. One of them was super-major, which accounted for the fact that about one-half of its chromosome at metaphase was located at chromosome 3, and other two were minor and located at chromosomes 5 and 9, respectively. All GISH-NORs were located in A sub-genome chromosomes, separate from the other four allopolyploid cotton species. GISH-NOR were detected with D genome species as probe, but not A. The greatly abnormal sizes and sites of (AD)4 NORs or GISH-NORs indicate a possible mechanism for 45S rDNA diversification following (AD)4 speciation. Comparisons of GISH intensities and GISH-NOR production with gDNA probes between A and D genomes show that the better relationship of (AD)4 is with A genome. The shortest two chromosomes of A sub-genome of G. mustelinum were shorter than the longest chromosome of D sub-genome chromosomes. Therefore, the longest 13 chromosomes of tetraploid cotton being classified as A sub-genome, while the shorter 13 chromosomes being classified as D sub-genome in traditional cytogenetic and karyotype analyses may not be entirely correct. Wu Q, Liu F, Li S, Song G, Wang C, Zhang X, Wang Y, Stelly D, Wang K (2013) Uniqueness of the Gossypium mustelinum genome revealed by GISH and 45S rDNA FISH. J. Integr. Plant Biol. 55(7), 654–662. PMID:23758934

  16. Virus-Induced Gene Silencing in Cultivated Cotton (Gossypium spp.) Using Tobacco Rattle Virus.

    PubMed

    Mustafa, Roma; Shafiq, Muhammad; Mansoor, Shahid; Briddon, Rob W; Scheffler, Brian E; Scheffler, Jodi; Amin, Imran

    2016-01-01

    The study described here has optimized the conditions for virus-induced gene silencing (VIGS) in three cultivated cotton species (Gossypium hirsutum, G. arboreum, and G. herbaceum) using a Tobacco rattle virus (TRV) vector. The system was used to silence the homolog of the Arabidopsis thaliana chloroplastos alterados 1 (AtCLA1) gene, involved in chloroplast development, in G. herbaceum, G. arboreum, and six commercial G. hirsutum cultivars. All plants inoculated with the TRV vector to silence CLA1 developed a typical albino phenotype indicative of silencing this gene. Although silencing in G. herbaceum and G. arboreum was complete, silencing efficiency differed for each G. hirsutum cultivar. Reverse transcriptase polymerase chain reaction (PCR) and real-time quantitative PCR showed a reduction in mRNA levels of the CLA1 homolog in all three species, with the highest efficiency (lowest CLA1 mRNA levels) in G. arboreum followed by G. herbaceum and G. hirsutum. The results indicate that TRV is a useful vector for VIGS in Gossypium species. However, selection of host cultivar is important. With the genome sequences of several cotton species recently becoming publicly available, this system has the potential to provide a very powerful tool for the rapid, large-scale reverse-genetic analysis of genes in Gossypium spp.

  17. Characterization of the global transcriptome for cotton (Gossypium hirsutum L.) anther and development of SSR marker.

    PubMed

    Zhang, Xianwen; Ye, Zhenwei; Wang, Tiankang; Xiong, Hairong; Yuan, Xiaoling; Zhang, Zhigang; Yuan, Youlu; Liu, Zhi

    2014-11-10

    Cotton is an important fiber plant, and it's attractive to elucidate the molecular mechanism of anther development due to the close relationship between the anther fertility and boll-setting, and also fiber yield. In the present paper, 47.2 million paired-end reads with average length of 82.87 bp from the anthers of TM-1 (Gossypium hirsutum L.), a genetic standard line, were generated through transcriptome sequencing, and 210,965 unigenes of more than 100 bp were obtained. BLAST, KEGG, COG, and GO analyses showed that the genes were enriched in the processes of transcription, translation, and post-translation as well as hormone signal transduction, the transcription factor families, and cell wall-related genes mainly participating in cell expansion and carbohydrate metabolism. Further analysis identified 11,153 potential SSRs. A suit of 5122 primer pair sequences were designed, and 82 of 300 randomly selected primer pairs produced reproducible amplicons that were polymorphic among 22 cotton accessions from G. hirsutum, Gossypium barbadense and Gossypium arboreum. The UPGMA clustering analysis further confirmed high quality and effectiveness of these novel SSR markers. The present study provided insights into the transcriptome profile of the cotton and established a public information platform for functional genomics and molecular breeding.

  18. Duplicate gene expression in allopolyploid Gossypium reveals two temporally distinct phases of expression evolution

    PubMed Central

    Flagel, Lex; Udall, Joshua; Nettleton, Dan; Wendel, Jonathan

    2008-01-01

    Background Polyploidy has played a prominent role in shaping the genomic architecture of the angiosperms. Through allopolyploidization, several modern Gossypium (cotton) species contain two divergent, although largely redundant genomes. Owing to this redundancy, these genomes can play host to an array of evolutionary processes that act on duplicate genes. Results We compared homoeolog (genes duplicated by polyploidy) contributions to the transcriptome of a natural allopolyploid and a synthetic interspecific F1 hybrid, both derived from a merger between diploid species from the Gossypium A-genome and D-genome groups. Relative levels of A- and D-genome contributions to the petal transcriptome were determined for 1,383 gene pairs. This comparison permitted partitioning of homoeolog expression biases into those arising from genomic merger and those resulting from polyploidy. Within allopolyploid Gossypium, approximately 24% of the genes with biased (unequal contributions from the two homoeologous copies) expression patterns are inferred to have arisen as a consequence of genomic merger, indicating that a substantial fraction of homoeolog expression biases occur instantaneously with hybridization. The remaining 76% of biased homoeologs reflect long-term evolutionary forces, such as duplicate gene neofunctionalization and subfunctionalization. Finally, we observed a greater number of genes biased toward the paternal D-genome and that expression biases have tended to increases during allopolyploid evolution. Conclusion Our results indicate that allopolyploidization entails significant homoeolog expression modulation, both immediately as a consequence of genomic merger, and secondarily as a result of long-term evolutionary transformations in duplicate gene expression. PMID:18416842

  19. Effects of partial defoliation on carbon and nitrogen partitioning and photosynthetic carbon uptake by two-year-old cork oak (Quercus suber) saplings.

    PubMed

    Cerasoli, S; Scartazza, A; Brugnoli, E; Chaves, M M; Pereira, J S

    2004-01-01

    At the end of the growing season in late July, 20-month-old cork oak (Quercus suber L.) saplings were partially defoliated (63% of leaf area) to evaluate their ability to recover leaf area after defoliation. At 18 and 127 days after defoliation, changes in starch and nitrogen pools were determined in leaves and perennial organs, and variations in photosynthetic carbon uptake were investigated. To determine the role of stored nitrogen in regrowth after defoliation, plant nitrogen was labeled in the previous winter by enriching the nutrient solution with 15N. Plants recovered the lost leaf area in 127 days. Although there was remobilization of starch and nitrogen from leaves and perennial organs, the availability of resources for growth in the following spring was not decreased by defoliation. On the contrary, starch concentration in coarse roots was higher in defoliated saplings than in control saplings, presumably as a result of the higher net CO2 exchange rate in newly developed leaves compared with pre-existing leaves.

  20. Effects of insecticide treatments on subsequent defoliation by western spruce budworm in Oregon and Washington: 1982-92. Forest Service general technical report

    SciTech Connect

    Sheehan, K.A.

    1996-03-01

    Effects of insecticide treatments conducted in Oregon and Washington from 1982 through 1992 on subsequent defoliation by western spruce budworm (Choristoneura occidentalis Freeman) were evaluated by using aerial sketchmaps and a geographic information system. For each treatment, the extent and severity of defoliation was calculated for the treated areas and a set of four nested rings surrounding the treated area (0-0.5 mile, 0.5.1 mile, 1-2 miles) for up to 8 years: 3 years prior to treatment, the year of treatment, and 4 years following treatment, insecticide treatments applied in 1982 and 1983 coincided with reduced percentages of defoliation by western spruce budworm during the year following treatment. However, the percentage of defoliation usually returned to pretreatment levels by the second year, and defoliation severity in treated and adjacent untreated areas was nearly identical following treatment. For the period from 1985 through 1992, defoliation patterns (including both extent and severity) following treatment were generally similar in treated and adjacent untreated areas.

  1. Ecotypic variation in growth responses to simulated herbivory: trade-off between maximum relative growth rate and tolerance to defoliation in an annual plant

    PubMed Central

    Camargo, Iván D.; Tapia-López, Rosalinda; Núñez-Farfán, Juan

    2015-01-01

    It has been hypothesized that slow-growing plants are more likely to maximize above-ground biomass and fitness when defoliated by herbivores than those with an already high relative growth rate (RGR). Some populations of the annual herb Datura stramonium L. can tolerate foliar damage better than others. The physiological basis of this difference is examined here in a comparative study of two ecotypes that differ in tolerance and maximum growth rate, using a growth analytical approach. One hundred and fifty-four plants of each ecotype grown under controlled conditions were suddenly defoliated (35 % of total leaf area removed) and a similar sample size of plants remained undefoliated (control). Ontogenetic plastic changes in RGR and its growth components [net assimilation rate (NAR), specific leaf area and leaf weight ratio (LWR)] after defoliation were measured to determine whether these plastic changes maximize plant growth and fitness. Different ontogenetic phases of the response were discerned and increased RGR of defoliated plants was detected at the end of the experimental period, but brought about by a different growth component (NAR or LWR) in each ecotype. These changes in RGR are putatively related to increases in fitness in defoliated environments. At the intra-specific scale, data showed a trade-off between the ability to grow under benign environmental conditions and the ability to tolerate resource limitation due to defoliation. PMID:25725085

  2. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum.

    PubMed

    Xin, Shan; Tao, Chengcheng; Li, Hongbin

    2016-01-01

    Apoplastic ascorbate oxidase (AO) plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1) gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana) showed that the GhAO1 promoter exhibited high activity, driving strong reporter gene expression in tobacco trichomes, leaves and roots. Promoter 5'-deletion analysis demonstrated that truncated GhAO1 promoters with serial 5'-end deletions had different GUS activities. A 360-bp fragment was sufficient to activate GUS expression. The P-1040 region had less GUS activity than the P-720 region, suggesting that the 320-bp region from nucleotide -720 to -1040 might include a cis-element acting as a silencer. Interestingly, an auxin-responsive cis-acting element (TGA-element) was uncovered in the promoter. To analyze the function of the TGA-element, tobacco leaves transformed with promoters with different 5' truncations were treated with indole-3-acetic acid (IAA). Tobacco leaves transformed with the promoter regions containing the TGA-element showed significantly increased GUS activity after IAA treatment, implying that the fragment spanning nucleotides -1760 to -1600 (which includes the TGA-element) might be a key component for IAA responsiveness. Analyses of the AO promoter region and AO expression pattern in Gossypium arboreum (Ga, diploid cotton with an AA genome), Gossypium raimondii (Gr, diploid cotton with a DD genome) and Gossypium hirsutum (Gh, tetraploid cotton with an AADD genome) indicated that AO promoter activation and AO transcription were detected together only in D genome/sub-genome (Gr and Gh) cotton. Taken together, these results suggest that the 1,920-bp GhAO1 promoter is a functional sequence with a

  3. Forest defoliator outbreaks under climate change: effects on the frequency and severity of outbreaks of five pine insect pests.

    PubMed

    Haynes, Kyle J; Allstadt, Andrew J; Klimetzek, Dietrich

    2014-06-01

    To identify general patterns in the effects of climate change on the outbreak dynamics of forest-defoliating insect species, we examined a 212-year record (1800-2011) of outbreaks of five pine-defoliating species (Bupalus piniarius, Panolis flammea, Lymantria monacha, Dendrolimus pini, and Diprion pini) in Bavaria, Germany for the evidence of climate-driven changes in the severity, cyclicity, and frequency of outbreaks. We also accounted for historical changes in forestry practices and examined effects of past insecticide use to suppress outbreaks. Analysis of relationships between severity or occurrence of outbreaks and detrended measures of temperature and precipitation revealed a mixture of positive and negative relationships between temperature and outbreak activity. Two moth species (P. flammea and Dendrolimus pini) exhibited lower outbreak activity following years or decades of unusually warm temperatures, whereas a sawfly (Diprion pini), for which voltinism is influenced by temperature, displayed increased outbreak occurrence in years of high summer temperatures. We detected only one apparent effect of precipitation, which showed Dendrolimus pini outbreaks tending to follow drought. Wavelet analysis of outbreak time series suggested climate change may be associated with collapse of L. monacha and Dendrolimus pini outbreak cycles (loss of cyclicity and discontinuation of outbreaks, respectively), but high-frequency cycles for B. piniarius and P. flammea in the late 1900s. Regional outbreak severity was generally not related to past suppression efforts (area treated with insecticides). Recent shifts in forestry practices affecting tree species composition roughly coincided with high-frequency outbreak cycles in B. piniarius and P. flammea but are unlikely to explain the detected relationships between climate and outbreak severity or collapses of outbreak cycles. Our results highlight both individualistic responses of different pine-defoliating species to

  4. Differences in plastic responses to defoliation due to variation in the timing of treatments for two species of Sesbania (Fabaceae).

    PubMed

    Marshall, Diane L; Abrahamson, Nathan J; Avritt, Joy J; Hall, Paula M; Medeiros, Juliana S; Reynolds, Jerusha; Shaner, Marieken G M; Simpson, Healther L; Trafton, Alea N; Tyler, Anna P; Walsh, Sharon

    2005-05-01

    Plastic responses to stress in components of reproduction can have important effects on plant fitness and can vary both within and between species. Responses may also depend on when in the life cycle stress occurs. Here, it is predicted that the timing of initiation of a stress, defoliation, would affect the pattern of plastic responses. These differences should occur because some components of reproduction, such as flower number, are determined earlier in a plant's life than others, such as individual seed mass. To test this prediction, 50 % artificial defoliation treatments were initiated at four different times for Sesbania macrocarpa and S. vesicaria. Responses were measured in plant size, number of flowers, number of flowers/plant size, fruit set, number of seeds per fruit, individual seed mass and total seed mass per plant. For S. vesicaria, changes in the timing of stress changed the severity, but not the pattern of response. For S. macrocarpa, plastic responses to defoliation varied strikingly between early and late treatments. Late treatments resulted in over-compensation in this species. Sesbania macrocarpa was generally more plastic than S. vesicaria and the species showed opposite responses for most components of reproduction. While there were effects of timing of defoliation and differences between species, the nature of these effects did not precisely fit our predictions. Our results suggest that differences in the length and flexibility of the life cycles of the two species allowed for unexpected variation in responses. For example, because flower production continued after the last treatment in S. vesicaria, responses were not constrained to reductions in individual seed mass.

  5. ccNET: Database of co-expression networks with functional modules for diploid and polyploid Gossypium

    PubMed Central

    You, Qi; Xu, Wenying; Zhang, Kang; Zhang, Liwei; Yi, Xin; Yao, Dongxia; Wang, Chunchao; Zhang, Xueyan; Zhao, Xinhua; Provart, Nicholas J.; Li, Fuguang; Su, Zhen

    2017-01-01

    Plant genera with both diploid and polyploid species are a common evolutionary occurrence. Polyploids, especially allopolyploids such as cotton and wheat, are a great model system for heterosis research. Here, we have integrated genome sequences and transcriptome data of Gossypium species to construct co-expression networks and identified functional modules from different cotton species, including 1155 and 1884 modules in G. arboreum and G. hirsutum, respectively. We overlayed the gene expression results onto the co-expression network. We further provided network comparison analysis for orthologous genes across the diploid and allotetraploid Gossypium. We also constructed miRNA-target networks and predicted PPI networks for both cotton species. Furthermore, we integrated in-house ChIP-seq data of histone modification (H3K4me3) together with cis-element analysis and gene sets enrichment analysis tools for studying possible gene regulatory mechanism in Gossypium species. Finally, we have constructed an online ccNET database (http://structuralbiology.cau.edu.cn/gossypium) for comparative gene functional analyses at a multi-dimensional network and epigenomic level across diploid and polyploid Gossypium species. The ccNET database will be beneficial for community to yield novel insights into gene/module functions during cotton development and stress response, and might be useful for studying conservation and diversity in other polyploid plants, such as T. aestivum and Brassica napus. PMID:28053168

  6. Remote sensing of tamarisk biomass, insect herbivory, and defoliation: Novel methods in the Grand Canyon Region, Arizona

    USGS Publications Warehouse

    Sankey, Temuulen Ts.; Sankey, Joel B.; Horne, Rene; Bedford, Ashton

    2016-01-01

    Tamarisk is an invasive, riparian shrub species in the southwestern USA. The northern tamarisk beetle (Diorhabda carinulata) has been introduced to several states to control tamarisk. We classified tamarisk distribution in the Glen Canyon National Recreation Area, Arizona using a 0.2 m resolution, airborne multispectral data and estimated tamarisk beetle effects (overall accuracy of 86 percent) leading to leaf defoliation in a 49,408 m2 area. We also estimated individual tamarisk tree biomass and their uncertainties using airbonre liday data (100 points/m2). On average, total above ground tamarisk biomass was 8.67 kg/m2 (SD=17.6). The tamarisk beetle defoliation resulted in a mean leaf biomass loss of 0.52 kg/m2 and an equivalent of 25,692 kg across the entire study area. Our defoliated tamarisk map and biomass estimates can help inform restoration treatments to reduce tamarisk. Continued monitoring of tamarisk and tamarisk beetle effects are recommended to understand the currently-unknown eventual equilibrium between the two species and the cascading effects on ecosystem processes.

  7. Predicted effects of gypsy moth defoliation and climate change on forest carbon dynamics in the New Jersey pine barrens.

    PubMed

    Kretchun, Alec M; Scheller, Robert M; Lucash, Melissa S; Clark, Kenneth L; Hom, John; Van Tuyl, Steve

    2014-01-01

    Disturbance regimes within temperate forests can significantly impact carbon cycling. Additionally, projected climate change in combination with multiple, interacting disturbance effects may disrupt the capacity of forests to act as carbon sinks at large spatial and temporal scales. We used a spatially explicit forest succession and disturbance model, LANDIS-II, to model the effects of climate change, gypsy moth (Lymantria dispar L.) defoliation, and wildfire on the C dynamics of the forests of the New Jersey Pine Barrens over the next century. Climate scenarios were simulated using current climate conditions (baseline), as well as a high emissions scenario (HadCM3 A2 emissions scenario). Our results suggest that long-term changes in C cycling will be driven more by climate change than by fire or gypsy moths over the next century. We also found that simulated disturbances will affect species composition more than tree growth or C sequestration rates at the landscape level. Projected changes in tree species biomass indicate a potential increase in oaks with climate change and gypsy moth defoliation over the course of the 100-year simulation, exacerbating current successional trends towards increased oak abundance. Our research suggests that defoliation under climate change may play a critical role in increasing the variability of tree growth rates and in determining landscape species composition over the next 100 years.

  8. Predicted Effects of Gypsy Moth Defoliation and Climate Change on Forest Carbon Dynamics in the New Jersey Pine Barrens

    PubMed Central

    Kretchun, Alec M.; Scheller, Robert M.; Lucash, Melissa S.; Clark, Kenneth L.; Hom, John; Van Tuyl, Steve

    2014-01-01

    Disturbance regimes within temperate forests can significantly impact carbon cycling. Additionally, projected climate change in combination with multiple, interacting disturbance effects may disrupt the capacity of forests to act as carbon sinks at large spatial and temporal scales. We used a spatially explicit forest succession and disturbance model, LANDIS-II, to model the effects of climate change, gypsy moth (Lymantria dispar L.) defoliation, and wildfire on the C dynamics of the forests of the New Jersey Pine Barrens over the next century. Climate scenarios were simulated using current climate conditions (baseline), as well as a high emissions scenario (HadCM3 A2 emissions scenario). Our results suggest that long-term changes in C cycling will be driven more by climate change than by fire or gypsy moths over the next century. We also found that simulated disturbances will affect species composition more than tree growth or C sequestration rates at the landscape level. Projected changes in tree species biomass indicate a potential increase in oaks with climate change and gypsy moth defoliation over the course of the 100-year simulation, exacerbating current successional trends towards increased oak abundance. Our research suggests that defoliation under climate change may play a critical role in increasing the variability of tree growth rates and in determining landscape species composition over the next 100 years. PMID:25119162

  9. Remote sensing of spruce budworm defoliation using EO-1 Hyperion hyperspectral data: an example in Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Zhang, Y.

    2016-04-01

    Each year, the spruce budworm (SBW) causes severe, widespread damage to spruces and fir in east coast Canada. Early estimation of the defoliation can provide crucial support to mitigate the socio-economic impact on vulnerable forests. Remote sensing techniques are suitable to investigate the affected regions that usually consist of large and inaccessible forestry areas. Using satellite images, surface reflectance values at two or more wavelengths are combined to generate vegetation indices (VIs), revealing a relative abundance of features of interest. Forest health analysis based on VIs is considered as one of the primary information sources for monitoring vegetation conditions. Especially the spectral resolution of Hyperion hyperspectral satellite imagery used in this study allows for a detailed examination of the red to near-infrared portion of the spectrum to identify areas of stressed vegetation. Several narrow-band vegetation indices are used to indicate the overall amount and quality of photosynthetic material and moisture content in vegetation. By integrating the information from VIs that focus on different aspects of overall health and vigour in forested areas, the study aims at detecting defoliated condition in a forested region in the Province of Quebec, Canada. In June and August of 2014 two Hyperion images were acquired by NASA's EO-1 satellite for this study. Changes in vegetation health and vigour are observed and quantitatively compared using the multi-temporal remote sensing images. The experimental results suggest that the VI- based forest health analysis is effective in estimating SBW defoliation in the study area.

  10. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea)

    PubMed Central

    Case, Ashley E.; Mayfield, Albert E.; Clark, Stacy L.; Schlarbaum, Scott E.; Reynolds, Barbara C.

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests. PMID:27001964

  11. Remote Sensing of Tamarisk Biomass, Insect Herbivory, and Defoliation: Novel Lidar and Multispectral Methods in the Grand Canyon Region, Arizona

    NASA Astrophysics Data System (ADS)

    Sankey, T.; Sankey, J. B.; Horne, R.; Bedford, A.; Cagney, L.

    2016-12-01

    Tamarisk is an invasive, riparian shrub species that has dramatically altered riparian forests throughout the western USA. The northern tamarisk beetle (Diorhabda carinulata) has been introduced to several states to control tamarisk. Here we used the fusion of very high resolution, airborne lidar and multispectral data to classify tamarisk distribution along the Colorado River in the Grand Canyon Region, Arizona and estimated tamarisk beetle effects (overall accuracy of 86 percent) leading to leaf defoliation in a 49,408 m2 area. We also estimated individual tamarisk tree biomass and their uncertainties. On average, total aboveground tamarisk biomass was 8.68 kg/m2 (SD = 17.6). The tamarisk beetle defoliation resulted in a mean leaf biomass loss of 0.52 kg/m2 and an equivalent input of 25,692 kg of leaf litter and > 300 kg of N to the riparian floodplain. Our defoliated tamarisk map and biomass estimates can help inform restoration treatments to reduce tamarisk. Continued monitoring of tamarisk and tamarisk beetle effects with our lidar and multispectral methods are recommended to understand the currently-unknown eventual equilibrium between the two species and the cascading effects on ecosystem processes.

  12. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea).

    PubMed

    Case, Ashley E; Mayfield, Albert E; Clark, Stacy L; Schlarbaum, Scott E; Reynolds, Barbara C

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests.

  13. Nitrate Variability in Hydrological Flowpaths for a Mid-Appalachian Forested Catchment Following a Large-Scale Defoliation

    NASA Astrophysics Data System (ADS)

    Riscassi, A. L.; Scanlon, T. M.

    2007-12-01

    Nitrogen (N) leakage from forested watersheds due to disturbance is a well-documented, but not well understood process that contributes to the degradation of receiving waters through eutrophication. Several studies have shown that large scale defoliation events in small forested watersheds in the Eastern U.S. cause immediate and dramatic increases in N flux to streams. Recovery times can differ dramatically depending upon location. Reasons for these differences are not well understood, however, because N transport and transformation processes are difficult to track over these long recovery timescales. This research focuses on a large-scale gypsy moth defoliation event that impacted Shenandoah National Park (SNP) in the late 1980s to early 1990s. Water chemistry and discharge have been monitored at a number of catchments within SNP over the timeframe since the defoliation. Recovery of these systems to pre-defoliation N levels has been observed to be unusually slow, lasting over a decade. Availability of high-frequency (i.e. hourly) stream chemistry and discharge data during storm events throughout the period of recovery allows us to investigate short- and long-term mechanisms for N "leaks" from forested watersheds. Through geochemical hydrograph separation techniques, we can determine how nitrate concentrations vary between event, soil, and groundwater during and in the years following a disturbance. Analyses focus on Paine Run, a 12.4 km2 catchment where over 50 storms have been characterized since the 1990-1992 defoliation. Standard geochemical hydrograph separation is performed using conservative tracers to determine the relative flow contributions from the three flow components for each measurement time step. Computed discharge components, along with measured steam nitrate concentrations (NO3 -) at each time-step, were used to solve for the relative concentration of NO3 - in each of the hydrologic zones for storms by solving the over-determined set of mixing

  14. Tamarisk Water Flux Patterns Before, During and After Episodic Defoliation by the Salt Cedar Leaf Beetle on the Colorado Plateau, USA

    NASA Astrophysics Data System (ADS)

    Hultine, K. R.; Nagler, P. L.; Dennison, P. E.

    2008-12-01

    Tamarisk (Tamarix) species are among the most successful plant invaders in the western United States, and has had significant impacts on watershed hydrology and water resources. Accordingly, local, state and federal agencies have undertaken considerable efforts to eradicate tamarisk and restore riparian habitats to pre-invasion status. A biological control - the saltcedar leaf beetle (Diorhabda elongata) - was released in the summer of 2004 at several locations in eastern Utah, USA to control the spread and impact of tamarisk within the Colorado River watershed. Beginning in April of 2008, sap flux techniques were used to monitor changes in transpiration fluxes in response to canopy defoliation by the beetle. Specifically we installed modified (10 mm length) heat dissipation probes into the main stem of 20 mature tamarisk trees within a single stand on the Colorado Plateau. In July, the saltcedar leaf beetle reduced the total leaf area to near 0% of pre-beetle invasion status. Consequently, sap flux declined by up to 80% compared to pre-beetle invasion fluxes. By mid-August, refoliation of the canopy occurred, and sap flux rates returned to pre- defoliation status. Sap flux rates prior to defoliation were modeled against atmospheric vapor pressure deficit in order to predict the amount of water salvage from defoliation. Sap flux from June 1 through September 1 was on average 36% lower than predicted values. Combined with scaling techniques, the heat dissipation approach shows a high potential for monitoring changes in watershed hydrology in response to tamarisk defoliation by the saltcedar leaf beetle. Nevertheless, tamarisk sap flux studies with heat dissipation probes presents several challenges, including, narrow sapwood depth, low flux rates in response to defoliation, and large thermal gradients that are inevitable in warm climates (particularly after defoliation removes canopy shading). We will present results from ongoing research to address these potential

  15. Molecular data and phylogeny of Nosema infecting lepidopteran forest defoliators in the genera Choristoneura and Malacosoma.

    PubMed

    Kyei-Poku, George; Gauthier, Debbie; van Frankenhuyzen, Kees

    2008-01-01

    Nosema isolates from five lepidopteran forest defoliators, Nosema fumiferanae from spruce budworm, Choristoneura fumiferana; a Nosema sp. from jack pine budworm, Choristoneura pinus pinus and western spruce budworm, Choristoneura occidentalis (Nosema sp. CPP and Nosema sp. CO, respectively); Nosema thomsoni from large aspen tortrix, Choristoneura conflictana; and Nosema disstriae, from the forest tent caterpillar, Malacosoma disstria were compared based on their small subunit (SSU) ribosomal RNA (rRNA) gene sequences. Four of the species sequenced, N. fumiferanae, Nosema sp. CPP, Nosema sp. CO, and N. disstriae have a high SSU rDNA sequence identity (0.6%-1.5%) and are members of the "true Nosema" clade. They all showed the reverse arrangement of the (large subunit [LSU]-internal transcribed spacer [ITS]-SSU) of the rRNA gene. The fifth species, N. thomsoni has the usual (SSU-ITS-LSU) arrangement and is not a member of this clade showing only an 82% sequence similarity. We speculate, therefore, that a genetic reversal may have occurred in the common ancestor to the "true Nosema" clade. Although, the mechanism for rearrangement of the rRNA gene subunits is not known we provide a possible explanation for the localization. N. fumiferanae, Nosema sp. CPP, and Nosema sp. CO clustered together on the inferred phylogenetic tree. The high sequence similarities, the reverse arrangement in the rRNA gene subunits, and the phylogenetic clustering suggest that these three species are closely related but separate species.

  16. Framework for video-based monitoring of forest insect defoliation and discoloration

    NASA Astrophysics Data System (ADS)

    Zhao, Feifei; Wang, Yafei; Qiao, Yanyou

    2015-01-01

    Pest damage is a general problem that disturbs the growth of forests, influencing carbon sequestration and causing economic losses. In the past decades, many studies have been conducted to monitor and detect forest insect damage using satellite remote sensing technology. Satellite remote sensing has a satellite or aerial vision allowing the monitoring of extensive forest areas, but it usually requires constant time periods and is prone to cloud interference. To enable more efficient and effective monitoring of forest pest damage, a video-based monitoring framework is presented. This framework comprises three key parts: (1) video positioning of forest insect damage based on digital elevation model (DEM) and the parameters obtained from the pan-tilt-zoom camera, (2) integration of two-dimensional/three-dimensional geographic information system and video surveillance to provide more intuitionistic monitoring and assistance for positioning, (3) on-site verification conducted by ground surveys and guided through global positioning system (GPS) integrated in the embedded devices. The experiment was carried out over two forest areas to validate the proposed method. Results showed that the framework bears a sound positioning accuracy and high detection ratio, which could be effectively used in detecting and monitoring forest insect defoliation and discoloration.

  17. Hybridization of an invasive shrub affects tolerance and resistance to defoliation by a biological control agent

    USGS Publications Warehouse

    Williams, Wyatt I.; Friedman, Jonathan M.; Gaskin, John F.; Norton, Andrew P.

    2014-01-01

    Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgression between two parent species of the invasive shrub tamarisk (Tamarix spp.) in the western United States, and how differences in plant traits affect interactions with a biological control agent. Introgression varied strongly with latitude of origin and was highly correlated with plant performance. Increased levels of T. ramosissima introgression resulted in both higher investment in roots and tolerance to defoliation and less resistance to insect attack. Because tamarisk hybridization occurs predictably on the western U.S. landscape, managers may be able to exploit this information to maximize control efforts. Genetic differentiation in plant traits in this system underpins the importance of plant hybridization and may explain why some biological control releases are more successful than others.

  18. Molecular characterization of the Gossypium Diversity Reference Set of the US National Cotton Germplasm Collection.

    PubMed

    Hinze, Lori L; Fang, David D; Gore, Michael A; Scheffler, Brian E; Yu, John Z; Frelichowski, James; Percy, Richard G

    2015-02-01

    A core marker set containing markers developed to be informative within a single commercial cotton species can elucidate diversity structure within a multi-species subset of the Gossypium germplasm collection. An understanding of the genetic diversity of cotton (Gossypium spp.) as represented in the US National Cotton Germplasm Collection is essential to develop strategies for collecting, conserving, and utilizing these germplasm resources. The US collection is one of the largest world collections and includes not only accessions with improved yield and fiber quality within cultivated species, but also accessions possessing sources of abiotic and biotic stress resistance often found in wild species. We evaluated the genetic diversity of a subset of 272 diploid and 1,984 tetraploid accessions in the collection (designated the Gossypium Diversity Reference Set) using a core set of 105 microsatellite markers. Utility of the core set of markers in differentiating intra-genome variation was much greater in commercial tetraploid genomes (99.7 % polymorphic bands) than in wild diploid genomes (72.7 % polymorphic bands), and may have been influenced by pre-selection of markers for effectiveness in the commercial species. Principal coordinate analyses revealed that the marker set differentiated interspecific variation among tetraploid species, but was only capable of partially differentiating among species and genomes of the wild diploids. Putative species-specific marker bands in G. hirsutum (73) and G. barbadense (81) were identified that could be used for qualitative identification of misclassifications, redundancies, and introgression within commercial tetraploid species. The results of this broad-scale molecular characterization are essential to the management and conservation of the collection and provide insight and guidance in the use of the collection by the cotton research community in their cotton improvement efforts.

  19. Molecular characterization of a transcriptionally active Ty1/copia-like retrotransposon in Gossypium.

    PubMed

    Cao, Yuefen; Jiang, Yurong; Ding, Mingquan; He, Shae; Zhang, Hua; Lin, Lifeng; Rong, Junkang

    2015-06-01

    A transcriptionally active Ty1/copia -like retrotransposon was identified in the genome of Gossypium barbadense. The different heat activation of this element was observed in two tetraploid cotton species. Most retrotransposons from plants are transcriptionally silent, or activated under certain conditions. Only a small portion of elements are transcriptionally active under regular condition. A long terminal repeat (LTR) retrotransposon was isolated from the cultivated Sea Island cotton (H7124) genome during the investigation of the function of a homeodomain leucine zipper gene (HD1) in trichome growth. Insertion of this element in HD1 gene of At sub-genome was related to the trichomeless stem in Gossypium barbadense. The element, named as GBRE-1, had all features of a typical Ty1/copia retrotransposon and possessed high similarity to the members of ONSEN retrotransposon family. It was 4997 bp long, comprising a single 4110 bp open reading frame, which encoded 1369 amino acids including the conserved domains of gag and pol. The expression of GBRE-1 was detected under regular condition in G. barbadense and G. hirsutum, and its expression level was increased under heat-stress condition in G. hirsutum. Besides, its expression pattern was similar to that of the ONSEN retrotransposon. Abundant cis-regulatory motifs related to stress-response and transcriptional regulation were found in the LTR sequence. These results suggested that GBRE-1 was a transcriptionally active retrotransposon in Gossypium. To our knowledge, this is the first report of the isolation of a complete Ty1/copia-type retrotransposon with present-day transcriptional activity in cotton.

  20. Mapping quantitative trait loci for lint yield and fiber quality across environments in a Gossypium hirsutum × Gossypium barbadense backcross inbred line population.

    PubMed

    Yu, Jiwen; Zhang, Ke; Li, Shuaiyang; Yu, Shuxun; Zhai, Honghong; Wu, Man; Li, Xingli; Fan, Shuli; Song, Meizhen; Yang, Daigang; Li, Yunhai; Zhang, Jinfa

    2013-01-01

    Identification of stable quantitative trait loci (QTLs) across different environments and mapping populations is a prerequisite for marker-assisted selection (MAS) for cotton yield and fiber quality. To construct a genetic linkage map and to identify QTLs for fiber quality and yield traits, a backcross inbred line (BIL) population of 146 lines was developed from a cross between Upland cotton (Gossypium hirsutum) and Egyptian cotton (Gossypium barbadense) through two generations of backcrossing using Upland cotton as the recurrent parent followed by four generations of self pollination. The BIL population together with its two parents was tested in five environments representing three major cotton production regions in China. The genetic map spanned a total genetic distance of 2,895 cM and contained 392 polymorphic SSR loci with an average genetic distance of 7.4 cM per marker. A total of 67 QTLs including 28 for fiber quality and 39 for yield and its components were detected on 23 chromosomes, each of which explained 6.65-25.27% of the phenotypic variation. Twenty-nine QTLs were located on the At subgenome originated from a cultivated diploid cotton, while 38 were on the Dt subgenome from an ancestor that does not produce spinnable fibers. Of the eight common QTLs (12%) detected in more than two environments, two were for fiber quality traits including one for fiber strength and one for uniformity, and six for yield and its components including three for lint yield, one for seedcotton yield, one for lint percentage and one for boll weight. QTL clusters for the same traits or different traits were also identified. This research represents one of the first reports using a permanent advanced backcross inbred population of an interspecific hybrid population to identify QTLs for fiber quality and yield traits in cotton across diverse environments. It provides useful information for transferring desirable genes from G. barbadense to G. hirsutum using MAS.

  1. Potential of VIIRS Time Series Data for Aiding the USDA Forest Service Early Warning System for Forest Health Threats: A Gypsy Moth Defoliation Case Study

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.; Ryan, Robert E.; Smoot, James; Kuper, Phillip; Prados, Donald; Russell, Jeffrey; Ross, Kenton; Gasser, Gerald; Sader, Steven; McKellip, Rodney

    2007-01-01

    This report details one of three experiments performed during FY 2007 for the NASA RPC (Rapid Prototyping Capability) at Stennis Space Center. This RPC experiment assesses the potential of VIIRS (Visible/Infrared Imager/Radiometer Suite) and MODIS (Moderate Resolution Imaging Spectroradiometer) data for detecting and monitoring forest defoliation from the non-native Eurasian gypsy moth (Lymantria dispar). The intent of the RPC experiment was to assess the degree to which VIIRS data can provide forest disturbance monitoring information as an input to a forest threat EWS (Early Warning System) as compared to the level of information that can be obtained from MODIS data. The USDA Forest Service (USFS) plans to use MODIS products for generating broad-scaled, regional monitoring products as input to an EWS for forest health threat assessment. NASA SSC is helping the USFS to evaluate and integrate currently available satellite remote sensing technologies and data products for the EWS, including the use of MODIS products for regional monitoring of forest disturbance. Gypsy moth defoliation of the mid-Appalachian highland region was selected as a case study. Gypsy moth is one of eight major forest insect threats listed in the Healthy Forest Restoration Act (HFRA) of 2003; the gypsy moth threatens eastern U.S. hardwood forests, which are also a concern highlighted in the HFRA of 2003. This region was selected for the project because extensive gypsy moth defoliation occurred there over multiple years during the MODIS operational period. This RPC experiment is relevant to several nationally important mapping applications, including agricultural efficiency, coastal management, ecological forecasting, disaster management, and carbon management. In this experiment, MODIS data and VIIRS data simulated from MODIS were assessed for their ability to contribute broad, regional geospatial information on gypsy moth defoliation. Landsat and ASTER (Advanced Spaceborne Thermal Emission

  2. Genome-wide comparative analysis of NBS-encoding genes in four Gossypium species.

    PubMed

    Xiang, Liuxin; Liu, Jinggao; Wu, Chaofeng; Deng, Yushan; Cai, Chaowei; Zhang, Xiao; Cai, Yingfan

    2017-04-12

    Nucleotide binding site (NBS) genes encode a large family of disease resistance (R) proteins in plants. The availability of genomic data of the two diploid cotton species, Gossypium arboreum and Gossypium raimondii, and the two allotetraploid cotton species, Gossypium hirsutum (TM-1) and Gossypium barbadense allow for a more comprehensive and systematic comparative study of NBS-encoding genes to elucidate the mechanisms of cotton disease resistance. Based on the genome assembly data, 246, 365, 588 and 682 NBS-encoding genes were identified in G. arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively. The distribution of NBS-encoding genes among the chromosomes was nonrandom and uneven, and was tended to form clusters. Gene structure analysis showed that G. arboreum and G. hirsutum possessed a greater proportion of CN, CNL, and N genes and a lower proportion of NL, TN and TNL genes compared to that of G. raimondii and G. barbadense, while the percentages of RN and RNL genes remained relatively unchanged. The percentage changes among them were largest for TNL genes, about 7 times. Exon statistics showed that the average exon numbers per NBS gene in G. raimondii and G. barbadense were all greater than that in G. arboretum and G. hirsutum. Phylogenetic analysis revealed that the TIR-NBS genes of G. barbadense were closely related with that of G. raimondii. Sequence similarity analysis showed that diploid cotton G. arboreum possessed a larger proportion of NBS-encoding genes similar to that of allotetraploid cotton G. hirsutum, while diploid G. raimondii possessed a larger proportion of NBS-encoding genes similar to that of allotetraploid cotton G. barbadense. The synteny analysis showed that more NBS genes in G. raimondii and G. arboreum were syntenic with that in G. barbadense and G. hirsutum, respectively. The structural architectures, amino acid sequence similarities and synteny of NBS-encoding genes between G. arboreum and G. hirsutum, and between G

  3. Analysis of xyloglucan endotransglycosylase/hydrolase (XTH) genes from allotetraploid (Gossypium hirsutum) cotton and its diploid progenitors expressed during fiber elongation.

    PubMed

    Michailidis, Georgios; Argiriou, Anagnostis; Darzentas, Nikos; Tsaftaris, Athanasios

    2009-03-01

    Multiple cellular pathways have been shown to be involved during fiber initiation and elongation stages in the cultivated allotetraploid cotton (Gossypium hirsutum). The cell wall enzymes xyloglucan endotransglycosylase/hydrolases (XTH) have been reported to be associated with the biosynthesis of the cell wall and the growth of cotton fibers, probably regulating the plasticity of the primary cell wall. Among various cotton fiber cDNAs found to be preferentially expressed in cotton fibers, a xyloglucan endotransglycosylase (XTH) cDNA was significantly up-regulated during the elongation stage of cotton fiber development. In the present study, we isolated and characterized genomic clones encoding cotton XTH from cultivated cotton (Gossypium hirsutum) and its diploid progenitors (Gossypium arboreum and Gossypium raimondii), designated GhXTH1-1, GhXTH1-2, GaXTH1 and GrXTH, respectively. In addition, we isolated and characterized, by in silico methods, the putative promoter of XTH1 from Gossypium hirsutum. Sequence analysis revealed more than 50% homology to XTH's at the protein level. DNA gel blot hybridization indicated that at least two copies of GhXTH1 are present in Gossypium hirsutum whereas the diploid progenitor species Gossypium arboreum and Gossypium raimondii has only a single copy. Quantitative real-time PCR and high-resolution melting experiments indicated that in Gossypium hirsutum cultivars, in cotton fibers during early stages of fiber elongation specifically expressing only the GhXTH1-1 gene and expression levels of GhXTH1-1 in fibers varies among cultivars differing in fiber percentage and fiber length.

  4. Regulation of forest defoliating insects through small mammal predation: reconsidering the mechanisms.

    PubMed

    Kollberg, Ida; Bylund, Helena; Huitu, Otso; Björkman, Christer

    2014-12-01

    Population densities of forest defoliating insects may be regulated by small mammal predation on the pupae. When outbreaks do occur, they often coincide with warm, dry weather and at barren forest sites. A proposed reason for this is that weather and habitat affect small mammal population density (numerical response) and hence pupal predation. We propose an alternative explanation: weather and habitat affect small mammal feeding behaviour (functional response) and hence the outbreak risks of forest pest insects. We report results from laboratory and field-enclosure experiments estimating rates of pupal predation by bank voles (Myodes glareolus) on an outbreak insect, the European pine sawfly (Neodiprion sertifer), at different temperatures (15 and 20 °C), in different microhabitats (sheltered and non-sheltered), and with or without access to alternative food (sunflower seeds). We found that the probability of a single pupa being eaten at 20 °C was lower than at 15 °C (0.49 and 0.72, respectively). Pupal predation was higher in the sheltered microhabitat than in the open one, and the behaviour of the voles differed between microhabitats. More pupae were eaten in situ in the sheltered microhabitat whereas in the open area more pupae were removed and eaten elsewhere. Access to alternative food did not affect pupal predation. The results suggest that predation rates on pine sawfly pupae by voles are influenced by temperature- and habitat-induced variation in the physiology and behaviour of the predator, and not necessarily solely through effects on predator densities as previously proposed.

  5. Foraging behaviour of the exotic wasp Vespula germanica (Hymenoptera: Vespidae) on a native caterpillar defoliator.

    PubMed

    Pietrantuono, A L; Moreyra, S; Lozada, M

    2017-09-19

    Vespula germanica is a social wasp and an opportunistic predator. While foraging, these wasps learn and integrate different kinds of cues. They have successfully invaded many parts of the world, including native Nothofagus and Lophozonia forests located in the Andean-Patagonian region, where they forage on native arthropods. Perzelia arda, a lepidopteron defoliator of Lophozonia obliqua, uses the foliage to hide in and feed on. The purpose of this work is to study whether V. germanica use olfactory cues when foraging on P. arda. To do this, we used a Y-tube olfactometer and established three treatments to compare pairs of all combinations of stimuli (larvae, leaves with larval traces, and leaves without larval traces) and controls. Data were analysed via two developed models that showed decisions made by V. germanica and allowed to establish a scale of preferences between the stimuli. The analysis demonstrates that V. germanica wasps choose P. arda as larval prey and are capable of discriminating between the offered stimuli (deviance information criterion (DIC) null model = 873.97; DIC simple model = 84.5, n = 152). According to the preference scale, V. germanica preferred leaves with traces of larvae, suggesting its ability to associate these traces with the presence of the prey. This may be because, under natural conditions, larvae are never exposed outside their shelters of leaves and therefore V. germanica uses indirect signals. The presence of V. germanica foraging on P. arda highlights the flexible foraging behaviour of this wasp which may also act as a positive biological control, reducing lepidopteran populations.

  6. Three Centuries of Synchronous Forest Defoliator Outbreaks in Western North America

    PubMed Central

    Flower, Aquila

    2016-01-01

    Insect outbreaks often occur synchronously across large spatial scales, but the long-term temporal stability of the phenomenon and the mechanisms behind it are not well understood. In this study, I use a widespread lepidopteran defoliator native to western North America—the western spruce budworm—as a case study to explore patterns of and potential causes for synchronous population fluctuations. Analyses of synchrony are typically severely limited by the short historical records available for many species. To overcome this limitation, I compiled multi-century dendrochronological reconstructions of western spruce budworm outbreaks from across much of the species’ range. This allowed me to analyze synchrony at a sub-continental spatial scale over the last three centuries. I found statistically significant synchrony among regional outbreak records up to 2,000 km apart and identified numerous outbreak periods that occurred synchronously across much of the species’ range. I quantified spatial and temporal associations between climate and synchronous outbreak periods using paleoclimate reconstructions. The spatial patterns of outbreak histories and climate records were remarkably similar, with higher similarity in outbreak histories apparent between regions with more similar climate conditions. Synchronous outbreaks typically occurred during periods of average or above average moisture availability preceded by periods of low moisture availability. My results suggest that climatic variability has played a key role in synchronizing western spruce budworm population fluctuations in disjunct forests across western North America for at least the last three centuries. Widespread synchrony appears to be a natural part of this species’ population dynamics, though synchronous outbreaks have occurred more frequently during the 20th century than during prior centuries. This study uses a novel combination of statistical methods and dendrochronological data to provide

  7. Three Centuries of Synchronous Forest Defoliator Outbreaks in Western North America.

    PubMed

    Flower, Aquila

    2016-01-01

    Insect outbreaks often occur synchronously across large spatial scales, but the long-term temporal stability of the phenomenon and the mechanisms behind it are not well understood. In this study, I use a widespread lepidopteran defoliator native to western North America-the western spruce budworm-as a case study to explore patterns of and potential causes for synchronous population fluctuations. Analyses of synchrony are typically severely limited by the short historical records available for many species. To overcome this limitation, I compiled multi-century dendrochronological reconstructions of western spruce budworm outbreaks from across much of the species' range. This allowed me to analyze synchrony at a sub-continental spatial scale over the last three centuries. I found statistically significant synchrony among regional outbreak records up to 2,000 km apart and identified numerous outbreak periods that occurred synchronously across much of the species' range. I quantified spatial and temporal associations between climate and synchronous outbreak periods using paleoclimate reconstructions. The spatial patterns of outbreak histories and climate records were remarkably similar, with higher similarity in outbreak histories apparent between regions with more similar climate conditions. Synchronous outbreaks typically occurred during periods of average or above average moisture availability preceded by periods of low moisture availability. My results suggest that climatic variability has played a key role in synchronizing western spruce budworm population fluctuations in disjunct forests across western North America for at least the last three centuries. Widespread synchrony appears to be a natural part of this species' population dynamics, though synchronous outbreaks have occurred more frequently during the 20th century than during prior centuries. This study uses a novel combination of statistical methods and dendrochronological data to provide analyses of

  8. Effects of defoliating insect resistance QTLs and a cry1Ac transgene in soybean near-isogenic lines.

    PubMed

    Zhu, S; Walker, D R; Boerma, H R; All, J N; Parrott, W A

    2008-02-01

    The crystal proteins coded by transgenes from Bacillus thuringiensis (Bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean, Glycine max (L.) Merr. Additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of Bt crops. The objective of this study was to evaluate the effects and interactions of three insect resistance quantitative trait loci (QTLs; QTL-M, QTL-H, and QTL-G) originating from Japanese soybean PI 229358 and a cry1Ac gene in a "Benning" genetic background. A set of 16 BC(6)F(2)-derived near isogenic lines (NILs) was developed using marker-assisted backcrosses and evaluated for resistance to soybean looper [SBL, Pseudoplusia includens (Walker)] and corn earworm [CEW, Helicoverpa zea (Boddie)] in field cage, greenhouse, and detached leaf assays. Both Bt and QTL-M had significantly reduced defoliation by both SBL and CEW and reduced larval weight of CEW. The antibiosis QTL-G had a significant effect on reducing CEW larval weight and also a significant effect on reducing defoliation by SBL and CEW in some assays. The antixenosis QTL-H had no main effect, but it appeared to function through interaction with QTL-M and QTL-G. Adding QTL-H and QTL-G further enhanced the resistance of the Bt and QTL-M combination to CEW in the field cage assay. These results should help guide the development of strategies for effective management of insect pests and for sustainable deployment of Bt genes.

  9. Identifying and breeding drought tolerant cottons (gossypium spp.) treated with ems-mutant agent on the texas high plains

    USDA-ARS?s Scientific Manuscript database

    Cotton (Gossypium spp.), like many crop species worldwide, suffers from low levels of natural genetic diversity. Ethyl MethaneSulfonate (EMS) causes random mutations and has been used as a tool to increase genetic diversity. Therefore, this novel genetic diversity was used for identifying drought to...

  10. Diurnal pollen tube growth is exceptionally sensitive to high temperature in field-grown Gossypium hirsutum pistils

    USDA-ARS?s Scientific Manuscript database

    For Gossypium hirsutum L. pollination, germination, and pollen tube growth must occur in a highly concerted fashion on the day of flowering for fertilization to occur. Because reproductive success is influenced by photosynthetic activity of major source leaves, we hypothesized that high temperatures...

  11. Genetic effects of chromosomes 01, 04, and 18 from three tetraploid gossypium species in topcrosses with five elite cultivars

    USDA-ARS?s Scientific Manuscript database

    Chromosome substitution lines (CSL) have been developed for selected chromosomes from two tetraploid species of Gossypium and have been shown to be effective ways to target introgression of useful alleles from exotic tetraploid species into Upland cotton, G. hirsutum L. Genetic effects of chromosome...

  12. Identification of exotic genetic components and DNA methylation pattern analysis of three cotton introgression lines from Gossypium bickii.

    PubMed

    He, Shou-Pu; Sun, Jun-Ling; Zhang, Chao; Du, Xiong-Ming

    2011-01-01

    The impact of alien DNA fragments on plant genome has been studied in many species. However, little is known about the introgression lines of Gossypium. To study the consequences of introgression in Gossypium, we investigated 2000 genomic and 800 epigenetic sites in three typical cotton introgression lines, as well as their cultivar (Gossypium hirsutum) and wild parents (Gossypium bickii), by amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP). The results demonstrate that an average of 0.5% of exotic DNA segments from wild cotton is transmitted into the genome of each introgression line, with the addition of other forms of genetic variation. In total, an average of 0.7% of genetic variation sites is identified in introgression lines. Simultaneously, the overall cytosine methylation level in each introgression line is very close to that of the upland cotton parent (an average of 22.6%). Further dividing patterns reveal that both hypomethylation and hypermethylation occurred in introgression lines in comparison with the upland cotton parent. Sequencing of nine methylation polymorphism fragments showed that most (7 of 9) of the methylation alternations occurred in the noncoding sequences. The molecular evidence of introgression from wild cotton into introgression lines in our study is identified by AFLP. Moreover, the causes of petal variation in introgression lines are discussed.

  13. The Li2 mutation results in reduced subgenome expression bias in elongating fibers of allotetraploid cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Next generation sequencing (RNA-seq) technology was used to evaluate the effects of the Ligon lintless-2 (Li2) short fiber mutation on transcriptomes of both subgenomes of allotetraploid cotton (Gossypium hirsutum L.) as compared to its near-isogenic wild type. Sequencing was performed on 4 librari...

  14. Cotton (Gossypium hirsutum L.) boll rotting bacteria vectored by the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidea)

    USDA-ARS?s Scientific Manuscript database

    Determine the capacity of the brown stink bug (Euschistus servus) to transmit an infective Pantoea agglomerans into cotton (Gossypium hirsutum, L.) bolls. A laboratory colony of the brown stink bug (BSB) was maintained on fresh green beans. The P. agglomerans mutant strain Sc 1-R that holds rifamp...

  15. Identification of the unsaturated heptadecyl fatty acids in the seed oils of Thespesia populnea and Gossypium hirsutum

    USDA-ARS?s Scientific Manuscript database

    The fatty acid composition of the seed oils of Thespesia populnea and cotton variety SG-747 (Gossypium hirsutum) were studied to identity their 17-carbon fatty acids. With a combination of chemical derivatization, gas chromatography, and mass spectrometry, 8-heptadecenoic acid, 9-heptadecenoic acid...

  16. Cloning and characterization of homeologous cellulose synthase catalytic subunit 2 genes from allotetraploid cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Cellulose synthase catalytic subunits (CesAs) are the catalytic sites within a multisubunit complex for cellulose biosynthesis in plants. CesAs have been extensively studied in diploid plants, but are not well characterized in polyploid plants. Gossypium hirsutum is an allotetraploid cotton specie...

  17. DNA sequences of Pima (Gossypium barbadense L.) cotton leaf for examining transcriptome diversity and SNP biomarker discovery

    USDA-ARS?s Scientific Manuscript database

    As an initial step to explore the transcriptome genetic diversity and to discover single nucleotide polymorphic (SNP)-biomarkers for marker assisted breeding within Pima (Gossypium barbadense L.) cotton, leaves from 25 day plants of three diverse genotypes were used to develop cDNA libraries. Using ...

  18. Rapid diversification of the cotton genus (Gossypium: Malvaceae) revealed by analysis of sixteen nuclear and chloroplast genes.

    Treesearch

    Richard C. Cronn; Randall L. Small; Tamara Hanselkorn; Jonathan F. Wendel

    2002-01-01

    Previous molecular phylogenetic studies have failed to resolve the branching order among the major cotton (Gossypium) lineages, and it has been unclear whether this reflects actual history (rapid radiation) or sampling properties of the genes evaluated. In this paper, we reconsider the phylogenetic relationships of diploid cotton genome groups using DNA sequences from...

  19. Seed oil and protein diversity among Gossypium accessions in the U.S. National Cotton Germplasm Collection

    USDA-ARS?s Scientific Manuscript database

    Identifying and reporting genetic variability is an important tool to increase the utilization of germplasm collections. In an effort to further realize the potential of cottonseed, we have characterized seed composition traits of Gossypium spp. accessions available in the U.S. National Cotton Germ...

  20. Genomic Identification and Comparative Expansion Analysis of the Non-Specific Lipid Transfer Protein Gene Family in Gossypium

    PubMed Central

    Li, Feng; Fan, Kai; Ma, Fanglu; Yue, Erkui; Bibi, Noreen; Wang, Ming; Shen, Hao; Hasan, Md Mosfeq-Ul; Wang, Xuede

    2016-01-01

    Plant non-specific lipid transfer proteins (nsLTPs) are involved in many biological processes. In this study, 51, 47 and 91 nsLTPs were identified in Gossypium arboreum, G. raimondii and their descendant allotetraploid G. hirsutum, respectively. All the nsLTPs were phylogenetically divided into 8 distinct subfamilies. Besides, the recent duplication, which is considered cotton-specific whole genome duplication, may have led to nsLTP expansion in Gossypium. Both tandem and segmental duplication contributed to nsLTP expansion in G. arboreum and G. hirsutum, while tandem duplication was the dominant pattern in G. raimondii. Additionally, the interspecific orthologous gene pairs in Gossypium were identified. Some GaLTPs and GrLTPs lost their orthologs in the At and Dt subgenomes, respectively, of G. hirsutum. The distribution of these GrLTPs and GaLTPs within each subfamily was complementary, suggesting that the loss and retention of nsLTPs in G. hirsutum might not be random. Moreover, the nsLTPs in the At and Dt subgenomes might have evolved symmetrically. Furthermore, both intraspecific and interspecific orthologous genes showed considerable expression variation, suggesting that their functions were strongly differentiated. Our results lay an important foundation for expansion and evolutionary analysis of the nsLTP family in Gossypium, and advance nsLTP studies in other plants, especially polyploid plants. PMID:27976679

  1. Genetics of the ovule fiberless and foliar glabrous traits in the Gossypium arboreum germplasm line in PI 529740

    USDA-ARS?s Scientific Manuscript database

    Accession PI 529740 from the Gossypium arboreum (G. arboreum) germplasm collection and characterized by fiberless seeds and glabrous leaves and stems was crossed with two G. arboreum accessions, PI 417890 or PI 529729, to develop F2 populations for genetic analysis. Segregation data indicated these...

  2. Registration of RMBUP-C4, a random mated population with Gossypium hirsutum L. alleles, introgresssed into Upland cotton germplasm

    USDA-ARS?s Scientific Manuscript database

    RMBUP-C4 (Random Mated Barbadense Upland Population Cycle 4) (Reg. No. GP_____: PI______) is a unique random mated germplasm population of Upland cotton (Gossypium hirsutum L.) which has introgression of G. barbadense L. alleles. This population involved five cycles of random mating beginning ...

  3. Population structure and genetic diversity of the boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), on Gossypium in North America

    USDA-ARS?s Scientific Manuscript database

    While the boll weevil, Anthonomus grandis, has been identified as one of the most devastating pests in U.S. history, its origin and activity in Mexico, both on wild and cultivated cotton hosts (genus Gossypium), is poorly understood. Three forms (geographical or host-associated races) of A. grandis ...

  4. Genetic Dissection of Chromosome Substitution Lines of Cotton to Discover Novel Gossypium barbadense L. Alleles for Improvement of Agronomic Traits

    USDA-ARS?s Scientific Manuscript database

    Efforts to combine the best features of high-yielding Upland cultivars of Gossypium hirsutum (2n=52) with the superior fiber characteristics of G. barbadense (2n=52) have generally fallen well short of desired goals. In this study, we have used hypoaneuploid-based chromosome substitution as a means ...

  5. Reniform nematode (Rotylenchulus reniformis) resistance locus from Gossypium aridum identified and introgressed into upland cotton (G. hirsutum)

    USDA-ARS?s Scientific Manuscript database

    SSR markers associated with reniform nematode (Rotylenchulus reniformis) resistance were identified and mapped using progeny from a cross between a tri-species hybrid [Gossypium arboreum × (G 371 - G. hirsutum × G. aridum -)] and G. hirsutum MD51ne. The 50 most resistant and 26 most susceptible prog...

  6. Next Generation Genetic Mapping of the Ligon-lintless-2 (Li2) Locus in Upland Cotton (Gossypium hirsutum L.)

    USDA-ARS?s Scientific Manuscript database

    Next generation sequencing offers new ways to identify the genetic mechanisms that underlie mutant phenotypes. The release of a reference diploid Gossypium raimondii (D5) genome and bioinformatics tools to sort tetraploid reads into subgenomes has brought cotton genetic mapping into the genomics er...

  7. Detection, validation and application of genotyping-by-sequencing based single nucleotide polymorphisms in upland cotton (Gossypium hirsutum L.).

    USDA-ARS?s Scientific Manuscript database

    The presence of two closely related sub-genomes in the allotetraploid Upland cotton (Gossypium hirsutum L.) combined with a narrow genetic base of the cultivated varieties has hindered the identification of polymorphic genetic markers and their utilization in improving this important crop. Genotypi...

  8. Phylogeny of the New World diploid cottons (Gossypium L., Malvaceae) based on sequences of three low-copy nuclear genes.

    Treesearch

    I. Alvarez; R. Cronn; J.F. Wendel

    2005-01-01

    American diploid cottons (Gossypium L., subgenus Houzingenia Fryxell) form a monophyletic group of 13 species distributed mainly in western Mexico, extending into Arizona, Baja California, and with one disjunct species each in the Galapagos Islands and Peru. Prior phylogenetic analyses based on an alcohol dehydrogenase gene (...

  9. Genetic diversity in Gossypium hirsutum L. for cotton leaf curl disease in association with agronomic and fiber traits

    USDA-ARS?s Scientific Manuscript database

    Information of genetic diversity in germplasm for cotton leaf curl disease (CLCuD) resistance/susceptibility and economic characters is essential before starting a breeding program to development germplasm with disease resistance. In this study, 17 conventional cotton (Gossypium hirsutum L.) genoty...

  10. Metabolic and enzymatic changes associated with carbon mobilization, utilization and replenishment triggered in grain amaranth (Amaranthus cruentus) in response to partial defoliation by mechanical injury or insect herbivory

    PubMed Central

    2012-01-01

    Background Amaranthus cruentus and A. hypochondriacus are crop plants grown for grain production in subtropical countries. Recently, the generation of large-scale transcriptomic data opened the possibility to study representative genes of primary metabolism to gain a better understanding of the biochemical mechanisms underlying tolerance to defoliation in these species. A multi-level approach was followed involving gene expression analysis, enzyme activity and metabolite measurements. Results Defoliation by insect herbivory (HD) or mechanical damage (MD) led to a rapid and transient reduction of non-structural carbohydrates (NSC) in all tissues examined. This correlated with a short-term induction of foliar sucrolytic activity, differential gene expression of a vacuolar invertase and its inhibitor, and induction of a sucrose transporter gene. Leaf starch in defoliated plants correlated negatively with amylolytic activity and expression of a β-amylase-1 gene and positively with a soluble starch synthase gene. Fatty-acid accumulation in roots coincided with a high expression of a phosphoenolpyruvate/phosphate transporter gene. In all tissues there was a long-term replenishment of most metabolite pools, which allowed damaged plants to maintain unaltered growth and grain yield. Promoter analysis of ADP-glucose pyrophosphorylase and vacuolar invertase genes indicated the presence of cis-regulatory elements that supported their responsiveness to defoliation. HD and MD had differential effects on transcripts, enzyme activities and metabolites. However, the correlation between transcript abundance and enzymatic activities was very limited. A better correlation was found between enzymes, metabolite levels and growth and reproductive parameters. Conclusions It is concluded that a rapid reduction of NSC reserves in leaves, stems and roots followed by their long-term recovery underlies tolerance to defoliation in grain amaranth. This requires the coordinate action of genes

  11. Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau.

    PubMed

    Qi, Juan; Nie, Zhongnan; Jiao, Ting; Zhang, Degang

    2015-01-01

    Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

  12. Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau

    PubMed Central

    Qi, Juan; Nie, Zhongnan; Jiao, Ting; Zhang, Degang

    2015-01-01

    Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries. PMID:26513363

  13. GraP: platform for functional genomics analysis of Gossypium raimondii

    PubMed Central

    Zhang, Liwei; Guo, Jinyan; You, Qi; Yi, Xin; Ling, Yi; Xu, Wenying; Hua, Jinping; Su, Zhen

    2015-01-01

    Cotton (Gossypium spp.) is one of the most important natural fiber and oil crops worldwide. Improvement of fiber yield and quality under changing environments attract much attention from cotton researchers; however, a functional analysis platform integrating omics data is still missing. The success of cotton genome sequencing and large amount of available transcriptome data allows the opportunity to establish a comprehensive analysis platform for integrating these data and related information. A comprehensive database, Platform of Functional Genomics Analysis in Gossypium raimondii (GraP), was constructed to provide multi-dimensional analysis, integration and visualization tools. GraP includes updated functional annotation, gene family classifications, protein–protein interaction networks, co-expression networks and microRNA–target pairs. Moreover, gene set enrichment analysis and cis-element significance analysis tools are also provided for gene batch analysis of high-throughput data sets. Based on these effective services, GraP may offer further information for subsequent studies of functional genes and in-depth analysis of high-throughput data. GraP is publically accessible at http://structuralbiology.cau.edu.cn/GraP/, with all data available for downloading. PMID:25982315

  14. Comparative genomics of Gossypium and Arabidopsis: Unraveling the consequences of both ancient and recent polyploidy

    PubMed Central

    Rong, Junkang; Bowers, John E.; Schulze, Stefan R.; Waghmare, Vijay N.; Rogers, Carl J.; Pierce, Gary J.; Zhang, Hua; Estill, James C.; Paterson, Andrew H.

    2005-01-01

    Both ancient and recent polyploidy, together with post-polyploidization loss of many duplicated gene copies, complicates angiosperm comparative genomics. To explore an approach by which these challenges might be mitigated, genetic maps of extant diploid and tetraploid cottons (Gossypium spp.) were used to infer the approximate order of 3016 loci along the chromosomes of their hypothetical common ancestor. The inferred Gossypium gene order corresponded more closely than the original maps did to a similarly inferred ancestral gene order predating an independent paleopolyploidization (α) in Arabidopsis. At least 59% of the cotton map and 53% of the Arabidopsis transcriptome showed correspondence in multilocus gene arrangements based on one or both of two software packages (CrimeStatII, FISH). Genomic regions in which chromosome structural rearrangement has been rapid (obscuring gene order correspondence) have also been subject to greater divergence of individual gene sequences. About 26%-44% of corresponding regions involved multiple Arabidopsis or cotton chromosomes, in some cases consistent with known, more ancient, duplications. The genomic distributions of multiple-locus probes provided early insight into the consequences for chromosome structure of an ancient large-scale duplication in cotton. Inferences that mitigate the consequences of ancient duplications improve leveraging of genomic information for model organisms in the study of more complex genomes. PMID:16109973

  15. Genetic Diversity of the Two Commercial Tetraploid Cotton Species in the Gossypium Diversity Reference Set

    PubMed Central

    Gazave, Elodie; Gore, Michael A.; Fang, David D.; Scheffler, Brian E.; Yu, John Z.; Jones, Don C.; Frelichowski, James; Percy, Richard G.

    2016-01-01

    A diversity reference set has been constructed for the Gossypium accessions in the US National Cotton Germplasm Collection to facilitate more extensive evaluation and utilization of accessions held in the Collection. A set of 105 mapped simple sequence repeat markers was used to study the allelic diversity of 1933 tetraploid Gossypium accessions representative of the range of diversity of the improved and wild accessions of G. hirsutum and G. barbadense. The reference set contained 410 G. barbadense accessions and 1523 G. hirsutum accessions. Observed numbers of polymorphic and private bands indicated a greater diversity in G. hirsutum as compared to G. barbadense as well as in wild-type accessions as compared to improved accessions in both species. The markers clearly differentiated the 2 species. Patterns of diversity within species were observed but not clearly delineated, with much overlap occurring between races and regions of origin for wild accessions and between historical and geographic breeding pools for cultivated accessions. Although the percentage of accessions showing introgression was higher among wild accessions than cultivars in both species, the average level of introgression within individual accessions, as indicated by species-specific bands, was much higher in wild accessions of G. hirsutum than in wild accessions of G. barbadense. The average level of introgression within individual accessions was higher in improved G. barbadense cultivars than in G. hirsutum cultivars. This molecular characterization reveals the levels and distributions of genetic diversity that will allow for better exploration and utilization of cotton genetic resources. PMID:26774060

  16. A draft physical map of a D-genome cotton species (Gossypium raimondii)

    PubMed Central

    2010-01-01

    Background Genetically anchored physical maps of large eukaryotic genomes have proven useful both for their intrinsic merit and as an adjunct to genome sequencing. Cultivated tetraploid cottons, Gossypium hirsutum and G. barbadense, share a common ancestor formed by a merger of the A and D genomes about 1-2 million years ago. Toward the long-term goal of characterizing the spectrum of diversity among cotton genomes, the worldwide cotton community has prioritized the D genome progenitor Gossypium raimondii for complete sequencing. Results A whole genome physical map of G. raimondii, the putative D genome ancestral species of tetraploid cottons was assembled, integrating genetically-anchored overgo hybridization probes, agarose based fingerprints and 'high information content fingerprinting' (HICF). A total of 13,662 BAC-end sequences and 2,828 DNA probes were used in genetically anchoring 1585 contigs to a cotton consensus genetic map, and 370 and 438 contigs, respectively to Arabidopsis thaliana (AT) and Vitis vinifera (VV) whole genome sequences. Conclusion Several lines of evidence suggest that the G. raimondii genome is comprised of two qualitatively different components. Much of the gene rich component is aligned to the Arabidopsis and Vitis vinifera genomes and shows promise for utilizing translational genomic approaches in understanding this important genome and its resident genes. The integrated genetic-physical map is of value both in assembling and validating a planned reference sequence. PMID:20569427

  17. Genetic Diversity of the Two Commercial Tetraploid Cotton Species in the Gossypium Diversity Reference Set.

    PubMed

    Hinze, Lori L; Gazave, Elodie; Gore, Michael A; Fang, David D; Scheffler, Brian E; Yu, John Z; Jones, Don C; Frelichowski, James; Percy, Richard G

    2016-05-01

    A diversity reference set has been constructed for the Gossypium accessions in the US National Cotton Germplasm Collection to facilitate more extensive evaluation and utilization of accessions held in the Collection. A set of 105 mapped simple sequence repeat markers was used to study the allelic diversity of 1933 tetraploid Gossypium accessions representative of the range of diversity of the improved and wild accessions of G. hirsutum and G. barbadense. The reference set contained 410 G. barbadense accessions and 1523 G. hirsutum accessions. Observed numbers of polymorphic and private bands indicated a greater diversity in G. hirsutum as compared to G. barbadense as well as in wild-type accessions as compared to improved accessions in both species. The markers clearly differentiated the 2 species. Patterns of diversity within species were observed but not clearly delineated, with much overlap occurring between races and regions of origin for wild accessions and between historical and geographic breeding pools for cultivated accessions. Although the percentage of accessions showing introgression was higher among wild accessions than cultivars in both species, the average level of introgression within individual accessions, as indicated by species-specific bands, was much higher in wild accessions of G. hirsutum than in wild accessions of G. barbadense. The average level of introgression within individual accessions was higher in improved G. barbadense cultivars than in G. hirsutum cultivars. This molecular characterization reveals the levels and distributions of genetic diversity that will allow for better exploration and utilization of cotton genetic resources.

  18. Long noncoding RNAs and their proposed functions in fibre development of cotton (Gossypium spp.).

    PubMed

    Wang, Maojun; Yuan, Daojun; Tu, Lili; Gao, Wenhui; He, Yonghui; Hu, Haiyan; Wang, Pengcheng; Liu, Nian; Lindsey, Keith; Zhang, Xianlong

    2015-09-01

    Long noncoding RNAs (lncRNAs) are transcripts of at least 200 bp in length, possess no apparent coding capacity and are involved in various biological regulatory processes. Until now, no systematic identification of lncRNAs has been reported in cotton (Gossypium spp.). Here, we describe the identification of 30 550 long intergenic noncoding RNA (lincRNA) loci (50 566 transcripts) and 4718 long noncoding natural antisense transcript (lncNAT) loci (5826 transcripts). LncRNAs are rich in repetitive sequences and preferentially expressed in a tissue-specific manner. The detection of abundant genome-specific and/or lineage-specific lncRNAs indicated their weak evolutionary conservation. Approximately 76% of homoeologous lncRNAs exhibit biased expression patterns towards the At or Dt subgenomes. Compared with protein-coding genes, lncRNAs showed overall higher methylation levels and their expression was less affected by gene body methylation. Expression validation in different cotton accessions and coexpression network construction helped to identify several functional lncRNA candidates involved in cotton fibre initiation and elongation. Analysis of integrated expression from the subgenomes of lncRNAs generating miR397 and its targets as a result of genome polyploidization indicated their pivotal functions in regulating lignin metabolism in domesticated tetraploid cotton fibres. This study provides the first comprehensive identification of lncRNAs in Gossypium.

  19. Genome-wide investigation and transcriptome analysis of the WRKY gene family in Gossypium.

    PubMed

    Ding, Mingquan; Chen, Jiadong; Jiang, Yurong; Lin, Lifeng; Cao, YueFen; Wang, Minhua; Zhang, Yuting; Rong, Junkang; Ye, Wuwei

    2015-02-01

    WRKY transcription factors play important roles in various stress responses in diverse plant species. In cotton, this family has not been well studied, especially in relation to fiber development. Here, the genomes and transcriptomes of Gossypium raimondii and Gossypium arboreum were investigated to identify fiber development related WRKY genes. This represents the first comprehensive comparative study of WRKY transcription factors in both diploid A and D cotton species. In total, 112 G. raimondii and 109 G. arboreum WRKY genes were identified. No significant gene structure or domain alterations were detected between the two species, but many SNPs distributed unequally in exon and intron regions. Physical mapping revealed that the WRKY genes in G. arboreum were not located in the corresponding chromosomes of G. raimondii, suggesting great chromosome rearrangement in the diploid cotton genomes. The cotton WRKY genes, especially subgroups I and II, have expanded through multiple whole genome duplications and tandem duplications compared with other plant species. Sequence comparison showed many functionally divergent sites between WRKY subgroups, while the genes within each group are under strong purifying selection. Transcriptome analysis suggested that many WRKY genes participate in specific fiber development processes such as fiber initiation, elongation and maturation with different expression patterns between species. Complex WRKY gene expression such as differential Dt and At allelic gene expression in G. hirsutum and alternative splicing events were also observed in both diploid and tetraploid cottons during fiber development process. In conclusion, this study provides important information on the evolution and function of WRKY gene family in cotton species.

  20. Development of New Candidate Gene and EST-Based Molecular Markers for Gossypium Species

    PubMed Central

    Buyyarapu, Ramesh; Kantety, Ramesh V.; Yu, John Z.; Saha, Sukumar; Sharma, Govind C.

    2011-01-01

    New source of molecular markers accelerate the efforts in improving cotton fiber traits and aid in developing high-density integrated genetic maps. We developed new markers based on candidate genes and G. arboreum EST sequences that were used for polymorphism detection followed by genetic and physical mapping. Nineteen gene-based markers were surveyed for polymorphism detection in 26 Gossypium species. Cluster analysis generated a phylogenetic tree with four major sub-clusters for 23 species while three species branched out individually. CAP method enhanced the rate of polymorphism of candidate gene-based markers between G. hirsutum and G. barbadense. Two hundred A-genome based SSR markers were designed after datamining of G. arboreum EST sequences (Mississippi Gossypium arboreum   EST-SSR: MGAES). Over 70% of MGAES markers successfully produced amplicons while 65 of them demonstrated polymorphism between the parents of G. hirsutum and G. barbadense RIL population and formed 14 linkage groups. Chromosomal localization of both candidate gene-based and MGAES markers was assisted by euploid and hypoaneuploid CS-B analysis. Gene-based and MGAES markers were highly informative as they were designed from candidate genes and fiber transcriptome with a potential to be integrated into the existing cotton genetic and physical maps. PMID:22315588

  1. Composition and Expression of Conserved MicroRNA Genes in Diploid Cotton (Gossypium) Species

    PubMed Central

    Gong, Lei; Kakrana, Atul; Arikit, Siwaret; Meyers, Blake C.; Wendel, Jonathan F.

    2013-01-01

    MicroRNAs are ubiquitous in plant genomes but vary greatly in their abundance within and conservation among plant lineages. To gain insight into the evolutionary birth/death dynamics of microRNA families, we sequenced small RNA and 5′-end PARE libraries generated from two closely related species of Gossypium. Here, we demonstrate that 33 microRNA families, with similar copy numbers and average evolutionary rates, are conserved in the two congeneric cottons. Analysis of the presence/absence of these microRNA families in other land plants sheds light on their depth of phylogenetic origin and lineage-specific loss/gain. Conserved microRNA families in Gossypium exhibit a striking interspecific asymmetry in expression, potentially connected to relative proximity to neighboring transposable elements. A complex correlated expression pattern of microRNA target genes with their controlling microRNAs indicates that possible functional divergence of conserved microRNA families can also exist even within a single plant genus. PMID:24281048

  2. GraP: platform for functional genomics analysis of Gossypium raimondii.

    PubMed

    Zhang, Liwei; Guo, Jinyan; You, Qi; Yi, Xin; Ling, Yi; Xu, Wenying; Hua, Jinping; Su, Zhen

    2015-01-01

    Cotton (Gossypium spp.) is one of the most important natural fiber and oil crops worldwide. Improvement of fiber yield and quality under changing environments attract much attention from cotton researchers; however, a functional analysis platform integrating omics data is still missing. The success of cotton genome sequencing and large amount of available transcriptome data allows the opportunity to establish a comprehensive analysis platform for integrating these data and related information. A comprehensive database, Platform of Functional Genomics Analysis in Gossypium raimondii (GraP), was constructed to provide multi-dimensional analysis, integration and visualization tools. GraP includes updated functional annotation, gene family classifications, protein-protein interaction networks, co-expression networks and microRNA-target pairs. Moreover, gene set enrichment analysis and cis-element significance analysis tools are also provided for gene batch analysis of high-throughput data sets. Based on these effective services, GraP may offer further information for subsequent studies of functional genes and in-depth analysis of high-throughput data. GraP is publically accessible at http://structuralbiology.cau.edu.cn/GraP/, with all data available for downloading. © The Author(s) 2015. Published by Oxford University Press.

  3. Suppression of Rotylenchulus reniformis 122-cm Deep Endorses Resistance Introgression in Gossypium

    PubMed Central

    Robinson, A. F.; Akridge, J. R.; Bradford, J. M.; Cook, C. G.; Gazaway, W. S.; McGawley, E. C.; Starr, J. L.; Young, L. D.

    2006-01-01

    Nine sources of resistance to Rotylenchulus reniformis in Gossypium (cotton) were tested by measuring population density (Pf) and root-length density 0 to 122 cm deep. A Pf in the plow layer less than the autumn sample treatment threshold used by consultants was considered the minimum criterion for acceptable resistance, regardless of population density at planting (Pi). Other criteria were ample roots and a Pf lower than on the susceptible control, as in pot studies. In a Texas field in 2001 and 2002, no resistant accessions had Pf less than the control but all did in microplots into which nematodes from Louisiana were introduced. An environmental chamber experiment ruled out nematode genetic variance and implicated unknown soil factors. Pf in field experiments in Louisiana, Mississippi, and Alabama were below threshold for zero, six and four of the accessions and above threshold in the control. Gossypium arboreum A2–87 and G. barbadense GB-713 were the most resistant accessions. Results indicate that cultivars developed from these sources will suppress R. reniformis populations but less than in pots in a single season. PMID:19259448

  4. Development of New Candidate Gene and EST-Based Molecular Markers for Gossypium Species.

    PubMed

    Buyyarapu, Ramesh; Kantety, Ramesh V; Yu, John Z; Saha, Sukumar; Sharma, Govind C

    2011-01-01

    New source of molecular markers accelerate the efforts in improving cotton fiber traits and aid in developing high-density integrated genetic maps. We developed new markers based on candidate genes and G. arboreum EST sequences that were used for polymorphism detection followed by genetic and physical mapping. Nineteen gene-based markers were surveyed for polymorphism detection in 26 Gossypium species. Cluster analysis generated a phylogenetic tree with four major sub-clusters for 23 species while three species branched out individually. CAP method enhanced the rate of polymorphism of candidate gene-based markers between G. hirsutum and G. barbadense. Two hundred A-genome based SSR markers were designed after datamining of G. arboreum EST sequences (Mississippi Gossypium arboreum  EST-SSR: MGAES). Over 70% of MGAES markers successfully produced amplicons while 65 of them demonstrated polymorphism between the parents of G. hirsutum and G. barbadense RIL population and formed 14 linkage groups. Chromosomal localization of both candidate gene-based and MGAES markers was assisted by euploid and hypoaneuploid CS-B analysis. Gene-based and MGAES markers were highly informative as they were designed from candidate genes and fiber transcriptome with a potential to be integrated into the existing cotton genetic and physical maps.

  5. [First occurrence of Alcaeorrhynchus grandis (Dallas) (Hemiptera: Pentatomidae) preying on defoliating caterpillars of oil palm in the State of Pará, Brazil].

    PubMed

    Ribeiro, Rafael C; Lemos, Walkymário P; Bernardino, Aline S; Buecke, Joel; Müller, Antonio A

    2010-01-01

    The oil palm Elaeis guineensis is usually attacked by pests, particularly, defoliating caterpillars. Between 2004 and 2006 a stinkbug predator (Asopinae) was registered preying on caterpillars of Brassolis sophorae L., Opsiphanes invirae Hübner (Lepidoptera: Nymphalidae) and Sibine spp. (Lepidoptera: Limacodidae), reducing their populations in commercial oil palm plantations in the State of Pará, Brazil. Specimens of the natural enemy were collected, mounted, and identified as Alcaeorrhynchus grandis (Dallas) (Hemiptera: Pentatomidae), corresponding to the first report of the occurrence of this stinkbug attacking defoliating caterpillars of oil palm in Brazil.

  6. Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity

    PubMed Central

    Martemyanov, Vyacheslav V.; Pavlushin, Sergey V.; Dubovskiy, Ivan M.; Yushkova, Yuliya V.; Morosov, Sergey V.; Chernyak, Elena I.; Efimov, Vadim M.; Ruuhola, Teija; Glupov, Victor V.

    2015-01-01

    The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects’ fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content) on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula—gypsy moth Lymantria dispar—nucleopolyhedrovirus as the tritrophic system. We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus. PMID:26115118

  7. Small mammal abundance and habitat relationships on deciduous forested sites with different susceptibility to gypsy moth defoliation

    NASA Astrophysics Data System (ADS)

    Yahner, Richard H.; Smith, Harvey R.

    1991-01-01

    Small mammals are important predators of gypsy moths ( Lymantria dispar L.), which are major defoliators of deciduous forests in the northeastern United States. Abundance and habitat relationships of small mammals were studied during summers 1984 and 1985 on forested sites at Moshannon and Rothrock state forests in two physiographic regions of Pennsylvania (Allegheny High Plateaus Province and Valley and Ridge Province, respectively) that varied in potential susceptibility to defoliation. The white-footed mouse ( Peromyscus leucopus), which is a major vertebrate predator of gypsy moths, was the most common small mammal on all sites. Of the four common species, northern short-tailed shrews ( Blarina brevicauda), southern red-backed voles ( Clethrionomys gapperi), and white-footed mice were more abundant at Moshannon compared to Rothrock State Forest, but masked shrews ( Sorex cinereus) were more abundant at Rothrock. Elevation was a major factor affecting abundance and distribution of small mammals. Because of the greater abundance of small mammals and more suitable physiographic features at Moshannon compared to Rothrock State Forest, small mammals may be more effective as predators on gypsy moths in the Allegheny High Plateaus than the Valley and Ridge Province of Pennsylvania.

  8. Photosynthesis, carbohydrate storage and survival of a native and an introduced tree species in relation to light and defoliation.

    PubMed

    Gleason, S M; Ares, A

    2004-10-01

    Fraxinus uhdei (Wenz.) Lingelsh (tropical ash), a species introduced to Hawaii from Mexico, invades forests of the endemic tree Acacia koa A.Gray (koa). We examined physiological and morphological characteristics of koa and tropical ash to explore possible mechanisms that may facilitate invasion of koa forests by tropical ash. Seedlings of both species were grown in a greenhouse in three light treatments: 100% photosynthetic photon flux (PPF); 18% PPF; and 2% PPF inside the greenhouse. Light compensation point, maximum CO2 assimilation rate and dark respiration rate of seedlings differed significantly among light treatments, but were similar between species. A defoliation experiment indicated that tropical ash was better able to survive defoliation than koa, especially under high-light conditions. Tropical ash seedlings allocated more carbon (C) and nitrogen (N) to storage per unit PPF than koa seedlings. Total nonstructural carbohydrates were positively correlated with plant survival in both species. The patterns of C and N allocation associated with tropical ash seedlings favor their survival in high light, under intense herbivory and on sites where N availability is seasonal or highly variable. Variation in carbohydrate storage between koa and tropical ash greatly exceeded variation in photosynthetic performance at the leaf level.

  9. Interactive effects of mechanical stress, sand burial and defoliation on growth and mechanical properties in Cynanchum komarovii.

    PubMed

    Xu, L; Yu, F-H; Werger, M; Dong, M; Anten, N P R

    2013-01-01

    In drylands, wind, sand burial and grazing are three important factors affecting growth and mechanical properties of plants, but their interactive effects have not yet been investigated. Plants of the semi-shrub Cynanchum komarovii, common in semi-arid parts of NE Asia, were subjected to brushing, burial and defoliation. We measured biomass allocation and relative increment rates of dry mass (RGR(m)), height (RGR(h)) and basal diameter (RGR(d)). We also measured the stem mechanical properties, Young's modulus (E), second moment of area (I), flexural stiffness (EI) and breaking stress (σ(b)), and scaled these traits to the whole-plant level to determine the maximum lateral force (F(lateral)) and the buckling safety factor (BSF). Brushing increased RGR(m); neither burial nor defoliation independently affected RGR(m), but together they reduced it. Among buried plants, brushing positively affected stem rigidity and strength through increasing RGR(d), E, I and EI, and at whole plant level this resulted in a larger BSF and F(lateral). However, among unburied plants this pattern was not observed. Our results thus show that effects of mechanical stress and grazing on plants can be strongly modified by burial, and these interactions should be taken into account when considering adaptive significance of plant mechanical traits in drylands.

  10. Genome-wide divergence, haplotype distribution and population demographic histories for Gossypium hirsutum and Gossypium barbadense as revealed by genome-anchored SNPs

    PubMed Central

    Reddy, Umesh K.; Nimmakayala, Padma; Abburi, Venkata Lakshmi; Reddy, C. V. C. M.; Saminathan, Thangasamy; Percy, Richard G.; Yu, John Z.; Frelichowski, James; Udall, Joshua A.; Page, Justin T.; Zhang, Dong; Shehzad, Tariq; Paterson, Andrew H.

    2017-01-01

    Use of 10,129 singleton SNPs of known genomic location in tetraploid cotton provided unique opportunities to characterize genome-wide diversity among 440 Gossypium hirsutum and 219 G. barbadense cultivars and landrace accessions of widespread origin. Using the SNPs distributed genome-wide, we examined genetic diversity, haplotype distribution and linkage disequilibrium patterns in the G. hirsutum and G. barbadense genomes to clarify population demographic history. Diversity and identity-by-state analyses have revealed little sharing of alleles between the two cultivated allotetraploid genomes, with a few exceptions that indicated sporadic gene flow. We found a high number of new alleles, representing increased nucleotide diversity, on chromosomes 1 and 2 in cultivated G. hirsutum as compared with low nucleotide diversity on these chromosomes in landrace G. hirsutum. In contrast, G. barbadense chromosomes showed negative Tajima’s D on several chromosomes for both cultivated and landrace types, which indicate that speciation of G. barbadense itself, might have occurred with relatively narrow genetic diversity. The presence of conserved linkage disequilibrium (LD) blocks and haplotypes between G. hirsutum and G. barbadense provides strong evidence for comparable patterns of evolution in their domestication processes. Our study illustrates the potential use of population genetic techniques to identify genomic regions for domestication. PMID:28128280

  11. Rhizosphere interactions, carbon allocation, and nitrogen acquisition of two perennial North American grasses in response to defoliation and elevated atmospheric CO2

    USDA-ARS?s Scientific Manuscript database

    Carbon allocation and N acquisition by plants following defoliation may be linked through plant-microbe interactions in the rhizosphere. Feedbacks between herbivory and plant-microbe interactions may also be affected by increasing atmospheric CO2, through plant responses to changes in carbon and nit...

  12. Cottonwood leaf beetle (Coleoptera: Chrysomelidae) defoliation impact on Populus growth and above-ground volume in a short-rotation woody crop plantation

    Treesearch

    David R. Coyle; Joel D. McMillin; Richard B. Hall; Elwood R. Hart

    2002-01-01

    AbstractThe impact of cottonwood leaf beetle Chrysomela scripta F. defoliation on four plantation-grown Populus clones was examined over three growing seasons. We used a split-plot design with two treatments: protected (by insecticides) and an unprotected control. Tree height and...

  13. Radial growth of grand fir and Douglas-fir 10 years after defoliation by the Douglas-fir tussock moth in the Blue Mountains outbreak.

    Treesearch

    Boyd E. Wickman

    1986-01-01

    Radial-growth recovery related to amount of tree defoliation was measured 10 years after a severe outbreak of Douglas-fir tussock moth (Orgyia pseudotsugata (McDunnough). For the period 1978-82, growth of qrand fir surpassed and was significantly greater than in the preoutbreak period, 1968-72. Douglas-fir growth during the postoutbreak period...

  14. Historical patterns of spruce budworm defoliation and bark beetle outbreaks in North American conifer forests: an atlas and description of digital maps

    Treesearch

    David W. Williams; Richard A. Birdsey

    2003-01-01

    This atlas presents maps of historical defoliation by the eastern and western spruce budworms and historical outbreaks of the mountain and southern pine beetles during the past half century. The maps encompass various regions of the conterminous United States and eastern Canada. This publication also serves as documentation for an extended set of digital maps, which...

  15. Sap flux-scaled transpiration by tamarisk (Tamarix spp.) before, during and after episodic defoliation by the saltcedar leaf beetle (Diorhabda carinulata)

    USGS Publications Warehouse

    Hultine, K.R.; Nagler, P.L.; Morino, K.; Bush, S.E.; Burtch, K.G.; Dennison, P.E.; Glenn, E.P.; Ehleringer, J.R.

    2010-01-01

    The release of the saltcedar beetle (Diorhabda carinulata) has resulted in the periodic defoliation of tamarisk (Tamarix spp.) along more than 1000 river km in the upper Colorado River Basin and is expected to spread along many other river reaches throughout the upper basin, and possibly into the lower Colorado River Basin. Identifying the impacts of these release programs on tamarisk water use and subsequent water cycling in arid riparian systems are largely unknown, due in part to the difficulty of measuring water fluxes in these systems. We used lab-calibrated, modified heat-dissipation sap flux sensors to monitor tamarisk water use (n=20 trees) before, during and after defoliation by the saltcedar leaf beetle during the 2008 and 2009 growing seasons (May-October) in southeastern Utah. We incorporated a simple model that related mean stem sap flux density (Js) with atmospheric vapor pressure deficit (vpd) before the onset of defoliation in 2008. The model was used to calculate differences between predicted Js and Js measured throughout the two growing seasons. Episodic defoliation resulted in a 16% reduction in mean annual rates of Js in both 2008 and 2009, with decreases occurring only during the periods in which the trees were defoliated (about 6-8 weeks per growing season). In other words, rates of Js rebounded to values predicted by the model when the trees produced new leaves after defoliation. Sap flux data were scaled to stand water use by constructing a tamarisk-specific allometric equation to relate conducting sapwood area to stem diameter, and by measuring the size distribution of stems within the stand. Total water use in both years was 0.224m, representing a reduction of about 0.04myr-1. Results showed that repeated defoliation/refoliation cycles did not result in a progressive decrease in either leaf production or water use over the duration of the study. This investigation improves ground-based estimates of tamarisk water use, and will support

  16. Sequencing of allotetraploid cotton (Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement.

    PubMed

    Zhang, Tianzhen; Hu, Yan; Jiang, Wenkai; Fang, Lei; Guan, Xueying; Chen, Jiedan; Zhang, Jinbo; Saski, Christopher A; Scheffler, Brian E; Stelly, David M; Hulse-Kemp, Amanda M; Wan, Qun; Liu, Bingliang; Liu, Chunxiao; Wang, Sen; Pan, Mengqiao; Wang, Yangkun; Wang, Dawei; Ye, Wenxue; Chang, Lijing; Zhang, Wenpan; Song, Qingxin; Kirkbride, Ryan C; Chen, Xiaoya; Dennis, Elizabeth; Llewellyn, Danny J; Peterson, Daniel G; Thaxton, Peggy; Jones, Don C; Wang, Qiong; Xu, Xiaoyang; Zhang, Hua; Wu, Huaitong; Zhou, Lei; Mei, Gaofu; Chen, Shuqi; Tian, Yue; Xiang, Dan; Li, Xinghe; Ding, Jian; Zuo, Qiyang; Tao, Linna; Liu, Yunchao; Li, Ji; Lin, Yu; Hui, Yuanyuan; Cao, Zhisheng; Cai, Caiping; Zhu, Xiefei; Jiang, Zhi; Zhou, Baoliang; Guo, Wangzhen; Li, Ruiqiang; Chen, Z Jeffrey

    2015-05-01

    Upland cotton is a model for polyploid crop domestication and transgenic improvement. Here we sequenced the allotetraploid Gossypium hirsutum L. acc. TM-1 genome by integrating whole-genome shotgun reads, bacterial artificial chromosome (BAC)-end sequences and genotype-by-sequencing genetic maps. We assembled and annotated 32,032 A-subgenome genes and 34,402 D-subgenome genes. Structural rearrangements, gene loss, disrupted genes and sequence divergence were more common in the A subgenome than in the D subgenome, suggesting asymmetric evolution. However, no genome-wide expression dominance was found between the subgenomes. Genomic signatures of selection and domestication are associated with positively selected genes (PSGs) for fiber improvement in the A subgenome and for stress tolerance in the D subgenome. This draft genome sequence provides a resource for engineering superior cotton lines.

  17. Dirigent Proteins from Cotton (Gossypium sp.) for the Atropselective Synthesis of Gossypol.

    PubMed

    Effenberger, Isabelle; Zhang, Bin; Li, Ling; Wang, Qiang; Liu, Yuxiu; Klaiber, Iris; Pfannstiel, Jens; Wang, Qingmin; Schaller, Andreas

    2015-12-01

    Gossypol is a defense compound in cotton plants for protection against pests and pathogens. Gossypol biosynthesis involves the oxidative coupling of hemigossypol and results in two atropisomers owing to hindered rotation around the central binaphthyl bond. (+)-Gossypol predominates in vivo, thus suggesting stereochemically controlled biosynthesis. The aim was to identify the factors mediating (+)-gossypol formation in cotton and to investigate their potential for asymmetric biaryl synthesis. A dirigent protein from Gossypium hirsutum (GhDIR4) was found to confer atropselectivity to the coupling of hemigossypol in presence of laccase and O2 as an oxidizing agent. (+)-Gossypol was obtained in greater than 80% enantiomeric excess compared to racemic gossypol in the absence of GhDIR4. The identification of GhDIR4 highlights a broader role for DIRs in plant secondary metabolism and may eventually lead to the development of DIRs as tools for the synthesis of axially chiral binaphthyls.

  18. Cytogenetic Characteristics of New Monosomic Stocks of Cotton (Gossypium hirsutum L.).

    PubMed

    Sanamyan, Marina F; Petlyakova, Julia E; Sharipova, Elnora A; Abdurakhmonov, Ibrokhim Y

    2011-01-01

    The use of aneuploid lines significantly increases the effectiveness of molecular-genetic analysis and the development of superior quality breeding lines via substitutions by alien chromosomes. To date, however, a complete set of aneuploid series for each cotton chromosome is not available. Here, we present the development of a monosomic stock collection of cotton (Gossypium hirsutum L.) from Uzbekistan, including the origin of 92 primary monosomics, meiotic metaphase-I analysis, study of tetrads of microspores, pollen fertility, and monosomic transmission rates for some monosomic lines. We report desynaptic effects of some monosomes detected both in parental and daughter monosomics, a positive role of interchanges in translocation heterozygous monosomics due to selective advantages of gametes with deficiency and a simultaneous interchange, pollen fertility variation, and strong differences in transmission rates. This monosomic cotton collection, developed using single genome background, will be useful for future breeding, genetic, cytogenetic, and molecular-genetic investigations of the cotton genome.

  19. RNA Interference for Functional Genomics and Improvement of Cotton (Gossypium sp.).

    PubMed

    Abdurakhmonov, Ibrokhim Y; Ayubov, Mirzakamol S; Ubaydullaeva, Khurshida A; Buriev, Zabardast T; Shermatov, Shukhrat E; Ruziboev, Haydarali S; Shapulatov, Umid M; Saha, Sukumar; Ulloa, Mauricio; Yu, John Z; Percy, Richard G; Devor, Eric J; Sharma, Govind C; Sripathi, Venkateswara R; Kumpatla, Siva P; van der Krol, Alexander; Kater, Hake D; Khamidov, Khakimdjan; Salikhov, Shavkat I; Jenkins, Johnie N; Abdukarimov, Abdusattor; Pepper, Alan E

    2016-01-01

    RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium sp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function and biological roles of many key cotton genes involved in fiber development, fertility and somatic embryogenesis, resistance to important biotic and abiotic stresses, and oil and seed quality improvements as well as the key agronomic traits including yield and maturity. Here, we have comparatively reviewed seminal research efforts in previously used antisense approaches and currently applied breakthrough RNAi studies in cotton, analyzing developed RNAi methodologies, achievements, limitations, and future needs in functional characterizations of cotton genes. We also highlighted needed efforts in the development of RNAi-based cotton cultivars, and their safety and risk assessment, small and large-scale field trials, and commercialization.

  20. Cytogenetic Characteristics of New Monosomic Stocks of Cotton (Gossypium hirsutum L.)

    PubMed Central

    Sanamyan, Marina F.; Petlyakova, Julia E.; Sharipova, Elnora A.; Abdurakhmonov, Ibrokhim Y.

    2011-01-01

    The use of aneuploid lines significantly increases the effectiveness of molecular-genetic analysis and the development of superior quality breeding lines via substitutions by alien chromosomes. To date, however, a complete set of aneuploid series for each cotton chromosome is not available. Here, we present the development of a monosomic stock collection of cotton (Gossypium hirsutum L.) from Uzbekistan, including the origin of 92 primary monosomics, meiotic metaphase-I analysis, study of tetrads of microspores, pollen fertility, and monosomic transmission rates for some monosomic lines. We report desynaptic effects of some monosomes detected both in parental and daughter monosomics, a positive role of interchanges in translocation heterozygous monosomics due to selective advantages of gametes with deficiency and a simultaneous interchange, pollen fertility variation, and strong differences in transmission rates. This monosomic cotton collection, developed using single genome background, will be useful for future breeding, genetic, cytogenetic, and molecular-genetic investigations of the cotton genome. PMID:23533784

  1. RNA Interference for Functional Genomics and Improvement of Cotton (Gossypium sp.)

    PubMed Central

    Abdurakhmonov, Ibrokhim Y.; Ayubov, Mirzakamol S.; Ubaydullaeva, Khurshida A.; Buriev, Zabardast T.; Shermatov, Shukhrat E.; Ruziboev, Haydarali S.; Shapulatov, Umid M.; Saha, Sukumar; Ulloa, Mauricio; Yu, John Z.; Percy, Richard G.; Devor, Eric J.; Sharma, Govind C.; Sripathi, Venkateswara R.; Kumpatla, Siva P.; van der Krol, Alexander; Kater, Hake D.; Khamidov, Khakimdjan; Salikhov, Shavkat I.; Jenkins, Johnie N.; Abdukarimov, Abdusattor; Pepper, Alan E.

    2016-01-01

    RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium sp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function and biological roles of many key cotton genes involved in fiber development, fertility and somatic embryogenesis, resistance to important biotic and abiotic stresses, and oil and seed quality improvements as well as the key agronomic traits including yield and maturity. Here, we have comparatively reviewed seminal research efforts in previously used antisense approaches and currently applied breakthrough RNAi studies in cotton, analyzing developed RNAi methodologies, achievements, limitations, and future needs in functional characterizations of cotton genes. We also highlighted needed efforts in the development of RNAi-based cotton cultivars, and their safety and risk assessment, small and large-scale field trials, and commercialization. PMID:26941765

  2. Microsatellite loci for Gossypium davidsonii (Malvaceae) and other D-genome, Sonoran Desert endemic cotton species.

    PubMed

    Kuester, Adam P; Nason, John D

    2012-03-01

    Microsatellite primers previously developed for domesticated cotton (Gossypium hirsutum; tetraploid) were screened for their utility in investigating genetic structure and gene flow within G. davidsonii and five other wild, Mexican, D-genome cotton species (all diploid). We screened 50 microsatellite primer pairs from the Cotton Marker Database, identifying 10 loci as polymorphic within G. davidsonii. In genotyping approximately 200 individuals from four populations, we found that the number of alleles per locus ranged from seven to 17, and mean observed and expected heterozygosity ranged from 0.145 to 0.492 and from 0.436 to 0.734, respectively. We genotyped six to 20 individuals from each of the remaining species, finding these 10 loci to cross-amplify in all cases and in most cases to be polymorphic. These markers may be useful for further investigation of population genetics of G. davidsonii and other wild D-genome cotton species.

  3. Morphology and metal binding characteristics of a natural polymer-kondagogu (Cochlospermum gossypium) gum.

    PubMed

    Vinod, V T P; Sashidhar, R B; Černík, Miroslav

    2013-07-15

    Kondagogu (Cochlospermum gossypium) gum (KG), a natural tree exudate, was investigated for its morphological, adsorption and metal interaction behavior with various toxic heavy metals (Pb, Cd, Ni, Cr and Fe). SEM, AFM and TEM techniques were used to study the morphological changes occurring after metal adsorption onto the biopolymer structure. The degree of biosorption of metals on KG biopolymer surfaces was assessed by small-angle X-ray scattering analysis. EDXA spectrum revealed that the ion-exchange mechanism plays a major role in the binding process between KG and metal ions. The higher electron density observed in the KG-Cd complex suggests that Cd is strongly bound to KG compared to the other metals. This work provides a potential platform for developing a hydrocolloid-based nanogel for bioremediation of environmental contaminants.

  4. Comprehensive analysis of TCP transcription factors and their expression during cotton (Gossypium arboreum) fiber early development.

    PubMed

    Ma, Jun; Liu, Fang; Wang, Qinglian; Wang, Kunbo; Jones, Don C; Zhang, Baohong

    2016-02-09

    TCP proteins are plant-specific transcription factors implicated to perform a variety of physiological functions during plant growth and development. In the current study, we performed for the first time the comprehensive analysis of TCP gene family in a diploid cotton species, Gossypium arboreum, including phylogenetic analysis, chromosome location, gene duplication status, gene structure and conserved motif analysis, as well as expression profiles in fiber at different developmental stages. Our results showed that G. arboreum contains 36 TCP genes, distributing across all of the thirteen chromosomes. GaTCPs within the same subclade of the phylogenetic tree shared similar exon/intron organization and motif composition. In addition, both segmental duplication and whole-genome duplication contributed significantly to the expansion of GaTCPs. Many these TCP transcription factor genes are specifically expressed in cotton fiber during different developmental stages, including cotton fiber initiation and early development. This suggests that TCP genes may play important roles in cotton fiber development.

  5. Progress in genome sequencing will accelerate molecular breeding in cotton (Gossypium spp.).

    PubMed

    Yan, Rong; Liang, Chengzhen; Meng, Zhigang; Malik, Waqas; Zhu, Tao; Zong, Xuefeng; Guo, Sandui; Zhang, Rui

    2016-12-01

    Cotton (Gossypium spp.) is the single most important spinning fiber that has economic significance worldwide. Cotton is one of the most value-added crops and an excellent model system for the analysis of polyploidization and cell development. Thus, the Cotton Genome Consortium has made rapid and significant progress in whole genome sequencing studies in the last decade. Developments in cotton genome sequencing and assembly provide powerful tools for dissecting the genetic and molecular bases of agronomically important traits and establishing regulatory networks on these processes, which leads to molecular breeding. Here, we briefly review these advances, emphasizing their implications in the genetic improvement of cotton with a particular focus on fiber quality and yield. Moreover, major progresses in chloroplast and mitochondrial genomes have also been summarized.

  6. Genes expressed in cotton (Gossypium hirsutum) buds isolated with a subtractive library.

    PubMed

    Pinheiro, M P N; Batista, V G L; Martins, N F; Santos, R C; Melo Filho, P A; Silva, C R C; Lima, L M

    2013-01-16

    A subtractive cDNA library from cotton buds was constructed to prospect for differentially expressed genes related to early bud development. A library was constructed and 768 cDNA sequences were obtained, comprising 168 clusters, with 126 contigs and 42 singlets. Both the Gossypium as well as Arabidopsis databases were utilized for the in silico analysis, since some genes identified in cotton have not yet been studied for functionality, although they have homology with genes from other species. The transcriptome revealed a large number of transcripts, some of them with unknown function, and others related to pollen development, pollen tubes, ovules, and fibers at different stages. The most populated contig was identified as fiber from 0-10 days after anthesis, with 12 reads. The success and novelty rates generated from the library were 67 and 51%, respectively. The information obtained here will provide a framework for research on functional cotton genomics.

  7. Photosynthetic electron transport in thylakoids from cotton cultivars (Gossypium sp.) differing in tolerance to prometryn.

    PubMed

    Khan, R A; Molin, W T

    1996-09-01

    A method to determine photosynthetic electron transport in thylakoid membranes is described for Gossypium barbadense (cv. Pima S-7) and G. hirsutum (cv. DP 5415). These cultivars differed markedly in tolerance to prometryn, a PS II inhibitor. The rates of photosynthetic electron transport obtained were 245 μmole oxygen mg(-1) chl h(1). Plant age and leaf size influenced the activity of the thylakoid preparations. Thylakoids from leaves of plants 24 to 37 d and 50-70 mm in diameter had the highest activities; thylakoids from cotyledons, fully expanded leaves and young leaves had low activity. Thylakoids from both species had similar photosynthetic activities and I50's for prometryn, atrazine and diuron. Thus, tolerance to prometryn was not due to differential binding at D1 protein.

  8. Extensive and biased intergenomic nonreciprocal DNA exchanges shaped a nascent polyploid genome, Gossypium (cotton).

    PubMed

    Guo, Hui; Wang, Xiyin; Gundlach, Heidrun; Mayer, Klaus F X; Peterson, Daniel G; Scheffler, Brian E; Chee, Peng W; Paterson, Andrew H

    2014-08-01

    Genome duplication is thought to be central to the evolution of morphological complexity, and some polyploids enjoy a variety of capabilities that transgress those of their diploid progenitors. Comparison of genomic sequences from several tetraploid (AtDt) Gossypium species and genotypes with putative diploid A- and D-genome progenitor species revealed that unidirectional DNA exchanges between homeologous chromosomes were the predominant mechanism responsible for allelic differences between the Gossypium tetraploids and their diploid progenitors. Homeologous gene conversion events (HeGCEs) gradually subsided, declining to rates similar to random mutation during radiation of the polyploid into multiple clades and species. Despite occurring in a common nucleus, preservation of HeGCE is asymmetric in the two tetraploid subgenomes. At-to-Dt conversion is far more abundant than the reciprocal, is enriched in heterochromatin, is highly correlated with GC content and transposon distribution, and may silence abundant A-genome-derived retrotransposons. Dt-to-At conversion is abundant in euchromatin and genes, frequently reversing losses of gene function. The long-standing observation that the nonspinnable-fibered D-genome contributes to the superior yield and quality of tetraploid cotton fibers may be explained by accelerated Dt to At conversion during cotton domestication and improvement, increasing dosage of alleles from the spinnable-fibered A-genome. HeGCE may provide an alternative to (rare) reciprocal DNA exchanges between chromosomes in heterochromatin, where genes have approximately five times greater abundance of Dt-to-At conversion than does adjacent intergenic DNA. Spanning exon-to-gene-sized regions, HeGCE is a natural noninvasive means of gene transfer with the precision of transformation, potentially important in genetic improvement of many crop plants.

  9. Duplication, divergence and persistence in the Phytochrome photoreceptor gene family of cottons (Gossypium spp.)

    PubMed Central

    2010-01-01

    Background Phytochromes are a family of red/far-red photoreceptors that regulate a number of important developmental traits in cotton (Gossypium spp.), including plant architecture, fiber development, and photoperiodic flowering. Little is known about the composition and evolution of the phytochrome gene family in diploid (G. herbaceum, G. raimondii) or allotetraploid (G. hirsutum, G. barbadense) cotton species. The objective of this study was to obtain a preliminary inventory and molecular-evolutionary characterization of the phytochrome gene family in cotton. Results We used comparative sequence resources to design low-degeneracy PCR primers that amplify genomic sequence tags (GSTs) for members of the PHYA, PHYB/D, PHYC and PHYE gene sub-families from A- and D-genome diploid and AD-genome allotetraploid Gossypium species. We identified two paralogous PHYA genes (designated PHYA1 and PHYA2) in diploid cottons, the result of a Malvaceae-specific PHYA gene duplication that occurred approximately 14 million years ago (MYA), before the divergence of the A- and D-genome ancestors. We identified a single gene copy of PHYB, PHYC, and PHYE in diploid cottons. The allotetraploid genomes have largely retained the complete gene complements inherited from both of the diploid genome ancestors, with at least four PHYA genes and two genes encoding PHYB, PHYC and PHYE in the AD-genomes. We did not identify a PHYD gene in any cotton genomes examined. Conclusions Detailed sequence analysis suggests that phytochrome genes retained after duplication by segmental duplication and allopolyploidy appear to be evolving independently under a birth-and-death-process with strong purifying selection. Our study provides a preliminary phytochrome gene inventory that is necessary and sufficient for further characterization of the biological functions of each of the cotton phytochrome genes, and for the development of 'candidate gene' markers that are potentially useful for cotton improvement via

  10. Integrated mapping and characterization of the gene underlying the okra leaf trait in Gossypium hirsutum L.

    PubMed

    Zhu, Qian-Hao; Zhang, Jian; Liu, Dexin; Stiller, Warwick; Liu, Dajun; Zhang, Zhengsheng; Llewellyn, Danny; Wilson, Iain

    2016-02-01

    Diverse leaf morphology has been observed among accessions of Gossypium hirsutum, including okra leaf, which has advantages and disadvantages in cotton production. The okra leaf locus has been mapped to chromosome 15 of the Dt subgenome, but the underlying gene has yet to be identified. In this study, we used a combination of targeted association analysis, F2 population-based fine mapping, and comparative sequencing of orthologues to identify a candidate gene underlying the okra leaf trait in G. hirsutum. The okra leaf gene identified, GhOKRA, encoded a homeodomain leucine-zipper class I protein, whose closely related genes in several other plant species have been shown to be involved in regulating leaf morphology. The transcript levels of GhOKRA in shoot apices were positively correlated with the phenotypic expression of the okra leaf trait. Of the multiple sequence variations observed in the coding region among GrOKRA of Gossypium raimondii and GhOKRA-Dt of normal and okra/superokra leaf G. hirsutum accessions, a non-synonymous substitution near the N terminus and the variable protein sequences at the C terminus may be related to the leaf shape difference. Our results suggest that both transcription and protein activity of GhOKRA may be involved in regulating leaf shape. Furthermore, we found that non-reciprocal homoeologous recombination, or gene conversion, may have played a role in the origin of the okra leaf allele. Our results provided tools for further investigating and understanding the fundamental biological processes that are responsible for the cotton leaf shape variation and will help in the design of cotton plants with an ideal leaf shape for enhanced cotton production.

  11. Salt stress responsiveness of a wild cotton species (Gossypium klotzschianum) based on transcriptomic analysis.

    PubMed

    Wei, Yangyang; Xu, Yanchao; Lu, Pu; Wang, Xingxing; Li, Zhenqing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Yuhong; Zhang, Zhenmei; Lin, Zhongxu; Liu, Fang; Wang, Kunbo

    2017-01-01

    Cotton is a pioneer of saline land crop, while salt stress still causes its growth inhibition and fiber production decrease. Phenotype identification showed better salt tolerance of a wild diploid cotton species Gossypium klotzschianum. To elucidate the salt-tolerant mechanisms in G. klotzschianum, we firstly detected the changes in hormones, H2O2 and glutathione (GSSH and GSH), then investigated the gene expression pattern of roots and leaves treated with 300 mM NaCl for 0, 3, 12, 48 h, and each time control by RNA-seq on the Illumina-Solexa platform. Physiological determination proved that the significant increase in hormone ABA at 48 h, while that in H2O2 was at 12 h, likewise, the GSH content decrease at 48 h and the GSSH content increase at 48 h, under salt stress. In total, 37,278 unigenes were identified from the transcriptome data, 8,312 and 6,732 differentially expressed genes (DEGs) were discovered to be involved in salt stress tolerance in roots and leaves, respectively. Gene function annotation and expression analysis elucidated hormone biosynthesis and signal transduction, reactive oxygen species (ROS), and salt overly sensitive (SOS) signal transduction related genes revealed the important roles of them in signal transmission, oxidation balance and ion homeostasis in response to salinity stress. This is a report which focuses on primary response to highly salty stress (upto 300 mM NaCl) in cotton using a wild diploid Gossypium species, broadening our understanding of the salt tolerance mechanism in cotton and laying a solid foundation of salt resistant for the genetic improvement of upland cotton with the resistance to salt stress.

  12. Lipid metabolites in seeds of diverse Gossypium accessions: molecular identification of a high oleic mutant allele.

    PubMed

    Sturtevant, Drew; Horn, Patrick; Kennedy, Christopher; Hinze, Lori; Percy, Richard; Chapman, Kent

    2017-03-01

    Genetically diverse cottonseeds show altered compositions and spatial distributions of phosphatidylcholines and triacylglycerols. Lipidomics profiling led to the discovery of a novel FAD2 - 1 allele, fad2 - 1D - 1 , resulting in a high oleic phenotype. The domestication and breeding of cotton for elite, high-fiber cultivars have led to reduced variation of seed constituents within currently cultivated upland cotton genotypes. However, a recent screen of the genetically diverse U.S. National Cotton Germplasm Collection identified Gossypium accessions with marked differences in seed oil and protein content. Here, several of these accessions representing substantial variation in seed oil content were analyzed for quantitative and spatial differences in lipid compositions by mass spectrometric approaches. Results indicate considerable variation in amount and spatial distribution of pathway metabolites for triacylglycerol biosynthesis in embryos across Gossypium accessions, suggesting that this variation might be exploited by breeders for seed composition traits. By way of example, these lipid metabolite differences led to the identification of a mutant allele of the D-subgenome homolog of the delta-12 desaturase (fad2-1D-1) in a wild accession of G. barbadense that has a high oil and high oleic seed phenotype. This mutation is a 90-bp insertion in the 3' end of the FAD2-1D coding sequence and a modification of the 3' end of the gene beyond the coding sequence leading to the introduction of a premature stop codon. Given the large amounts of cottonseed produced around the world that is currently not processed into higher value products, these efforts might be one avenue to raise the overall value of the cotton crop for producers.

  13. The Complete Mitochondrial Genome of Gossypium hirsutum and Evolutionary Analysis of Higher Plant Mitochondrial Genomes

    PubMed Central

    Su, Aiguo; Geng, Jianing; Grover, Corrinne E.; Hu, Songnian; Hua, Jinping

    2013-01-01

    Background Mitochondria are the main manufacturers of cellular ATP in eukaryotes. The plant mitochondrial genome contains large number of foreign DNA and repeated sequences undergone frequently intramolecular recombination. Upland Cotton (Gossypium hirsutum L.) is one of the main natural fiber crops and also an important oil-producing plant in the world. Sequencing of the cotton mitochondrial (mt) genome could be helpful for the evolution research of plant mt genomes. Methodology/Principal Findings We utilized 454 technology for sequencing and combined with Fosmid library of the Gossypium hirsutum mt genome screening and positive clones sequencing and conducted a series of evolutionary analysis on Cycas taitungensis and 24 angiosperms mt genomes. After data assembling and contigs joining, the complete mitochondrial genome sequence of G. hirsutum was obtained. The completed G.hirsutum mt genome is 621,884 bp in length, and contained 68 genes, including 35 protein genes, four rRNA genes and 29 tRNA genes. Five gene clusters are found conserved in all plant mt genomes; one and four clusters are specifically conserved in monocots and dicots, respectively. Homologous sequences are distributed along the plant mt genomes and species closely related share the most homologous sequences. For species that have both mt and chloroplast genome sequences available, we checked the location of cp-like migration and found several fragments closely linked with mitochondrial genes. Conclusion The G. hirsutum mt genome possesses most of the common characters of higher plant mt genomes. The existence of syntenic gene clusters, as well as the conservation of some intergenic sequences and genic content among the plant mt genomes suggest that evolution of mt genomes is consistent with plant taxonomy but independent among different species. PMID:23940520

  14. Correlated responses of root growth and sugar concentrations to various defoliation treatments and rhythmic shoot growth in oak tree seedlings (Quercus pubescens)

    PubMed Central

    Willaume, Magali; Pagès, Loïc

    2011-01-01

    Background and Aims To understand whether root responses to aerial rhythmic growth and contrasted defoliation treatments can be interpreted under the common frame of carbohydrate availability; root growth was studied in parallel with carbohydrate concentrations in different parts of the root system on oak tree seedlings. Methods Quercus pubescens seedlings were submitted to selective defoliation (removal of mature leaves, cotyledons or young developing leaves) at appearance of the second flush and collected 1, 5 or 10 d later for morphological and biochemical measurements. Soluble sugar and starch concentrations were measured in cotyledons and apical and basal root parts. Key Results Soluble sugar concentration in the root apices diminished during the expansion of the second aerial flush and increased after the end of aerial growth in control seedlings. Starch concentration in cotyledons regularly decreased. Continuous removal of young leaves did not alter either root growth or apical sugar concentration. Starch storage in basal root segments was increased. After removal of mature leaves (and cotyledons), root growth strongly decreased. Soluble sugar concentration in the root apices drastically decreased and starch reserves in the root basal segments were emptied 5 d after defoliation, illustrating a considerable shortage in carbohydrates. Soluble sugar concentrations recovered 10 d after defoliation, after the end of aerial growth, suggesting a recirculation of sugar. No supplementary recourse to starch in cotyledons was observed. Conclusions The parallel between apical sugar concentration and root growth patterns, and the correlations between hexose concentration in root apices and their growth rate, support the hypothesis that the response of root growth to aerial periodic growth and defoliation treatments is largely controlled by carbohydrate availability. PMID:21239407

  15. Do elevations in temperature, CO2, and nutrient availability modify belowground carbon gain and root morphology in artificially defoliated silver birch seedlings?

    PubMed Central

    Huttunen, Liisa; Saravesi, Karita; Markkola, Annamari; Niemelä, Pekka

    2013-01-01

    Climate warming increases the risk of insect defoliation in boreal forests. Losses in photosynthetically active surfaces cause reduction in net primary productivity and often compromise carbon reserves of trees. The concurrent effects of climate change and removal of foliage on root growth responses and carbohydrate dynamics are poorly understood, especially in tree seedlings. We investigated if exposures to different combinations of elevated temperature, CO2, and nutrient availability modify belowground carbon gain and root morphology in artificially defoliated 1-year-old silver birches (Betula pendula). We quantified nonstructural carbohydrates (insoluble starch as a storage compound; soluble sucrose, fructose, and glucose) singly and in combination in fine roots of plants under winter dormancy. Also the total mass, fine root proportion, water content, and length of roots were defined. We hypothesized that the measured properties are lower in defoliated birch seedlings that grow with ample resources than with scarce resources. On average, fertilization markedly decreased both the proportion and the carbohydrate concentrations of fine roots in all seedlings, whereas the effect of fertilization on root water content and dry mass was the opposite. However, defoliation mitigated the effect of fertilization on the root water content, as well as on the proportion of fine roots and their carbohydrate concentrations by reversing the outcomes. Elevation in temperature decreased and elevation in CO2 increased the absolute contents of total nonstructural carbohydrates, whereas fertilization alleviated both these effects. Also the root length and mass increased by CO2 elevation. This confirms that surplus carbon in birch tissues is used as a substrate for storage compounds and for cell wall synthesis. To conclude, our results indicate that some, but not all elements of climate change alter belowground carbon gain and root morphology in defoliated silver birch seedlings. PMID

  16. QTL analysis of cotton fiber length in advanced backcross populations derived from a cross between Gossypium hirsutum and G. mustelinum.

    PubMed

    Wang, Baohua; Draye, Xavier; Zhuang, Zhimin; Zhang, Zhengsheng; Liu, Min; Lubbers, Edward L; Jones, Don; May, O Lloyd; Paterson, Andrew H; Chee, Peng W

    2017-06-01

    QTLs for fiber length mapped in three generations of advanced backcross populations derived from crossing Gossypium hirsutum and Gossypium mustelinum showed opportunities to improve elite cottons by introgression from wild relatives. The molecular basis of cotton fiber length in crosses between Gossypium hirsutum and Gossypium mustelinum was dissected using 21 BC3F2 and 12 corresponding BC3F2:3 and BC3F2:4 families. Sixty-five quantitative trait loci (QTLs) were detected by one-way analysis of variance. The QTL numbers detected for upper-half mean length (UHM), fiber uniformity index (UI), and short fiber content (SFC) were 19, 20, and 26 respectively. Twenty-three of the 65 QTLs could be detected at least twice near adjacent markers in the same family or near the same markers across different families/generations, and 32 QTLs were detected in both one-way variance analyses and mixed model-based composite interval mapping. G. mustelinum alleles increased UHM and UI and decreased SFC for five, one, and one QTLs, respectively. In addition to the main-effect QTLs, 17 epistatic QTLs were detected which helped to elucidate the genetic basis of cotton fiber length. Significant among-family genotypic effects were detected at 18, 16, and 16 loci for UHM, UI, and SFC, respectively. Six, two, and two loci showed genotype × family interaction for UHM, UI and SFC, respectively, illustrating complexities that might be faced in introgression of exotic germplasm into cultivated cotton. Co-location of many QTLs for UHM, UI, and SFC accounted for correlations among these traits, and selection of these QTLs may improve the three traits simultaneously. The simple sequence repeat (SSR) markers associated with G. mustelinum QTLs will assist breeders in transferring and maintaining valuable traits from this exotic source during cultivar development.

  17. Declines in dissolved silica concentrations in western Virginia streams (1988-2003): Gypsy moth defoliation stimulates diatoms?

    NASA Astrophysics Data System (ADS)

    Grady, Amy E.; Scanlon, Todd M.; Galloway, James N.

    2007-03-01

    Dissolved silica concentrations in western Virginia streams showed a significant bias toward declines (p < 0.0001) over the time period from 1988 to 2003. Streams with the greatest declines were those that had the highest mean dissolved silica concentrations, specific to watersheds underlain by basaltic and granitic bedrock. We examined potential geochemical, hydrological, and biological factors that could account for the observed widespread declines, focusing on six core watersheds where weekly stream chemistry data were available. No relationships were evident between stream water dissolved silica concentrations and pH, a finding supported by the results from a geochemical model applied to the dominant bedrock mineralogy. Along with changes in watershed acidity, changes in precipitation and discharge were also discounted since no significant trends were observed over the study period. Analyses of two longer-term data sets that extend back to 1979 revealed that the initiation of the dissolved silica declines coincided with the timing of a gypsy moth (Lymantria dispar) defoliation event. We develop a conceptual model centered on benthic diatoms, which are found within each of the six core watersheds but in greater abundance in the more silica-rich streams. Gypsy moth defoliation led to greater sunlight penetration and enhanced nitrate concentrations in the streams, which could have spurred population growth and silica uptake. The model can explain why the observed declines are primarily driven by decreased concentrations during low-flow conditions. This study illustrates lasting effects of disturbance on watershed biogeochemistry, in this case causing decadal-scale variability in stream water dissolved silica concentrations.

  18. Genome sequence of cultivated Upland cotton (Gossypium hirsutum TM-1) provides insights into genome evolution.

    PubMed

    Li, Fuguang; Fan, Guangyi; Lu, Cairui; Xiao, Guanghui; Zou, Changsong; Kohel, Russell J; Ma, Zhiying; Shang, Haihong; Ma, Xiongfeng; Wu, Jianyong; Liang, Xinming; Huang, Gai; Percy, Richard G; Liu, Kun; Yang, Weihua; Chen, Wenbin; Du, Xiongming; Shi, Chengcheng; Yuan, Youlu; Ye, Wuwei; Liu, Xin; Zhang, Xueyan; Liu, Weiqing; Wei, Hengling; Wei, Shoujun; Huang, Guodong; Zhang, Xianlong; Zhu, Shuijin; Zhang, He; Sun, Fengming; Wang, Xingfen; Liang, Jie; Wang, Jiahao; He, Qiang; Huang, Leihuan; Wang, Jun; Cui, Jinjie; Song, Guoli; Wang, Kunbo; Xu, Xun; Yu, John Z; Zhu, Yuxian; Yu, Shuxun

    2015-05-01

    Gossypium hirsutum has proven difficult to sequence owing to its complex allotetraploid (AtDt) genome. Here we produce a draft genome using 181-fold paired-end sequences assisted by fivefold BAC-to-BAC sequences and a high-resolution genetic map. In our assembly 88.5% of the 2,173-Mb scaffolds, which cover 89.6%∼96.7% of the AtDt genome, are anchored and oriented to 26 pseudochromosomes. Comparison of this G. hirsutum AtDt genome with the already sequenced diploid Gossypium arboreum (AA) and Gossypium raimondii (DD) genomes revealed conserved gene order. Repeated sequences account for 67.2% of the AtDt genome, and transposable elements (TEs) originating from Dt seem more active than from At. Reduction in the AtDt genome size occurred after allopolyploidization. The A or At genome may have undergone positive selection for fiber traits. Concerted evolution of different regulatory mechanisms for Cellulose synthase (CesA) and 1-Aminocyclopropane-1-carboxylic acid oxidase1 and 3 (ACO1,3) may be important for enhanced fiber production in G. hirsutum.

  19. Molecular evolution and phylogenetic analysis of genes related to cotton fibers development from wild and domesticated cotton species in Gossypium.

    PubMed

    Zhu, Huayu; Lv, Junhong; Zhao, Liang; Tong, Xiangchao; Zhou, Baoliang; Zhang, Tianzhen; Guo, Wangzhen

    2012-06-01

    The domestication of both diploid and tetraploid cotton species was carried out for fiber utilization. To understand the origin and domestication of fibers, 18 genes related to fiber development were individually cloned and sequenced from 22 different cotton species. Their structures, phylogenetic relationship and molecular evolution were further studied. In the orthologous and homeologous loci of the 18 genes, the sequence and structure of 72.22% were conserved and 27.78% were diverse. Tree topologies constructed based on the combined sequences showed that all 13 D-genome species were congruent with Fryxell's subsection taxonomy, the A- and D-subgenomes independently evolved in the allopolyploid after polyploid formation, and Gossypium raimondii had the closest relationship with all allotetraploids of D-subgenomes. The molecular evolutionary rates revealed approximately equivalent rates among different D-genome species, and purifying selection acted on all genes in the wild D-genome species. Among orthologs and homeologs, the D-subgenomes had higher evolutionary rates than the A-subgenomes in tetraploid cotton species, and the cultivars had higher evolutionary rates than either the semi-domesticated or wild species. Our study revealed that human domestication altered the molecular evolutionary pattern of genes related to fiber development, and Gossypium hirsutum endured greater selective pressures than Gossypium barbadense during the domestication process.

  20. Genome-wide identification of the TIFY gene family in three cultivated Gossypium species and the expression of JAZ genes

    PubMed Central

    Sun, Quan; Wang, Guanghao; Zhang, Xiao; Zhang, Xiangrui; Qiao, Peng; Long, Lu; Yuan, Youlu; Cai, Yingfan

    2017-01-01

    TIFY proteins are plant-specific proteins containing TIFY, JAZ, PPD and ZML subfamilies. A total of 50, 54 and 28 members of the TIFY gene family in three cultivated cotton species—Gossypium hirsutum, Gossypium barbadense and Gossypium arboretum—were identified, respectively. The results of phylogenetic analysis showed that these TIFY genes were divided into eight clusters. The different clusters of gene family members often have similar gene structures, including the number of exons. The results of quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed that different JAZ genes displayed distinct expression patterns in the leaves of upland cotton under treatment with Gibberellin (GA), methyl jasmonate (MeJA), Jasmonic acid (JA) and abscisic acid (ABA). Different groups of JAZ genes exhibited different expression patterns in cotton leaves infected with Verticillium dahliae. The results of the comparative analysis of TIFY genes in the three cultivated species will be useful for understanding the involvement of these genes in development and stress resistance in cotton. PMID:28186193

  1. Characterization and expression analysis of TERMINAL FLOWER1 homologs from cultivated alloteraploid cotton (Gossypium hirsutum) and its diploid progenitors.

    PubMed

    Argiriou, Anagnostis; Michailidis, Georgios; Tsaftaris, Athanasios S

    2008-10-09

    The seasonal cycle and persistence of a plant is governed by a combination of the determinate or indeterminate status of shoot and root apical meristems. A perennial plant is one in which the apical meristem of at least one of its shoot axes remains indeterminate beyond the first growth season. TERMINAL FLOWER1 (TFL1) genes play important roles in regulating flowering time, the fate of inflorescence meristem and perenniality. To investigate the role of TFL1-like genes in the determination of the apical meristems in an industrially important crop cultivated for its fibers, we isolated and characterized two TFL1 homologs (TFL1a and TFL1b) from tetraploid cultivated cotton (Gossypium hirsutum) and its diploid progenitors (Gossypium arboreum and Gossypium raimondii). All isolated genes maintain the same exon-intron organization. Their phylogenetic analysis at the amino acid level confirmed that the isolated sequences are TFL1-like genes and collocate in the TFL1 clade of the PEBP protein family. Expression analysis revealed that the genes TFL1a and TFL1b have slightly different expression patterns, suggesting different functional roles in the determination of the meristems. Additionally, promoter analysis by computational methods revealed the presence of common binding motifs in TFL1-like promoters. These are the first reported TFL1-like genes isolated from cotton, the most important crop for the textile industry.

  2. Genetic diversity and structure of elite cotton germplasm (Gossypium hirsutum L.) using genome-wide SNP data.

    PubMed

    Ai, XianTao; Liang, YaJun; Wang, JunDuo; Zheng, JuYun; Gong, ZhaoLong; Guo, JiangPing; Li, XueYuan; Qu, YanYing

    2017-07-28

    Cotton (Gossypium spp.) is the most important natural textile fiber crop, and Gossypium hirsutum L. is responsible for 90% of the annual cotton crop in the world. Information on cotton genetic diversity and population structure is essential for new breeding lines. In this study, we analyzed population structure and genetic diversity of 288 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China, using genome-wide single nucleotide polymorphisms (SNP) markers. The average polymorphsim information content (PIC) was 0.25, indicating a relatively low degree of genetic diversity. Population structure analysis revealed extensive admixture and identified three subgroups. Phylogenetic analysis supported the subgroups identified by STRUCTURE. The results from both population structure and phylogenetic analysis were, for the most part, in agreement with pedigree information. Analysis of molecular variance revealed a larger amount of variation was due to diversity within the groups. Establishment of genetic diversity and population structure from this study could be useful for genetic and genomic analysis and systematic utilization of the standing genetic variation in upland cotton.

  3. Breeding Potential of Introgression Lines Developed from Interspecific Crossing between Upland Cotton (Gossypium hirsutum) and Gossypium barbadense: Heterosis, Combining Ability and Genetic Effects

    PubMed Central

    Li, Xingli; Pei, Wenfeng

    2016-01-01

    Upland cotton (Gossypium hirstum L.), which produces more than 95% of the world natural cotton fibers, has a narrow genetic base which hinders progress in cotton breeding. Introducing germplasm from exotic sources especially from another cultivated tetraploid G. barbadense L. can broaden the genetic base of Upland cotton. However, the breeding potential of introgression lines (ILs) in Upland cotton with G. barbadense germplasm integration has not been well addressed. This study involved six ILs developed from an interspecific crossing and backcrossing between Upland cotton and G. barbadense and represented one of the first studies to investigate breeding potentials of a set of ILs using a full diallel analysis. High mid-parent heterosis was detected in several hybrids between ILs and a commercial cultivar, which also out-yielded the high-yielding cultivar parent in F1, F2 and F3 generations. A further analysis indicated that general ability (GCA) variance was predominant for all the traits, while specific combining ability (SCA) variance was either non-existent or much lower than GCA. The estimated GCA effects and predicted additive effects for parents in each trait were positively correlated (at P<0.01). Furthermore, GCA and additive effects for each trait were also positively correlated among generations (at P<0.05), suggesting that F2 and F3 generations can be used as a proxy to F1 in analyzing combining abilities and estimating genetic parameters. In addition, differences between reciprocal crosses in F1 and F2 were not significant for yield, yield components and fiber quality traits. But maternal effects appeared to be present for seed oil and protein contents in F3. This study identified introgression lines as good general combiners for yield and fiber quality improvement and hybrids with high heterotic vigor in yield, and therefore provided useful information for further utilization of introgression lines in cotton breeding. PMID:26730964

  4. Breeding Potential of Introgression Lines Developed from Interspecific Crossing between Upland Cotton (Gossypium hirsutum) and Gossypium barbadense: Heterosis, Combining Ability and Genetic Effects.

    PubMed

    Zhang, Jinfa; Wu, Man; Yu, Jiwen; Li, Xingli; Pei, Wenfeng

    2016-01-01

    Upland cotton (Gossypium hirstum L.), which produces more than 95% of the world natural cotton fibers, has a narrow genetic base which hinders progress in cotton breeding. Introducing germplasm from exotic sources especially from another cultivated tetraploid G. barbadense L. can broaden the genetic base of Upland cotton. However, the breeding potential of introgression lines (ILs) in Upland cotton with G. barbadense germplasm integration has not been well addressed. This study involved six ILs developed from an interspecific crossing and backcrossing between Upland cotton and G. barbadense and represented one of the first studies to investigate breeding potentials of a set of ILs using a full diallel analysis. High mid-parent heterosis was detected in several hybrids between ILs and a commercial cultivar, which also out-yielded the high-yielding cultivar parent in F1, F2 and F3 generations. A further analysis indicated that general ability (GCA) variance was predominant for all the traits, while specific combining ability (SCA) variance was either non-existent or much lower than GCA. The estimated GCA effects and predicted additive effects for parents in each trait were positively correlated (at P<0.01). Furthermore, GCA and additive effects for each trait were also positively correlated among generations (at P<0.05), suggesting that F2 and F3 generations can be used as a proxy to F1 in analyzing combining abilities and estimating genetic parameters. In addition, differences between reciprocal crosses in F1 and F2 were not significant for yield, yield components and fiber quality traits. But maternal effects appeared to be present for seed oil and protein contents in F3. This study identified introgression lines as good general combiners for yield and fiber quality improvement and hybrids with high heterotic vigor in yield, and therefore provided useful information for further utilization of introgression lines in cotton breeding.

  5. Mapping QTLs for drought tolerance in an F2:3 population from an inter-specific cross between Gossypium tomentosum and Gossypium hirsutum.

    PubMed

    Zheng, J Y; Oluoch, G; Riaz Khan, M K; Wang, X X; Cai, X Y; Zhou, Z L; Wang, C Y; Wang, Y H; Li, X Y; Liu, F; Wang, K B

    2016-08-05

    Cotton is one of the most important natural fiber crops in the world. Its growth and yield is greatly limited by drought. A quantitative trait locus (QTL) analysis was therefore conducted to investigate the genetic basis of drought tolerance in cotton (Gossypium spp) using 188 F2:3 lines developed from an inter-specific cross between a wild cotton species, G. tomentosum, and an upland cotton, G. hirsutum (CRI-12). A genetic map was constructed using 1295 simple sequence repeat markers, which amplified 1342 loci, distributed on 26 chromosomes, covering 3328.24 cM. A field experiment was conducted in two consecutive years (2014 and 2015) and 11 morphological and physiological traits were recorded under water-limited (W1)/well-watered (W2) regimes at three growth stages (bud, flowering, and full boll). The traits measured included chlorophyll content, plant height, leaf area, leaf number, leaf fresh weight, leaf dry weight, boll weight, number of bolls per plant, and the number of fruiting branches. Sixty-seven and 35 QTLs were found under the W1 and W2 conditions, respectively. Of these, the majority exhibited partial dominance or over-dominance genetic effects for increasing the trait values. Four consistent QTLs were found under the W1 treatment on chromosomes 5, 8, 9, and 16, whereas no consistent QTL was found in W2. Thirteen QTL clusters were also identified on nine chromosomes (2, 3, 5, 6, 9, 14, 15, 16, and 21). These results will help to elucidate the genetic basis of drought tolerance in cotton.

  6. Transcriptome Analysis Suggests That Chromosome Introgression Fragments from Sea Island Cotton (Gossypium barbadense) Increase Fiber Strength in Upland Cotton (Gossypium hirsutum).

    PubMed

    Lu, Quanwei; Shi, Yuzhen; Xiao, Xianghui; Li, Pengtao; Gong, Juwu; Gong, Wankui; Liu, Aiying; Shang, Haihong; Li, Junwen; Ge, Qun; Song, Weiwu; Li, Shaoqi; Zhang, Zhen; Rashid, Md Harun Or; Peng, Renhai; Yuan, Youlu; Huang, Jinling

    2017-10-05

    As high-strength cotton fibers are critical components of high quality cotton, developing cotton cultivars with high-strength fibers as well as high yield is a top priority for cotton development. Recently, chromosome segment substitution lines (CSSLs) have been developed from high-yield Upland cotton (Gossypium hirsutum) crossed with high-quality Sea Island cotton (G. barbadense). Here, we constructed a CSSL population by crossing CCRI45, a high-yield Upland cotton cultivar, with Hai1, a Sea Island cotton cultivar with superior fiber quality. We then selected two CSSLs with significantly higher fiber strength than CCRI45 (MBI7747 and MBI7561), and one CSSL with lower fiber strength than CCRI45 (MBI7285), for further analysis. We sequenced all four transcriptomes at four different time points postanthesis, and clustered the 44,678 identified genes by function. We identified 2200 common differentially-expressed genes (DEGs): those that were found in both high quality CSSLs (MBI7747 and MBI7561), but not in the low quality CSSL (MBI7285). Many of these genes were associated with various metabolic pathways that affect fiber strength. Upregulated DEGs were associated with polysaccharide metabolic regulation, single-organism localization, cell wall organization, and biogenesis, while the downregulated DEGs were associated with microtubule regulation, the cellular response to stress, and the cell cycle. Further analyses indicated that three genes, XLOC_036333 [mannosyl-oligosaccharide-α-mannosidase (MNS1)], XLOC_029945 (FLA8), and XLOC_075372 (snakin-1), were potentially important for the regulation of cotton fiber strength. Our results suggest that these genes may be good candidates for future investigation of the molecular mechanisms of fiber strength formation and for the improvement of cotton fiber quality through molecular breeding. Copyright © 2017 Lu et al.

  7. Plot- and landscape-level changes in climate and vegetation following defoliation of exotic saltcedar (Tamarix sp.) from the biocontrol agent Diorhabda carinulata along a stream in the Mojave Desert (USA)

    USGS Publications Warehouse

    Bateman, H.L.; Nagler, P.L.; Glenn, E.P.

    2013-01-01

    The biocontrol agent, northern tamarisk beetle (Diorhabda carinulata), has been used to defoliate non-native saltcedar (Tamarix spp.) in USA western riparian systems since 2001. Biocontrol has the potential to impact biotic communities and climatic conditions in affected riparian areas. To determine the relationships between biocontrol establishment and effects on vegetation and climate at the plot and landscape scales, we measured temperature, relative humidity, foliage canopy, solar radiation, and used satellite imagery to assess saltcedar defoliation and evapotranspiration (ET) along the Virgin River in the Mojave Desert. Following defoliation solar radiation increased, daily humidity decreased, and maximum daily temperatures tended to increase. MODIS and Landsat satellite imagery showed defoliation was widespread, resulting in reductions in ET and vegetation indices. Because biocontrol beetles are spreading into new saltcedar habitats on arid western rivers, and the eventual equilibrium between beetles and saltcedar is unknown, it is necessary to monitor trends for ecosystem functions and higher trophic-level responses in habitats impacted by biocontrol.

  8. CO2 assimilation of primary and regrowth foliage of red maple (Acer rubrum L.) and red oak (Quercus rubra L.): response to defoliation.

    PubMed

    Heichel, G H; Turner, N C

    1983-03-01

    The CO2 assimilation of primary foliage of red maple (Acer rubrum L.) and red oak (Quercus rubra L.), and of regrowth foliage produced in response to simulated insect defoliation, was measured throughout the season by infrared gas analysis: parallel measurements of leaf conductance were obtained by ventilated diffusion porometry. The rate of net photosynthesis, measured at a quantum flux density of 1,150 μmol m(-2)s(-1), of primary foliage of both species increased from slightly negative values to about 5 μmol m(-2)s(-1) by early June. Thereafter the rate of photosynthesis of maple slowly declined to about 4 μmol m(-2)s(-1) before onset of a senescent decline in early September, while that of oak slowly increased to about 8 μmol m(-2)s(-1) before onset of senescence. Manual defoliation to simulate insect attack in mid-June elicited refoliation proportional to the severity of defoliation in early July. After 100% defoliation, fully expanded regrowth foliage of maple, but not of oak, had a rate of net photosynthesis from mid-July through September that was about 50% higher than in the primary foliage of undefoliated trees. A 30 to 60% enhancement of photosynthesis of residual primary foliage remaining on 50 and 75% defoliated trees during July was also observed. The seasonal patterns of CO2 exchange of primary and regrowth foliage, and the enhancement of CO2 assimilation in residual foliage, was paralleled by similar changes in leaf conductance to water vapour.Carbon budgets of leaf canopies of each species showed that the net assimilation of the leaf canopy of both species ranged from 19 to 67% more than what would have been expected solely from replacement of leaf area. This response was greater in maple than in oak, presumably a reflection of the high rate of CO2 assimilation of regrowth maple foliage compared with that of the undefoliated control in maple.The increased CO2 assimilation of regrowth maple foliage and the increases in CO2 assimilation of

  9. Comparative transcriptome analysis of Gossypium hirsutum L. in response to sap sucking insects: aphid and whitefly

    PubMed Central

    2013-01-01

    Background Cotton (Gossypium hirsutum L.) is a major fiber crop that is grown worldwide; it faces extensive damage from sap-sucking insects, including aphids and whiteflies. Genome-wide transcriptome analysis was performed to understand the molecular details of interaction between Gossypium hirsutum L. and sap-sucking pests, namely Aphis gossypii (Aphid) and Bemisia tabacci (Whiteflies). Roche’s GS-Titanium was used to sequence transcriptomes of cotton infested with aphids and whiteflies for 2 h and 24 h. Results A total of 100935 contigs were produced with an average length of 529 bp after an assembly in all five selected conditions. The Blastn of the non-redundant (nr) cotton EST database resulted in the identification of 580 novel contigs in the cotton plant. It should be noted that in spite of minimal physical damage caused by the sap-sucking insects, they can change the gene expression of plants in 2 h of infestation; further change in gene expression due to whiteflies is quicker than due to aphids. The impact of the whitefly 24 h after infestation was more or less similar to that of the aphid 2 h after infestation. Aphids and whiteflies affect many genes that are regulated by various phytohormones and in response to microbial infection, indicating the involvement of complex crosstalk between these pathways. The KOBAS analysis of differentially regulated transcripts in response to aphids and whiteflies indicated that both the insects induce the metabolism of amino acids biosynthesis specially in case of whiteflies infestation at later phase. Further we also observed that expression of transcript related to photosynthesis specially carbon fixation were significantly influenced by infestation of Aphids and Whiteflies. Conclusions A comparison of different transcriptomes leads to the identification of differentially and temporally regulated transcripts in response to infestation by aphids and whiteflies. Most of these differentially expressed contigs were

  10. Sister-chromatid exchanges and cell-cycle delay in Chinese hamster V79 cells treated with 9 organophosphorus compounds (8 pesticides and 1 defoliant).

    PubMed

    Chen, H H; Sirianni, S R; Huang, C C

    1982-03-01

    Significant increase of sister-chromatid exchanges (SCE) in V79 cells treated with 2 organophosphorus pesticides (OPP), fenthion and oxydemeton-methyl, was observed. The other 7 compounds (6 OPP and 1 defoliant) namely, amaze, azinphos-methyl, bolstar, DEF-defoliant, fensulfothion, monitor and nemacur caused no increase of SCE frequencies at the doses tested. All the compounds except fensulfothion and oxydemeton-methyl induced cell-cycle delay in varying degrees. Cell-cycle delay caused by an OPP was found to be dose-dependent. Based on these data as well as others reported, it would appear that OPP which induce no SCE increase and no or slight cell-cycle delay could be considered as good candidates to substitute the pesticides that have been found to be harmful to the environment.

  11. Development of a data management front end for use with a LANDSAT based information system. [assessing gypsy moth defoliation damage in Pennsylvania

    NASA Technical Reports Server (NTRS)

    Turner, B. J. (Principal Investigator)

    1982-01-01

    A user friendly front end was constructed to facilitate access to the LANDSAT mosaic data base supplied by JPL and to process both LANDSAT and ancillary data. Archieval and retrieval techniques were developed to efficiently handle this data base and make it compatible with requirements of the Pennsylvania Bureau of Forestry. Procedures are ready for: (1) forming the forest/nonforest mask in ORSER compressed map format using GSFC-supplied classification procedures; (2) registering data from a new scene (defoliated) to the mask (which may involve mosaicking if the area encompasses two LANDSAT scenes; (3) producing a masked new data set using the MASK program; (4) analyzing this data set to produce a map showing degrees of defoliation, output on the Versatec plotter; and (5) producing color composite maps by a diazo-type process.

  12. Development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen forest in eastern China

    NASA Astrophysics Data System (ADS)

    Jing, Jun; Xia, Lingdan; Li, Kai

    2016-09-01

    The aim of this work was to understand the development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen broad-leaved forest in China. We measured the main developmental parameters of three typical defoliating insects (i.e., Ourapteryx ebuleata szechuana, Biston marginata, and Euproctis angulata) and their preferences for five host plants at temperatures from 16°C to 31°C at 3°C intervals in the Tiantong National Forest Research station in eastern China. The results showed the following. 1) An appropriate rise in temperature increases the survival rate with an increase in the number of offspring. The developmental durations for these three insects were shortened, and pupal weight increased with an increase in temperature. 2) A shift in the preference for host plants for these three insects was observedat elevated temperatures. They all preferred to feed on Schima superba and Castanopsis sclerophylla at elevated temperatures, showing an opposite response to the other three plants. The daily leaf consumption of the three insects was positively correlated with their feeding preference, with more leaves being consumed from the plants they preferred. 3) For O. ebuleata szechuana larvae, daily leaf consumption initially increased and then decreased with increasing temperatures. In contrast, Biston marginata and Euproctis angulata larvae consumed more leaves at elevated temperatures. The feeding preferences of O. ebuleata szechuana and Biston marginata were more sensitive to changing temperatures than that of Euproctis angulata laevae. We concluded that increased numbers of offspring and generations, pupal weights, and a shift in preference to two plants for these three defoliating insects might lead to severe damage to these two plants which would enhance the fragmentation and decrease the stability of the forest communities under changing temperatures. Meanwhile, the variations in the responses of

  13. Does gibberellin biosynthesis play a critical role in the growth of Lolium perenne? Evidence from a transcriptional analysis of gibberellin and carbohydrate metabolic genes after defoliation

    PubMed Central

    Liu, Qianhe; Jones, Chris S.; Parsons, Anthony J.; Xue, Hong; Rasmussen, Susanne

    2015-01-01

    Global meat and milk production depends to a large extent on grazed pastures, with Lolium perenne being the major forage grass in temperate regions. Defoliation and subsequent regrowth of leaf blades is a major and essential event with respect to L. perenne growth and productivity. Following defoliation, carbohydrates (mainly fructans and sucrose) have to be mobilized from heterotrophic tissues to provide energy and carbon for regrowth of photosynthetic tissues. This mobilization of reserve carbohydrates requires a substantial change in the expression of genes coding for enzymes involved in carbohydrate metabolism. Here we tested the hypothesis that gibberellins (GA) are at the core of the processes regulating the expression of these genes. Thus, we examined the transcript profiles of genes involved in carbohydrate and GA metabolic pathways across a time course regrowth experiment. Our results show that following defoliation, the immediate reduction of carbohydrate concentrations in growing tissues is associated with a concomitant increase in the expression of genes encoding carbohydrate mobilizing invertases, and was also associated with a strong decrease in the expression of fructan synthesizing fructosyltransferase genes. We also show that the decrease in fructan levels is preceded by increased expression of the GA activating gene GA3-oxidase and decreased expression of the GA inactivating gene GA2-oxidase in sheaths. GA3-oxidase expression was negatively, while GA2-oxidase positively linked to sucrose concentrations. This study provides indicative evidence that gibberellins might play a role in L. perenne regrowth following defoliation and we hypothesize that there is a link between gibberellin regulation and sugar metabolism in L. perenne. PMID:26579182

  14. The Influence of Apical and Basal Defoliation on the Canopy Structure and Biochemical Composition of Vitis vinifera cv. Shiraz Grapes and Wine

    PubMed Central

    Zhang, Pangzhen; Wu, Xiwen; Needs, Sonja; Liu, Di; Fuentes, Sigfredo; Howell, Kate

    2017-01-01

    Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit zone to reduce the leaf photosynthetic area, and to increase sunlight exposure of grape bunches. Apical leaf removal is not commonly practiced, and therefore its influence on canopy structure and resultant wine aroma is not well-studied. This study quantified the influences of apical and basal defoliation on canopy structure parameters using canopy cover photography and computer vision algorithms. The influence of canopy structure changes on the chemical compositions of grapes and wines was investigated over two vintages (2010–2011 and 2015–2016) in Yarra Valley, Australia. The Shiraz grapevines were subjected to five different treatments: no leaf removal (Ctrl); basal (TB) and apical (TD) leaf removal at veraison and intermediate ripeness, respectively. Basal leaf removal significantly reduced the leaf area index and foliage cover and increased canopy porosity, while apical leaf removal had limited influences on canopy parameters. However, the latter tended to result in lower alcohol level in the finished wine. Statistically significant increases in pH and decreases in TA was observed in shaded grapes, while no significant changes in the color profile and volatile compounds of the resultant wine were found. These results suggest that apical leaf removal is an effective method to reduce wine alcohol concentration with minimal influences on wine composition. PMID:28736728

  15. Growth and physiology of woody plants in response to elevated CO{sub 2} and defoliation in an open-top field study

    SciTech Connect

    Volin, J.C.; Kruger, E.L.; Lindroth, R.L.

    1995-06-01

    Seedlings of sugar maple (Acer saccharum) and trembling aspen (Populus tremuloides) were exposed for an entire growing season to ambient (-357 {mu}mol mol{sup -1}) or elevated ({approximately}650 {mu}mol mol{sup -1}) levels of CO{sub 2}. To simulate natural defoliation, a subset of the seedlings within each CO{sub 2} treatment also had 50 % of their foliage clipped in late June. During the growing season there were three sequential harvests. The first was coincident with defoliation, followed by a mid-season harvest in early August and a final harvest after leaf senescence. Allocational, morphological and physiological determinants of growth were measured at each harvest. This is the first of two years of CO{sub 2} exposure, and preliminary analyses indicate an increase in both photosynthesis and growth for trembling aspen and sugar maple. However, after accounting for initial growth differences, the magnitude of this enhancement appears to have diminished over the course of the growing season, which can largely be explained by changes in physiological response. Interestingly, there was no growth {open_quotes}acclimation{close_quotes} to an enriched-CO{sub 2} environment for sugar maple seedlings that had been artificially defoliated.

  16. Defoliation effects on enzyme activities of the ectomycorrhizal fungus Suillus granulatus in a Pinus contorta (lodgepole pine) stand in Yellowstone National Park.

    PubMed

    Cullings, Ken; Ishkhanova, Galina; Henson, Joan

    2008-11-01

    Ectomycorrhizal (EM) basidiomycete fungi are obligate mutualists of pines and hardwoods that receive fixed C from the host tree. Though they often share most recent common ancestors with wood-rotting fungi, it is unclear to what extent EM fungi retain the ability to express enzymes that break down woody substrates. In this study, we tested the hypothesis that the dominant EM fungus in a pure pine system retains the ability to produce enzymes that break down woody substrates in a natural setting, and that this ability is inducible by reduction of host photosynthetic potential via partial defoliation. To achieve this, pines in replicate blocks were defoliated 50% by needle removal, and enzyme activities were measured in individual EM root tips that had been treated with antibiotics to prevent possible bacterial activity. Results indicate that the dominant EM fungal species (Suillus granulatus) expressed all enzymes tested (endocellulase D: -glucosidase, laccase, manganese peroxidase, lignin peroxidase, phosphatase and protease), and that activities of these enzymes increased significantly (P < 0.001) in response to defoliation. Thus, this EM fungus (one of the more specialized mutualists of pine) has the potential to play a significant role in C, N and P cycling in this forested ecosystem. Therefore, many above-ground factors that reduce photosynthetic potential or divert fixed C from roots may have wide-reaching ecosystem effects.

  17. Identification of a new sucrose transporter in rye-grass (LpSUT2): effect of defoliation and putative fructose sensing.

    PubMed

    Berthier, Alexandre; Meuriot, Frédéric; Dédaldéchamp, Fabienne; Lemoine, Rémi; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie

    2014-11-01

    Rye-grass fast regrowth after defoliation results from an efficient mobilization of C reserves which are transported as sucrose towards regrowing leaves, and which can be supported by one or several sucrose transporters (SUTs) like LpSUT1. Therefore, our objectives were to isolate, identify, characterize and immunolocalize such sucrose transporters. A protein (LpSUT2) showing a twelve spanning trans-membrane domain, extended N terminal and internal cytoplasmic loop, and kinetic properties consistent with well-known sucrose transporters, was isolated and successfully characterized. Along with LpSUT1, it was mainly localized in mesophyll cells of leaf sheaths and elongating leaf bases. These transporters were also found in parenchyma bundle sheath (PBS) cells but they were not detected in the sieve element/companion cell complex of the phloem. Unlike LpSUT1 transcript levels which increased as a response to defoliation in source and sink tissues, LpSUT2 transcript levels were unaffected by defoliation and weakly expressed. Interestingly, sucrose transport by LpSUT2 was inhibited by fructose. LpSUT1 and LpSUT2 appeared to have different functions. LpSUT1 is proposed to play a key role in C storage and mobilization by allowing sucrose transport between PBS and mesophyll cells, depending on the plant C status. LpSUT2 could be involved in sucrose/fructose sensing at sub-cellular level. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. Genetic gains from selection for fiber traits in Gossypium hirsutum L.

    PubMed

    de Faria, G M P; Sanchez, C F B; de Carvalho, L P; da Silva Oliveira, M; Cruz, C D

    2016-11-21

    Brazil is among the five largest producers of cotton in the world, cultivating the species Gossypium hirsutum L. r. latifolium Hutch. The cultivars should have good fiber quality as well as yield. Genetic improvement of fiber traits requires the study of the genetic structure of the populations under improvement, leading to the identification of promising parent plants. To this end, it is important to acquire some information, such as estimates of genetic variance components and heritability coefficients, which will support the appropriate choice of the breeding strategy to be employed as well as enable the estimation of gains from selection. This study aimed to evaluate some agronomic characteristics, such as fiber quality and yield, estimating genetic parameters for the purpose of predicting earnings. Twelve cultivars of cotton, including four male progenitors (CNPA 01-42, BRS Verde, Glandless, and Okra leaf) and eight female progenitors (Delta opal, CNPA 7H, Aroeira, Antares, Sucupira, Facual, Precoce 3, and CNPA 8H), were used in performing crosses according to design I, proposed by Comstock and Robinson (1948). The experimental design was a randomized block with four replications. We observed genetic variability among all traits as well as higher efficiency of selection for the gains related to traits. Our results showed that the combined selection presented the highest genetic gains for all traits. For fiber length, the female/male selection and the combined selection resulted in the highest genetic gain.

  19. Identification of biotic and abiotic stress up-regulated ESTs in Gossypium arboreum.

    PubMed

    Barozai, Muhammad Younas Khan; Husnain, Tayyab

    2012-02-01

    Asiatic desi cotton (Gossypium arboreum) shows great potential against biotic and abiotic stresses. The stress resistant nature makes it a best source for the identification of biotic and abiotic stress resistant genes. As in many plants same set of genes show responding behavior against the various abiotic and biotic stresses. Thus in the present study the ESTs from the G. arboreum drought stressed leaves were subjected to find the up-regulated ESTs in abiotic and biotic stresses through homology and in-silico analysis. A cDNA library has been constructed from the drought stressed G. arboreum plant. 778 clones were randomly picked and sequenced. All these sequences were subjected to in-silico identification of biotic and abiotic up-regulated ESTs. Total 39 abiotic and biotic up-regulated ESTs were identified. The results were further validated by real-time PCR; by randomly selection of ten ESTs. These findings will help to develop stress resistant crop varieties for better yield and growth performance under stresses.

  20. Structural analysis of Gossypium hirsutum fibers grown under greenhouse and hydroponic conditions.

    PubMed

    Natalio, Filipe; Tahir, Muhammad Nawaz; Friedrich, Norman; Köck, Margret; Fritz-Popovski, Gerhard; Paris, Oskar; Paschke, Reinhard

    2016-06-01

    Cotton is the one of the world's most important crops. Like any other crop, cotton growth/development and fiber quality is highly dependent on environmental factors. Increasing global weather instability has been negatively impacting its economy. Cotton is a crop that exerts an intensive pressure over natural resources (land and water) and demands an overuse of pesticides. Thus, the search for alternative cotton culture methods that are pesticide-free (biocotton) and enable customized standard fiber quality should be encouraged. Here we describe a culture of Gossypium hirsutum ("Upland" Cotton) utilizing a greenhouse and hydroponics in which the fibers are morphological similar to conventional cultures and structurally fit into the classical two-phase cellulose I model with 4.19nm crystalline domains surrounded by amorphous regions. These fibers exhibit a single crystalline form of cellulose I-Iß, monoclinic unit cell. Fiber quality bulk analysis shows an improved length, strength, whiteness when compared with soil-based cultures. Finally, we show that our fibers can be spun, used for production of non-woven fabrics and indigo-vat stained demonstrating its potential in industrial and commercial applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Surface plasmon resonance detection of transgenic Cry1Ac cotton ( Gossypium spp.).

    PubMed

    Zhao, Zhuoya; Chen, Yanshan; Xu, Wenzhong; Ma, Mi

    2013-03-27

    The detection and identification of genetically modified (GM) plants are challenging issues that have arisen from the potential negative impacts of extensive cultivation of transgenic plants. The screening process is a long-term focus and needs specific detection strategies. Surface plasmon resonance (SPR) has been used to detect a variety of biomolecules including proteins and nucleic acids due to its ability to monitor specific intermolecular interactions. In the present study, two high-throughput, label-free, and specific methods based on SPR technology were developed to detect transgenic Cry1Ac cotton ( Gossypium spp.) by separately targeting protein and DNA. In the protein-based detection system, monoclonal anti-Cry1Ac antibodies were immobilized on the surface of a CM5 sensor chip. Conventional cotton samples were used to define the detection threshold. Transgenic cotton was easily identified within 5 min per sample. For the DNA-based model, a 25-mer biotinylated oligonucleotide probe was immobilized on an SA sensor chip. PCR products of Cry1Ac (230 bp) were used to investigate the reaction conditions. The sensitivity of the constructed sensor chip was identified at concentrations as low as 0.1 nM based on its complementary base pairing.

  2. Molecular cloning and expression analysis of five GhRAXs in upland cotton (Gossypium hirsutum L.).

    PubMed

    Dai, T C; Wang, Z M

    2015-10-05

    The formation of axillary meristems in leaf axils is a prerequisite for the development of lateral shoots, which largely contribute to plant architecture. Several transcription factor-encoding genes, including CUC3, RAX, LAS, LOF1, and ROX, have been cloned by screening for axillary meristem mutants in Arabidopsis thaliana. These genes will facilitate our understanding of the mechanisms underlying axillary meristem development. In this study, we report the cloning of five genes from cotton (Gossypium hirsutum L.) that are orthologous to A. thaliana REGULATORS OFAXILLARY MERISTEMS (RAX) and tomato Blind (Bl), and they are designated GhRAX1, 2, 3, 4, and 5. Sequence analyses indicated that all five genes shared conserved protein domains with RAX and Bl. Phylogenetic analyses of protein sequences revealed that GhRAX2/3/4 were close to RAX1, whereas GhRAX1 and GhRAX5 were close to RAX3. Expression patterns of these genes in different tissues were also analyzed using real-time PCR.

  3. Comprehensive analysis of TCP transcription factors and their expression during cotton (Gossypium arboreum) fiber early development

    PubMed Central

    Ma, Jun; Liu, Fang; Wang, Qinglian; Wang, Kunbo; Jones, Don C.; Zhang, Baohong

    2016-01-01

    TCP proteins are plant-specific transcription factors implicated to perform a variety of physiological functions during plant growth and development. In the current study, we performed for the first time the comprehensive analysis of TCP gene family in a diploid cotton species, Gossypium arboreum, including phylogenetic analysis, chromosome location, gene duplication status, gene structure and conserved motif analysis, as well as expression profiles in fiber at different developmental stages. Our results showed that G. arboreum contains 36 TCP genes, distributing across all of the thirteen chromosomes. GaTCPs within the same subclade of the phylogenetic tree shared similar exon/intron organization and motif composition. In addition, both segmental duplication and whole-genome duplication contributed significantly to the expansion of GaTCPs. Many these TCP transcription factor genes are specifically expressed in cotton fiber during different developmental stages, including cotton fiber initiation and early development. This suggests that TCP genes may play important roles in cotton fiber development. PMID:26857372

  4. Characterization and Functional Analysis of PEBP Family Genes in Upland Cotton (Gossypium hirsutum L.)

    PubMed Central

    Wang, Congcong; Pang, Chaoyou; Wei, Hengling; Wang, Hantao; Song, Meizhen; Fan, Shuli; Yu, Shuxun

    2016-01-01

    Upland cotton (Gossypium hirsutum L.) is a naturally occurring photoperiod-sensitive perennial plant species. However, sensitivity to the day length was lost during domestication. The phosphatidylethanolamine-binding protein (PEBP) gene family, of which three subclades have been identified in angiosperms, functions to promote and suppress flowering in photoperiod pathway. Recent evidence indicates that PEBP family genes play an important role in generating mobile flowering signals. We isolated homologues of the PEBP gene family in upland cotton and examined their regulation and function. Nine PEBP-like genes were cloned and phylogenetic analysis indicated the genes belonged to four subclades (FT, MFT, TFL1 and PEBP). Cotton PEBP-like genes showed distinct expression patterns in relation to different cotton genotypes, photoperiod responsive and cultivar maturity. The GhFT gene expression of a semi-wild race of upland cotton were strongly induced under short day condition, whereas the GhPEBP2 gene expression was induced under long days. We also elucidated that GhFT but not GhPEBP2 interacted with FD-like bZIP transcription factor GhFD and promote flowering under both long- and short-day conditions. The present result indicated that GhPEBP-like genes may perform different functions. This work corroborates the involvement of PEBP-like genes in photoperiod response and regulation of flowering time in different cotton genotypes, and contributes to an improved understanding of the function of PEBP-like genes in cotton. PMID:27552108

  5. Comparative Evolutionary and Developmental Dynamics of the Cotton (Gossypium hirsutum) Fiber Transcriptome

    PubMed Central

    Yoo, Mi-Jeong; Wendel, Jonathan F.

    2014-01-01

    The single-celled cotton (Gossypium hirsutum) fiber provides an excellent model to investigate how human selection affects phenotypic evolution. To gain insight into the evolutionary genomics of cotton domestication, we conducted comparative transcriptome profiling of developing cotton fibers using RNA-Seq. Analysis of single-celled fiber transcriptomes from four wild and five domesticated accessions from two developmental time points revealed that at least one-third and likely one-half of the genes in the genome are expressed at any one stage during cotton fiber development. Among these, ∼5,000 genes are differentially expressed during primary and secondary cell wall synthesis between wild and domesticated cottons, with a biased distribution among chromosomes. Transcriptome data implicate a number of biological processes affected by human selection, and suggest that the domestication process has prolonged the duration of fiber elongation in modern cultivated forms. Functional analysis suggested that wild cottons allocate greater resources to stress response pathways, while domestication led to reprogrammed resource allocation toward increased fiber growth, possibly through modulating stress-response networks. This first global transcriptomic analysis using multiple accessions of wild and domesticated cottons is an important step toward a more comprehensive systems perspective on cotton fiber evolution. The understanding that human selection over the past 5,000+ years has dramatically re-wired the cotton fiber transcriptome sets the stage for a deeper understanding of the genetic architecture underlying cotton fiber synthesis and phenotypic evolution. PMID:24391525

  6. Characterization and Functional Analysis of PEBP Family Genes in Upland Cotton (Gossypium hirsutum L.).

    PubMed

    Zhang, Xiaohong; Wang, Congcong; Pang, Chaoyou; Wei, Hengling; Wang, Hantao; Song, Meizhen; Fan, Shuli; Yu, Shuxun

    2016-01-01

    Upland cotton (Gossypium hirsutum L.) is a naturally occurring photoperiod-sensitive perennial plant species. However, sensitivity to the day length was lost during domestication. The phosphatidylethanolamine-binding protein (PEBP) gene family, of which three subclades have been identified in angiosperms, functions to promote and suppress flowering in photoperiod pathway. Recent evidence indicates that PEBP family genes play an important role in generating mobile flowering signals. We isolated homologues of the PEBP gene family in upland cotton and examined their regulation and function. Nine PEBP-like genes were cloned and phylogenetic analysis indicated the genes belonged to four subclades (FT, MFT, TFL1 and PEBP). Cotton PEBP-like genes showed distinct expression patterns in relation to different cotton genotypes, photoperiod responsive and cultivar maturity. The GhFT gene expression of a semi-wild race of upland cotton were strongly induced under short day condition, whereas the GhPEBP2 gene expression was induced under long days. We also elucidated that GhFT but not GhPEBP2 interacted with FD-like bZIP transcription factor GhFD and promote flowering under both long- and short-day conditions. The present result indicated that GhPEBP-like genes may perform different functions. This work corroborates the involvement of PEBP-like genes in photoperiod response and regulation of flowering time in different cotton genotypes, and contributes to an improved understanding of the function of PEBP-like genes in cotton.

  7. Genetic diversity of sea-island cotton (Gossypium barbadense) revealed by mapped SSRs.

    PubMed

    Wang, X Q; Feng, C H; Lin, Z X; Zhang, X L

    2011-12-08

    In order to evaluate the genetic diversity of sea-island cotton (Gossypium barbadense), 237 commonly mapped SSR markers covering the cotton genome were used to genotype 56 sea-island cotton accessions. A total of 218 polymorphic primer pairs (91.98%) amplified 361 loci, with a mean of 1.66 loci. Polymorphism information content values of the SSR primers ranged from 0.035 to 0.862, with a mean of 0.320. The highest mean polymorphism information content value for the SSR motifs was from a compound motif (0.402), and for the chromosomes it was Chr10 (0.589); the highest ratio of polymorphic primers in Xinjiang accessions was from Chr21 (83.33%). Genetic diversity was high in Xinjiang accessions. AMOVA showed that variation was 8 and 92% among populations and within populations, respectively. The 56 sea-island accessions were divided into three groups in the UPGMA dendrogram: Xinhai5 was in the first group; accessions from Xinjiang, except the five main ones, were in the second group, and the other 34 accessions were in the third group. Accessions from the former Soviet Union and Xinjiang main accessions were closely related. Both PCA and UPGMA confirmed that Xinhai5 was distinct from the other accessions, and accessions from Xinjiang were in an independent group. Given the differences between principal components analysis and UPGMA results, it is necessary to combine molecular markers and pedigree information so that genetic diversity can be objectively analyzed.

  8. Elucidation of thermotolerance diversity in cotton (Gossypium hirsutum L.) using physio-molecular approaches.

    PubMed

    Rana, R M; Khan, S H; Ali, Z; Khan, A I; Khan, I A

    2011-06-14

    Cotton (Gossypium hirsutum) is an important cash crop, but high temperature during its growing season is one of the major factors that limit its productivity. This problem compels plant breeders to breed for heat tolerance, which can help to overcome this challenge. It is very important to make a comprehensive screening of heat-tolerant genotypes so that only the best are chosen. Here we report the combined use of several techniques that can help breeders to screen their germplasm. Twelve cultivated cotton genotypes were evaluated for thermotolerance, using assays that included electrolyte leakage, chlorophyll accumulation and protein profiling, as well as RAPDs to assess genetic diversity. Two genotypes (B-557 and NIAB-78) showed tolerant behavior in three thermotolerance assays. RAPD analysis results showed maximum similarity in a range of 86.7-66.7% between the genotypes MNH-554 and CIM-443. We conclude that combined use should be made of relative electrolyte leakage, chlorophyll stability and differential display with SDS-PAGE to aid in screening for stress tolerance. RAPD-based diversity analysis will further help to improve the efficiency of breeding programs.

  9. Competitive adsorption of toxic heavy metal contaminants by gum kondagogu (Cochlospermum gossypium): a natural hydrocolloid.

    PubMed

    Vinod, V T P; Sashidhar, R B; Sukumar, A A

    2010-02-01

    Gum kondagogu (Cochlospermum gossypium), a naturally occurring tree biopolymer, is exploited as a biosorbent to remove metal ions from aqueous solutions. The removal efficiency of toxic metals by gum kondagogu was determined quantitatively in the order Cd2+ > Cu2+ > Fe2+ > Se2+ > Pb2+ > total Cr > Ni2+ > Zn2+ > Co2+ > As2+ at pH 5.0+/-0.1 and temperature 25+/-2 degrees C by inductively coupled plasma-mass spectrometry (ICP-MS). The biosorption (%) of various metal ions tested was found to be in the range of 97.3-16.7%, at pH 5.0. The morphological and mechanisms of interaction of toxic metal ions with gum kondagogu were assessed by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDXA) and X-ray diffraction (XRD) spectrum. The analysis indicated that biosorption process included morphological changes, precipitation, complexation and ion exchange mechanism for the removal of metal ions by the gum. XRD analysis indicated the amorphous nature of gum kondagogu, which facilitate metal biosorption. The metal ions adsorption leads to its deposition on the gum kondagogu matrix in a crystalline state.

  10. Transcriptome analysis reveals long noncoding RNAs involved in fiber development in cotton (Gossypium arboreum).

    PubMed

    Zou, Changsong; Wang, Qiaolian; Lu, Cairui; Yang, Wencui; Zhang, Youping; Cheng, Hailiang; Feng, Xiaoxu; Prosper, Mtawa Andrew; Song, Guoli

    2016-02-01

    Long noncoding RNAs (lncRNAs) play important roles in various biological regulatory processes in yeast, mammals, and plants. However, no systematic identification of lncRNAs has been reported in Gossypium arboreum. In this study, the strand-specific RNA sequencing (ssRNA-seq) of samples from cotton fibers and leaves was performed, and lncRNAs involved in fiber initiation and elongation processes were systematically identified and analyzed. We identified 5,996 lncRNAs, of which 3,510 and 2,486 can be classified as long intergenic noncoding RNAs (lincRNAs) and natural antisense transcripts (lncNAT), respectively. LincRNAs and lncNATs are similar in many aspects, but have some differences in exon number, exon length, and transcript length. Expression analysis revealed that 51.9% of lincRNAs and 54.5% of lncNATs transcripts were preferentially expressed at one stage of fiber development, and were significantly highly expressed than protein-coding transcripts (21.7%). During the fiber and rapid elongation stages, rapid and dynamic changes in lncRNAs may contribute to fiber development in cotton. This work describes a set of lncRNAs that are involved in fiber development. The characterization and expression analysis of lncRNAs will facilitate future studies on their roles in fiber development in cotton.

  11. Proteomic identification of differentially expressed proteins in Gossypium thurberi inoculated with cotton Verticillium dahliae.

    PubMed

    Zhao, Fu'an; Fang, Weiping; Xie, Deyi; Zhao, Yuanming; Tang, Zhongjie; Li, Wu; Nie, Lihong; Lv, Shuping

    2012-04-01

    Thurber's cotton (Gossypium thurberi) is the wild relative of cultivated cotton. It is highly resistant to cotton Verticillium wilt, a disease that significantly affects cotton yield and quality. To reveal the mechanism of disease resistance in G. thurberi and to clone resistance-related genes, we used two-dimensional electrophoresis (2-DE) and tandem time-of-flight mass spectrometry (MALDI-TOF-MS) to identify differentially expressed proteins in Thurber's cotton after inoculation with Verticillium dahliae. A total of 57 different protein spots were upregulated, including 52 known proteins representing 11% of the total protein spots. These proteins are involved in resistance to stress and disease, transcriptional regulation, signal transduction, protein processing and degradation, photosynthesis, production capacity, basic metabolism, and other processes. In addition, five disease resistance proteins showed intense upregulation, indicating that resistance genes (R genes) may play a critical role in resistance to Verticillium wilt in Thurber's cotton. Our results suggest that disease and stress resistance are the combined effects of multiple co-expressed genes. This provides a basis for further, detailed investigation into the mechanisms underlying Verticillium wilt resistance of G. thurberi and for cloning essential genes into cotton cultivars to produce Verticillium wilt resistant plants.

  12. MicroRNA-target gene responses to lead-induced stress in cotton (Gossypium hirsutum L.).

    PubMed

    He, Qiuling; Zhu, Shuijin; Zhang, Baohong

    2014-09-01

    MicroRNAs (miRNAs) play key roles in plant responses to various metal stresses. To investigate the miRNA-mediated plant response to heavy metals, cotton (Gossypium hirsutum L.), the most important fiber crop in the world, was exposed to different concentrations (0, 25, 50, 100, and 200 µM) of lead (Pb) and then the toxicological effects were investigated. The expression patterns of 16 stress-responsive miRNAs and 10 target genes were monitored in cotton leaves and roots by quantitative real-time PCR (qRT-PCR); of these selected genes, several miRNAs and their target genes are involved in root development. The results show a reciprocal regulation of cotton response to lead stress by miRNAs. The characterization of the miRNAs and the associated target genes in response to lead exposure would help in defining the potential roles of miRNAs in plant adaptation to heavy metal stress and further understanding miRNA regulation in response to abiotic stress.

  13. Proteomics profiling of fiber development and domestication in upland cotton (Gossypium hirsutum L.).

    PubMed

    Hu, Guanjing; Koh, Jin; Yoo, Mi-Jeong; Pathak, Dharminder; Chen, Sixue; Wendel, Jonathan F

    2014-12-01

    Comparative proteomic analyses were performed to detail the evolutionary consequences of strong directional selection for enhanced fiber traits in modern upland cotton (Gossypium hirsutum L.). Using two complementary proteomic approaches, 2-DE and iTRAQ LC-MS/MS, fiber proteomes were examined for four representative stages of fiber development. Approximately 1,000 protein features were characterized using each strategy, collectively resulting in the identification and functional categorization of 1,223 proteins. Unequal contributions of homoeologous proteins were detected for over a third of the fiber proteome, but overall expression was balanced with respect to the genome-of-origin in the allopolyploid G. hirsutum. About 30% of the proteins were differentially expressed during fiber development within wild and domesticated cotton. Notably, domestication was accompanied by a doubling of protein developmental dynamics for the period between 10 and 20 days following pollination. Expression levels of 240 iTRAQ proteins and 293 2-DE spots were altered by domestication, collectively representing multiple cellular and metabolic processes, including metabolism, energy, protein synthesis and destination, defense and stress response. Analyses of homoeolog-specific expression indicate that duplicated gene products in cotton fibers can be differently regulated in response to selection. These results demonstrate the power of proteomics for the analysis of crop domestication and phenotypic evolution.

  14. Comparative evolutionary and developmental dynamics of the cotton (Gossypium hirsutum) fiber transcriptome.

    PubMed

    Yoo, Mi-Jeong; Wendel, Jonathan F

    2014-01-01

    The single-celled cotton (Gossypium hirsutum) fiber provides an excellent model to investigate how human selection affects phenotypic evolution. To gain insight into the evolutionary genomics of cotton domestication, we conducted comparative transcriptome profiling of developing cotton fibers using RNA-Seq. Analysis of single-celled fiber transcriptomes from four wild and five domesticated accessions from two developmental time points revealed that at least one-third and likely one-half of the genes in the genome are expressed at any one stage during cotton fiber development. Among these, ~5,000 genes are differentially expressed during primary and secondary cell wall synthesis between wild and domesticated cottons, with a biased distribution among chromosomes. Transcriptome data implicate a number of biological processes affected by human selection, and suggest that the domestication process has prolonged the duration of fiber elongation in modern cultivated forms. Functional analysis suggested that wild cottons allocate greater resources to stress response pathways, while domestication led to reprogrammed resource allocation toward increased fiber growth, possibly through modulating stress-response networks. This first global transcriptomic analysis using multiple accessions of wild and domesticated cottons is an important step toward a more comprehensive systems perspective on cotton fiber evolution. The understanding that human selection over the past 5,000+ years has dramatically re-wired the cotton fiber transcriptome sets the stage for a deeper understanding of the genetic architecture underlying cotton fiber synthesis and phenotypic evolution.

  15. Methylation-sensitive amplified polymorphism analysis of Verticillium wilt-stressed cotton (Gossypium).

    PubMed

    Wang, W; Zhang, M; Chen, H D; Cai, X X; Xu, M L; Lei, K Y; Niu, J H; Deng, L; Liu, J; Ge, Z J; Yu, S X; Wang, B H

    2016-10-06

    In this study, a methylation-sensitive amplification polymorphism analysis system was used to analyze DNA methylation level in three cotton accessions. Two disease-sensitive near-isogenic lines, PD94042 and IL41, and one disease-resistant Gossypium mustelinum accession were exposed to Verticillium wilt, to investigate molecular disease resistance mechanisms in cotton. We observed multiple different DNA methylation types across the three accessions following Verticillium wilt exposure. These included hypomethylation, hypermethylation, and other patterns. In general, the global DNA methylation level was significantly increased in the disease-resistant accession G. mustelinum following disease exposure. In contrast, there was no significant difference in the disease-sensitive accession PD94042, and a significant decrease was observed in IL41. Our results suggest that disease-resistant cotton might employ a mechanism to increase methylation level in response to disease stress. The differing methylation patterns, together with the increase in global DNA methylation level, might play important roles in tolerance to Verticillium wilt in cotton. Through cloning and analysis of differently methylated DNA sequences, we were also able to identify several genes that may contribute to disease resistance in cotton. Our results revealed the effect of DNA methylation on cotton disease resistance, and also identified genes that played important roles, which may shed light on the future cotton disease-resistant molecular breeding.

  16. Analysis of upland cotton (Gossypium hirsutum) response to Verticillium dahliae inoculation by transcriptome sequencing.

    PubMed

    Shao, B X; Zhao, Y L; Chen, W; Wang, H M; Guo, Z J; Gong, H Y; Sang, X H; Cui, Y L; Wang, C H

    2015-10-27

    Verticillium wilt is one of the main diseases in cotton (Gossypium hirsutum), severely reduces yield and fiber quality, and is difficult to be con-trolled effectively. At present, the molecular mechanism that confers resistance to this disease is unclear. Transcriptome sequencing is an important method to detect resistance genes, explore metabolic pathways, and study resistance mechanisms. In this study, the transcriptome of a disease-resistant inbred cot-ton line inoculated with Verticillium dahliae was sequenced. A total of 126,402 unigenes were obtained using de novo assembly and data analysis, 99,712 (78.88%) of which were annotated into the Nr, Nt, Swiss-Prot, KEGG, COG, and GO databases. The expression patterns of 16 candidate disease-resis-tance genes showed that some genes were upregulated soon after V. dahliae inoculation and others were upregulated later, which may indicate instanta-neous basal defense and lagged specific defense, respectively. We conducted a preliminary analysis of the transcriptome database, which will contribute to further research regarding the cloning of disease-resistance genes.

  17. Proteomic profiling of developing cotton fibers from wild and domesticated Gossypium barbadense.

    PubMed

    Hu, Guanjing; Koh, Jin; Yoo, Mi-Jeong; Grupp, Kara; Chen, Sixue; Wendel, Jonathan F

    2013-10-01

    Pima cotton (Gossypium barbadense) is widely cultivated because of its long, strong seed trichomes ('fibers') used for premium textiles. These agronomically advanced fibers were derived following domestication and thousands of years of human-mediated crop improvement. To gain an insight into fiber development and evolution, we conducted comparative proteomic and transcriptomic profiling of developing fiber from an elite cultivar and a wild accession. Analyses using isobaric tag for relative and absolute quantification (iTRAQ) LC-MS/MS technology identified 1317 proteins in fiber. Of these, 205 were differentially expressed across developmental stages, and 190 showed differential expression between wild and cultivated forms, 14.4% of the proteome sampled. Human selection may have shifted the timing of developmental modules, such that some occur earlier in domesticated than in wild cotton. A novel approach was used to detect possible biased expression of homoeologous copies of proteins. Results indicate a significant partitioning of duplicate gene expression at the protein level, but an approximately equal degree of bias for each of the two constituent genomes of allopolyploid cotton. Our results demonstrate the power of complementary transcriptomic and proteomic approaches for the study of the domestication process. They also provide a rich database for mining for functional analyses of cotton improvement or evolution.

  18. Targeted mutagenesis in cotton (Gossypium hirsutum L.) using the CRISPR/Cas9 system

    PubMed Central

    Chen, Xiugui; Lu, Xuke; Shu, Na; Wang, Shuai; Wang, Junjuan; Wang, Delong; Guo, Lixue; Ye, Wuwei

    2017-01-01

    The CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 system has been widely used for genome editing in various plants because of its simplicity, high efficiency and design flexibility. However, to our knowledge, there is no report on the application of CRISPR/Cas9-mediated targeted mutagenesis in cotton. Here, we report the genome editing and targeted mutagenesis in upland cotton (Gossypium hirsutum L., hereafter cotton) using the CRISPR/Cas9 system. We designed two guide RNAs to target distinct sites of the cotton Cloroplastos alterados 1 (GhCLA1) and vacuolar H+-pyrophosphatase (GhVP) genes. Mutations in these two genes were detected in cotton protoplasts. Most of the mutations were nucleotide substitutions, with one nucleotide insertion and one substitution found in GhCLA1 and one deletion found in GhVP in cotton protoplasts. Subsequently, the two vectors were transformed into cotton shoot apexes through Agrobacterium-mediated transformation, resulting in efficient target gene editing. Most of the mutations were nucleotide deletions, and the mutation efficiencies were 47.6–81.8% in transgenic cotton plants. Evaluation using restriction-enzyme-PCR assay and sequence analysis detected no off-target mutations. Our results indicated that the CRISPR/Cas9 system was an efficient and specific tool for targeted mutagenesis of the cotton genome. PMID:28287154

  19. Global gene expression responses to waterlogging in roots and leaves of cotton (Gossypium hirsutum L.).

    PubMed

    Christianson, Jed A; Llewellyn, Danny J; Dennis, Elizabeth S; Wilson, Iain W

    2010-01-01

    Waterlogging stress causes yield reduction in cotton (Gossypium hirsutum L.). A major component of waterlogging stress is the lack of oxygen available to submerged tissues. While changes in expressed protein, gene transcription and metabolite levels have been studied in response to low oxygen stress, little research has been done on molecular responses to waterlogging in cotton. We assessed cotton growth responses to waterlogging and assayed global gene transcription responses in root and leaf cotton tissues of partially submerged plants. Waterlogging caused significant reductions in stem elongation, shoot mass, root mass and leaf number, and altered the expression of 1,012 genes (4% of genes assayed) in root tissue as early as 4 h after flooding. Many of these genes were associated with cell wall modification and growth pathways, glycolysis, fermentation, mitochondrial electron transport and nitrogen metabolism. Waterlogging of plant roots also altered global gene expression in leaf tissues, significantly changing the expression of 1,305 genes (5% of genes assayed) after 24 h of flooding. Genes affected were associated with cell wall growth and modification, tetrapyrrole synthesis, hormone response, starch metabolism and nitrogen metabolism The implications of these results for the development of waterlogging-tolerant cotton are discussed.

  20. Characterization of conserved circular RNA in polyploid Gossypium species and their ancestors.

    PubMed

    Zhao, Ting; Wang, Luyao; Li, Sai; Xu, Min; Guan, Xueying; Zhou, Baoliang

    2017-10-03

    Circular RNA (circRNA) is a regulatory class of long, non-coding RNA found in both plant and animal kingdoms. The profile and characterization of circRNA in cotton species remains to be explored. Here, using 24 rRNA-depleted RNA-seq libraries of putative diploid progenitors of Gossypium spp., G. arboreum and G. raimondii, their interspecies hybrid (F1 ) and allotetraploid G. hirsutum, 1,041, 1,478, 1,311 and 499 circRNAs were identified in each cotton species, respectively. A prevalence of 23 exon-circRNAs contain non-canonical GT/AG signals, and only ~10% of exon-circRNA is associated with reverse complementary intronic sequences. This result implies that plants employ a method of circRNA splicing distinct from that of animals. In addition, 432 circRNAs are stably expressed in multiple cotton species. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. SNP Marker Discovery in Pima Cotton (Gossypium barbadense L.) Leaf Transcriptomes

    PubMed Central

    Kottapalli, Pratibha; Ulloa, Mauricio; Kottapalli, Kameswara Rao; Payton, Paxton; Burke, John

    2016-01-01

    The objective of this study was to explore the known narrow genetic diversity and discover single-nucleotide polymorphic (SNP) markers for marker-assisted breeding within Pima cotton (Gossypium barbadense L.) leaf transcriptomes. cDNA from 25-day plants of three diverse cotton genotypes [Pima S6 (PS6), Pima S7 (PS7), and Pima 3-79 (P3-79)] was sequenced on Illumina sequencing platform. A total of 28.9 million reads (average read length of 138 bp) were generated by sequencing cDNA libraries of these three genotypes. The de novo assembly of reads generated transcriptome sets of 26,369 contigs for PS6, 25,870 contigs for PS7, and 24,796 contigs for P3-79. A Pima leaf reference transcriptome was generated consisting of 42,695 contigs. More than 10,000 single-nucleotide polymorphisms (SNPs) were identified between the genotypes, with 100% SNP frequency and a minimum of eight sequencing reads. The most prevalent SNP substitutions were C—T and A—G in these cotton genotypes. The putative SNPs identified can be utilized for characterizing genetic diversity, genotyping, and eventually in Pima cotton breeding through marker-assisted selection. PMID:27721653

  2. Chado use case: storing genomic, genetic and breeding data of Rosaceae and Gossypium crops in Chado

    PubMed Central

    Jung, Sook; Lee, Taein; Ficklin, Stephen; Yu, Jing; Cheng, Chun-Huai; Main, Dorrie

    2016-01-01

    The Genome Database for Rosaceae (GDR) and CottonGen are comprehensive online data repositories that provide access to integrated genomic, genetic and breeding data through search, visualization and analysis tools for Rosaceae crops and Gossypium (cotton). These online databases use Chado, an open-source, generic and ontology-driven database schema for biological data, as the primary data storage platform. Chado is highly normalized and uses ontologies to indicate the ‘types’ of data. Therefore, Chado is flexible such that it has been used to house genomic, genetic and breeding data for GDR and CottonGen. These data include whole genome sequence and annotation, transcripts, molecular markers, genetic maps, Quantitative Trait Loci, Mendelian Trait Loci, traits, germplasm, pedigrees, large scale phenotypic and genotypic data, ontologies and publications. We provide information about how to store these types of data in Chado using GDR and CottonGen as examples sites that were converted from an older legacy infrastructure. Database URL: GDR (www.rosaceae.org), CottonGen (www.cottongen.org) PMID:26989146

  3. Genome-wide identification and expression analysis of TCP transcription factors in Gossypium raimondii.

    PubMed

    Ma, Jun; Wang, Qinglian; Sun, Runrun; Xie, Fuliang; Jones, Don C; Zhang, Baohong

    2014-10-16

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play versatile functions in multiple aspects of plant growth and development. However, no systematical study has been performed in cotton. In this study, we performed for the first time the genome-wide identification and expression analysis of the TCP transcription factor family in Gossypium raimondii. A total of 38 non-redundant cotton TCP encoding genes were identified. The TCP transcription factors were divided into eleven subgroups based on phylogenetic analysis. Most TCP genes within the same subfamily demonstrated similar exon and intron organization and the motif structures were highly conserved among the subfamilies. Additionally, the chromosomal distribution pattern revealed that TCP genes were unevenly distributed across 11 out of the 13 chromosomes; segmental duplication is a predominant duplication event for TCP genes and the major contributor to the expansion of TCP gene family in G. raimondii. Moreover, the expression profiles of TCP genes shed light on their functional divergence.

  4. Chado use case: storing genomic, genetic and breeding data of Rosaceae and Gossypium crops in Chado.

    PubMed

    Jung, Sook; Lee, Taein; Ficklin, Stephen; Yu, Jing; Cheng, Chun-Huai; Main, Dorrie

    2016-01-01

    The Genome Database for Rosaceae (GDR) and CottonGen are comprehensive online data repositories that provide access to integrated genomic, genetic and breeding data through search, visualization and analysis tools for Rosaceae crops and Gossypium (cotton). These online databases use Chado, an open-source, generic and ontology-driven database schema for biological data, as the primary data storage platform. Chado is highly normalized and uses ontologies to indicate the 'types' of data. Therefore, Chado is flexible such that it has been used to house genomic, genetic and breeding data for GDR and CottonGen. These data include whole genome sequence and annotation, transcripts, molecular markers, genetic maps, Quantitative Trait Loci, Mendelian Trait Loci, traits, germplasm, pedigrees, large scale phenotypic and genotypic data, ontologies and publications. We provide information about how to store these types of data in Chado using GDR and CottonGen as examples sites that were converted from an older legacy infrastructure. Database URL: GDR (www.rosaceae.org), CottonGen (www.cottongen.org).

  5. Genome-wide identification and expression analysis of TCP transcription factors in Gossypium raimondii

    PubMed Central

    Ma, Jun; Wang, Qinglian; Sun, Runrun; Xie, Fuliang; Jones, Don C.; Zhang, Baohong

    2014-01-01

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play versatile functions in multiple aspects of plant growth and development. However, no systematical study has been performed in cotton. In this study, we performed for the first time the genome-wide identification and expression analysis of the TCP transcription factor family in Gossypium raimondii. A total of 38 non-redundant cotton TCP encoding genes were identified. The TCP transcription factors were divided into eleven subgroups based on phylogenetic analysis. Most TCP genes within the same subfamily demonstrated similar exon and intron organization and the motif structures were highly conserved among the subfamilies. Additionally, the chromosomal distribution pattern revealed that TCP genes were unevenly distributed across 11 out of the 13 chromosomes; segmental duplication is a predominant duplication event for TCP genes and the major contributor to the expansion of TCP gene family in G. raimondii. Moreover, the expression profiles of TCP genes shed light on their functional divergence. PMID:25322260

  6. Targeted mutagenesis in cotton (Gossypium hirsutum L.) using the CRISPR/Cas9 system.

    PubMed

    Chen, Xiugui; Lu, Xuke; Shu, Na; Wang, Shuai; Wang, Junjuan; Wang, Delong; Guo, Lixue; Ye, Wuwei

    2017-03-13

    The CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 system has been widely used for genome editing in various plants because of its simplicity, high efficiency and design flexibility. However, to our knowledge, there is no report on the application of CRISPR/Cas9-mediated targeted mutagenesis in cotton. Here, we report the genome editing and targeted mutagenesis in upland cotton (Gossypium hirsutum L., hereafter cotton) using the CRISPR/Cas9 system. We designed two guide RNAs to target distinct sites of the cotton Cloroplastos alterados 1 (GhCLA1) and vacuolar H(+)-pyrophosphatase (GhVP) genes. Mutations in these two genes were detected in cotton protoplasts. Most of the mutations were nucleotide substitutions, with one nucleotide insertion and one substitution found in GhCLA1 and one deletion found in GhVP in cotton protoplasts. Subsequently, the two vectors were transformed into cotton shoot apexes through Agrobacterium-mediated transformation, resulting in efficient target gene editing. Most of the mutations were nucleotide deletions, and the mutation efficiencies were 47.6-81.8% in transgenic cotton plants. Evaluation using restriction-enzyme-PCR assay and sequence analysis detected no off-target mutations. Our results indicated that the CRISPR/Cas9 system was an efficient and specific tool for targeted mutagenesis of the cotton genome.

  7. Increased Terpenoid Accumulation in Cotton (Gossypium hirsutum) Foliage is a General Wound Response

    PubMed Central

    Kunert, Grit; Gershenzon, Jonathan

    2008-01-01

    The subepidermal pigment glands of cotton accumulate a variety of terpenoid products, including monoterpenes, sesquiterpenes, and terpenoid aldehydes that can act as feeding deterrents against a number of insect herbivore species. We compared the effect of herbivory by Spodoptera littoralis caterpillars, mechanical damage by a fabric pattern wheel, and the application of jasmonic acid on levels of the major representatives of the three structural classes of terpenoids in the leaf foliage of 4-week-old Gossypium hirsutum plants. Terpenoid levels increased successively from control to mechanical damage, herbivory, and jasmonic acid treatments, with E-β-ocimene and heliocide H1 and H4 showing the highest increases, up to 15-fold. Herbivory or mechanical damage to older leaves led to terpenoid increases in younger leaves. Leaf-by-leaf analysis of terpenes and gland density revealed that higher levels of terpenoids were achieved by two mechanisms: (1) increased filling of existing glands with terpenoids and (2) the production of additional glands, which were found to be dependent on damage intensity. As the relative response of individual terpenoids did not differ substantially among herbivore, mechanical damage, and jasmonic acid treatments, the induction of terpenoids in cotton foliage appears to represent a non-specific wound response mediated by jasmonic acid. Electronic supplementary material The online version of this article (doi:10.1007/s10886-008-9453-z) contains supplementary material, which is available to authorized users. PMID:18386096

  8. Increase of cold tolerance in cotton plant (Gossypium hirsutum L.) by mepiquat chloride

    NASA Technical Reports Server (NTRS)

    Gausman, H. W.; Escobar, D. E.; Rodriguez, R. R. (Principal Investigator); Huang, S. Y.; Rittig, F. R.

    1982-01-01

    Three mepiquat chloride (MC) concentrations - 40, 70, and 100 g a.i./ha - were used to spray cotton (Gossypium hirsutum L., cultival McNair 220) plants to determine whether or not MC would increase their cold tolerance. Seven to ten days after the spray, the plants were exposed to three different cold treatments. No important difference in cold damage was noticed between the control and the MC-treated plants when they were exposed repeatedly to 4.5 C. No plants died when exposed to 0.5 C for 12 h; however, 90% of the 1st and 2nd leaves of the control plants were damaged. This was three times more damage than those leaves of plants treated with 70 and 100 g a.i./ha MC concentrations; 60% f the control and 10-20% of the MC-treated plants died when the plants were subjected to a cold hardening process with 15.5 C day (12 h) and 1.7 C night (12 h) for 10 days, and then, held at -2.2 C for 24 hours. The electrolyte leakage and reflectance measurement data showed that the cell membranes of the MC-treated plants sustained much less damage than those of the control. Freezing injury was easily assessed by reflectance measurements at the 1.65 micrometer wavelength.

  9. Wood Anatomy and Insect Defoliator Systems: Is there an anatomical response to sustained feeding by the western spruce budworm (Choristoneura occidentalis) on Douglas-fir (Pseudotusga menziesii)?

    NASA Astrophysics Data System (ADS)

    Axelson, Jodi; Gärtner, Holger; Alfaro, René; Smith, Dan

    2013-04-01

    The western spruce budworm (Choristoneura occidentalis Freeman) is the most widespread and destructive defoliator of coniferous forests in western North America, and has a long-term coexistence with its primary host tree, Douglas-fir (Pseudotsuga menziesii Franco). Western spruce budworm (WSB) outbreaks usually last for several years, and cause reductions in annual growth, stem defects, and regeneration delays. In British Columbia, the WSB is the second most damaging insect after the mountain pine beetle, and sustained and/or severe defoliation can result in the mortality of host trees. Numerous studies have used tree rings to reconstruct WSB outbreaks across long temporal scales, to evaluate losses in stand productivity, and examine isotope ratios. Although some studies have looked at the impacts of artificial defoliation on balsam fir in eastern North America, there has been no prior research on how WSB outbreaks affect the anatomical structure of the stem as described by intra-annual wood density and potential cell size variations. The objective of this study was to anatomically examine the response of Douglas-fir to sustained WSB outbreaks in two regions of southern British Columbia. We hypothesize that the anatomical intra-annual characteristics of the tree rings, such as cell wall thickness, latewood cell size, and/or lumen area changes during sustained WSB outbreaks. To test this hypothesis we sampled four permanent sample plots in coastal and dry interior sites, which had annually resolved defoliation data collected over a 7-12 year period. At each site diameter-at-breast height (cm), height (m), and crown position were recorded and three increment cores were extracted from 25 trees. Increment cores were prepared to permit anatomical and x-ray density analyses. For each tree, a 15µm thick micro section was cut from the radial plane. Digital images of the micro sections were captured and processed. In each annual ring, features such as cell lumen area (µm2

  10. A genetic map of an Australian wild Gossypium C genome and assignment of homoeologies with tetraploid cultivated cotton.

    PubMed

    Becerra Lopez-Lavalle, L A; Matheson, B; Brubaker, C L

    2011-09-01

    Genetic diversity for traits such as fibre quality or disease resistance to microorganisms is limited in the elite cotton germplasm; consequently, cotton breeders are looking for novel alleles in the secondary or even in the tertiary gene pools. The wild Australian Gossypium species (tertiary gene pool) represent an alternative source of novel alleles. However, to use these species efficiently, enabling tools are required. Chromosome-specific molecular markers are particularly useful tools to track the transmission of this exotic genetic material into the cultivated cotton during introgression. In this study, we report the construction of a genetic linkage map of the Australian wild C-genome species Gossypium sturtianum. The map, based on an F(2) population of 114 individuals, contains 291 AFLP loci. The map spans 1697 cM with an average distance of 5.8 cM between markers. To associate C-genome chromosomes with the A and D subgenomes of cultivated cotton, 29 SSR and RFLP-STS markers were assigned to chromosomes using cultivated cotton mapped marker information. Polymorphisms were revealed by 51 AFLP primer combinations and 38 RFLP-STS and 115 SSR cotton mapped markers. The utility of transferring RFLP-STS and SSR cotton mapped markers to other Gossypium species shows the usefulness of a comparative approach as a source of markers and for aligning the genetic map of G. sturtianum with the cultivated species in the future. This also indicates that the overall structure of the G. sturtianum linkage groups is similar to that of the A and D subgenomes of cotton at the gross structural level. Applications of the map for the Australia wild C-genome species and cotton breeding are discussed.

  11. The state of microbial complexes in soils of forest ecosystems after fires and defoliation of stands by gypsy moths

    NASA Astrophysics Data System (ADS)

    Bogorodskaya, A. V.; Baranchikov, Yu. N.; Ivanova, G. A.

    2009-03-01

    The state of microbial cenoses in the soils of forest ecosystems damaged by fires of different strengths and gypsy moth outbreaks (Central Siberia) was assessed by the intensity of the basal respiration, the content of carbon of the microbial biomass, and the microbial metabolic quotient. The degree of the disturbance of the microbial cenoses in the soils under pine forests after fires was higher than that in the soils under the forests defoliated by gypsy moths. The greatest changes of the microbial complexes were recorded after the fires of high and medium intensity. In the litters, the content of the microbial biomass, the intensity of basal respiration, and the microbial metabolic quotient value were restored on the fifth year after the fires, whereas in the upper (0-10 cm) soil layer, these parameters still differed from those in the control variant, especially after the highly intense fires. After the weak fires, the ecophysiological state of the microbial complexes was restored within two-three years.

  12. Enzymatic response of the eucalypt defoliator Thyrinteina arnobia (Stoll) (Lepidoptera: Geometridae) to a bis-benzamidine proteinase Inhibitor. i.

    PubMed

    Marinho-Prado, Jeanne Scardini; Lourenção, A L; Guedes, R N C; Pallini, A; Oliveira, J A; Oliveira, M G A

    2012-10-01

    Ingestion of proteinase inhibitors leads to hyperproduction of digestive proteinases, limiting the bioavailability of essential amino acids for protein synthesis, which affects insect growth and development. However, the effects of proteinase inhibitors on digestive enzymes can lead to an adaptive response by the insect. In here, we assessed the biochemical response of midgut proteinases from the eucalypt defoliator Thyrinteina arnobia (Stoll) to different concentrations of berenil, a bis-benzamidine proteinase inhibitor, on eucalyptus. Eucalyptus leaves were immersed in berenil solutions at different concentrations and fed to larvae of T. arnobia. Mortality was assessed daily. The proteolytic activity in the midgut of T. arnobia was assessed after feeding on plants sprayed with aqueous solutions of berenil, fed to fifth instars of T. arnobia for 48 h before midgut removal for enzymatic assays. Larvae of T. arnobia were able to overcome the effects of the lowest berenil concentrations by increasing their trypsin-like activity, but not as berenil concentration increased, despite the fact that the highest berenil concentration resulted in overproduction of trypsin-like proteinases. Berenil also prevented the increase of the cysteine proteinases activity in response to trypsin inhibition.

  13. Carbon reserves and canopy defoliation determine the recovery of Scots pine 4 yr after a drought episode.

    PubMed

    Galiano, L; Martínez-Vilalta, J; Lloret, F

    2011-05-01

    • Severe drought may increase physiological stress on long-lived woody vegetation, occasionally leading to mortality of overstory trees. Little is known about the factors determining tree survival and subsequent recovery after drought. • We used structural equation modeling to analyse the recovery of Scots pine (Pinus sylvestris) trees 4 yr after an extreme drought episode occurred in 2004-2005 in north-east Spain. Measured variables included the amount of green foliage, carbon reserves in the stem, mistletoe (Viscum album) infection, needle physiological performance and stem radial growth before, during and after the drought event. • The amount of green leaves and the levels of carbon reserves were related to the impact of drought on radial growth, and mutually correlated. However, our most likely path model indicated that current depletion of carbon reserves was a result of reduced photosynthetic tissue. This relationship potentially constitutes a feedback limiting tree recovery. In addition, mistletoe infection reduced leaf nitrogen content, negatively affecting growth. Finally, successive surveys in 2009-2010 showed a direct association between carbon reserves depletion and drought-induced mortality. • Severe drought events may induce long-term physiological disorders associated with canopy defoliation and depletion of carbon reserves, leading to prolonged recovery of surviving individuals and, eventually, to delayed tree death. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  14. Genetic diversity analysis of Gossypium arboreum germplasm accessions using genotyping-by-sequencing.

    PubMed

    Li, Ruijuan; Erpelding, John E

    2016-10-01

    The diploid cotton species Gossypium arboreum possesses many favorable agronomic traits such as drought tolerance and disease resistance, which can be utilized in the development of improved upland cotton cultivars. The USDA National Plant Germplasm System maintains more than 1600 G. arboreum accessions. Little information is available on the genetic diversity of the collection thereby limiting the utilization of this cotton species. The genetic diversity and population structure of the G. arboreum germplasm collection were assessed by genotyping-by-sequencing of 375 accessions. Using genome-wide single nucleotide polymorphism sequence data, two major clusters were inferred with 302 accessions in Cluster 1, 64 accessions in Cluster 2, and nine accessions unassigned due to their nearly equal membership to each cluster. These two clusters were further evaluated independently resulting in the identification of two sub-clusters for the 302 Cluster 1 accessions and three sub-clusters for the 64 Cluster 2 accessions. Low to moderate genetic diversity between clusters and sub-clusters were observed indicating a narrow genetic base. Cluster 2 accessions were more genetically diverse and the majority of the accessions in this cluster were landraces. In contrast, Cluster 1 is composed of varieties or breeding lines more recently added to the collection. The majority of the accessions had kinship values ranging from 0.6 to 0.8. Eight pairs of accessions were identified as potential redundancies due to their high kinship relatedness. The genetic diversity and genotype data from this study are essential to enhance germplasm utilization to identify genetically diverse accessions for the detection of quantitative trait loci associated with important traits that would benefit upland cotton improvement.

  15. Phenotypic Expression of rkn1-Mediated Meloidogyne incognita Resistance in Gossypium hirsutum Populations

    PubMed Central

    Wang, C.; Matthews, W. C.; Roberts, P. A.

    2006-01-01

    The root-knot nematode Meloidogyne incognita is a damaging pest of cotton (Gossypium hirsutum) worldwide. A major gene (rkn1) conferring resistance to M. incognita was previously identified on linkage group A03 in G. hirsutum cv. Acala NemX. To determine the patterns of segregation and phenotypic expression of rkn1, F1, F2, F2:3, BC1F1 and F2:7 recombinant inbred lines (RIL) from intraspecific crosses between Acala NemX and a closely related susceptible cultivar Acala SJ-2 were inoculated in greenhouse tests with M. incognita race 3. The resistance phenotype was determined by the extent of nematode-induced root galling and nematode egg production on roots. Suppression of root galling and egg production was highly correlated among individuals in all tests. Root galling and egg production on heterozygous plants did not differ from the susceptible parent phenotype 125 d or more after inoculation, but were slightly suppressed with shorter screening (60 d), indicating that rkn1 behaved as a recessive gene or an incompletely recessive gene, depending on the screening condition. In the RIL, rkn1 segregated in an expected 1 resistant: 1 susceptible ratio for a major resistance gene. However, within the resistant class, 21 out of 34 RIL were more resistant than the resistant parent Acala NemX, indicating transgressive segregation. These results suggest that rkn1-based resistance in G. hirsutum can be enhanced in progenies of crosses with susceptible genotypes. Allelism tests and molecular genetic analysis are needed to determine the relationship of rkn1 to other M. incognita resistance sources in cotton. PMID:19259455

  16. Analyses of Fusarium wilt race 3 resistance in Upland cotton (Gossypium hirsutum L.).

    PubMed

    Abdullaev, Alisher A; Salakhutdinov, Ilkhom B; Egamberdiev, Sharof Sh; Kuryazov, Zarif; Glukhova, Ludmila A; Adilova, Azoda T; Rizaeva, Sofiya M; Ulloa, Mauricio; Abdurakhmonov, Ibrokhim Y

    2015-06-01

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. For the last few decades, the FOV pathogen has become a significant problem in Uzbekistan causing severe wilt disease and yield losses of G. hirsutum L. cultivars. We present the first genetic analyses of FOV race 3 resistance on Uzbek Cotton Germplasm with a series of field and greenhouse artificial inoculation-evaluations and inheritance studies. The field experiments were conducted in two different sites: the experimental station in Zangiota region-Environment (Env) 1 and the Institute of Cotton Breeding (Env-2, Tashkent province). The Env-1 was known to be free of FOV while the Env-2 was known to be a heavily FOV infested soil. In both (Env-1 and Env-2) of these sites, field soil was inoculated with FOV race 3. F2 and an F3 Upland populations ("Mebane B1" × "11970") were observed with a large phenotypic variance for plant survival and FOV disease severity within populations and among control or check Upland accessions. Wilt symptoms among studied F2 individuals and F3 families significantly differed depending on test type and evaluation site. Distribution of Mendelian rations of susceptible (S) and resistant (R) phenotypes were 1S:1R field Env-1 and 3S:1R field Env-2 in the F2 population, and 1S:3R greenhouse site in the F3 population. The different segregation distribution of the Uzbek populations may be explained by differences in FOV inoculum level and environmental conditions during assays. However, genetic analysis indicated a recessive single gene action under high inoculum levels or disease pressure for FOV race 3 resistance. Uzbek germplasm may be more susceptible than expected to FOV race 3, and sources of resistance to FOV may be limited under the FOV inoculum levels present in highly-infested fields making the breeding process more complex.

  17. Genomic heterozygosity and hybrid breakdown in cotton (Gossypium): different traits, different effects.

    PubMed

    Dai, Baosheng; Guo, Huanle; Huang, Cong; Zhang, Xianlong; Lin, Zhongxu

    2016-04-12

    Hybrid breakdown has been well documented in various species. Relationships between genomic heterozygosity and traits-fitness have been extensively explored especially in the natural populations. But correlations between genomic heterozygosity and vegetative and reproductive traits in cotton interspecific populations have not been studied. In the current study, two reciprocal F2 populations were developed using Gossypium hirsutum cv. Emian 22 and G. barbadense acc. 3-79 as parents to study hybrid breakdown in cotton. A total of 125 simple sequence repeat (SSR) markers were used to genotype the two F2 interspecific populations. To guarantee mutual independence among the genotyped markers, the 125 SSR markers were checked by the linkage disequilibrium analysis. To our knowledge, this is a novel approach to evaluate the individual genomic heterozygosity. After marker checking, 83 common loci were used to assess the extent of genomic heterozygosity. Hybrid breakdown was found extensively in the two interspecific F2 populations particularly on the reproductive traits because of the infertility and the bare seeds. And then, the relationships between the genomic heterozygosity and the vegetative reproductive traits were investigated. The only relationships between hybrid breakdown and heterozygosity were observed in the (Emian22 × 3-79) F2 population for seed index (SI) and boll number per plant (BN). The maternal cytoplasmic environment may have a significant effect on genomic heterozygosity and on correlations between heterozygosity and reproductive traits. A novel approach was used to evaluate genomic heterozygosity in cotton; and hybrid breakdown was observed in reproductive traits in cotton. These findings may offer new insight into hybrid breakdown in allotetraploid cotton interspecific hybrids, and may be useful for the development of interspecific hybrids for cotton genetic improvement.

  18. Genetic diversity and population structure in the US Upland cotton (Gossypium hirsutum L.).

    PubMed

    Tyagi, Priyanka; Gore, Michael A; Bowman, Daryl T; Campbell, B Todd; Udall, Joshua A; Kuraparthy, Vasu

    2014-02-01

    Genetic diversity and population structure in the US Upland cotton was established and core sets of allelic richness were identified for developing association mapping populations in cotton. Elite plant breeding programs could likely benefit from the unexploited standing genetic variation of obsolete cultivars without the yield drag typically associated with wild accessions. A set of 381 accessions comprising 378 Upland (Gossypium hirsutum L.) and 3 G. barbadense L. accessions of the United States cotton belt were genotyped using 120 genome-wide SSR markers to establish the genetic diversity and population structure in tetraploid cotton. These accessions represent more than 100 years of Upland cotton breeding in the United States. Genetic diversity analysis identified a total of 546 alleles across 141 marker loci. Twenty-two percent of the alleles in Upland accessions were unique, specific to a single accession. Population structure analysis revealed extensive admixture and identified five subgroups corresponding to Southeastern, Midsouth, Southwest, and Western zones of cotton growing areas in the United States, with the three accessions of G. barbadense forming a separate cluster. Phylogenetic analysis supported the subgroups identified by STRUCTURE. Average genetic distance between G. hirsutum accessions was 0.195 indicating low levels of genetic diversity in Upland cotton germplasm pool. The results from both population structure and phylogenetic analysis were in agreement with pedigree information, although there were a few exceptions. Further, core sets of different sizes representing different levels of allelic richness in Upland cotton were identified. Establishment of genetic diversity, population structure, and identification of core sets from this study could be useful for genetic and genomic analysis and systematic utilization of the standing genetic variation in Upland cotton.

  19. Evolutionary Conservation and Divergence of Gene Coexpression Networks in Gossypium (Cotton) Seeds.

    PubMed

    Hu, Guanjing; Hovav, Ran; Grover, Corrinne E; Faigenboim-Doron, Adi; Kadmon, Noa; Page, Justin T; Udall, Joshua A; Wendel, Jonathan F

    2016-12-01

    The cotton genus (Gossypium) provides a superior system for the study of diversification, genome evolution, polyploidization, and human-mediated selection. To gain insight into phenotypic diversification in cotton seeds, we conducted coexpression network analysis of developing seeds from diploid and allopolyploid cotton species and explored network properties. Key network modules and functional associations were identified related to seed oil content and seed weight. We compared species-specific networks to reveal topological changes, including rewired edges and differentially coexpressed genes, associated with speciation, polyploidy, and cotton domestication. Network comparisons among species indicate that topologies are altered in addition to gene expression profiles, indicating that changes in transcriptomic coexpression relationships play a role in the developmental architecture of cotton seed development. The global network topology of allopolyploids, especially for domesticated G. hirsutum, resembles the network of the A-genome diploid more than that of the D-genome parent, despite its D-like phenotype in oil content. Expression modifications associated with allopolyploidy include coexpression level dominance and transgressive expression, suggesting that the transcriptomic architecture in polyploids is to some extent a modular combination of that of its progenitor genomes. Among allopolyploids, intermodular relationships are more preserved between two different wild allopolyploid species than they are between wild and domesticated forms of a cultivated cotton, and regulatory connections of oil synthesis-related pathways are denser and more closely clustered in domesticated vs. wild G. hirsutum. These results demonstrate substantial modification of genic coexpression under domestication. Our work demonstrates how network inference informs our understanding of the transcriptomic architecture of phenotypic variation associated with temporal scales ranging from

  20. QTL alleles for improved fiber quality from a wild Hawaiian cotton, Gossypium tomentosum.

    PubMed

    Zhang, Zhengsheng; Rong, Junkang; Waghmare, Vijay N; Chee, Peng W; May, O Lloyd; Wright, Robert J; Gannaway, John R; Paterson, Andrew H

    2011-11-01

    Seventeen backcross-self families from crosses between two Gossypium hirsutum recurrent parent lines (CA3084, CA3093) and G. tomentosum were used to identify quantitative trait loci (QTLs) controlling fiber quality traits. A total of 28 QTLs for fiber quality traits were identified (P < 0.001), including four for fiber elongation, eight for fiber fineness, four for fiber length, four for fiber strength, six for fiber uniformity, one for boll weight, and one for boll number. Three statistically significant marker-trait associations for lint yield were found in a single environment, but need further validation. Two-way analysis of variance revealed one locus with significant genotype × family interaction (P < 0.001) for fiber strength and a second locus with significant genotype × environment interaction (P < 0.001) in the CA3084 background, and two loci with significant genotype × background interaction (P < 0.001) for the 28 common markers segregating in both of the two recurrent backgrounds. Co-location of many QTLs for fiber quality traits partially explained correlations among these traits. Some G. tomentosum alleles were associated with multiple favorable effects, offering the possibility of rapid genetic gain by introgression. Many G. tomentosum alleles were recalcitrant to homozygosity, suggesting that they might be most effectively deployed in hybrid cottons. DNA markers linked to G. tomentosum QTLs identified in the present study promise to assist breeders in transferring and maintaining valuable traits from this exotic source during Upland cotton cultivar development. This study also adds further evidence to prior studies indicating that the majority of genetic variation associated with fiber quality in tetraploid cotton traces to the D-subgenome from a diploid ancestor that does not produce spinnable fiber.

  1. Drought-acclimated cotton does not show heterogeneities in stomatal aperture. [Gossypium hirsutum L

    SciTech Connect

    Wise, R.R.; Ortiz-Lopez, A.; Ort, D.R. )

    1991-05-01

    The presence of heterogeneities in stomatal aperture distribution has been demonstrated by others using either hormone-treated leaves or chamber grown plants droughted for the first time. The authors sought to determine if such patches' existed in droughted, field-grown plants or in plants that had been acclimated to low leaf water potentials. Cotton (Gossypium hirsutum L.) was grown in the field and subjected to drought by withholding irrigation and rain from 20 days after planting. Stomatal distribution was assayed by briefly exposing attached leaves of 3.5 month-old plants to {sup 14}CO{sub 2} and performing subsequent autoradiography. Stomatal distribution was homogeneous even at the lowest leaf water potentials ({Psi}leaf) of {minus}1.34 MPa. Stomatal patchiness could, however, be induced by uprooting the plant and allowing the shoot to air dry for 6-8 mins. Growth chamber grown plants were acclimated to drought by withholding irrigation for three 5-day cycles. This drought acclimation reduced the {Psi} leaf at which control rates of photosynthesis (measured as CO{sub 2} exchange with an IRGA) could be sustained by {approximately}07 MPa and was accompanied by a similar decline in the {Psi} leaf at which patchiness first appeared. This demonstration that the presence of patches can be altered by treatments causing an acclimation of photosynthesis and that patches do not exist in droughted, field grown cotton leads them to conclude that stomatal heterogeneities do not significantly influence the determination of accurate photosynthetic rates in plants allowed to fully acclimate to drought stress.

  2. Genotypic variations in photosynthetic and physiological adjustment to potassium deficiency in cotton (Gossypium hirsutum).

    PubMed

    Wang, Ning; Hua, Hanbai; Eneji, A Egrinya; Li, Zhaohu; Duan, Liusheng; Tian, Xiaoli

    2012-05-02

    A hydroponic culture experiment was conducted to determine genotypic variation in photosynthetic rate and the associated physiological changes in response to potassium (K) deficiency in cotton (Gossypium hirsutum L.) seedlings with contrasting two cotton cultivars in K efficiency. The K-efficient Liaomian18 produced 66.7% more biomass than the K-inefficient NuCOTN99(B) under K deficiency, despite their similar biomass under K sufficiency. Compared with NuCOTN99(B), Liaomian18 showed 19.4% higher net photosynthetic rate (P(n), per unit leaf area) under K deficient solutions and this was associated with higher photochemical efficiency and faster export of soluble sugars from the phloem. The lower net P(n) of NuCOTN99(B) was attributed to higher capacity for nitrate assimilation and lower export of soluble sugars. Furthermore, NuCOTN99(B) showed 38.4% greater ETR/P(n) than Liaomian18 under K deficiency, indicating that more electrons were driven to other sinks. Higher superoxide dismutase (SOD) and lower catalase (CAT) and ascorbate peroxidase (APX) activities resulted in higher levels of reactive oxygen species (ROS; e.g. O(2)(-)and H(2)O(2)) in NuCOTN99(B) relative to Liaomian18. Thus, the K inefficiency of NuCOTN99(B), indicated by lower biomass and net P(n) under K deficiency, was associated with excessively high nitrogen assimilation, lower export of carbon assimilates, and greater ROS accumulation in the leaf. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  3. Inheritance of long staple fiber quality traits of Gossypium barbadense in G. hirsutum background using CSILs.

    PubMed

    Wang, Peng; Zhu, Yajuan; Song, Xianliang; Cao, Zhibin; Ding, Yezhang; Liu, Bingliang; Zhu, Xiefei; Wang, Sen; Guo, Wangzhen; Zhang, Tianzhen

    2012-05-01

    Gossypium hirsutum is a high yield cotton species that exhibits only moderate performance in fiber qualities. A promising but challenging approach to improving its phenotypes is interspecific introgression, the transfer of valuable traits or genes from the germplasm of another species such as G. barbadense, an important cultivated extra long staple cotton species. One set of chromosome segment introgression lines (CSILs) was developed, where TM-1, the genetic standard in G. hirsutum, was used as the recipient parent and the long staple cotton G. barbadense Hai7124 was used as the donor parent by molecular marker-assisted selection (MAS) in BC(5)S(1–4) and BC(4)S(1–3) generations. After four rounds of MAS, the CSIL population was comprised of 174 lines containing 298 introgressed segments, of which 86 (49.4%) lines had single introgressed segments. The total introgressed segment length covered 2,948.7 cM with an average length of 16.7 cM and represented 83.3% of tetraploid cotton genome. The CSILs were highly varied in major fiber qualities. By integrated analysis of data collected in four environments, a total of 43 additive quantitative trait loci (QTL) and six epistatic QTL associated with fiber qualities were detected by QTL IciMapping 3.0 and multi-QTL joint analysis. Six stable QTL were detected in various environments. The CSILs developed and the analyses presented here will enhance the understanding of the genetics of fiber qualities in long staple G. barbadense and facilitate further molecular breeding to improve fiber quality in Upland cotton.

  4. Evolutionary Conservation and Divergence of Gene Coexpression Networks in Gossypium (Cotton) Seeds

    PubMed Central

    Hu, Guanjing; Grover, Corrinne E.; Faigenboim-Doron, Adi; Kadmon, Noa; Page, Justin T.; Udall, Joshua A.

    2016-01-01

    The cotton genus (Gossypium) provides a superior system for the study of diversification, genome evolution, polyploidization, and human-mediated selection. To gain insight into phenotypic diversification in cotton seeds, we conducted coexpression network analysis of developing seeds from diploid and allopolyploid cotton species and explored network properties. Key network modules and functional associations were identified related to seed oil content and seed weight. We compared species-specific networks to reveal topological changes, including rewired edges and differentially coexpressed genes, associated with speciation, polyploidy, and cotton domestication. Network comparisons among species indicate that topologies are altered in addition to gene expression profiles, indicating that changes in transcriptomic coexpression relationships play a role in the developmental architecture of cotton seed development. The global network topology of allopolyploids, especially for domesticated G. hirsutum, resembles the network of the A-genome diploid more than that of the D-genome parent, despite its D-like phenotype in oil content. Expression modifications associated with allopolyploidy include coexpression level dominance and transgressive expression, suggesting that the transcriptomic architecture in polyploids is to some extent a modular combination of that of its progenitor genomes. Among allopolyploids, intermodular relationships are more preserved between two different wild allopolyploid species than they are between wild and domesticated forms of a cultivated cotton, and regulatory connections of oil synthesis-related pathways are denser and more closely clustered in domesticated vs. wild G. hirsutum. These results demonstrate substantial modification of genic coexpression under domestication. Our work demonstrates how network inference informs our understanding of the transcriptomic architecture of phenotypic variation associated with temporal scales ranging from

  5. Identification of semiochemicals released by cotton, Gossypium hirsutum, upon infestation by the cotton aphid, Aphis gossypii.

    PubMed

    Hegde, Mahabaleshwar; Oliveira, Janser N; da Costa, Joao G; Bleicher, Ervino; Santana, Antonio E G; Bruce, Toby J A; Caulfield, John; Dewhirst, Sarah Y; Woodcock, Christine M; Pickett, John A; Birkett, Michael A

    2011-07-01

    The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of headspace samples of volatile organic compounds (VOCs) obtained from uninfested cotton seedlings, but significantly less time with those from A. gossypii infested plants. VOCs from uninfested and A. gossypii infested cotton seedlings were analyzed by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS), leading to the identification of (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), which were produced in larger amounts from A. gossypii infested plants compared to uninfested plants. In behavioral tests, A. gossypii spent significantly more time in the control (solvent) arms when presented with a synthetic blend of these four compounds, with and without the presence of VOCs from uninfested cotton. Coupled GC-electroantennogram (EAG) recordings with the lacewing C. lucasina showed significant antennal responses to VOCs from A. gossypii infested cotton, suggesting they have a role in indirect defense and indicating a likely behavioral role for these compounds for the predator as well as the aphid.

  6. Cotton plant, Gossypium hirsutum L., defense in response to nitrogen fertilization.

    PubMed

    Chen, Yigen; Schmelz, Eric A; Wäckers, Felix; Ruberson, John R

    2008-12-01

    Plants respond to insect herbivory by producing dynamic changes in an array of defense-related volatile and nonvolatile secondary metabolites. A scaled response relative to herbivory levels and nutrient availability would be adaptive, particularly under nutrient-limited conditions, in minimizing the costs of expressed defensive pathways and synthesis. In this study, we investigated effects of varying nitrogen (N) fertilization (42, 112, 196, and 280 ppm N) on levels of cotton plant (Gossypium hirsutum) phytohormones [jasmonic acid (JA) and salicylic acid (SA)], terpenoid aldehydes (hemigossypolone, heliocides H(1), H(2), H(3), and H(4)), and volatile production in response to beet armyworm (Spodoptera exigua) herbivory. Additional bioassays assessed parasitoid (Cotesia marginiventris) host-searching success in response to cotton plants grown under various N fertilizer regimes. At low N input (42 ppm N), herbivore damage resulted in significant increases in local leaf tissue concentrations of JA and volatiles and in systemic accumulation of terpenoid aldehydes. However, increased N fertilization of cotton plants suppressed S. exigua-induced plant hormones and led to reduced production of various terpenoid aldehydes in damaged mature leaves and undamaged young leaves. While increased N fertilization significantly diminished herbivore-induced leaf volatile concentrations, the parasitism of S. exigua larvae by the parasitoid C. marginiventris in field cages did not differ among N treatments. This suggests that, despite significant N fertilization effects on herbivore-induced plant defenses, at short range, the parasitoids were unable to differentiate between S. exigua larvae feeding on physiologically different cotton plants that share large constitutive volatile pools releasable when damaged by herbivores.

  7. Quantitative trait loci mapping and genetic dissection for lint percentage in upland cotton (Gossypium hirsutum).

    PubMed

    Wang, Min; Li, Chengqi; Wang, Qinglian

    2014-08-01

    Lint percentage is an important character of cotton yield components and it is also correlated with cotton fibre development. In this study, we used a high lint percentage variety, Baimian1, and a low lint percentage, TM-1 genetic standard for Gossypium hirsutum, as parents to construct a mapping populations in upland cotton (G. hirsutum). A quantitative trait locus/loci (QTL) analysis of lint percentage was performed by using two mapping procedures; composite interval mapping (CIM), inclusive composite interval mapping (ICIM) and the F2:3 populations in 2 years. Six main-effect QTL (M-QTL) for lint percentage (four significant and two suggestive) were detected in both years by CIM, and were located on chr. 3, chr. 19, chr. 26 and chr. 5/chr. 19. Of the six QTL, marker intervals and favourable gene sources of the significant M-QTL, qLP-3(2010) and qLP-3(2011) were consistent. These QTL were also detected by ICIM, and therefore, should preferentially be used for markerassisted selection (MAS) of lint percentage. Another M-QTL, qLP-19(2010), was detected by two mapping procedures, and it could also be a candidate for MAS. We detected the interaction between two M-QTL and environment, and 11 epistatic QTL (E-QTL) and their interaction with environment by using ICIM. The study also found two EST-SSRs, NAU1187 and NAU1255, linked to M-QTL for lint percentage that could be candidate markers affecting cotton fibre development.

  8. Spatial and temporal variation in fungal endophyte communities isolated from cultivated cotton (Gossypium hirsutum).

    PubMed

    Ek-Ramos, María J; Zhou, Wenqing; Valencia, César U; Antwi, Josephine B; Kalns, Lauren L; Morgan, Gaylon D; Kerns, David L; Sword, Gregory A

    2013-01-01

    Studies of fungi in upland cotton (Gossypium hirsutum) cultivated in the United States have largely focused on monitoring and controlling plant pathogens. Given increasing interest in asymptomatic fungal endophytes as potential biological control agents, surveys are needed to better characterize their diversity, distribution patterns and possible applications in integrated pest management. We sampled multiple varieties of cotton in Texas, USA and tested for temporal and spatial variation in fungal endophyte diversity and community composition, as well as for differences associated with organic and conventional farming practices. Fungal isolates were identified by morphological and DNA identification methods. We found members of the genera Alternaria, Colletotrichum and Phomopsis, previously isolated as endophytes from other plant species. Other recovered species such as Drechslerella dactyloides (formerly Arthrobotrys dactyloides) and Exserohilum rostratum have not, to our knowledge, been previously reported as endophytes in cotton. We also isolated many latent pathogens, but some species such as Alternaria tennuissima, Epicoccum nigrum, Acremonium alternatum, Cladosporium cladosporioides, Chaetomium globosum and Paecilomyces sp., are known to be antagonists against plant pathogens, insects and nematode pests. We found no differences in endophyte species richness or diversity among different cotton varieties, but did detect differences over time and in different plant tissues. No consistent patterns of community similarity associated with variety, region, farming practice, time of the season or tissue type were observed regardless of the ecological community similarity measurements used. Results indicated that local fungal endophyte communities may be affected by both time of the year and plant tissue, but the specific community composition varies across sites. In addition to providing insights into fungal endophyte community structure, our survey provides

  9. Spatial and Temporal Variation in Fungal Endophyte Communities Isolated from Cultivated Cotton (Gossypium hirsutum)

    PubMed Central

    Ek-Ramos, María J.; Zhou, Wenqing; Valencia, César U.; Antwi, Josephine B.; Kalns, Lauren L.; Morgan, Gaylon D.; Kerns, David L.; Sword, Gregory A.

    2013-01-01

    Studies of fungi in upland cotton (Gossypium hirsutum) cultivated in the United States have largely focused on monitoring and controlling plant pathogens. Given increasing interest in asymptomatic fungal endophytes as potential biological control agents, surveys are needed to better characterize their diversity, distribution patterns and possible applications in integrated pest management. We sampled multiple varieties of cotton in Texas, USA and tested for temporal and spatial variation in fungal endophyte diversity and community composition, as well as for differences associated with organic and conventional farming practices. Fungal isolates were identified by morphological and DNA identification methods. We found members of the genera Alternaria, Colletotrichum and Phomopsis, previously isolated as endophytes from other plant species. Other recovered species such as Drechslerella dactyloides (formerly Arthrobotrys dactyloides) and Exserohilum rostratum have not, to our knowledge, been previously reported as endophytes in cotton. We also isolated many latent pathogens, but some species such as Alternaria tennuissima, Epicoccum nigrum, Acremonium alternatum, Cladosporium cladosporioides, Chaetomium globosum and Paecilomyces sp., are known to be antagonists against plant pathogens, insects and nematode pests. We found no differences in endophyte species richness or diversity among different cotton varieties, but did detect differences over time and in different plant tissues. No consistent patterns of community similarity associated with variety, region, farming practice, time of the season or tissue type were observed regardless of the ecological community similarity measurements used. Results indicated that local fungal endophyte communities may be affected by both time of the year and plant tissue, but the specific community composition varies across sites. In addition to providing insights into fungal endophyte community structure, our survey provides

  10. The damaging effects of nitrogen ion beam implantation on upland cotton ( Gossypium hirsutum L.) pollen grains

    NASA Astrophysics Data System (ADS)

    Yu, Yanjie; Wu, Lijun; Wu, Yuejin; Wang, Qingya; Tang, Canming

    2008-09-01

    With the aim to study the effects of an ion beam on plant cells, upland cotton (Gossypium hirsutum L.) cultivar "Sumian 22" pollen grains were irradiated in vacuum (7.8 × 10-3 Pa) by low-energy nitrogen ions with an energy of 20 keV at various fluences ranging from 0.26 × 1016 to 0.78 × 1016 N+/cm2. The irradiation effects on pollen grains were tested, considering the ultrastructural changes in the exine and interior walls of pollen grains, their germination rate, the growth speed of the pollen tubes in the style, fertilization and boll development after the pistils were pollinated by the pollen grains which had been implanted with nitrogen ions. Nitrogen ions entered the pollen grains by etching and penetrating the exine and interior walls and destroying cell structures. A greater percentage of the pollen grains were destroyed as the fluence of N+ ions increased. Obviously, the nitrogen ion beam penetrated the exine and interior walls of the pollen grains and produced holes of different sizes. As the ion fluence increased, the amount and the density of pollen grain inclusions decreased and the size of the lacuna and starch granules increased. Pollen grain germination rates decreased with increasing ion fluence. The number of pollen tubes in the style declined with increased ion implantation into pollen grains, but the growth speed of the tubes did not change. All of the pollen tubes reached the end of the style at 13 h after pollination. This result was consistent with that of the control. Also, the weight and the diameter of the ovary decreased and shortened with increased ion beam implantation fluence. No evident change in the fecundation time of the ovule was observed. These results indicate that nitrogen ions can enter pollen grains and cause a series of biological changes in pollen grains of upland cotton.

  11. SSR marker-assisted improvement of fiber qualities in Gossypium hirsutum using G. barbadense introgression lines.

    PubMed

    Cao, Zhibin; Wang, Peng; Zhu, Xiefei; Chen, Hong; Zhang, Tianzhen

    2014-03-01

    This study demonstrates the first practical use of CSILs for the transfer of fiber quality QTLs into Upland cotton cultivars using SSR markers without detrimentally affecting desirable agronomic characteristics. Gossypium hirsutum is characterized by its high lint production and medium fiber quality compared to extra-long staple cotton G. barbadense. Transferring valuable traits or genes from G. barbadense into G. hirsutum is a promising but challenging approach through a traditional interspecific introgression strategy. We developed one set of chromosome segment introgression lines (CSILs), where TM-1, the genetic standard in G. hirsutum, was used as the recipient parent and the long staple cotton G. barbadense cv. Hai7124 was used as the donor parent by molecular marker-assisted selection (MAS). Among them, four CSILs, IL040-A4-1, IL080-D6-1, IL088-A7-3 and IL019-A2-6, found to be associated with superior fiber qualities including fiber length, strength and fineness QTL in Xinjiang were selected and backcrossed, and transferred these QTLs into three commercial Upland cotton cultivars such as Xinluzao (XLZ) 26, 41 and 42 grown in Xinjiang. By backcrossing and self-pollinating twice, five improved lines (3262-4, 3389-2, 3326-3, 3380-4 and 3426-5) were developed by MAS of background and introgressed segments. In diverse field trials, these QTLs consistently and significantly offered additive effects on the target phenotype. Furthermore, we also pyramided two segments from different CSILs (IL080-D6-1 and IL019-A2-6) into cultivar 0768 to accelerate breeding process purposefully with MAS. The improved lines pyramided by these two introgressed segments showed significant additive epistatic effects in four separate field trials. No significant alteration in yield components was observed in these modified lines. In summary, we first report that these CSILs have great potential to improve fiber qualities in Upland cotton MAS breeding programs.

  12. Structure, expression differentiation and evolution of duplicated fiber developmental genes in Gossypium barbadense and G. hirsutum

    PubMed Central

    2011-01-01

    Background Both Gossypium hirsutum and G. barbadense probably originated from a common ancestor, but they have very different agronomic and fiber quality characters. Here we selected 17 fiber development-related genes to study their structures, tree topologies, chromosomal location and expression patterns to better understand the interspecific divergence of fiber development genes in the two cultivated tetraploid species. Results The sequence and structure of 70.59% genes were conserved with the same exon length and numbers in different species, while 29.41% genes showed diversity. There were 15 genes showing independent evolution between the A- and D-subgenomes after polyploid formation, while two evolved via different degrees of colonization. Chromosomal location showed that 22 duplicate genes were located in which at least one fiber quality QTL was detected. The molecular evolutionary rates suggested that the D-subgenome of the allotetraploid underwent rapid evolutionary differentiation, and selection had acted at the tetraploid level. Expression profiles at fiber initiation and early elongation showed that the transcripts levels of most genes were higher in Hai7124 than in TM-1. During the primary-secondary transition period, expression of most genes peaked earlier in TM-1 than in Hai7124. Homeolog expression profile showed that A-subgenome, or the combination of A- and D-subgenomes, played critical roles in fiber quality divergence of G. hirsutum and G. barbadense. However, the expression of D-subgenome alone also played an important role. Conclusion Integrating analysis of the structure and expression to fiber development genes, suggests selective breeding for certain desirable fiber qualities played an important role in divergence of G. hirsutum and G. barbadense. PMID:21349199

  13. Cryptic interspecific introgression and genetic differentiation within Gossypium aridum (Malvaceae) and its relatives.

    PubMed

    Alvarez, Inés; Wendel, Jonathan F

    2006-03-01

    Interspecific gene flow is increasingly recognized as an important evolutionary phenomenon in plants. A surprising observation is that historical introgression is often inferred between species that presently have geographic and reproductive barriers that would appear to prohibit the inferred sexual exchange. A striking example concerns Gossypium aridum (subsection Erioxylum); previous analyses have shown that populations from Colima (southwestern Mexico) have a chloroplast genome (cpDNA) similar to that of a different taxonomic subsection (Integrifolia) that presently is confined to Baja California and the Galapagos Islands, whereas other G. aridum populations share a cpDNA lineage with each other and with other species in subsection Erioxylum. To evaluate further the possibility that this cpDNA evidence reflects introgression as opposed to some other evolutionary process, as well as to explore patterns of genetic diversity and similarity in both subsections, we conducted amplified fragment-length polymorphism (AFLP) analysis using 50 populations representing all seven species in the two subsections. Genetic diversity is high in G. aridum, and is strongly correlated with geography, as are similarities among the five species in subsection Erioxylum. This subsection is genetically distant from the two species in subsection Integrifolia, whose populations are highly similar inter se. Populations of G. aridum from Colima are genetically distinct from the remainder of the species, and exhibit a comparatively high frequency of AFLP fragments that otherwise are diagnostic of the Integrifolia lineage. These data implicate intersubsectional introgression between presently allopatric and genetically isolated clades, giving rise to a morphologically cryptic, introgressant entity. Biogeographic considerations suggest that this history was initiated following migration of one or more seeds from Baja California to the Colima coast, perhaps during the Pleistocene. We suggest

  14. Molecular cloning and characterization of enhanced disease susceptibility 1 (EDS1) from Gossypium barbadense.

    PubMed

    Su, Xiaofeng; Qi, Xiliang; Cheng, Hongmei

    2014-06-01

    Arabidopsis enhanced disease susceptibility 1 (EDS1) plays an important role in plant defense against biotrophic and necrotrophic pathogens. The necrotrophic pathogen Verticillium dahliae infection of Gossypium barbadense could lead to Verticillium wilt which seriously reduces the cotton production. Here, we cloned and characterized a G. barbadense homolog of EDS1, designated as GbEDS1. The full-length cDNA of the GbEDS1 gene was obtained by the technique of rapid-amplification of cDNA ends. The open reading frame of the GbEDS1 gene was 1,647 bp long and encoded a protein of 548 amino acids residues. Comparison of the cDNA and genomic DNA sequence of GbEDS1 indicated that this gene contained a single intron and two exons. Like other EDS1s, GbEDS1 contained a conserved N-terminal lipase domain and an EDS1-specific KNEDT motif. Subcellular localization assay revealed that GbEDS1-green fluorescence protein fusion protein was localized in both cytosol and nucleus. Interestingly, the transcript levels of GbEDS1 were dramatically increased in response to pathogen V. dahliae infection. To investigate the role of GbEDS1 in plant resistance against V. dahliae, a conserved fragment derived from GbEDS1 was used to knockdown the endogenous EDS1 in Nicotiana benthamiana by heterologous virus-induced gene silencing. Our data showed that silencing of NbEDS1 resulted in increased susceptibility to V. dahliae infection in N. benthamiana, suggesting a possible involvement of the novelly isolated GbEDS1 in the regulation of plant defense against V. dahliae.

  15. Bacillus gossypii sp. nov., isolated from the stem of Gossypium hirsutum.

    PubMed

    Kämpfer, Peter; Busse, Hans-Jürgen; McInroy, John A; Glaeser, Stefanie P

    2015-11-01

    A Gram-stain-positive, facultatively anaerobic, endospore-forming organism, isolated from the stem of Gossypium hirsutum, was studied to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity comparisons, strain JM-267T was grouped in the genus Bacillus, related most closely to the type strains of Bacillus simplex and Bacillus huizhouensis (both 97.8%), Bacillus muralis (97.7%), Bacillus butanolivorans and Bacillus psychrosaccharolyticus (both 97.3%). 16S rRNA gene sequence similarity to the sequences of the type strains of other Bacillus species was < 97.0%. The fatty acid profile supported the grouping of the strain to the genus Bacillus. As major fatty acids, anteiso-C15:0, iso-C15:0, iso-C14:0 and iso-C16:0 were detected. The polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major quinone was menaquinone 7 (MK-7). DNA-DNA hybridizations with B. simplex DSM 1321T, B. huizhouensis GSS03T, B. muralis LMG 20238T, B. butanolivorans LMG 23974T and B. psychrosaccharolyticus DSM 6T resulted in values clearly below 70%. In addition, physiological and biochemical test results allowed the clear phenotypic differentiation of strain JM-267T from the most closely related species. Hence, strain JM-267T is considered to represent a novel species of the genus Bacillus, for which the name Bacillus gossypii sp. nov. is proposed. The type strain is JM-267T ( = DSM 100034T = LMG 28742T).

  16. High efficient multisites genome editing in allotetraploid cotton (Gossypium hirsutum) using CRISPR/Cas9 system.

    PubMed

    Wang, Pengcheng; Zhang, Jun; Sun, Lin; Ma, Yizan; Xu, Jiao; Liang, Sijia; Deng, Jinwu; Tan, Jiafu; Zhang, Qinghua; Tu, Lili; Daniell, Henry; Jin, Shuangxia; Zhang, Xianlong

    2017-05-12

    Gossypium hirsutum is an allotetraploid with a complex genome. Most genes have multiple copies that belong to At and Dt subgenomes. Sequence similarity is also very high between gene homologues. To efficiently achieve site/gene-specific mutation is quite needed. Due to its high efficiency and robustness, the CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system has exerted broad site-specific genome editing from prokaryotes to eukaryotes. In this study, we utilized a CRISPR/Cas9 system to generate two sgRNAs in a single vector to conduct multiple sites genome editing in allotetraploid cotton. An exogenously transformed gene Discosoma red fluorescent protein2(DsRed2) and an endogenous gene GhCLA1 were chosen as targets. The DsRed2-edited plants in T0 generation reverted its traits to wild type, with vanished red fluorescence the whole plants. Besides, the mutated phenotype and genotype were inherited to their T1 progenies. For the endogenous gene GhCLA1, 75% of regenerated plants exhibited albino phenotype with obvious nucleotides and DNA fragments deletion. The efficiency of gene editing at each target site is 66.7-100%. The mutation genotype was checked for both genes with Sanger sequencing. Barcode-based high-throughput sequencing, which could be highly efficient for genotyping to a population of mutants, was conducted in GhCLA1-edited T0 plants and it matched well with Sanger sequencing results. No off-target editing was detected at the potential off-target sites. These results prove that the CRISPR/Cas9 system is highly efficient and reliable for allotetraploid cotton genome editing. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  17. Rapid evolutionary divergence of Gossypium barbadense and G. hirsutum mitochondrial genomes.

    PubMed

    Tang, Mingyong; Chen, Zhiwen; Grover, Corrinne E; Wang, Yumei; Li, Shuangshuang; Liu, Guozheng; Ma, Zhiying; Wendel, Jonathan F; Hua, Jinping

    2015-10-12

    The mitochondrial genome from upland cotton, G. hirsutum, was previously sequenced. To elucidate the evolution of mitochondrial genomic diversity within a single genus, we sequenced the mitochondrial genome from Sea Island cotton (Gossypium barbadense L.). Mitochondrial DNA from week-old etiolated seedlings was extracted from isolated organelles using discontinuous sucrose density gradient method. Mitochondrial genome was sequenced with Solexa using paired-end, 90 bp read. The clean reads were assembled into contigs using ABySS and finished via additional fosmid and BAC sequencing. Finally, the genome was annotated and analyzed using different softwares. The G. barbadense (Sea Island cotton) mitochondrial genome was fully sequenced (677,434-bp) and compared to the mitogenome of upland cotton. The G. barbadense mitochondrial DNA contains seven more genes than that of upland cotton, with a total of 40 protein coding genes (excluding possible pseudogenes), 6 rRNA genes, and 29 tRNA genes. Of these 75 genes, atp1, mttB, nad4, nad9, rrn5, rrn18, and trnD(GTC)-cp were each represented by two identical copies. A single 64 kb repeat was largely responsible for the 9 % difference in genome size between the two mtDNAs. Comparison of genome structures between the two mitochondrial genomes revealed 8 rearranged syntenic regions and several large repeats. The largest repeat was missing from the master chromosome in G. hirsutum. Both mitochondrial genomes contain a duplicated copy of rps3 (rps3-2) in conjunction with a duplication of repeated sequences. Phylogenetic and divergence considerations suggest that a 544-bp fragment of rps3 was transferred to the nuclear genome shortly after divergence of the A- and D- genome diploid cottons. These results highlight the insights to the evolution of structural variation between Sea Island and upland cotton mitochondrial genomes.

  18. Two temporally synthesized charge subunits interact to form the five isoforms of cottonseed (Gossypium hirsutum) catalase.

    PubMed Central

    Ni, W; Trelease, R N; Eising, R

    1990-01-01

    Five charge isoforms of tetrameric catalase were isolated from cotyledons of germinated cotton (Gossypium hirsutum L.) seedlings. Denaturing isoelectric focusing of the individual isoforms in polyacrylamide gels indicated that isoforms A (most anodic) and E (most cathodic) consisted of one subunit of different charge, whereas isoforms B, C and D each consisted of a mixture of these two subunits. Thus the five isoforms apparently were formed through combinations of two subunits in different ratios. Labelling cotyledons in vivo with [35S]methionine at three daily intervals in the dark, and translation in vivo of polyadenylated RNA isolated from cotyledons at the same ages, revealed synthesis of two different subunits. One of the subunits was synthesized in cotyledons at all ages studied (days 1-3), whereas the other subunit was detected only at days 2 and 3. This differential expression of two catalase subunits helped explain previous results from this laboratory showing that the two anodic forms (A and B) found in maturing seeds were supplemented with three cathodic forms (C-E) after the seeds germinated. These subunit data also helped clarify our new findings that proteins of isoforms A, B and C (most active isoforms) accumulated in cotyledons of plants kept in the dark for 3 days, then gradually disappeared during the next several days, whereas isoforms D and E (least active isoforms) remained in the cells. This shift in isoform pattern occurred whether seedlings were kept in the dark or exposed to continuous light after day 3, although exposure to light enhanced this process. These sequential molecular events were responsible for the characteristic developmental changes (rise and fall) in total catalase activity. We believe that the isoform changeover is physiologically related to the changeover in glyoxysome to leaf-type-peroxisome metabolism. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:1695843

  19. Overexpression of MIC-3 indicates a direct role for the MIC gene family in mediating Upland cotton (Gossypium hirsutum) resistance to root-knot nematode (Meloidogyne incognita)

    USDA-ARS?s Scientific Manuscript database

    Major quantitative trait loci (QTL) have been mapped to Upland cotton (Gossypium hirsutum L.) chromosomes 11 and 14 that govern the highly resistant phenotype in response to infection by root-knot nematode (RKN; Meloidogyne incognita Chitwood & White); however, nearly nothing is known regarding the ...

  20. Genotypic comparisons of chromosomes 01, 04 and 18 from three tetraploid species of gossypium in topcrosses with five elite cultivars of G. hirsutum L

    USDA-ARS?s Scientific Manuscript database

    Upland cotton, Gossypium hirsutum L. is planted on most of the hectareage of cultivated cotton in the United States and the world. The cultivated tetraploid species G. barbadense L. produces extra long, strong, and fine fibers. Breeders would like to move fiber quality alleles from this species in...