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1

Effects of 60-day NO2 fumigation on growth, oxidative stress and antioxidative response in Cinnamomum camphora seedlings*  

PubMed Central

Objective: To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO2) fumigation. Methods: Measurements were made up of the growth, chlorophyll content, chlorophyll fluorescence, antioxidant system and lipid peroxidation of one-year-old C. camphora seedlings exposed to NO2 (0.1, 0.5, and 4 ?l/L) fumigation in open top chambers over a period of 60 d. Results: After the first 30 d, 0.5 and 4.0 ?l/L NO2 showed insignificant effects on the growth of C. camphora seedlings. However, exposure to 0.5 and 4.0 ?l/L NO2 for 15 d significantly reduced their chlorophyll content (P<0.05), enhanced their malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (P<0.05), and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence (F v/F m)] (P<0.05). In the latter 30 d, 0.5 ?l/L NO2 showed a positive effect on the vitality of the seedlings, which was reflected by a recovery in the ratio of F v/F m and chlorophyll content, and obviously enhanced growth, SOD activity, ascorbate (AsA) content and glutathione reductase (GR) activity (P<0.05); 4.0 ?l/L NO2 then showed a negative effect, indicated by significant reductions in chlorophyll content and the ratio of F v/F m, and inhibited growth (P<0.05). Conclusion: The results suggest adaptation of C. camphora seedlings to 60-d exposure to 0.1 and 0.5 ?l/L NO2, but not to 60-d exposure to 4.0 ?l/L NO2. C. camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO2-induced oxidative stress. PMID:20205305

Chen, Zhuo-mei; Chen, Ying-xu; Du, Guo-jian; Wu, Xi-lin; Li, Feng

2010-01-01

2

Impact of elevated O3 on visible foliar symptom, growth and biomass of Cinnamomum camphora seedlings under different nitrogen loads.  

PubMed

The effects of elevated ozone (O(3)) and enhanced nitrogen (N) on the growth and biomass of Cinnamomum camphora, a subtropical evergreen broad-leaved tree species, were investigated. The seedlings, supplied with N (NH(4)NO(3) solution) at 0, 30 and 60 kg ha(-1) year(-1) (simplified as N0, N30, N60, respectively), were exposed to ambient (AA) or elevated O(3) (AA + 60 nmol mol(-1) and AA + 120 nmol mol(-1), designated as AA + 60 and AA + 120, respectively) for the 2009 and 2010 growing seasons. Symptomatic leaf percentages were significantly increased with O(3) concentration. AA + 120 significantly decreased the mean leaf size and chlorophyll content of both 2009- and 2010-emerged leaves, inhibited the growth of stem height and basal diameter, and reduced biomass accumulation of all plant parts except for leaves. By comparison, only the chlorophyll content of 2009-emerged leaves and root dry weight were significantly reduced under AA + 60. Specific leaf area, total leaf area and foliar biomass were not affected even at a higher O(3) level. On the other hand, N loads, especially N60, exerted significantly positive effects on all variables except mean leaf size and shoot/root ratio. No significant interactions between O(3) and N were detected, suggesting that the N supply at ?60 kg ha(-1) year(-1) did not significantly modify the response of C. camphora to O(3) in terms of seedling growth and biomass accumulation. PMID:21853164

Niu, Junfeng; Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Tian, Yuan

2011-10-01

3

Extraction of heavy metals from contaminated soil by Cinnamomum camphora.  

PubMed

83 acres of rice paddy fields in Taoyuan county, Taiwan, were polluted by cadmium (Cd), chromium (Cr) and copper (Cu) through a nearby irrigation channel, and rice plantation was ceased in 1987. Camphor trees (Cinnamomum camphora) have been planted in 2 acre of the above fields since 1991. Heavy metal accumulation of roots, leaves, branches and heartwood of camphor trees were analyzed during 20-year afforestation. Averaged Cd contents of the roots were found larger than the ones of the branches, leaves, sapwood and heartwood of camphor trees growing in three polluted plots. Averaged diameters at breast height (DBH) of the planted camphor trees were 13-15 cm. Cd pollution did not significantly impact the growth of camphor trees, as similar DBH's were found from both polluted and control sites. Annual growths of DBH were from 0.63 to 0.77 cm year(-1). Planting camphor trees sequestered 68.8 ton biomass per acre. During 20-year period, 0.69-1.98 ton C year(-1) ha(-1) were sequestered on three polluted plots. The above numbers exceeded IPCC LULUCF reference values 0.31-0.53 ton C year(-1) ha(-1) for activities at forest lands. PMID:25204813

Ho, Jian-Ren; Ma, Hwong-Wen; Wang, Yi-Chung; Ko, Chun-Han; Chang, Fang-Chih; Feng, Fong-Long; Wang, Ya-Nang

2014-12-01

4

Non-Stomatal Limitation to Photosynthesis in Cinnamomum camphora Seedings Exposed to Elevated O3  

PubMed Central

Ozone (O3) is the most phytotoxic air pollutant for global forests, with decreased photosynthesis widely regarded as one of its most common effects. However, controversy exists concerning the mechanism that underlies the depressing effects of O3 on CO2 assimilation. In the present study, seedlings of Cinnamomum camphora, a subtropical evergreen tree species that has rarely been studied, were exposed to ambient air (AA), ambient air plus 60 [ppb] O3 (AA+60), or ambient air plus 120 [ppb] O3 (AA+120) in open-top chambers (OTCs) for 2 years. Photosynthetic CO2 exchange and chlorophyll a fluorescence were investigated in the second growing season (2010). We aim to determine whether stomatal or non-stomatal limitation is responsible for the photosynthesis reduction and to explore the potential implications for forest ecosystem functions. Results indicate that elevated O3 (E-O3) reduced the net photosynthetic rates (PN) by 6.0-32.2%, with significant differences between AA+60 and AA+120 and across the four measurement campaigns (MCs). The actual photochemical efficiency of photosystem II (PSII) in saturated light (Fv?/Fm?) was also significantly decreased by E-O3, as was the effective quantum yield of PSII photochemistry (?PSII). Moreover, E-O3 significantly and negatively impacted the maximum rates of carboxylation (Vcmax) and electron transport (Jmax). Although neither the stomatal conductance (gs) nor the intercellular CO2 concentration (Ci) was decreased by E-O3, PN/gs was significantly reduced. Therefore, the observed reduction in PN in the present study should not be attributed to the unavailability of CO2 due to stomatal limitation, but rather to the O3-induced damage to Ribulose-1,5-bisphosphate carboxylase/oxygenase and the photochemical apparatus. This suggests that the down-regulation of stomatal conductance could fail to occur, and the biochemical processes in protoplasts would become more susceptible to injuries under long-term O3 exposure, which may have important consequences for forest carbon and water budget. PMID:24892748

Niu, Junfeng; Feng, Zhaozhong; Zhang, Weiwei; Zhao, Ping; Wang, Xiaoke

2014-01-01

5

Non-stomatal limitation to photosynthesis in Cinnamomum camphora seedings exposed to elevated O3.  

PubMed

Ozone (O3) is the most phytotoxic air pollutant for global forests, with decreased photosynthesis widely regarded as one of its most common effects. However, controversy exists concerning the mechanism that underlies the depressing effects of O3 on CO2 assimilation. In the present study, seedlings of Cinnamomum camphora, a subtropical evergreen tree species that has rarely been studied, were exposed to ambient air (AA), ambient air plus 60 [ppb] O3 (AA+60), or ambient air plus 120 [ppb] O3 (AA+120) in open-top chambers (OTCs) for 2 years. Photosynthetic CO2 exchange and chlorophyll a fluorescence were investigated in the second growing season (2010). We aim to determine whether stomatal or non-stomatal limitation is responsible for the photosynthesis reduction and to explore the potential implications for forest ecosystem functions. Results indicate that elevated O3 (E-O3) reduced the net photosynthetic rates (PN) by 6.0-32.2%, with significant differences between AA+60 and AA+120 and across the four measurement campaigns (MCs). The actual photochemical efficiency of photosystem II (PSII) in saturated light (Fv'/Fm') was also significantly decreased by E-O3, as was the effective quantum yield of PSII photochemistry (?PSII). Moreover, E-O3 significantly and negatively impacted the maximum rates of carboxylation (Vcmax) and electron transport (Jmax). Although neither the stomatal conductance (gs) nor the intercellular CO2 concentration (Ci) was decreased by E-O3, PN/gs was significantly reduced. Therefore, the observed reduction in PN in the present study should not be attributed to the unavailability of CO2 due to stomatal limitation, but rather to the O3-induced damage to Ribulose-1,5-bisphosphate carboxylase/oxygenase and the photochemical apparatus. This suggests that the down-regulation of stomatal conductance could fail to occur, and the biochemical processes in protoplasts would become more susceptible to injuries under long-term O3 exposure, which may have important consequences for forest carbon and water budget. PMID:24892748

Niu, Junfeng; Feng, Zhaozhong; Zhang, Weiwei; Zhao, Ping; Wang, Xiaoke

2014-01-01

6

Biosynthesis of silver and gold nanoparticles by novel sundried Cinnamomum camphora leaf  

NASA Astrophysics Data System (ADS)

The synthesis of nanocrystals is in the limelight in modern nanotechnology. Biosynthesis of nanoparticles by plant extracts is currently under exploitation. Not only could silver nanoparticles ranging from 55 to 80 nm in size be fabricated, but also triangular or spherical shaped gold nanoparticles could be easily modulated by reacting the novel sundried biomass of Cinnamomum camphora leaf with aqueous silver or gold precursors at ambient temperature. The marked difference of shape control between gold and silver nanoparticles was attributed to the comparative advantage of protective biomolecules and reductive biomolecules. The polyol components and the water-soluble heterocyclic components were mainly responsible for the reduction of silver ions or chloroaurate ions and the stabilization of the nanoparticles, respectively. The sundried leaf in this work was very suitable for simple synthesis of nanoparticles.

Huang, Jiale; Li, Qingbiao; Sun, Daohua; Lu, Yinghua; Su, Yuanbo; Yang, Xin; Wang, Huixuan; Wang, Yuanpeng; Shao, Wenyao; He, Ning; Hong, Jinqing; Chen, Cuixue

2007-03-01

7

[Spectroscopic analysis of the decay resistance of wood treated with extracts from the xylem of Cinnamomum Camphora with XRD and FTIR approaches].  

PubMed

Four kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree I of preservation and showed strong resistance to brown-rot fungus at tack. The wood treated with 4% camphor extracts, 10% ethyl acetate extracts, and 10% acetone extracts reached the demand of degree II and showed moderate decay resistance. The blocks treated with 10% hot water extracts and untreated samples meet the demand of degree III. Through XRD comparison, the author was found that the preservative effects of four extracts are proportional to the degree of crystallinity. Crystallization fields 2 theta diffraction angle were ordered from larger to little as 10% hot wa-ter extracts > untreated samples > 10% acetone extracts > 10% methanol extracts > 1% ethyl acetate extracts. According to FTIR analysis, the amount of degraded cellulose and hemicellulose increased with the decline of characteristic absorption peak at 1,374, 1,160, 1,106, 1,056 and 897 cm(-1), meaning that the preservative effect of corresponding preservatives were getting worse. The peak height of characterization of lignin is higher compared to the untreated wood. I1,510/I1,738, I1,510/I1,374, l51,510/ I1,160 of the treated blocks with 10% methanol extracts and 4% ACQ are the smallest in all the treated blocks, which proved that the degradation ability of brown--rot fungus to the holocellulose is the weakest, and the wood preservative is best. PMID:25208421

Li, Quan; Wang, Xiao-Xian; Lin, Jin-Guo

2014-03-01

8

Spatial distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China.  

PubMed

The concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in Camphor tree bark from Southern Jiangsu, China. Tree bark samples were collected in August 2012. The ?15PAHs concentrations were ranged from 6.18 to 1560 ng g(-1)dry weight (dw), with an average value of 407 ng g(-1)dw. Generally, the concentrations of PAHs in the suburban areas were the highest, followed by urban and rural areas. Principal component analysis and diagnostic ratios results showed that vehicle emission, biomass and coal combustion and industrial emission were the major sources of PAHs in tree bark from Southern Jiangsu. Good correlation was found between tree bark and polyurethane foam (PUF) samplers, indicating that both of them respond well to the gas-phase PAHs monitoring. PMID:24480428

Zhou, Li; Dong, Liang; Huang, Yeru; Shi, Shuangxin; Zhang, Lifei; Zhang, Xiulan; Yang, Wenlong; Li, Lingling

2014-07-01

9

[Levels and possible sources of organochlorine pesticides (OCPs) in camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China].  

PubMed

Thirty-three camphor tree bark samples were collected from Southern Jiangsu in August 2012. They were analyzed for organochlorine pesticides (OCPs), including hexachlorobenzene (HCB), DDTs (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT), trans-chlordane and cis-chlordane. The concentrations of HCB, sigma6 DDTs and sigma Chlordanes ranged (dw) from 0.31 ng x g(-1) to 1.81 ng x g(-1), 0.40 ng x g(-1) to 17.3 ng x g(-1) and n. d. to 1.03 ng x g(-1), respectively. Due to the high volatility, the spatial distribution of HCB in Southern Jiangsu was uniform. Compared to the other results, the HCB concentration in Southern Jiangsu was lower. The historical usage of technical DDT mixture and the dicofol-type DDT were the major sources of DDTs in southern Jiangsu. The TC/CC ratio is usually used to distinguish between aged and fresh chlordane. According to the ratio of TC/CC, the chlordane in the urban area was derived from the fresh application of technical chlordane, and that in the rural area was attributed to the historical usage. PMID:24881411

Zhou, Li; Zhang, Xiu-Lan; Yang, Wen-Long; Li, Ling-Ling; Shi, Shuang-Xin; Zhang, Li-Fei; Dong, Liang; Huang, Ye-Ru

2014-03-01

10

Biological activities of aqueous extract from Cinnamomum porrectum  

NASA Astrophysics Data System (ADS)

A study was carried out to evaluate biological activities of an extract obtained from Cinnamomum porrectum under reflux using water. Aqueous extract of Cinnamomum porrectum was tested for antibacterial activity against six Gram-positive and eight Gram-negative bacteria as well as MRSA. The results confirmed that the aqueous extract of Cinnamomum porrectum was bactericidal. Cytotoxic tests on Vero cell culture revealed that Cinnamomum porrectum was non-toxic which IC50 value higher than 0.02 mg/mL. Antiviral activity was tested based on the above IC50 values together with the measured EC50 values to obtain Therapeutic Index. The result showed that Cinnamomum porrectum has the ability to inhibit viral replication of HSV-1 in Vero cells.

Farah, H. Siti; Nazlina, I.; Yaacob, W. A.

2013-11-01

11

Biochem. J. (2002) 362, 659663 (Printed in Great Britain) 659 Cinnamomin, a type II ribosome-inactivating protein, is a storage protein in  

E-print Network

-inactivating protein, is a storage protein in the seed of the camphor tree (Cinnamomum camphora) Ren-shui LIU, Guo-inactivating protein (RIP) isolated in our laboratory from the seed of the camphor tree (Cinnamomum camphora in our laboratory from the seeds of the camphor tree (Cinnamomum camphora). Its enzymic mechanism

Tian, Weidong

12

Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii  

PubMed Central

Extensive studies have been carried out in the last decade to assess the pharmaceutical potential and screen the phytochemical constituents of Cinnamomum burmannii. Databases such as PubMed (MEDLINE), Science Direct (Embase, Biobase, biosis), Scopus, Scifinder, Google Scholar, Google Patent, Cochrane database, and web of science were searched using a defined search strategy. This plant is a member of the genus Cinnamomum and is traditionally used as a spice. Cinnamomum burmannii have been demonstrated to exhibit analgesic, antibacterial, anti-diabetic, anti-fungal, antioxidant, antirheumatic, anti-thrombotic, and anti-tumor activities. The chemical constituents are mostly cinnamyl alcohol, coumarin, cinnamic acid, cinnamaldehyde, anthocynin, and essential oils together with constituents of sugar, protein, crude fats, pectin, and others. This review presents an overview of the current status and knowledge on the traditional usage, the pharmaceutical, biological activities, and phytochemical constituents reported for C. burmannii. PMID:23055638

Al-Dhubiab, Bandar E.

2012-01-01

13

Allozyme Variation in Four Geographic Areas of Cinnamomum kanehlrae  

Microsoft Academic Search

The once dominant endemic broadleaf tree species In Taiwan, CInnamomum kanehlrae Hay., has become a rare and endangered species due to overcutting. A done bank, consisting of at least 220 clones collected istandwide, was established at the Uukuel station, Taiwan Forestry Research Institute. Genetic diversity wtthln and genetic dif- ferentiation among four geographic areas of C. kanehlrae were Investigated using

T.-P. Lin; Y.-P. Cheng; S.-G. Huang

14

Aporphine alkaloids of Cinnamomum mollissimum and their bioactivities.  

PubMed

A chemical investigation of the crude extracts of Cinnamomum mollissimum bark resulted in the isolation of five aporphine alkaloids, namely N-methyl-1,2,10-trimethoxyaporphine, N-methylhernagine, N-methylhemovine, hernagine and hernovine. Their structures were elucidated by spectral analysis. The alkaloid crude extract demonstrated significant antibacterial and antioxidant activities. PMID:24660455

Masnon, Fatin Fasihah; Hassan, Najmah P S; Ahmad, Farediah

2014-01-01

15

Determination of volatiles produced during radiation processing in Laurus cinnamomum  

NASA Astrophysics Data System (ADS)

In order to protect food from pathogenic microorganisms as well as increase its shelf-life, while keeping sensorial properties (e.g., odor and taste), which are important properties required by spice buyers, it is necessary to analyze volatile formation from irradiation of medicinal and food herbs. Possible changes in the odor of these herbs are evaluated by characterizing different radiation doses and effects on sensorial properties, in order to allow better application of the irradiation technology. The aim of the present study was to analyze volatile formation on cinnamon ( Laurus cinnamomum) samples after gamma irradiation. These samples were irradiated into plastic packages using a 60Co facility. Radiation doses applied were 0, 5, 10, 15, 20 and 25 kGy. For the analysis of the samples, solid-phase microextraction (SPME) was applied, while for the analysis of volatile compounds, CG/MS. Spice irradiation showed the highest decrease in volatile compounds. For L. cinnamomum, the irradiation decreased volatile compounds by nearly 56% and 89.5%, respectively, comparing to volatile from a sample which had not been previously irradiated.

Salum, D. C.; Araújo, M. M.; Fanaro, G. B.; Purgatto, E.; Villavicencio, A. L. C. H.

2009-07-01

16

Medicinal properties of ‘true’ cinnamon (Cinnamomum zeylanicum): a systematic review  

PubMed Central

Background In traditional medicine Cinnamon is considered a remedy for respiratory, digestive and gynaecological ailments. In-vitro and in-vivo studies from different parts of the world have demonstrated numerous beneficial medicinal effects of Cinnamomum zeylanicum (CZ). This paper aims to systematically review the scientific literature and provide a comprehensive summary on the potential medicinal benefits of CZ. Methods A comprehensive systematic review was conducted in the following databases; PubMed, Web of Science, SciVerse Scopus for studies published before 31st December 2012. The following keywords were used: “Cinnamomum zeylanicum”, “Ceylon cinnamon”, “True cinnamon” and “Sri Lankan cinnamon”. To obtain additional data a manual search was performed using the reference lists of included articles. Results The literature search identified the following number of articles in the respective databases; PubMed=54, Web of Science=76 and SciVerse Scopus=591. Thirteen additional articles were identified by searching reference lists. After removing duplicates the total number of articles included in the present review is 70. The beneficial health effects of CZ identified were; a) anti-microbial and anti-parasitic activity, b) lowering of blood glucose, blood pressure and serum cholesterol, c) anti-oxidant and free-radical scavenging properties, d) inhibition of tau aggregation and filament formation (hallmarks of Alzheimer’s disease), e) inhibitory effects on osteoclastogenesis, f) anti-secretagogue and anti-gastric ulcer effects, g) anti-nociceptive and anti-inflammatory activity, h) wound healing properties and i) hepato-protective effects. The studies reported minimal toxic and adverse effects. Conclusions The available in-vitro and in-vivo evidence suggests that CZ has many beneficial health effects. However, since data on humans are sparse, randomized controlled trials in humans will be necessary to determine whether these effects have public health implications. PMID:24148965

2013-01-01

17

A potential low-coumarin cinnamon substitute: Cinnamomum osmophloeum leaves.  

PubMed

The essential oils from leaves of Taiwan's indigenous cinnamon (Cinnamomum osmophloeum ct. cinnamaldehyde) have similar constituents as compared to that from commercial bark cinnamons. This indigenous cinnamon has been proven to have excellent bioactivities. To understand whether this indigenous cinnamon contains a high level of the hepatotoxic compound, coumarin, as often seen in Cassia cinnamons, current research focused on determining the coumarin content in this indigenous cinnamon and screening the low-coumarin clones. The results demonstrated that the coumarin contents in all tested indigenous cinnamon clones were much lower than that found in Cassia cinnamons. In addition, this indigenous cinnamon contains about 80% (w/w) of cinnamaldehyde and 0.4-2.7% (w/w) of eugenol in its leaf essential oils. This combination could provide this indigenous cinnamon a better shelf life compared to that of regular commercial cinnamons. These results suggested that leaves of this indigenous cinnamon could be a potential resource for a safer cinnamon substitute. PMID:24475880

Yeh, Ting-Feng; Lin, Chun-Ya; Chang, Shang-Tzen

2014-02-19

18

Efficacy of Cinnamomum cassia Blume. in age induced sexual dysfunction of rats  

PubMed Central

Objective Cinnamomum cassia has been suggested in Ayurveda for the management of sexual dysfunction. This research work was conducted to shed some light on the mechanism of action of the extract, and evaluate the efficacy of its methanol extract in age induced sexual dysfunction in male Wistar rats. Secondary objective of the project was to study the effect of treatment on sperm parameters and smooth muscle:collagen level in rat penile tissue. Methods Young and aged male rats were treated with methanol extract of Cinnamomum cassia at a dose of 100 mg/kg and sexual behavior was observed on 28th day in presence of female rats in estrous phase. Sildenafil was used as standard medicine. Effect of treatment was studied on epididymal sperm parameters, and Massons trichrome staining of rat penile tissues was performed to know the level of smooth muscle:collagen. Results The treatment significantly increased sexual function in aged rats that had decreased in comparison to young rats, but did not have any significant effect on sperm count, live and defective sperm percentage. However, treatment induced an increase in smooth muscle level and a decrease in collagen level in the aged rat penile tissue in comparison to that of age matched control. Conclusion Based on our studies, we found that Cinnamomum cassia extract was effective in management of sexual dysfunction in aged rats and hence we propose a possible mechanism of action for Cinnamomum cassia which could be responsible for restoring sexual activity in aged rat. PMID:24563594

Goswami, Sumanta Kumar; Inamdar, Mohammed Naseeruddin; Jamwal, Rohitash; Dethe, Shekhar

2013-01-01

19

An overview on chemical composition, bioactivity and processing of leaves of Cinnamomum tamala.  

PubMed

Dried leaves of Cinnamomum tamala, also known as Indian bay leaves, are a lesser-known spice used in the Indian subcontinent. It imparts a warm, peppery, clove-cinnamon like flavor to a variety of food preparations. Besides food applications, the leaves have also been traditionally used for curing a number of ailments and for other perceived health benefits. They find mention in the Aurvedic, Yunani, and other traditional medicinal literature. This review summarizes the effect of Cinnamomum tamala leaves on biological systems such as immune system, gastro-intestinal tract, liver and its antioxidant, antidiabetic, anti-inflammatory, anticancer, and antimicrobial activity. Chemical components that may be responsible for its flavor as well as bioactivity, have also been discussed. PMID:24236996

Sharma, Vasundhara; Rao, Lingamallu Jagan Mohan

2014-01-01

20

Immunosuppressive Effects of A-Type Procyanidin Oligomers from Cinnamomum tamala  

PubMed Central

Cinnamon barks extracts have been reported to regulate immune function; however, the component(s) in cinnamon barks responsible for this effect is/are not yet clear. The aim of this study is to find out the possible component(s) that can be used as therapeutic agents for immune-related diseases from cinnamon bark. In this study, the immunosuppressive effects of fraction (named CT-F) and five procyanidin oligomers compounds, cinnamtannin B1, cinnamtannin D1 (CTD-1), parameritannin A1, procyanidin B2, and procyanidin C1, from Cinnamomum tamala or Cinnamomum cassia bark were examined on splenocytes proliferation model induced by ConA or LPS. Then, the effects of activated compound CTD-1 on cytokine production and 2,4-dinitrofluorobenzene (DNFB) induced delayed-type hypersensitivity (DTH) response were detected to evaluate the immunosuppressive activity of CTD-1. It was found that CT-F and CTD-1 significantly inhibited the splenocyte proliferation induced by ConA or LPS. CTD-1 dose-dependently reduced the level of IFN-? and IL-2 and intensively suppressed DNFB-induced DTH responses. These findings suggest that the immunosuppressive activities of cinnamon bark are in part due to procyanidin oligomers. CTD-1 may be a potential therapeutic agent for immune-related diseases.

Chen, Liang; Yang, Yang; Yuan, Pulong; Yang, Yifu; Chen, Kaixian; Jia, Qi; Li, Yiming

2014-01-01

21

Historical spatial range expansion and a very recent bottleneck of Cinnamomum kanehirae Hay. (Lauraceae) in Taiwan inferred from nuclear genes  

Microsoft Academic Search

BACKGROUND: Species in the varied geographic topology of Taiwan underwent obvious demographic changes during glacial periods. Cinnamomum kanehirae has been exploited for timber and to obtain medicinal fungi for the past 100 years. Understanding anthropogenic factors influencing the demography of this species after the last glacial maximum (LGM) is critically important for the conservation of this species. RESULTS: Populations of

Pei-Chun Liao; Dai-Chang Kuo; Chia-Chia Lin; Kuo-Chieh Ho; Tsan-Piao Lin; Shih-Ying Hwang

2010-01-01

22

A new coumarin and cytotoxic activities of constituents from Cinnamomum cassia.  

PubMed

A new coumarin derivative, coumacasia (1) and eight known compounds, coumarin (2), cinnamaldehyde (3), 2-methoxycinnamaldehyde (4), 2-hydroxycinnamaldehyde (5), coniferaldehyde (6), cinnamic acid (7), 2-hydroxycinnamic acid (8), and cinnamic alcohol (9), were isolated from the methanol extract of Cinnamomum cassia. Their structures were elucidated by spectral data and by comparison with the reported literature. The cytotoxic activities of compounds 1-9 were evaluated with two human cancer cell lines, HL-60 and A-549. Compound 1 showed growth inhibitory effects in the HL-60 and A-549 cell lines with IC50 values of 8.2 +/- 0.5 and 11.3 +/- 1.1 microM, respectively. Compounds 3-6, and 8 exhibited moderate cytotoxicity with IC50 values ranging from 20.5 to 65.6 microM. PMID:24868863

Ngoc, Tran Minh; Nhiem, Nguyen Xuan; Khoi, Nguyen Minh; Son, Doan Cao; Hung, Tran Viet; Van Kiem, Phan

2014-04-01

23

REFORESTATION AND SEEDLING SYMBIONTS  

EPA Science Inventory

Tree seedlings are dependent on symbiotic associations with microorganisms including bacteria, fungi, and actinomycetes for normal growth and development. itrogen fixing leguminous and non-leguminous trees form symbiotic relationships with Rhizobium (bacteria) and Frankia (actino...

24

5.NF Grass Seedlings  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The students in Raulâs class were growing grass seedlings in different conditions for a science project. He noticed that Pabloâs seedlings were $1\\frac...

25

Essential oil alloaromadendrene from mixed-type Cinnamomum osmophloeum leaves prolongs the lifespan in Caenorhabditis elegans.  

PubMed

Cinnamomum osmophloeum Kaneh. is an indigenous tree species in Taiwan. The present study investigates phytochemical characteristics, antioxidant activities, and longevity of the essential oils from the leaves of the mixed-type C. osmophloeum tree. We demonstrate that the essential oils from leaves of mixed-type C. osmophloeum exerted in vivo antioxidant activities on Caenorhabditis elegans. In addition, minor (alloaromadendrene, 5.0%) but not major chemical components from the leaves of mixed-type C. osmophloeum have a key role against juglone-induced oxidative stress in C. elegans. Additionally, alloaromadendrene not only acts protective against oxidative stress but also prolongs the lifespan of C. elegans. Moreover, mechanistic studies show that DAF-16 is required for alloaromadendrene-mediated oxidative stress resistance and longevity in C. elegans. The results in the present study indicate that the leaves of mixed-type C. osmophloeum and essential oil alloaromadendrene have the potential for use as a source for antioxidants or treatments to delay aging. PMID:24918691

Yu, Chan-Wei; Li, Wen-Hsuan; Hsu, Fu-Lan; Yen, Pei-Ling; Chang, Shang-Tzen; Liao, Vivian Hsiu-Chuan

2014-07-01

26

Anti-Inflammatory Activities of Cinnamomum cassia Constituents In Vitro and In Vivo  

PubMed Central

We have investigated the anti-inflammatory effects of Cinnamomum cassia constituents (cinnamic aldehyde, cinnamic alcohol, cinnamic acid, and coumarin) using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) and carrageenan (Carr)-induced mouse paw edema model. When RAW264.7 macrophages were treated with cinnamic aldehyde together with LPS, a significant concentration-dependent inhibition of nitric oxide (NO), tumor necrosis factor (TNF-?), and prostaglandin E2 (PGE2) levels productions were detected. Western blotting revealed that cinnamic aldehyde blocked protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear transcription factor kappa B (NF-?B), and I?B?, significantly. In the anti-inflammatory test, cinnamic aldehyde decreased the paw edema after Carr administration, and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw tissue. We also demonstrated cinnamic aldehyde attenuated the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in the edema paw after Carr injection. Cinnamic aldehyde decreased the NO, TNF-?, and PGE2 levels on the serum level after Carr injection. Western blotting revealed that cinnamic aldehyde decreased Carr-induced iNOS, COX-2, and NF-?B expressions in the edema paw. These findings demonstrated that cinnamic aldehyde has excellent anti-inflammatory activities and thus has great potential to be used as a source for natural health products. PMID:22536283

Liao, Jung-Chun; Deng, Jeng-Shyan; Chiu, Chuan-Sung; Hou, Wen-Chi; Huang, Shyh-Shyun; Shie, Pei-Hsin; Huang, Guang-Jhong

2012-01-01

27

Polyketide and benzopyran compounds of an endophytic fungus isolated from Cinnamomum mollissimum: biological activity and structure  

PubMed Central

Objective To study bioactivity and compounds produced by an endophytic Phoma sp. fungus isolated from the medicinal plant Cinnamomum mollissimum. Methods Compounds produced by the fungus were extracted from fungal broth culture with ethyl acetate. This was followed by bioactivity profiling of the crude extract fractions obtained via high performance liquid chromatography. The fractions were tested for cytotoxicity to P388 murine leukemic cells and antimicrobial activity against bacteria and pathogenic fungi. Compounds purified from active fractions which showed antibacterial, antifungal and cytotoxic activities were identified using capillary nuclear magnetic resonance analysis, mass spectrometry and admission to AntiMarin database. Results Three known compounds, namely 4-hydroxymellein, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one and 1-(2,6-dihydroxyphenyl) ethanone, were isolated from the fungus. The polyketide compound 4-hydroxymellein showed high inhibitory activity against P388 murine leukemic cells (94.6%) and the bacteria Bacillus subtilis (97.3%). Meanwhile, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one, a benzopyran compound, demonstrated moderate inhibitory activity against P388 murine leukemic cells (48.8%) and the fungus Aspergillus niger (56.1%). The second polyketide compound, 1 (2,6-dihydroxyphenyl) ethanone was inactive against the tested targets. Conclusions These findings demonstrate the potential of endophytes as producers of pharmacologically important compounds, including polyketides which are major secondary metabolites in fungi. PMID:25183332

Santiago, Carolina; Sun, Lin; Munro, Murray Herbert Gibson; Santhanam, Jacinta

2014-01-01

28

Therapeutic effects on murine oral candidiasis by oral administration of cassia (Cinnamomum cassia) preparation.  

PubMed

We examined the effects of spices and herbs on Candida albicans growth using in vitro assay and therapeutic activity of some selected herbal preparations against murine oral candidiasis. All tested samples: lemongrass (Cymbopogon citratus), lemon balm (Melissa officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), roselle (Hibiscus sabdariffa), green tea (Camellia sinensis), and cassia (Cinnamomum cassia) inhibited Candida mycelial growth in vitro. The results of this assay showed that the anti-Candida activity of lemongrass, green tea, and cassia is stronger than that of the other tested herbs. Oral administration of lemongrass or green tea did not result in significant improvement in the murine oral candidiasis, while the administration of cassia improved the symptoms and reduced the number of viable Candida cells in the oral cavity. The results of in vitro Candida growth assay including GC/MS analysis suggested that cinnamaldehyde in the cassia preparation was the principal component responsible for the inhibitory activity of Candida mycelial growth. These findings suggest that oral intake of a cassia preparation is a clinical candidate for a prophylactic or therapeutic tool against oral Candida infection. PMID:20185867

Taguchi, Yuuki; Takizawa, Toshio; Ishibashi, Hiroko; Sagawa, Takehito; Arai, Ryo; Inoue, Shigeharu; Yamaguchi, Hideyo; Abe, Shigeru

2010-01-01

29

Effect of Cinnamomum zeylanicum extract on scopolamine-induced cognitive impairment and oxidative stress in rats.  

PubMed

Objective Cinnamomum zeylanicum (CZ) is commonly known as cinnamon in traditional system of medicine having antibacterial, antioxidant, antidiabetic, hypolipidemic, and other activities. The present study was designed to assess the effect of extract of CZ bark on cognitive performance of scopolamine (SCOP)-treated rats and on associated altered oxidative stress markers in the brain of rats. Methods The extract was administered orally in three doses (100, 200, and 400 mg/kg) for a period of 21 days. SCOP was administered in the dose of 1.0 mg/kg intraperitoneally. The Morris water maze and passive avoidance step-down tasks were performed to assess cognitive functions. At the end of the study, oxidative stress parameters namely, malondialdehyde (MDA) and reduced glutathione (GSH) were also analyzed in the brain tissue of rats. Results SCOP-treated group showed significantly impaired acquisition and retention of memory as compared to the saline- and vehicle-treated groups. Pretreatment with CZ extract (200 and 400 mg/kg) for 21 days significantly reversed SCOP-induced amnesia as evidenced by increased step-down latency in passive avoidance and decreased latency in Morris water maze test compared to the SCOP-treated group. SCOP administration also caused the increase of MDA and reduction of GSH levels. Pretreatment with CZ extract (200 and 400 mg/kg) resulted in a significant decrease in MDA levels and increase in GSH levels as compared to the SCOP-treated animals. Discussion The results suggest that CZ can induce cognitive improvement in SCOP-treated rats and this effect can be attributed to a certain extent to decreased oxidative stress. PMID:24559058

Jain, Seema; Sangma, Tultul; Shukla, Santosh Kumar; Mediratta, Pramod Kumari

2014-02-21

30

Antibacterial activity of leaf essential oil and its constituents from Cinnamomum longepaniculatum  

PubMed Central

Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enteritidis CMCC (B) 50041, were used in the antibacterial tests of Cinnamomum longepaniculatum leaf essential oil and its five chemical constituents. The effect of 1, 8-cineole on the ultrastructural structure of the bacteria (S. aureus and E. coli) was also investigated by transmission electron microscopy. The C. longepaniculatum leaf essential oil and the five chemical constituents showed variable levels of inhibition. Their MIC ( minimum inhibitory concentration ) and MBC (minimal bacteriocidal concentration) values were all in the range of 0.781 µL/mL~6.25 µL/mL and 0.781 µL/mL~12.5 µL/mL respectively except ?-terpinene. The MIC values of ?-terpinene against E. coli and S. aureus were all higher than 50 µL/mL, but the MIC and MBC values of ?-terpinene against S. enteritidis was only 3.125 µL/mL. Among them, ?-terpineol possessed the best antibacterial activity. Under the transmission electron microscope, cell size of treated E. coli decreased, cell wall and cell membrane ruptured, and nucleoplasm was reduced and gathered onto the side. After the S. aureus was treated with 1, 8-cineole, the cell size and shape were damaged and nucleus cytoplasm was concentrated or reduced or agglomerated on the side. These results suggest that C. longepaniculatum leaf essential oil and its constituents have excellent antibacterial activities, the antibacterial mechanism of 1, 8-cineole against E. coli and S. aureus might attributable to its hydrophobicity. PMID:25126170

Li, Li; Li, Zheng-Wen; Yin, Zhong-Qiong; Wei, Qin; Jia, Ren-Yong; Zhou, Li-Jun; Xu, Jiao; Song, Xu; Zhou, Yi; Du, Yong-Hua; Peng, Lian-Ci; Kang, Shuai; Yu, Wang

2014-01-01

31

Activity of Cinnamomum osmophloeum leaf essential oil against Anopheles gambiae s.s  

PubMed Central

Background The increasing status of insecticide resistant mosquitoes in sub-Saharan Africa is a threatening alert to the existing control efforts. All sibling species of An. gambiae complex have evolved insecticide resistance in wild populations for different approved classes of the insecticides currently in use in the field. An alternative compound for vector control is absolutely urgently needed. In this study, the larvicidal activity and chemical composition of the Cinnamomum osmophloeum leaf essential oils were investigated. Methods C. osmophloeum leaf essential oils were extracted by hydrodistillation in a Clevenger-type apparatus for 6 hours, and their chemical compositions identified using GC-MS. These oils were evaluated against An. gambiae s.s. in both laboratory and semi-field situations. The WHO test procedures for monitoring larvicidal efficacy in malaria vectors were used. Results The composition of C. osmophloeum leaf essential oil has been found to have 11 active compounds. The most abundant compound was trans-cinnamaldehyde (70.20%) and the least abundant was caryophyllene oxide (0.08%). The larvicidal activity was found to be dosage and time dependant both in laboratory and semi-field environments with mortality ranging from 0% to 100%. The LC50 value was found to vary from 22.18 to 58.15 ?g/ml in the laboratory while in semi-field environments it was 11.91 to 63.63 ?g/ml. The LC90 value was found to range between 57.71 to 91.54 ?g/ml in the laboratory while in semi-field environments was 52.07 to 173.77 ?g/ml. Mortality ranged from 13% to 100% in the laboratory while in semi-field environments it ranged between 43% to 100% within mortality recording time intervals of 12, 24, 48, and 72 hours. Conclusions The larvicidal activity shown by C. osmophloeum leaf essential oil is a promising alternative to existing larvicides or to be incorporated in integrated larval source management compounds for An. gambiae s.s control. The efficacy observed in this study is attributed to both major and minor compounds of the essential oils. PMID:24885613

2014-01-01

32

Photographic Technique for Grass Seedling Root Systems  

Microsoft Academic Search

In descriptive studies of seedling root morphology a seedling root system must be clearly visible to develop clear photographs. A technique for photographing grass seedling root systems has been developed for morphological-developmental studies. Seedlings were carefully washed form the growing media and placed in a thin tank with two glass sides filled with water and with a grid pattern on

P. R. Newman; Lowell E. Moser

1988-01-01

33

Parts of a Soybean Seedling  

NSDL National Science Digital Library

This illustrated guide to a soybean seedling (Glycine max, Dicotyledon) is designed to help students recognize and learn the plant's individual parts. Along with an explanation of dicotyledon embryos, it includes a short description of the labeled parts.

34

Parts of a Corn Seedling  

NSDL National Science Digital Library

This illustrated guide to a corn seedling (Zea mays, Monocotyledon) is designed to help students recognize and learn the plant's individual parts. Along with an explanation of monocotyledon embryos, it includes a short description of the root system and coleoptile.

35

Evaluation of the anti-inflammatory and anti-proliferation tumoral cells activities of Antrodia camphorata, Cordyceps sinensis, and Cinnamomum osmophloeum bark extracts  

Microsoft Academic Search

The extracts of chloroform (1) and methanol (2) from Antrodia camphorata (AC), and chloroform (3) and n-butanol (4) fractions of methanol extract from Cordyceps sinensis (CS), and hexane (5), ethyl acetate (6), and methanol (7) from Cinnamomum osmophloeum bark (CO) were evaluated for their anti-inflammatory as well as tumor-cell growth inhibitory activities in vitro. All the tested extracts dose dependently

Yerra Koteswara Rao; Shih-Hua Fang; Yew-Min Tzeng

2007-01-01

36

Acute and chronic antihypertensive effects of Cinnamomum zeylanicum stem bark methanol extract in L-NAME-induced hypertensive rats  

PubMed Central

Background Previous study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats. Methods The acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content. Results Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs’ weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue’s concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group). Conclusion MECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia. PMID:23368533

2013-01-01

37

Original article Water relations of spruce seedlings  

E-print Network

Original article Water relations of spruce seedlings sprayed with a surfactant M Borghetti Istituto whether the water relations of Norway spruce (Picea abies Karst) seedlings are affected by repeated treatments with ABS (sodium dodecylbenzensulphonate). Begin- ning in August 1987 4-yr-old spruce seedlings

Paris-Sud XI, Université de

38

Ethanol extracts of Cinnamomum kanehirai Hayata leaves induce apoptosis in human hepatoma cell through caspase-3 cascade  

PubMed Central

Inducing apoptosis to susceptible cells is the major mechanism of most cytotoxic anticancer drugs in current use. Cinnamomum kanehirai Hayata (Lauraceae), a unique and native tree of Taiwan, is the major host for the medicinal fungus Antrodia cinnamomea which exhibits anti-cancer activity. Because of the scarcity of A. cinnamomea, C. kanehirai Hayata instead, is used as fork medicine in liver cancer. Here we observed the C. kanehirai Hayata ethanol extract could inhibit the cellular viability of both HepG2 and HA22T/VGH human hepatoma cell lines in a dose- and time-dependent manner. We found the mode of cell death was apoptosis according to cell morphological changes by Liu’s stain, oligonucleosomal DNA fragmentation by gel electrophoresis, externalization of phosphotidyl serine by detecting Annexin V and hypoploid population by cell cycle analysis. Our results showed that the extracts caused cleavage of caspase-3 and increased enzyme activity of caspase-8 and caspase-9. Caspase 3 inhibitor partially reversed the viability inhibition by the extract. Furthermore, the up-regulation of Bax and down-regulation of Bcl-2 were also noted by the extract treatment. In conclusion, C. kanehirai Hayata ethanol extract induced intrinsic pathway of apoptosis through caspase-3 cascade in human hepatoma HA22T/VGH and HepG2 cells, which might shed new light on hepatoma therapy.

Liu, Yu-Kuo; Chen, Kuan-Hsing; Leu, Yann-Lii; Way, Tzong-Der; Wang, Ling-Wei; Chen, Yu-Jen; Liu, Yu-Ming

2015-01-01

39

Effect of cinnamomum zeylanicum blume essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species.  

PubMed

Cinnamomum zeylanicum Blume is known for a wide range of medicinal properties. This study aimed to assess the interference of C. zeylanicum essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species. The essential oil presented strong antifungal effect causing the growth inhibition of the assayed strains and development of large growth inhibition zones. MIC50 and MIC90 values were 40 and 80 ?L/mL, respectively. 80, 40 and 20 ?L/mL of the oil strongly inhibited the radial mycelial growth of A. niger, A. flavus and A. fumigatus along 14 days. 80 and 40 ?L/mL of the oil caused a 100% inhibition of the fungal spore germination. Main morphological changes observed under light microscopy provided by the essential oil in the fungal strains were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. It is concluded that C. zeylanicum essential oil could be known as potential antifungal compound, particularly, to protect against the growth of Aspergillus species. PMID:24031186

Carmo, Egberto Santos; de Oliveira Lima, Edeltrudes; de Souza, Evandro Leite; de Sousa, Frederico Barbosa

2008-01-01

40

Inhibitory effects of Cinnamomum burmannii Blume stem bark extract and trans-cinnamaldehyde on nasopharyngeal carcinoma cells; synergism with cisplatin  

PubMed Central

Nasopharyngeal carcinoma (NPC) is a malignancy that occurs in the epithelium of the nasopharynx. The standard treatment of NPC patients with locoregionally advanced stages is problematic and is often associated with toxicities. Therefore, it is essential to screen for naturally occurring compounds with strong apoptosis-inducing activity and minimal toxicity. This study investigated the effects of the standardized methanol extract of Cinnamomum burmannii Blume stem bark and its main constituent, trans-cinnamaldehyde (TCA), on human NPC cell lines. The content of TCA in C. burmannii methanol extract was standardized to be 13.61% w/w by means of gas chromatography-mass spectrometry (GC-MS). NPC cell proliferation was clearly inhibited within 24 h of treatment, with TCA exhibiting greater activity than the methanol extract. TCA was more active against NPC cells compared with cisplatin. There was a pronounced downregulation of the proliferation markers, Ki67 and proliferating cell nuclear antigen (PCNA) in the TCA-treated cells; while morphological observation indicated the induction of apoptosis. Caspase activation and prominent DNA damage, which are markers of apoptosis induction were detected. TCA demonstrated the ability to scavenge nitric oxide. The simultaneous combination of TCA and cisplatin produced synergistic anti-proliferative effects. Collectively, these data indicate the potential use of TCA for the treatment of NPC. PMID:23837058

DAKER, MAELINDA; LIN, VOON YEE; AKOWUAH, GABRIEL AKYIREM; YAM, MUN FEI; AHMAD, MARIAM

2013-01-01

41

Protein tyrosine phosphatase 1B inhibitory activity of Indonesian herbal medicines and constituents of Cinnamomum burmannii and Zingiber aromaticum.  

PubMed

We screened water and methanol extracts of 28 Indonesian medicinal plants for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activities. Nine water extracts, i.e., Alstonia scholaris leaf, Blumea balsamifera, Cinnamomum burmannii, Cymbopogon nardus, Melaleuca leucadendra, Phyllanthus niruri, Piper nigrum, Syzygium aromaticum, and Sy. polyanthum, exhibited ?70 % inhibition at 25 ?g/mL, whereas 11 methanol extracts, i.e., Als. scholaris, Andrographis paniculata, B. balsamifera, Ci. burmannii, Curcuma heyneana, Glycyrrhiza glabra, M. leucadendra, Punica granatum, Rheum palmatum, Sy. polyanthum, and Z. aromaticum, exhibited ?70 % inhibition at 25 ?g/mL. Water extracts of B. balsamifera (IC50, 2.26 ?g/mL) and M. leucadendra (IC50, 2.05 ?g/mL), and methanol extracts of Ci. burmannii (IC50, 2.47 ?g/mL), Pu. granatum (IC50, 2.40 ?g/mL), and Sy. polyanthum (IC50, 1.03 ?g/mL) exhibited strong inhibitory activity, which was comparable with that of the positive control, RK-682 (IC50, 2.05 ?g/mL). The PTP1B inhibitory activity of the constituents of Ci. burmannii and Z. aromaticum was then evaluated. 5'-Hydroxy-5-hydroxymethyl-4?,5?-methylenedioxy-1,2,3,4-dibenzo-1,3,5-cycloheptatriene (2; IC50, 29.7 ?M) and trans-cinnamaldehyde (5; IC50, 57.6 ?M) were the active constituents of Ci. burmannii, while humulatrien-5-ol-8-one (21; IC50, 27.7 ?M), kaempferol-3,4'-di-O-methyl ether (32; IC50, 17.5 ?M), and (S)-6-gingerol (33; IC50, 28.1 ?M) were those of Z. aromaticum. These results suggest that these medicinal plants may contribute to the treatment and/or prevention of type II diabetes and/or obesity through PTP1B inhibition. PMID:22645080

Saifudin, Azis; Kadota, Shigetoshi; Tezuka, Yasuhiro

2013-04-01

42

Attenuating effect of standardized lyophilized Cinnamomum zeylanicum bark extract against streptozotocin-induced experimental dementia of Alzheimer's type.  

PubMed

Abstract Background: The Cinnamomum zeylanicum (CZ; family Lauraceae) bark, an important spice, has also been used traditionally for nervous stress, as a nervine tonic, and as a stimulant. Therefore, the present study was designed to evaluate the effect of the standardized lyophilized aqueous extract of CZ bark (LCZE) on learning and memory in rodents at 50, 100, and 200 mg/kg, p.o. dose levels against streptozotocin (STZ)-induced memory impairment. Methods: LCZE was standardized based on the cinnamaldehyde content using high-performance thin-layer chromatography (HPTLC). The effect on learning and memory was evaluated using two widely used behavioral models, the Morris water maze (MWM) test and the object recognition test (ORT). The effect of LCZE on the acetylcholinesterase (AChE) activity and oxidative stress parameters in the cerebral cortex and hippocampus of rat brain was also evaluated. Results: LCZE significantly (p<0.05) and dose-dependently attenuated STZ-induced cognitive deficit in both models in comparison to only STZ-treated animals. In the MWM test, LCZE (100 and 200 mg/kg) significantly decreased the transfer latency and increased the time spent by the animals in target quadrant. Similarly in the ORT, the LCZE-treated animals exhibited an improved discrimination between a familiar object and a novel object, indicating the reversal of STZ-induced memory impairment. LCZE also restored STZ-induced alteration in AChE activity and oxidative stress parameters in both brain parts. Conclusions: The results clearly indicate toward the memory-enhancing effect of LCZE, which could be due to the synergistic effect of anti-AChE and antioxidant activities. PMID:25301673

Malik, Jai; Munjal, Kavita; Deshmukh, Rahul

2014-10-10

43

ESTABLISHMENT AND SEEDLING GROWTH OF BIG BLUESTEM AND SWITCHGRASS POPULATIONS DIVERGENTLY SELECTED FOR SEEDLING TILLER NUMBER.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Selection at the seedling stage in grass breeding would be extremely useful if seedling traits are correlated to desired agronomic traits. The objective of this study was to evaluate seedling morphological development, plant growth, and field establishment of big bluestem (Andropogon gerardii Vitma...

44

Grass Seed Structure and Seedling Emergence  

NSDL National Science Digital Library

This activity discusses both seed structure and seedling emergence in monocots. Through active learning elements, photos and text students will discover the basic anatomy of seeds and the function of each structure. The process of seedling emergence is presented in detail including the difference between emergence in cool-season and warm-season grasses.

45

Modulation of quorum sensing controlled behaviour of bacteria by growing seedling, seed and seedling extracts of leguminous plants  

Microsoft Academic Search

Effect of growing seedling, seeds and seedlings extracts from seven leguminous plants (Pisum sativum, Vigna radiata, Vigna mungo, Cajanus cajan, Lentil culinaris, Cicer arietinum and Trigonella foenum graecum) were screened for their ability to influence quorum sensing controlled pigment production in Chromobacterium violaceum indicator strains (CV12472 and CVO26). Germinating seedling and seedling extracts of only P. sativum (pea) showed inhibition

Qaseem Fatima; Maryam Zahin; Mohd Sajjad Ahmad Khan; Iqbal Ahmad

2010-01-01

46

Host-Plant Chemistry Influences Oviposition Choice of the Spicebush Swallowtail Butterfly  

Microsoft Academic Search

The spicebush swallowtail, Papilio troilus (L.), lays its eggs on plants in the family Lauraceae. Sassafras [Sassafras albidum (Nutt.) Nees], spicebush [Lindera benzoin (L.) Spreng.], redbay (Persea borbonia (L.)] and camphortree [Cinnamomum camphora (Nees) Eberm.] are four of its known host plants. In one-choice tests, free-flying spicebush swallowtail females laid eggs on chemical extracts of the leaves of each of

Maureen Carter; Paul Feeny

1999-01-01

47

J. N. Am. Benthol. Soc., 2009, 28(2):491503 2009 by The North American Benthological Society  

E-print Network

Wales, Australia, the exotic tree camphor laurel (Cinnamomum camphora) has aggressively invaded riparian the riparian zone was dominated by camphor laurel because of the reputed chemical toxicity of the leaf litter. We also investigated the sublethal effects of camphor laurel litter by comparing growth rates

Wisenden, Brian D.

48

Seedling Diversity and the Homologies of Seedling Organs in the Order Poales (Monocotyledons)  

PubMed Central

Background and Aims Seedlings of monocots are much more diverse than those of other angiosperms, often with very derived character states. This makes morphological interpretation difficult. The morphology of seedlings of most of the 16 families of the Poales alliance are only incompletely known. The present study aims first to develop an unambiguous terminology for the description of monocotyledonous seedlings. This makes possible clear morphological comparisons and the use of homologous terms for organs. Finally, plotting of well defined characters onto a molecular tree allows the polarization of character states. Method Seedlings were grown in Petri dishes on moist filter paper under permanent light conditions and analysed using light and scanning electron microscopy. Only seeds collected at natural habitats or from plants with a well documented source were used. Seedling vouchers are deposited in the alcohol collection of Monocot seedlings in the Botanische Staatssammlung München (M). Key Results Based on an unambiguous terminology, seedlings of a great number of genera are described and presented as figures, representing all families of Poales except Ecdeiocoleaceae. Seedlings of Rapateaceae, Joinvilleaceae and Mayacaceae are described for the first time. Morphological comparisons reveal a plausible interpretation of even very modified organ structures, including those of the grass seedling. Conclusions This study demonstrates that detailed studies of seedling morphology can provide interesting morphological insights and also new facts for phylogenetic analyses. However, the morphological diversity of seedlings in the monocots is as yet incompletely known, and in some, e.g. Alismatales or Zingiberales, the seedling structure is particularly poorly understood in terms of comparative morphology. PMID:17933843

Tillich, Hans-Jürgen

2007-01-01

49

DESIGN ISSUES FOR EVALUATING SEEDLING EXPOSURE STUDIES  

EPA Science Inventory

Tree seedling studies, covering a wide range of experimental conditions in pollutant treatment, species, facilities, and exposure regimes, have become commonplace in forestry research for assessing the actual and potential environmental effects of air pollutants on forest ecosyst...

50

Seedling herbivory and the influence of plant species richness in seedling neighbourhoods  

Microsoft Academic Search

The aim of this experiment was to determine how increasing species richness within artificially created grassland gaps affected the overall magnitude of seedling losses to, and the selectivity of, seedling herbivores. Using chemical exclusion methods, the influence of molluscs the principal invertebrate herbivores in temperate grasslands, was assessed at three levels of plant species diversity (3, 6, and 12 species

M. E. Hanley

2004-01-01

51

Clinorotation affects soybean seedling morphology  

NASA Technical Reports Server (NTRS)

Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight, and dry weight) was noted for pine, oat, and mung bean. In the CHROMEX-01 and 02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiments with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of the assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and the morphology of soybean seedlings grown in the Biological Research In Canister (BRIC) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-3) flown on STS-63 (February 3-11, 1995).

Hilaire, Emmanuel; Guikema, James A.; Brown, Christopher S.

1995-01-01

52

Genetically improved ponderosa pine seedlings outgrow nursery-run seedlings with and without competition -- Early findings  

SciTech Connect

Three classes of ponderosa pine (Pinus ponderosa) seedlings (nursery-run, wind-pollinated, control-pollinated) were evaluated for stem height and diameter at the USDA Forest Service's Placerville Nursery and the Georgetown Range District in northern California. Pines in all three classes were grown with competing vegetation or maintained in a free-to-grow condition. Control-pollinated seedlings were statistically taller than nursery-run counterparts when outplanted, and after 1 and 2 growing seasons in the field with and without competition. They also had significantly larger diameters when outplanted and after 2 growing seasons in the field when free to grow. Wind-pollinated seedlings grew taller than nursery-run seedlings when free to grow. A large amount of competing vegetation [bearclover (Chamaebatia foliolosa)--29,490 plants per acre; herbaceous vegetation--11,500; hardwood sprouts--233; and whiteleaf manzanita (Arctostaphylos viscida) seedlings--100] ensure that future pine development will be tested rigorously.

McDonald, P.M.; Fiddler, G.O. (Dept. of Agriculture Forest Service, Redding, CA (United States)); Kitzmiller, J.H. (Dept. of Agriculture Forest Service, Chico, CA (United States). Chico Tree Improvement Center)

1994-04-01

53

[Seedling index of Salvia miltiorrhiza and its simulation model].  

PubMed

Through the correlation analysis on the quantitative traits and their ratios of Salvia miltiorrhiza seedlings and seedling quality, a series of representative indices reflecting the seedling quality of the plant species were determined, and the seedling index suitable to the S. miltiorrhiza seedlings was ascertained by correlation degree analysis. Meanwhile, based on the relationships between the seedling index and the air temperature, solar radiation and air humidity, a simulation model for the seedling index of S. miltiorrhiza was established. The experimental data of different test plots and planting dates were used to validate the model. The results showed that the root diameter, stem diameter, crown dry mass, root dry mass, and plant dry mass had significant positive relationships with the other traits, and could be used as the indicators of the seedling's health. The seedling index of S. miltiorrhiza could be calculated by (stem diameter/root diameter + root dry mass/crown dry mass) x plant dry mass. The stem diameter, root dry mass, crown dry mass and plant dry mass had higher correlations with the seedling index, and thus, the seedling index determined by these indicators could better reflect the seedling's quality. The coefficient of determination (R2) between the predicted and measured values based on 1:1 line was 0.95, and the root mean squared error (RMSE) was 0.15, indicating that the model established in this study could precisely reflect the quantitative relationships between the seedling index of S. miltiorrhiza and the environmental factors. PMID:23359940

Huang, Shu-Hua; Xu, Fu-Li; Wang, Wei-Ling; Du, Jun-Bo; Ru, Mei; Wang, Jing; Cao, Xian-Yan

2012-10-01

54

Seedling growth and development on space shuttle  

NASA Astrophysics Data System (ADS)

Young pine seedlings, and mung bean and oat seeds were flown on shuttle flights, STS-3 and STS-51F, in March, 1982 and July/August, 1985, respectively. The plant growth units built to support the two experiments functioned mechanically as anticipated and provided the necessary support data. Pine seedlings exposed to the microgravity environment of the space shuttle for 8 days continued to grow at a rate similar to ground controls. Pine stems in flight seedlings, however, averaged 10 to 12% less lignin than controls. Flight mung beans grew slower than control beans and their stems contained about 25% less lignin than control seedlings. Reduced mung bean growth in microgravity was partly due to slower germination rate. Lignin also was reduced in flight oats as compared to controls. Oats and mung beans exhibited upward growing roots which were not observed in control seedlings. Chlorophll A/B ratios were lower in flight tissues than controls. The sealed PGCs exhibited large variations in atmospheric gas composition but the changes were similar between flight and ground controls. Ethylene was present in low concentrations in all chambers.

Cowles, J.; Lemay, R.; Jahns, G.

1994-11-01

55

Anaerobic metabolism in Brassica seedlings  

NASA Astrophysics Data System (ADS)

Germination typically depends on oxidative respiration. The lack of convection under space conditions may create hypoxic or conditions during seed germination. We investigated the effect of reduced oxygen on seed germination and metabolism to understand how metabolic constraints affect seed growth and responsiveness to reorientation. Germination was completely inhibited when seeds were imbibed in the absence of oxygen; germination occurred at 5% oxygen and higher levels. Adding oxygen after 72 h resulted in immediate germination (protrusion of the radicle). Hypoxia typically activates alcohol dehydrogenase (ADH, EC 1.1.1.1) and lactate dehydrogenase (LDH, EC 1.1.1.27) which produce ethanol and/or L-lactate, respectively. We report on the expression of ADH1 and LDH1, and changes in total soluble sugars, starch, pH, and L-lactate in seedlings grown at 28°C in 0, 2.5, 5, 10% and ambient (21%) oxygen conditions as controls. The highest consumption (lowest level) of sugars was seen at 0% oxygen but the lowest level of starch occurred 24 h after imbibition under ambient condition. Expression levels of ADH1 in ambient oxygen condition increased within 24 h but increased threefold under hypoxic conditions; LDH1 increased up to 8-fold under hypoxia compared to controls but ADH1 and LDH1 were less expressed as the oxygen levels increased. The intracellular pH of seeds decreased as the content of L-lactate increased for all oxygen concentrations. These results indicate that germination of Brassica is sensitive to oxygen levels and that oxygen availability during germination is an important factor for metabolic activities. (Supported by NASA grant NNX10AP91G)

Park, Myoung-Ryoul; Hasenstein, Karl H.

56

USE OF SEWAGE SLUDGE FOR FOREST-TREE SEEDLING PRODUCTION  

EPA Science Inventory

Research was undertaken to determine the beneficial and harmful effects of using dewatered, digested sewage sludge in: (1) containerized production of forest tree seedlings, (2) tree seedling production in a conventional outdoor nursery, (3) establishment and growth of transplant...

57

ORIGINAL PAPER Growth of planted black spruce seedlings following  

E-print Network

ORIGINAL PAPER Growth of planted black spruce seedlings following mechanical site preparation to improve growth conditions of planted black spruce seedlings in boreal forested peatlands where closed thick organic layers. Keywords Black spruce . Forest floor disturbance . Mechanical site preparation

Boyer, Edmond

58

Changes of nucleic acids of wheat seedlings under spaceflight conditions  

NASA Technical Reports Server (NTRS)

The effects of space flight on the growth of wheat seedlings and their nucleic acid content were studied. It was shown that both space and ground seedlings have almost the same appearance, dry weight and nucleic acid content in the root, coleoptile and leaves. The only difference found is in the RNA and DNA content, which is twice as much in the ground seedling apices as in the space-grown seedlings.

Sytnyk, K. M.; Musatenko, L. I.

1983-01-01

59

Subamolide B Isolated from Medicinal Plant Cinnamomum subavenium Induces Cytotoxicity in Human Cutaneous Squamous Cell Carcinoma Cells through Mitochondrial and CHOP-Dependent Cell Death Pathways  

PubMed Central

Subamolide B is a butanolide isolated from Cinnamomum subavenium, a medicinal plant traditionally used to treat various ailments including carcinomatous swelling. We herein reported for the first time that subamolide B potently induced cytotoxicity against diverse human skin cancer cell lines while sparing nonmalignant cells. Mechanistic studies on human cutaneous squamous cell carcinoma (SCC) cell line SCC12 highlighted the involvement of apoptosis in subamolide B-induced cytotoxicity, as evidenced by the activation of caspases-8, -9, -4, and -3, the increase in annexin V-positive population, and the partial restoration of cell viability by cotreatment with the pan-caspase inhibitor z-VAD-fmk. Additionally, subamolide B evoked cell death pathways mediated by FasL/Fas, mitochondria, and endoplasmic reticulum (ER) stress, as supported by subamolide B-induced FasL upregulation, BCL-2 suppression/cytosolic release of cytochrome c, and UPR activation/CHOP upregulation, respectively. Noteworthy, ectopic expression of c-FLIPL or dominant-negative mutant of FADD failed to impair subamolide B-induced cytotoxicity, whereas BCL-2 overexpression or CHOP depletion greatly rescued subamolide B-stimulated cells. Collectively, these results underscored the central role of mitochondrial and CHOP-mediated cell death pathways in subamolide B-induced cytotoxicity. Our findings further implicate the potential of subamolide B for cutaneous SCC therapy or as a lead compound for developing novel chemotherapeutic agents. PMID:23573140

Yang, Shu-Yi; Wang, Hui-Min; Wu, Tai-Wen; Chen, Yi-Ju; Shieh, Jeng-Jer; Lin, Ju-Hwa; Ho, Tsing-Fen; Luo, Ren-Jie; Chen, Chung-Yi; Chang, Chia-Che

2013-01-01

60

Repellency of Cinnamomum cassia bark compounds and cream containing cassia oil to Aedes aegypti (Diptera: Culicidae) under laboratory and indoor conditions.  

PubMed

Patch and skin bioassays were used in laboratory and indoor tests to evaluate the repellency of (E)-cinnamaldehyde, identified in Cinnamomum cassia Blume bark and essential oil, and a cream containing 5% (w/w) cassia oil against Aedes aegypti (L.) females. Results were compared with those of a known C. cassia compound cinnamyl alcohol, N,N-diethyl-m-toluamide (DEET) and two commercial repellents: MeiMei cream containing citronella and geranium oils and Repellan S aerosol containing 19% DEET. In patch bioassay tests with A. aegypti females, (E)-cinnamaldehyde at 0.153 mg cm(-2) and DEET at 0.051 mg cm(-2) provided 93 and 89% protection at 40 min after exposure. In skin bioassay tests, (E)-cinnamaldehyde at 0.051 mg cm(-2) and DEET at 0.025 mg cm(-2) provided 87 and 95% protection at 30 min after application. (E)-Cinnamaldehyde was significantly more effective than cinnamyl alcohol in both bioassays. In indoor tests with four human volunteers, 5% cassia oil cream provided 94, 83 and 61% protection against A. aegypti females exposed for 30, 50 and 70 min after application respectively. Cassia oil cream was a slightly less effective repellent than MeiMei cream. Repellan S aerosol provided 91% repellency at 120 min after application. Products containing cassia oil merit further study as potential repellents for the protection of humans and domestic animals from blood-feeding vectors and the diseases they transmit. PMID:16894642

Chang, Kyu-Sik; Tak, Jun-Hyung; Kim, Soon-Il; Lee, Won-Ja; Ahn, Young-Joon

2006-11-01

61

Safety and Tolerability of Essential Oil from Cinnamomum zeylanicum Blume Leaves with Action on Oral Candidosis and Its Effect on the Physical Properties of the Acrylic Resin  

PubMed Central

The anti-Candida activity of essential oil from Cinnamomum zeylanicum Blume, as well as its effect on the roughness and hardness of the acrylic resin used in dental prostheses, was assessed. The safety and tolerability of the test product were assessed through a phase I clinical trial involving users of removable dentures. Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were determined against twelve Candida strains. Acrylic resin specimens were exposed to artificial saliva (GI), C. zeylanicum (GII), and nystatin (GIII) for 15 days. Data were submitted to ANOVA and Tukey posttest (? = 5%). For the phase I clinical trial, 15 healthy patients used solution of C. zeylanicum at MIC (15 days, 3 times a day) and were submitted to clinical and mycological examinations. C. zeylanicum showed anti-Candida activity, with MIC = 625.0?µg/mL being equivalent to MFC. Nystatin caused greater increase in roughness and decreased the hardness of the material (P < 0.0001), with no significant differences between GI and GII. As regards the clinical trial, no adverse clinical signs were observed after intervention. The substance tested had a satisfactory level of safety and tolerability, supporting new advances involving the clinical use of essential oil from C. zeylanicum. PMID:25574178

Oliveira, Julyana de Araújo; da Silva, Ingrid Carla Guedes; Trindade, Leonardo Antunes; Lima, Edeltrudes Oliveira; Carlo, Hugo Lemes; Cavalcanti, Alessandro Leite; de Castro, Ricardo Dias

2014-01-01

62

Hydrogen potassium adenosine triphosphatase activity inhibition and downregulation of its expression by bioactive fraction DLBS2411 from Cinnamomum burmannii in gastric parietal cells  

PubMed Central

This study assessed the gastric acid antisecretory effect of DLBS2411 fractionated from Cinnamomum burmannii. Hydrogen potassium adenosine triphosphatase (H+/K+ ATPase) activity and its gene expression were observed, and the antioxidant activity of DLBS2411 was also investigated. Treatment of DLBS2411 decreased the level of H+/K+ ATPase messenger RNA expression on human embryonic kidney 293 cells and rat gastric parietal cells in a dose-dependent manner, in vitro and ex vivo. DLBS2411 also acted as a competitive inhibitor by showing inhibition in gastric H+/K+ ATPase activity at various pHs. In gastric ulcer animal models induced with indomethacin and ethanol, DLBS2411showed a reduction in the number of petechiae, suggesting that the fraction also confers gastroprotective activity. Moreover, DLBS2411 was also found to have potent antioxidant activity. Taken together, DLBS2411 is a promising novel agent for the management of dyspepsia, a condition of hyperacidity and diseases in the stomach requiring gastroprotection. PMID:24101879

Tjandrawinata, Raymond R; Nailufar, Florensia; Arifin, Poppy F

2013-01-01

63

Safety and Tolerability of Essential Oil from Cinnamomum zeylanicum Blume Leaves with Action on Oral Candidosis and Its Effect on the Physical Properties of the Acrylic Resin.  

PubMed

The anti-Candida activity of essential oil from Cinnamomum zeylanicum Blume, as well as its effect on the roughness and hardness of the acrylic resin used in dental prostheses, was assessed. The safety and tolerability of the test product were assessed through a phase I clinical trial involving users of removable dentures. Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were determined against twelve Candida strains. Acrylic resin specimens were exposed to artificial saliva (GI), C. zeylanicum (GII), and nystatin (GIII) for 15 days. Data were submitted to ANOVA and Tukey posttest (? = 5%). For the phase I clinical trial, 15 healthy patients used solution of C. zeylanicum at MIC (15 days, 3 times a day) and were submitted to clinical and mycological examinations. C. zeylanicum showed anti-Candida activity, with MIC = 625.0?µg/mL being equivalent to MFC. Nystatin caused greater increase in roughness and decreased the hardness of the material (P < 0.0001), with no significant differences between GI and GII. As regards the clinical trial, no adverse clinical signs were observed after intervention. The substance tested had a satisfactory level of safety and tolerability, supporting new advances involving the clinical use of essential oil from C. zeylanicum. PMID:25574178

Oliveira, Julyana de Araújo; da Silva, Ingrid Carla Guedes; Trindade, Leonardo Antunes; Lima, Edeltrudes Oliveira; Carlo, Hugo Lemes; Cavalcanti, Alessandro Leite; de Castro, Ricardo Dias

2014-01-01

64

Some evidences on the mode of action of Cinnamomum verum bark essential oil, alone and in combination with piperacillin against a multi-drug resistant Escherichia coli strain.  

PubMed

The purpose of this study was to investigate the mode of action of the cinnamon bark essential oil (CB) when use singly and in combination with piperacillin on its antimicrobial and synergistic activity against plasmid-conferred multi-drug resistant Escherichia coli J53 R1. Viable count of this combination showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis of the membrane permeabilizing effects of CB on treated cultures through their stability against sodium dodecyl sulfate (SDS) revealed that the essential oils played a role in disrupting the bacterial cell membrane. Scanning electron microscopy analysis and zeta potential measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, reduction in bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed the presence of potential quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry (GC-MS) of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%) and eugenol (6.57%) were found to be the major components in the essential oil. These findings suggest that CB has the potential to reverse bacteria resistance to piperacillin in E. coli J53 R1 and may operate via two mechanisms: alteration of outer membrane permeability and inhibition of bacterial QS. PMID:25381741

Yap, Polly Soo Xi; Krishnan, Thiba; Chan, Kok-Gan; Lim, Swee Hua Erin

2014-11-10

65

Essential oil from leaves of Cinnamomum osmophloeum acts as a xanthine oxidase inhibitor and reduces the serum uric acid levels in oxonate-induced mice.  

PubMed

The xanthine oxidase (XOD) inhibitory activity and anti-hyperuricemia effect in mice of Cinnamomum osmophloeum, which is an endemic tree in Taiwan, were evaluated in this study. The results demonstrated that the essential oil of C. osmophloeum leaves presented the strongest XOD inhibition activity (IC(50)=16.3 ?g/ml); however, no significant XOD inhibition activities were found in ethanolic and hot water extracts. Furthermore, among the main compounds of essential oil, the cinnamaldehyde exhibited the potent XOD inhibition activity with an IC(50)=8.4 ?g/ml. Besides, the reducing serum uric acid levels in oxonate-induced mice by cinnamaldehyde were further investigated. The hyperuricemic mice were oral administrated cinnamaldehyde at a dosage of 150 mg/kg, the uric acid value in serum was reduced from 5.25±0.63 to 2.10±0.04 mg/dl, the levels of serum uric acid in mice was lowered down by 84.48% as compared to the hyperuricemic control group. Based on the results obtained in this study, cinnamaldehyde may be a potential lead compound for developing the pharmaceutic for anti-hyperuricemia agent. PMID:18693097

Wang, S Y; Yang, C W; Liao, J W; Zhen, W W; Chu, F H; Chang, S T

2008-11-01

66

Rhizoctonia seedling damping-off in sugar beet in Michigan  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia solani is an important seedling pathogen of sugar beet, causing damping-off following seedling emergence. Anastomosis group (AG)-4 has been the primary seedling pathogen reported on sugar beet, however, recent screening has found high incidence of infection by AG-2-2. Isolations of R. so...

67

Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub  

PubMed Central

The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment. PMID:22511952

Yang, Xuejun; Baskin, Carol C.; Baskin, Jerry M.; Liu, Guangzheng; Huang, Zhenying

2012-01-01

68

Response of black walnut seedlings to storage duration and temperature  

E-print Network

Response of black walnut seedlings to storage duration and temperature Barrett C. Wilson Douglass F) procedure to cold hardiness testing (at 3, -10, -20, and -40 °C) of container-grown black walnut seedlings resistance and growth potential of black walnut seedlings. Background Cold hardiness assessment provides

69

Soil moisture levels and mycorrhizal infection in black walnut seedlings  

Microsoft Academic Search

The influence of soil moisture on endomycorrhizal infection in black walnut was studied using four groups of potted seedlings watered at different time intervals. Seedlings watered every day or every second day had much longer lateral roots but fewer infected root segments than seedlings watered every third or fourth day. These results suggest that controlling the soil moisture level may

Filex Ponder Jr

1983-01-01

70

GENETIC ANALYSIS OF APHANOMYCES SEEDLING RESISTANCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aphanomyces seedling disease is one of the causal agents preventing good stand persistence in sugarbeet. Aphanomyces generally becomes more of a problem for growers when plants are four to six weeks old, especially after a heavy rain and in flooded areas of the field. There has been no reliable seed...

71

ACID FOG EFFECTS ON CONIFER SEEDLINGS  

EPA Science Inventory

Experiments were performed to assess the effects of acid fog on foliar injury, biomass production, and nutrient leaching in selected conifers. ne-year old seedlings of Pseudotsuga menzieii, Pinus ponderosa, Tsuga heterophylla and Thuja plicata were exposed episodically to fog eve...

72

Nursery performance of peach seedling rootstocks  

Technology Transfer Automated Retrieval System (TEKTRAN)

The nursery performance of a cross-section of both historically important and current commercial peach [Prunus persica (L.) Batsch] seedling type rootstocks was studied over three growing seasons at six nurseries serving the southeastern US peach industry. Rootstock lines differed significantly in ...

73

Original article Vulnerability of young oak seedlings  

E-print Network

Original article Vulnerability of young oak seedlings (Quercus robur L) to embolism: responses with Ophiostoma querci and water stress on pedunculate oak (Quercus robur) were tested with potted saplings. O in the oak decline symptoms as occurring in Europe may therefore be questioned. water stress I embolism / oak

Paris-Sud XI, Université de

74

Seedling recruitment in forests: Calibrating models to predict patterns of tree seedling dispersion  

SciTech Connect

Recruitment, the addition of new individuals into a community, is an important factor that can substantially affect community composition and dynamics. We present a method for calibrating spatial models of plant recruitment that does not require identifying the specific parent of each recruitment. This method calibrates seedling recruitment functions by comparing tree seedling distributions with adult distributions via a maximum likelihood analysis. The models obtained from this method can then be used to predict the spatial distributions of seedlings from adult distributions. We calibrated recruitment functions for 10 tree species characteristic of transition oak-northern hardwood forests. Significant differences were found in recruitment abundances and spatial distributions. Predicted seedling recruitment limitation for test stands varied substantially between species, with little recruitment limitation for some species and strong recruitment limitation for others. Recruitment was limited due to low overall recruit production or to restricted recruit dispersion. When these seedling recruitment parameters were incorporated into a spatial, individual-based model of forest dynamics, called SOR-TIE, alterations of recruitment parameters produced substantial changes in species abundance, providing additional support for the potential importance of seedling recruitment processes in community structure and dynamics. 45 refs., 9 figs., 3 tabs.

Ribbens, E.; Silander, J.A. Jr.; Pacala, S.W. (Univ. of Connecticut, Storrs, CT (United States))

1994-09-01

75

Solar irradiance and the development of endomycorrhizal green ash seedlings.  

PubMed

We investigated the effects and interaction of four irradiances, 37, 53, 70 and 100% full sunlight, and the endomycorrhizae Glomus macrocarpum and Glomus fasciculatum on the development of seedlings of Fraxinus pennsylvanica Marsh. At all irradiances, mycorrhizal seedlings were taller and larger in diameter than nonmycorrhizal seedlings. Seedlings inoculated with G. macrocarpum showed the best height growth at 70% or less of full sunlight, whereas seedlings inoculated with G. fasciculatum grew best at 37 and 53% full sunlight. Leaf area was greatest in shaded seedlings and was enhanced by mycorrhizal inoculation. Shoot/root ratios were greater for mycorrhizal than for nonmycorrhizal seedlings. At intermediate light intensities, percent root length colonized was greatest, whereas the concentrations of soluble sugar and starch in roots were at intermediate levels. PMID:14969881

Borges, R G; Chaney, W R

1993-10-01

76

Ethylene-orchestrated circuitry coordinates a seedling’s response to soil cover and etiolated growth  

PubMed Central

The early life of terrestrial seed plants often starts under the soil in subterranean darkness. Over time and through adaptation, plants have evolved an elaborate etiolation process that enables seedlings to emerge from soil and acquire autotrophic ability. This process, however, requires seedlings to be able to sense the soil condition and relay this information accordingly to modulate both the seedlings’ growth and the formation of photosynthetic apparatus. The mechanism by which soil overlay drives morphogenetic changes in plants, however, remains poorly understood, particularly with regard to the means by which the cellular processes of different organs are coordinated in response to disparate soil conditions. Here, we illustrate that the soil overlay quantitatively activates seedlings’ ethylene production, and an EIN3/EIN3-like 1–dependent ethylene-response cascade is required for seedlings to successfully emerge from the soil. Under soil, an ERF1 pathway is activated in the hypocotyl to slow down cell elongation, whereas a PIF3 pathway is activated in the cotyledon to control the preassembly of photosynthetic machinery. Moreover, this latter PIF3 pathway appears to be coupled to the ERF1-regulated upward-growth rate. The coupling of these two pathways facilitates the synchronized progression of etioplast maturation and hypocotyl growth, which, in turn, ultimately enables seedlings to maintain the amount of protochlorophyllide required for rapid acquisition of photoautotrophic capacity without suffering from photooxidative damage during the dark-to-light transition. Our findings illustrate the existence of a genetic signaling pathway driving soil-induced plant morphogenesis and define the specific role of ethylene in orchestrating organ-specific soil responses in Arabidopsis seedlings. PMID:24599595

Zhong, Shangwei; Shi, Hui; Xue, Chang; Wei, Ning; Guo, Hongwei; Deng, Xing Wang

2014-01-01

77

The Standardized BHH10 Extract, a Combination of Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, Reverses Bone Mass and Metabolism in a Rat Model of Postmenopausal Osteoporosis  

PubMed Central

Jasin-hwan-gagambang (BHH10), a modified prescription of Jasin-hwan, contains Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, and it has been traditionally used to treat osteoporosis and other inflammatory diseases. In this study, we systematically investigated the protective effects of BHH10 in ovariectomy (OVX)-induced rats. Sprague–Dawley rats were randomly divided into sham and OVX subgroups. The rats in the OVX group were treated with vehicle, BHH10, alendronate (ALN), and 17?-estradiol (E2). BHH10 treatment significantly inhibited OVX-induced increases in body weight and uterus atrophy. In addition, it significantly increased the bone mineral density (BMD) and prevented a decrease in trabecular bone volume, connectivity density, trabecular number, thickness, and separation at the total femur and femur neck. The OVX rats showed significant decreases in the serum levels of calcium and phosphorous and significant increases in the serum levels of cholesterol, low-density lipoprotein cholesterol, alkaline phosphatase, osteocalcin, C-telopeptide type 1 collagen, and bone morphogenetic protein-2. These changes were significantly reduced to near sham levels by administration of BHH10 to OVX rats. BHH10-treated rats had a greater bone mass, a better structural architecture of the bone, and higher levels of biochemical markers of the bone than did the ALN-treated or E2-treated rats. These results suggest that BHH10 reverses osteoporosis in OVX rats by stimulating bone formation or regulating bone resorption and is not associated with toxicity. © 2014 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd. PMID:25230217

Huh, Jeong-Eun; Kim, Soo-Jeong; Kang, Jung-Won; Nam, Dong-Woo; Choi, Do-Young; Park, Dong-Suk; Lee, Jae-Dong

2015-01-01

78

GC-MS analysis and screening of antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala oil in streptozotocin induced diabetes mellitus in rats  

PubMed Central

Aim of the study This study was made to investigate the antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala, (Buch.-Ham.) Nees & Eberm (Tejpat) oil (CTO) in streptozotocin (STZ) induced diabetes in rats along with evaluation of chemical constituents. Materials and methods The GC-MS (Gas chromatography–mass spectrometry) analysis of the oil showed 31 constituents of which cinnamaldehyde was found the major component (44.898%). CTO and cinnamaldehyde was orally administered to diabetic rats to study its effect in both acute and chronic antihyperglycemic models. The body weight, oral glucose tolerance test and biochemical parameters viz. glucose level, insulin level, liver glycogen content, glycosylated hemoglobin, total plasma cholesterol, triglyceride and antioxidant parameters were estimated for all treated groups and compared against diabetic control group. Results CTO (100?mg/kg and 200?mg/kg), cinnamaldehyde (20?mg/kg) and glibenclamide (0.6?mg/kg) in respective groups of diabetic animals administered for 28?days reduced the blood glucose level in streptozotocin induced diabetic rats. There was significant increase in body weight, liver glycogen content, plasma insulin level and decrease in the blood glucose, glycosylated hemoglobin and total plasma cholesterol in test groups as compared to control group. The results of CTO and cinnamaldehyde were found comparable with standard drug glibenclamide. In vitro antioxidant studies on CTO using various models showed significant antioxidant activity. In vivo antioxidant studies on STZ induced diabetic rats revealed decreased malondialdehyde (MDA) and increased reduced glutathione (GSH). Conclusion Thus the investigation results that CTO has significant antidiabetic, antioxidant and hypolipidemic activity. PMID:22882757

2012-01-01

79

On the biomechanics of seedling anchorage  

NASA Astrophysics Data System (ADS)

We propose a minimal model for the response of vegetation to pullout constraints at early development stage. We try to capture both the average mechanical properties of the root system and the stochastic component of the uprooting process of seedlings. We identify a minimal set of relevant physical components in the purpose of quantifying the uprooting process: length of the root fibres, elastic response of the fibres and adhesion between the roots and the soil matrix. We present for validation a dataset extracted from Edmaier et al. (under revision), accounting for 98 uprooting experiments using Avena sativa L. seedlings (common oat), growing in non-cohesive sediment under controlled conditions. The corresponding root system has a very simple architecture, with three root fibres of different lengths. The response of the system to the constraint is however complex: the stress-strain signal presents sudden jumps followed by partial elastic recoveries. The analysis of the jumps and partial recoveries gives an insight into the resilience of the system. The anchorage of less mature seedlings rapidly collapses after the peak force has been reached, while more mature seedlings usually recover from partial failures. We explore this crossover with our validation dataset. The type of seedlings we study has been used in flume experiments investigating the feedbacks between the vegetation and the river morphodynamics (see for example Perona et al. (2012)). An understanding of the characteristics of the uprooting curve (maximal uprooting force and total uprooting work) of such vegetation reveals the ability of seedlings to withstand environmental constraints in terms of duration or intensity (see Edmaier et al., under revision), and is therefore helpful for planning future experiments. REFERENCES - P. Perona, P. Molnar, B. Crouzy, E. Perucca, Z. Jiang, S. McLelland, D. Wüthrich, K. Edmaier, R. Francis, C. Camporeale, et al., Biomass selection by floods and related timescales: Part 1. Experimental observations, Advances in Water Resources 39 (2012) 85-96. - K. Edmaier, P. Burlando and P. Perona, Mechanisms of vegetation uprooting by flow in alluvial non-cohesive sediment. Hydrology And Earth System Sciences, vol. 15, p. 1615-1627, 2011. - K. Edmaier, B. Crouzy, P. Perona, Experimental characterization of root anchoring in non-cohesive sediment, Earth Surface Processes and Landforms (under revision).

Crouzy, Benoît; Edmaier, Katharina; Perona, Paolo

2014-05-01

80

TEMPORAL ALLOCATION OF 14C TO EXTRAMATRICAL HYPHAE OF ECTOMYCORRHIZAL PONDEROSA PINE SEEDLINGS  

EPA Science Inventory

Ponderosa pine seedlings were inoculated with Hebeloma crustuliniforme either in growth pouches before they were transplanted to root-mycocosms (P seedlings), or at the time of transfer to root-mycocosms (V seedlings). ninoculated seedlings served as controls (U seedlings). he us...

81

Photocontrol of anthocyanin formation in turnip seedlings  

Microsoft Academic Search

The participation of the red\\/far-red reversible reaction of phytochrome in the control of anthocyanin formation in turnip seedlings has been demonstrated. A brief exposure to red light following a preliminary irradiation period in blue, increased anthocyanin content compared with blue alone; this effect was reversed by a subsequent short exposure to far-red. The sensitivity to red light was largely restricted

Renate Grill

1965-01-01

82

A potato seedling that chips from cold storage without conditioning  

Microsoft Academic Search

Summary  A potato seedling, F5208, that produced good-colored chips from tubers removed directly from cold storage is discussed. This\\u000a seedling yielded well, accumulated negligible quantities of reducing sugars in cold storage and had a high specific gravity\\u000a resulting in substantial yields of chips. The performance of this seedling suggests that it will be possible to develop potato\\u000a varieties that do not

R. B. Hyde; C. Walkof

1962-01-01

83

Temperature-dependent Expression of Betacyanin Synthesis in Amaranthus Seedlings.  

PubMed

Two phenomena related to temperature effects have been observed during the induction of betacyanin synthesis by a cytokinin (benzyladenine) in Amaranthus tricolor seedlings. One is a total inhibition of betacyanin accumulation at a temperature (39 C) at which seedling growth is unimpaired, and where there is still adequate uptake of benzyladenine. The other is the apparent induction of a higher potential for subsequent betacyanin synthesis following pretreatment of the seedlings at an elevated temperature. PMID:16660712

Elliott, D C

1979-02-01

84

Evaluation of Tree Seedling Mortality and Protective Strategies in Riparian Forest Restoration  

E-print Network

Evaluation of Tree Seedling Mortality and Protective Strategies in Riparian Forest Restoration William S. Keeton Riparian forest restoration can be severely constrained by tree seedling mortality. I. Keywords: riparian restoration, seedling mortality, herbivory, tree shelters, northern hardwoods R

Vermont, University of

85

Earthworms as seedling predators: Importance of seeds and seedlings for earthworm nutrition  

Microsoft Academic Search

Anecic earthworms have been shown to collect, concentrate and bury seeds in their burrows. Moreover, recent studies suggest that earthworms function as granivores and seedling herbivores thereby directly impacting plant community assembly. However, this has not been proven unequivocally. Further, it remains unclear if earthworms benefit from seed ingestion, i.e., if they assimilate seed carbon. We set up a series

Nico Eisenhauer; Olaf Butenschoen; Stefan Radsick; Stefan Scheu

2010-01-01

86

Heritable Chlorophyll Deficiencies in Seedling Cotton.  

E-print Network

in these particular plants. (The color of red- and non-red-stem plants has been shown to be inherited in a simple monohybrid condition (Balls, 1918). Our data on this anthocyanin character, which will be, presented in a later bulletin, shows that here... as to character of seedling. The counts are found in Table 2. One progeny, 218-113, gave a 3:l ratio or a total of 87 non-yellows to 22 yellows, with a deviation only 1.42 times the probable error from the calculated ratio. This indicates a fair probability...

Stroman, G. N. (Govan Napoleon); Mahoney, C. H. (Charles Harold)

1925-01-01

87

Osmotic adjustment in sessile oak seedlings in response to drought  

E-print Network

Note Osmotic adjustment in sessile oak seedlings in response to drought C Collet JM Guehl 1 �quipe-year-old sessile oak seedlings were submitted to drought developed at two different rates (0.050 and 0.013 MPa·day-1).Drought was controlled by combining levels of irrigation and grass competition. At the end

Boyer, Edmond

88

The Vestigial Root of Dodder ( Cuscuta pentagona ) Seedlings  

Microsoft Academic Search

Seedlings of dodder are unique among dicotyledonous plants in that they emerge as a leafless, cotyledonless shoot with only a small swollen rootlike structure at the base of the tissue. Although growth of the shoot end of the dodder seedling is dramatic, no change in ''root'' length occurs, and the root tip is withered and senescent within 7 d of

Timothy D. Sherman; Andrew J. Bowling; T. Wayne Barger; Kevin C. Vaughn

2008-01-01

89

Valley Oak Seedling Growth Associated with Selected Grass Species1  

E-print Network

Valley Oak Seedling Growth Associated with Selected Grass Species1 Karen C. Danielsen William L of alien annual grasses into native perennial grasslands has increased oak seedling mortality by decreasing soil moisture availability. We conducted greenhouse experiments to test if the alien annual grass Avena

Standiford, Richard B.

90

Temporal patterns in seedling establishment on pocket gopher disturbances.  

PubMed

Disturbances often facilitate seedling establishment, and can change the species composition of a community by increasing recruitment of disturbance-adapted species. To understand the effects of pocket gopher disturbances on alpine seedling dynamics, we examined the gopher disturbances' effects on seedling emergence and survival on gopher disturbances 0 to 5 years old. In contrast to results from most other ecosystems, these recently created gopher mounds had lower seedling emergence and survival rates than undisturbed areas. A lack of correlation between species' abundances on gopher mounds and undisturbed sites in one of the two communities studied suggested that a suite of disturbance-adapted species recruited onto the mounds. To explain low seedling emergence on recent gopher mounds, we quantified gopher mound seed banks and studied recruitment in a site with mounds that ranged from 0 to >20 years old. Seed numbers in first-year gopher mound soils were extremely low relative to undisturbed soils, and this pattern was mirrored in seedling establishment patterns over the long term. Gopher disturbance depressed seedling emergence density for the first 5 years. Subsequently, emergence density increased until at least 20 years following the disturbance. Emergence on disturbances more than 20 years old was higher than on undisturbed sites. Therefore, gopher disturbances probably facilitate seedling establishment in alpine dry and moist meadow; however, this process takes place over decades. PMID:14557865

Forbis, Tara A; Larmore, Jason; Addis, Elizabeth

2004-01-01

91

The tolerance of newly emerged broadleaved tree seedlings to the  

E-print Network

The tolerance of newly emerged broadleaved tree seedlings to the herbicides clopyralid, cycloxydim of broad-spectrum contact herbicides is seldom possible. Hence in the work reported here, the tolerance of young tree seedlings to the potentially more selective, post-emergence herbicides clopyralid, cycloxydim

92

Neighbor Effects in Mast Year Seedlings of Acer saccharum  

Microsoft Academic Search

The size and age distributions of Acer saccharum Marsh. seedlings were studied in a mature hardwood forest in southeastern Ontario between 26 June and 26 September 1986. Ninety-one percent of the seedlings surveyed were produced in 1984 which was a mast year for this population of sugar maple. Mean height within quadrats was negatively correlated with the density of two-

Kimberly M. Taylor; L. W. Aarssen

1989-01-01

93

WEED SEEDLING EMERGENCE MODELLING: CONVERTING OBSERVATIONS INTO EQUATIONS FOR WEEDEM  

Technology Transfer Automated Retrieval System (TEKTRAN)

The timing and extent of weed seedling emergence are critical variables for successful weed management in arable crops. Although observations of the timing and extent of weed seedling emergence have been reported often, our abilities to predict these variables have not progressed as rapidly as neede...

94

The influence of ammonium on nitrate reduction in wheat seedlings  

Microsoft Academic Search

Ammonium markedly inhibited nitrate absorption by nitrogenstarved wheat seedlings but did not decrease the proportion of absorbed nitrate that was reduced. Seedlings high in nitrate (absorbed prior to the experimental periods) reduced similar amounts of this nitrate regardless of whether or not ammonium was present and being absorbed during the period of measurement. Ammonium or products of ammonium assimilation did

P. L. Minotti; Doris Craig Williams; W. A. Jackson

1969-01-01

95

Creeping Bentgrass Seedling Tolerance to Herbicides and Paclobutrazol  

Microsoft Academic Search

The tolerance of creeping bentgrass (Agrostis stolonifera L.) seedlings to many herbicides has not been evaluated. Three fi eld studies were conducted between fall and spring from 1998 to 2002 to assess creeping bentgrass seedling tolerance to fi ve herbicides and paclobutrazol. The primary objectives of this investigation were to assess bentgrass tolerance to these chemicals when applied at various

John E. Kaminski; Peter H. Dernoeden; Cale A. Bigelow

96

SEEDBED SURFACE GEOMETRY EFFECTS ON SOIL CRUSTING AND SEEDLING EMERGENCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seedling emergence is the crucial first step in crop establishment; however, crops frequently must penetrate or lift a thin, dense, soil crust formed during rainstorms. Shaping the soil surface into a small ridge or cap above the seed may promote crust fractures and improve seedling emergence and vi...

97

Accumulation and speciation of vanadium in Lycium seedling.  

PubMed

Lycium seedling was subjected to varying doses of V for 40-45 days to examine the effects on uptake, accumulation, and speciation of V in Lycium seedling by differential centrifugation and enzymolysis. V concentrations in Lycium seedling organs were in sequence as follows: root>leaf>stem. V uptake into stem and leaf were primarily combined with acid-soluble polar compounds, polysaccharide, and immobile materials on the cell walls. There were different speciations of V in root with different V stress levels. Enzymolysis results suggest that about 60% of the V in Lycium seedling root was combined with pectin and cellulose. It is the antidotal effect of pectin and cellulose in the cell wall that reduced the V damage to Lycium seedling. PMID:24859852

Hou, Ming; Lu, Chang; Wei, Kexiang

2014-06-01

98

Importation of aquaculture seedlings to Japan.  

PubMed

Japan is one of the largest consumers of fishery products in the world. Importation of various fishery commodities - including larvae and eggs for aquaculture - is increasing due to high consumer demand. Elvers of Anguilla anguilla have been imported from Europe since the late 1960s. Eyed eggs of coho salmon (Oncorhynchus kisutch) are imported from North America. During the last decade, over-production caused the price of Japanese amberjack (or 'yellowtail') (Seriola quinqueradiata) and Japanese seabream (Pagrus major) to drop, forcing farmers to venture into the culture of other species. A variety of marine fish seedlings are now imported from Asian countries. Almost all aquaculture production of coho salmon, greater amberjack (Seriola dumerili), seabass (Lateolabrax japonicus), rockfish (Sebastes spp.) and groupers (Epinephlus septemfaciatus, etc.) depends on imported seedlings. These species accounted for approximately 9% by value of marine finfish production in Japan in 1993. Apart from ubiquitous or endemic pathogens, a considerable number of exotic microorganisms and parasites are suspected to have accompanied fish eggs and larvae imported for aquaculture purposes. On a voluntary basis, 80-90% of imported salmon eggs are being examined for bacterial kidney disease and salmon viruses by semi-governmental organisation. Voluntary inspections are also being conducted on some other fish species imported from foreign countries. No legislation exists, however, for the control of exotic fish pathogens. PMID:8890372

Wakabayashi, H

1996-06-01

99

Process-based modeling of temperature and water profiles in the seedling recruitment zone: Part II. Seedling emergence timing  

Technology Transfer Automated Retrieval System (TEKTRAN)

Predictions of seedling emergence timing for spring wheat are facilitated by process-based modeling of the microsite environment in the shallow seedling recruitment zone. Hourly temperature and water profiles within the recruitment zone for 60 days after planting were simulated from the process-base...

100

Effects of flooding regime and seedling treatment on early survival and growth of nuttall oak  

USGS Publications Warehouse

Effects of flooding on survival and growth of three different types of Nuttall oak (Quercus texana Buckl.) seedlings were observed at the end of third and fifth growing seasons at Yazoo National Wildlife Refuge, Mississippi, U.S.A. Three types of seedlings were planted in January 1995 in a split-plot design, with four replications at each of two elevations on floodprone, former cropland in Sharkey clay soil. The lower of the two planting elevations was inundated for 21 days during the first growing season, whereas the higher elevation did not flood during the 5-year period of this study. The three types of 1-0 seedlings were bareroot seedlings, seedlings grown in containers (3.8 ?? 21a??cm plastic seedling cones), and container-grown seedlings inoculated with vegetative mycelia of Pisolithus tinctorius (Pers.) Coker. Survival of all the three seedling types was greatest at the lower, intermittently flooded elevation, indicating that drought and related effects on plant competition were more limiting to seedling survival than flooding. At the lower elevation, survival of mycorrhizal-inoculated container seedlings was greater than that of noninoculated container seedlings. Survival among bareroot seedlings and inoculated container seedlings was not significantly different at either elevation. At the higher, nonflooded elevation, however, bareroot seedling survival was greater than the survival of container seedlings without inoculation. Differences were significant among the inoculated and the noninoculated container seedlings, with higher survival of inoculated seedlings at both elevations, though differences were only significant in year 3. At the end of the fifth year, height of bareroot seedlings was significantly greater than the heights of both types of container-grown seedlings at both planting elevations. Because seedlings grown in the plastic seedlings cones did not survive better than the bareroot seedlings at either planting elevation, the bareroot stock appear to be the economically superior choice for regeneration in Sharkey soil.

Burkett, V.R.; Draugelis-Dale, R.O.; Williams, H.M.; Schoenholtz, S.H.

2005-01-01

101

Modulation of quorum sensing controlled behaviour of bacteria by growing seedling, seed and seedling extracts of leguminous plants.  

PubMed

Effect of growing seedling, seeds and seedlings extracts from seven leguminous plants (Pisum sativum, Vigna radiata, Vigna mungo, Cajanus cajan, Lentil culinaris, Cicer arietinum and Trigonella foenum graecum) were screened for their ability to influence quorum sensing controlled pigment production in Chromobacterium violaceum indicator strains (CV12472 and CVO26). Germinating seedling and seedling extracts of only P. sativum (pea) showed inhibition of violacein production. Interestingly, the T. foenum graecum (fenugreek) seed extracts enhances the pigment production. Quorum sensing regulated swarming motility in Pseudomonas aerugionsa PAO1 was reduced by pea seedling extract while enhanced by the fenugreek seed extracts. These findings suggest that plant metabolites of some legumes interact actively with bacterial quorum sensing and could modulate its associated functions. PMID:23100836

Fatima, Qaseem; Zahin, Maryam; Khan, Mohd Sajjad Ahmad; Ahmad, Iqbal

2010-06-01

102

DIVERGENT SELECTION FOR SEEDLING TILLER NUMBER IN BIG BLUESTEM AND SWITCHGRASS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grass seedling tiller number and shoot weight are traits associated with seedling vigor. The response to selection for high shoot weight and divergent selection for seedling tiller number in big bluestem (Andropogon gerardii Vitman) and switchgrass (Panicum virgatum L.) seedlings and realized herit...

103

Effect of sand burial depth on seed germination and seedling emergence of Calligonum L. species  

Microsoft Academic Search

A greenhouse study was conducted to determine the effects of sand burial on seed germination and seedling emergence of ten Calligonum L. species. The results suggested that the deeper the seeds in sand, the lower and slower their germination and seedling emergence. Seedling emergence occurred from a maximum depth of 12 cm with most seedlings emerging from 2 and 4

Jun Ren; Ling Tao; Xin-Min Liu

2002-01-01

104

Effects of "short" photoperiods on seedling growth of Pinus brutia.  

PubMed

This study investigated how nurseries could benefit by inducing "short" photoperiods as low as 4 hr to produce "better" seedlings characterized by more vigorous roots; a substantial feature to overcome transplanting stress. The carryover effect of the photoperiod was also investigated on seedlings that grew for 30 days more underthe consistent 14 hr photoperiod. Seedlings of Pinus brutia were subjected to 4, 6, 8 and 14 hr photoperiod for 3 week. Fifteen seedlings were used to evaluate the leaf area, the root and shoot dry weight and their ratio. Six and sixteen seedlings were used to evaluate the shoot electrolyte leakage and the root growth potential, respectively. Based on the results, the 6 and 8 hr photoperiod indicated greater root allocation (4.8 and 4.9 mg, respectively) and chlorophyll content (3.7 and 4.4, respectively). They also indicated greater leaf area values (3.3 and 3.5 cm2, respectively) along with the 14 hr (3.4 cm2). The photoperiod effect continued even after seedlings were subjected at consistent photoperiod. Overall, "short" photoperiods could provide "better" P. brutia seedlings to accommodate immediate massive reforestation and afforestation needs. PMID:23033672

Iakovoglou, V; Radoglou, K; Kostopoulou, P; Dini-Papanastasi, O

2012-03-01

105

Growth of ponderosa pine seedlings as affected by air pollution  

NASA Astrophysics Data System (ADS)

The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

106

Interactions between birds, fruit bats and exotic plants in urban Hong Kong, South China  

Microsoft Academic Search

I observed the use of exotic plant species by native birds and bats in 8 km2 of urban Hong Kong. Twenty-nine plant taxa were used repeatedly. Five species accounted for most interactions with birds:\\u000a Cinnamomum camphora (10 bird species), Ficus religiosa (6), Livistona chinensis (7) and Pyracantha crenulata (6) provided fruits, while Bombax ceiba (6) supplied nectar. Panicum maximum (2)

Richard T. Corlett

2005-01-01

107

Chemical composition and the insecticidal activity of certain plants applied as powders and essential oils against two stored-products coleopteran beetles  

Microsoft Academic Search

Powders and essential oils were prepared from the aerial parts of Cinnamomum camphora, Ocimum basilicum, Chenopodium ambrosioides, and seeds of Pimpinella anisum. Their adulticidal activities and effects on the F1 progeny of Trogoderma granarium (Everts) and Tribolium castaneum (Herbst) were evaluated. The chemical composition of the plant oils were identified by gas chromatography (GC) and GC\\/mass\\u000a spectrometry (MS). All of

Gomah E. NenaahSahar; Sahar I. A. Ibrahim

108

Mapping urban forest tree species using IKONOS imagery: preliminary results  

Microsoft Academic Search

A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species\\/groups\\u000a in the City of Tampa, Florida, USA. The eight species\\/groups consist of sand live oak (Quercus geminata), laurel oak (Quercus laurifolia), live oak (Quercus virginiana), magnolia (Magnolia grandiflora), pine (species group), palm (species group), camphor (Cinnamomum camphora), and red maple (Acer rubrum).

Ruiliang Pu

2011-01-01

109

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications.  

PubMed

This month's featured review article; "Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications" is authored by Cristiano de Mello Gallep. The mini-review presents the use of ultra-weak photon emission (UPE) emitted by seedlings in toxicological and chronobiological applications. Chronic and acute stress induces pattern changes in UPE, giving a new parameter for real-time analysis of germination tests. The UPE time profile for a single seedling is shown for the first time, with pronounced circadian cycles in synchronism with the local gravimetric tide. The cover of this issue of Luminescence features the measuring of UPE time profile emitted by a single sunflower seedling, shown superposed to the local gravimetric tide, dg; also the UPE total counts x germination rate for samples stressed by wastewater sediment solutions. PMID:25511676

de Mello Gallep, Cristiano

2014-12-01

110

Space Station Live: Seedling Growth - Duration: 5:54.  

NASA Video Gallery

Public Affairs Officer Lori Meggs talks with Carol Jacobs, payload operations director at the Marshall Space Flight Center's POIC, about the Seedling Growth experiment talking place aboard the Inte...

111

Pulsed induction of circadian clock genes in Arabidopsis seedlings.  

PubMed

The Alc-inducible system is a simple, yet effective, "gene switch" that can be used to transiently induce gene expression in Arabidopsis. Here we provide a protocol for using the Alc-inducible system to give a pulse in expression of a circadian clock gene in transgenic seedlings. The line we use as an example harbors an Alc-inducible copy of the CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) gene (Alc?CCA1). Alc?CCA1 seedlings are grown on solid MS medium and subsequently treated with ethanol vapor. Because the ethanol is quickly absorbed into the medium upon exposure, the seedlings are moved to fresh plates following treatment to avoid continuous induction. After the induction, the seedlings are harvested over a time-course for future total RNA and/or protein extraction that can be used for subsequent gene expression analyses. PMID:24792053

Knowles, Stephen M; Lu, Sheen X; Tobin, Elaine M

2014-01-01

112

SEEDLING EFFECT ON ROOT SUBSTRATE pH  

Microsoft Academic Search

Paper used for seed germination tests may or may not contain limestone. The presence of limestone presented a pH buffer in this study that could interfere with studies addressing pH, calcium (Ca), or magnesium (Mg) effects on seedling development. Alternatively, pH of unbuffered chromatography paper was changed sufficiently by seedlings to confound research objectives that are pH dependent. Gradients across

Jin-Sheng Huang; Paul V. Nelson; Ji-Weon Lee

2001-01-01

113

Some aspects of drought resistance in loblolly pine seedlings  

E-print Network

SCm ASPECTS OF DROUGHT RESISTANCE IN LOBLOLLY PINE SEEDLINGS by Holger Brix A Dissertation Submitted to the Graduate School of the Agricultural and Mechanical College of Tex^s in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY August 1959 SCAPE TOFADRUG HDIDUNRL SOME ASPECTS OF DROUGHT RESISTANCE IN LOBLOLLY PINE SEEDLINGS A Dissertation by Holger Brix Approved as to style and content: (Co-Chairman) T f ~ ~ r (Co-Chairman) (Head of Department...

Brix, Holger

2013-10-04

114

Water transfer via ectomycorrhizal fungal hyphae to conifer seedlings  

Microsoft Academic Search

Little is known about water transfer via mycorrhizal hyphae to plants, despite its potential importance in seedling establishment\\u000a and plant community development, especially in arid environments. Therefore, this process was investigated in the study reported\\u000a in this paper in laboratory-based tripartite mesocosms containing the shrub Arctostaphylos viscida (manzanita) and young seedlings of sugar pine (Pinus lambertiana) and Douglas-fir (Pseudotsuga menziesii).

Agneta H. Plamboeck; Todd E. Dawson; Louise M. Egerton-Warburton; Malcolm North; Thomas D. Bruns; José Ignacio Querejeta

2007-01-01

115

The effect of paclobutrazol on mineral nutrition of apple seedlings  

Microsoft Academic Search

Greenhouse grown ‘Golden Delicious’ apple seedlings were treated with soil drenches of paclobutrazol (PP333) at rates equivalent to 0.1, 0.2, 0.4, 0.8, and 1.6 kg of active ingredient (a.i.) ha. Eleven weeks after treatment initiation, seedlings were harvested, divided into leaves, stems, and roots, weighed and analyzed for the content of macro?and microelements. Shoot growth rate, leaf area, and total

Dariusz Swietlik; Stephen S. Miller

1985-01-01

116

Carex Seedling Emergence in Restored and Natural Prairie Wetlands  

Microsoft Academic Search

Carex species, common dominants of wet meadows and widespread in ecosystems in the northern hemisphere, seldom naturally recolonize\\u000a drained wetlands following hydrologic restoration. We conducted a seedling emergence experiment with five Carex species in restored and natural prairie wetlands to determine if recolonization is limited by the suitability of conditions\\u000a for seed germination and seedling emergence. Seeds were sown unstratified

Karin M. Kettenring; Susan M. Galatowitsch

2011-01-01

117

How do riparian woody seedlings survive seasonal drought?  

Microsoft Academic Search

In semi-arid regions, a major population limitation for riparian trees is seedling desiccation during the dry season that\\u000a follows annual spring floods. We investigated the stress response of first-year pioneer riparian seedlings to experimental\\u000a water table declines (0, 1 and 3 cm day?1), focusing on the three dominant cottonwood and willows (family Salicaceae) in California’s San Joaquin Basin. We analyzed\\u000a growth and

John C. Stella; John J. Battles

2010-01-01

118

Protocol to Grow 14-Day Old Seedlings of Maize in a Growth Chamber 1 PROTOCOL TO GROW 14-DAY OLD SEEDLINGS OF MAIZE IN A  

E-print Network

Protocol to Grow 14-Day Old Seedlings of Maize in a Growth Chamber 1 PROTOCOL TO GROW 14-DAY OLD SEEDLINGS OF MAIZE IN A GROWTH CHAMBER (Last revised: April, 2007) This protocol was adapted by Dr. Kazuhiro to Grow 14-Day Old Seedlings of Maize in a Growth Chamber 2 Materials and Supplies Product Supplier

Wurtele, Eve Syrkin

119

Cytokinins in Seedling Roots of Pea  

PubMed Central

The natural occurrence of cytokinins existing both in a free form and as a constituent of transfer RNA was examined in serial segments of young seedling roots of pea. Purified ethanol extracts of root apices were resolved into four factors capable of inducing soybean callus tissue proliferation. The most active factor was identified as zeatin or some closely related compound; it produced polyploid divisions and tracheary element differentiation when tested on cultured pea root segments. The terminal 0- to 1-millimeter root tip contained 43 to 44 times more free cytokinin on a fresh weight or a per cell basis than the next 1- to 5-millimeter root segment. Extracts of more proximal segments behind the tip contained no measurable free cytokinin. Acid hydrolysates of transfer RNA exhibited reproducible cytokinin activity. Bioassays revealed that the predominant amounts of free cytokinin and that present in transfer RNA were restricted to the extreme root tip. There was approximately 27 times more free cytokinin than the amount detected in transfer RNA in root apices. PMID:16657915

Short, Keith C.; Torrey, John G.

1972-01-01

120

The Vibration Ring. Phase 1; [Seedling Fund  

NASA Technical Reports Server (NTRS)

The vibration ring was conceived as a driveline damping device to prevent structure-borne noise in machines. It has the appearance of a metal ring, and can be installed between any two driveline components like an ordinary mechanical spacer. Damping is achieved using a ring-shaped piezoelectric stack that is poled in the axial direction and connected to an electrical shunt circuit. Surrounding the stack is a metal structure, called the compression cage, which squeezes the stack along its poled axis when excited by radial driveline forces. The stack in turn generates electrical energy, which is either dissipated or harvested using the shunt circuit. Removing energy from the system creates a net damping effect. The vibration ring is much stiffer than traditional damping devices, which allows it to be used in a driveline without disrupting normal operation. In phase 1 of this NASA Seedling Fund project, a combination of design and analysis was used to examine the feasibility of this concept. Several designs were evaluated using solid modeling, finite element analysis, and by creating prototype hardware. Then an analytical model representing the coupled electromechanical response was formulated in closed form. The model was exercised parametrically to examine the stiffness and loss factor spectra of the vibration ring, as well as simulate its damping effect in the context of a simplified driveline model. The results of this work showed that this is a viable mechanism for driveline damping, and provided several lessons for continued development.

Asnani, Vivake M.; Krantz, Timothy L.; Delap, Damon C.; Stringer, David B.

2014-01-01

121

Gene Expression in Plant Lipid Metabolism in Arabidopsis Seedlings  

PubMed Central

Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, ?-oxidation and triacylglycerol (TAG) synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3), DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS) was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6) in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX) lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis. PMID:25264899

Hsiao, An-Shan; Haslam, Richard P.; Michaelson, Louise V.; Liao, Pan; Napier, Johnathan A.; Chye, Mee-Len

2014-01-01

122

Why are there few seedlings beneath the myrmecophyte Triplaris americana?  

NASA Astrophysics Data System (ADS)

We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

2007-07-01

123

Influence of mitochondrial ?-oxidation on early pea seedling development.  

PubMed

This work investigates the role of mitochondrial ?-oxidation in early pea (Pisumsativum) seedling development using the epoxy fatty acid etomoxir. Etomoxir was used to effect selective chemical intervention in this biological system. The effect of this intervention on chloroplast structure and membrane composition was determined by transmission electron microscopy and lipidomic analysis by electrospray ionization (ESI) tandem mass spectrometry. ?-oxidation was assayed radiochemically using 14C-palmitic acid. Chlorophyll and starch were assayed spectrophotometrically and lipid content determined by soxhlet extraction.Following emergence of the plumule, there was a switch from utilization of starch to lipid by the cotyledons. Etomoxir had a potent inhibitory effect on mitochondrial but not on peroxisomal ?-oxidation. Seedlings grown hydroponically in 50 ?M etomoxir in the light were phenotypically very different from water-grown controls. Chloroplast structure and fatty acid compositions were altered, etomoxir-treated plants containing more saturated fatty acids in their chloroplast lipids than controls. Etomoxir had no observable phenotypic effect on dark grown seedlings. When etiolated seedlings were exposed to light for 48 h, carnitine (on which mitochondrial ?-oxidation depends)stimulated chlorophyll synthesis whilst etomoxir reduced chlorophyll synthesis. The development of newly emergent embryos into independent autotrophic seedlings is dependent upon mitochondrial ?-oxidation in the cotyledons. PMID:19140943

Masterson, Christine; Wood, Clifford

2009-03-01

124

Response of Pinus ponderosa Seedlings to Stylet-Bearing Nematodes.  

PubMed

Of 12 stylet-bearing nematodes used for inoculations, Pratylenchus penetrans, P. brachyurus, P. vulnus, Ditylenchus destructor, Meloidogyne incognita, M. javanica, and M. hapla reproduced on Pinus ponderosa, while Xiphinema index, Aphelenchus avenae, Paratylenehus neoamblycephalus, Tylenchulus semipenetrans, and Macroposthonia xenoplax did not. P. vulnus, P. brachyurus, P. penetrans, A. avenae, D. destructor, T. semipenetrans, and P. neoamblycephalus significantly suppressed both the shoot and root wet weights of ponderosa pine seedlings obtained from stands in five different locations. X. index significantly suppressed root wet weights, M. xenoplax siguificantly suppressed shoot wet weight, and M. incognita, M. javanica, and M. hapla suppressed neither at the inoculation levels used. Injurious nematodes tended to suppress root growth more than shoot growth. Seedlings from two locations produced greater shoot growth wet weight than did seedlings from the other three locations. The more injurious nematodes tended to cause an increase in the water content of shoots. Frequency analyses of seedling population shoot-root ratios indicated that ponderosa pine seedlings could be selected for better shoot-root ratios as well as for resistance to several pathogenic nematodes. PMID:19300659

Viglierchio, D R

1979-10-01

125

Starch bioengineering affects cereal grain germination and seedling establishment  

PubMed Central

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. PMID:24642850

Hebelstrup, Kim H.; Blennow, Andreas

2014-01-01

126

Starch bioengineering affects cereal grain germination and seedling establishment.  

PubMed

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. PMID:24642850

Shaik, Shahnoor S; Carciofi, Massimiliano; Martens, Helle J; Hebelstrup, Kim H; Blennow, Andreas

2014-06-01

127

Effect of sorghum seedlings and previous crop, on soil fluorescent pseudomonas spp.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aims: The hypotheses that sorghum seedlings [Sorghum bicolor (L.) Moench] varying in sorgoleone production will differentially modify soil microorganisms and will effect subsequent planting of wheat (Triticum aestivum L.) seedlings were tested. Methods: Wheat cultivar Lewjain, and sorghum genotypes ...

128

Austral Ecology (2004) 29, 383390 Seed mass and seedling establishment after fire in  

E-print Network

Sciences, Macquarie University, Sydney, New SouthWales 2109,Australia (Email: amoles@bio at encounter' has been shown to be crucial in determining the outcome of seedling­ seedling competition in pot

Moles, Angela

129

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications.  

PubMed

The detection of ultraweak light emission in seedlings has been explored in toxicological and chronobiological studies. The main studies in this area are reviewed briefly, including a report on applied tests held in the last 7 years at LaFA--UNICAMP (Brazil). In general, results indicate that a linear relation for total light emission versus germination performance is found if only strong stress situations are considered, when external factors depress a seedling's development, even when considering a sequential series of tests. Light emitted by a single seedling was detected in a compact apparatus, and data are presented here for the first time showing pronounced circadian cycles are evident, with similar time and frequency profiles as those of the local gravimetric tide. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24687546

de Mello Gallep, Cristiano

2014-12-01

130

[Inhibition of isocitrate lyase in watermelon seedlings by white light].  

PubMed

The isocitrate lyase activity (E.C. 4.1.3.1.) from watermelon cotyledons (Citrullus vulgaris SCHRAD.) is inhibited by white light (Fig. 5). To exclude artefacts during enzyme preparation the following experiments were performed (Table 1 and 2): 1. Mixing of raw extracts from cotyledons of light and dark grown seedlings. 2. Joint homogenization a) of cotyledons from light and dark grown seedlings, b) of purified isocitrate lyase together with cotyledons from light or dark grown seedlings. The total activity corresponded to an amount which was expected for the sum of the individual activities. The results justify the conclusion that the inhibition of the isocitrate lyase by light is real, and that the measured enzyme activities are close to the true enzyme concentrations in the plant tissue. - The relatively slow inhibition of the enzyme activity caused by light seems to be correlated with the formation of the photosynthetic apparatus. PMID:24515664

Hock, B

1969-12-01

131

Diurnal Changes in the Chilling Sensitivity of Seedlings  

PubMed Central

Seedlings of tomato (Lycopersicon esculentum, Mill.) varied diurnally in their sensitivity to chilling temperatures. If chilled near the end of the dark period when they were most sensitive, the time taken to kill half of the seedlings was approximately 3 days, whereas in samples taken 4 hours after the onset of dark, a period of 6 days of chilling was required. Sensitivity dropped rapidly after the onset of the light period. This rhythm was exogenously controlled by the diurnal changes in light, rather than in the temperature. The susceptibility of predawn seedlings could be reduced by exposure to light, by water stress, or by abscisic acid applied to the leaves. However, the subsequent changes in sensitivity to chilling did not correlate with stomatal aperture. Six other chilling-sensitive species showed similar diurnal changes in their chilling sensitivity. Images Fig. 2 PMID:16662448

King, Ann I.; Reid, Michael S.; Patterson, Brian D.

1982-01-01

132

Grazing on regeneration sites encourages pine seedling growth. Forest Service research paper (Final)  

Microsoft Academic Search

Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the seedlings were significantly taller, with longer leaders with season-long grazing than without

R. D. Ratliff; R. G. Denton

1995-01-01

133

Factors affecting the production of terpenes in seedlings of Pinus elliottii  

E-print Network

of terpenes was calculated using an internal standard, and data were subjected to statistical tests. For seedlings in the greenhouse, terpene content increased with seedling age. Upon wounding the seedlings, total resin acid production increased... significantly, and total monoterpene production also increased but not significantly. Seedlings responded to wounding very rapidly, within one hour. Fungal infection also induced resin acid increases, but not significantly. The compositions of terpenes were...

Ishihara, Hiroichi

1987-01-01

134

Effects of Temperature on the Pattern of Anthocyanin Accumulation in Seedlings of Polygonum cuspidatum  

Microsoft Academic Search

Polygonum cuspidatum   seedling. Anthocyanin accumulated first in the lower part of hypocotyls and then the site of accumulation gradually extended\\u000a toward the upper part of hypocotyls when seedlings were irradiated with white light (WL) at 25 C. Etiolated seedlings accumulated\\u000a anthocyanin only in the upper parts (hook and cotyledons) when the seedlings were irradiated with WL at 5 C. De-etiolated

Fumiyasu Yamaguchi; Masayuki Nozue; Hitoshi Yasuda; Hiroyoshi Kubo

2000-01-01

135

Growth retardant activity of paclobutrazol enantiomers in wheat seedlings  

Microsoft Academic Search

The resolved enantiomers of paclobutrazol appeared to have different primary modes of action as plant growth retardants in rht3 (tall) wheat seedlings. 2S,3S-Paclobutrazol reduced shoot growth more effectively than root growth, whereas the opposite was the case with the 2R,3R-enantiomer. Low concentrations (0.03–1.0 µM) of 2S,3S-paclobutrazol specifically inhibited gibberellin A1 (GA1) production in Rht3 (dwarf) seedlings without affecting shoot growth,

J. R. Lenton; N. E. J. Appleford; K. E. Temple-Smith

1994-01-01

136

90sr uptake by 'pinus ponderosa' and 'pinus radiata' seedlings inoculated with ectomycorrhizal fungi  

Microsoft Academic Search

In the study, the authors inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi; inoculated and nonincoculated (control) seedlings were compared for their ability to remove Sr90 from an organic growth medium. Seedlings were grown for 3 months in a growth chamber in glass tubes containing 165 cu cm of sphagnum peat moss and

J. A. Entry; P. T. Rygiewicz; W. H. Emmingham

1994-01-01

137

Double-stocking for overcoming damage to conifer seedlings by pocket gophers  

Microsoft Academic Search

A 5-yr study was conducted on national forests in Idaho and Oregon to evaluate how doubling the seedling stocking rate of lodgepole pine (Pinus contorta) would relate to 5-year survival and the uniformity of distribution of seedlings in the presence of northern pocket gopher (Thomomys talpoides) damage. Either 4 or 8 seedlings were planted in 40-m2 subplots (1000 or 2000

Richard M. Engeman; Richard M. Anthony; Victor G. Barnes; Heather W. Krupa; James Evans

1998-01-01

138

Effects of the period of glyphosate treatment on oak seedlings: phenological and physiotogical aspects  

E-print Network

and physiological characteristics of oak seedlings. Materials and Methods 1 yr old oak seedlings (Quercus petraea (MEffects of the period of glyphosate treatment on oak seedlings: phenological and physiotogical Vandceuvre-les-Nancy, France Introduction Young oak trees are very sensitive to weed competition, especially

Paris-Sud XI, Université de

139

OIKOS 101: 499504, 2003 Do seedlings in gaps interact? A field test of assumptions in ESS  

E-print Network

of seedlings colonizing experimental gaps in a grazed grassland community. In small gaps (3 cm diameterOIKOS 101: 499­504, 2003 Do seedlings in gaps interact? A field test of assumptions in ESS seed seedlings in gaps interact? A field test of assumptions in ESS seed size models. ­ Oikos 101: 499­504. ESS

Silvertown, Jonathan

140

Relationships between xanthoxin, phototropism, and elongation growth in the sunflower seedling Helianthus annuus L  

Microsoft Academic Search

For phototropic curvature of a green sunflower seedling, only the hypocotyl has to be illuminated; the tip and cotyledons are not involved in stimulus perception. The etiolated seedling is phototropically insensitive, illumination of only the hypocotyl renders it sensitive. It is concluded that the photoreceptor is located within the responding organ. In curving seedlings, the endogenous indoleacetic acid (IAA) remains

J. M. Franssen; J. Bruinsma

1981-01-01

141

Seedling Growth and Survival of Western Red Cedar (Thuja Plicata), Six Years Later  

Microsoft Academic Search

In 2005, western red cedar (Thuja plicata) seedlings were planted in Forest Park in Portland, Oregon to ascertain whether mammalian predation had a role in low seedling recruitment in the park. Nine study sites, three in each section (urban, middle and rural) of the park were located along an urban-rural land use gradient. At each site, 27 seedlings were planted.

Conor F. Colahan; Eric Weinbender

2012-01-01

142

An Investigation into the Effect of Light Intensity on Azadirachta excelsa Jack. Seedlings ?????? ????????1  

Microsoft Academic Search

This study investigated the effect of light intensity upon growth rate and seedling quality of Azadirachta excelsa seedlings. The experiment was carried out at the Songlkha nursery centre, Southern Thailand. The seedlings were grown in a completely randomised experiment under four different light regimes: 10%, 30%, 50% and 100%, with three replicates for each treatment. The result showed that the

Jintana Bupabanpot

143

Time trajectories of mass and density in a Chamaecyparis obtusa seedling population  

Microsoft Academic Search

In an overcrowded population of tree seedlings of hinoki (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.), the allometric power relation existed between mean dry weights of seedling parts, such as stems, leaves and roots and whole seedlings during the course of self-thinning. The allometric exponent was significantly less than unity in the leaves, higher than unity in the stems and not

Kazuharu Ogawa

2001-01-01

144

Away-field advantage: mangrove seedlings grow best in litter from other mangrove species  

E-print Network

1880 Away-field advantage: mangrove seedlings grow best in litter from other mangrove species and mixture status influenced mangrove seedling growth, biomass allocation, and stoichiometry, we performed mesocosm experiments. Two species of mangrove seedlings, Avicennia germinans, black mangrove and Rhizo

Chapman, Samantha

145

Adaptations enhancing survival and establishment of seedlings on coastal dune systems  

Microsoft Academic Search

Studies on the survival and establishment of seedlings in coastal and lacustrine sand dune systems suggest that nutrient deficiency, lack of moisture, sand accretion, salt spray and predation are probably the most important limiting factors. Seedlings employ both avoidance and tolerance strategies to with-stand the different stresses. For example, seedling recruitment of dune species coincided with periods of high moisture

M. A. Maun

1994-01-01

146

[Physiological responses of mycorrhizal Pinus massoniana seedlings to drought stress and drought resistance evaluation].  

PubMed

A greenhouse pot experiment was conducted to study the effects of inoculating Pisolithus tinctorius, Cenococcum geophilum, Cantharellus cibarius, and Suillus luteus on the physiological characteristics of Pinus massoniana seedlings under the conditions of drought stress and re-watering, with the drought resistance of the mycorrhizal seedlings evaluated. Under drought stress, the MDA content and membrane' s relative permeability of P. massoniana seedlings increased, but these two indices in the inoculated (mycorrhizal) seedlings were significantly lower than these in the un-inoculated (control) seedlings. After re-watering, the MDA content and membrane's relative permeability of mycorrhizal seedlings had a rapid decrease, as compared with the control. In the first 21 days of drought stress, the production rate of superoxide radical of the seedlings increased, and the SOD, POD and NR activities of mycorrhizal seedlings increased significantly. With the extending of drought stress, the seedlings after re-watering had different recovery ability. Under the re-watering after 14 days drought stress, the SOD, POD and NR activities recovered. The drought resistance of the mycorrhizal seedlings was in the order of Suillus luteus 1 > Suillus luteus 7 > Cantharellus cibarius > Cenococcum geophilum > Pisolithus tinctorius. The SOD and MDA activities had a greater correlation with the mycorrhizal seedlings drought resistance, being able to be used as the indicators to evaluate the drought resistance of mycorrhizal seedlings. PMID:23755475

Wang, Yi; Ding, Gui-jie

2013-03-01

147

SPATIAL EFFECTS OF RETENTION TREES ON MYCORRHIZAS OF DOUGLAS-FIR SEEDLINGS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Retention forestry places seedlings in proximity to residual trees, exposing seedlings to additional sources of ectomycorrhizal fungus (EMF) inoculum. To investigate this, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were planted near (2-6 m) and far (16-30 m) from 44- to 72-year-ol...

148

Phytol. (1995), 130, 447-459 Sensitivity of seedlings of black cherry  

E-print Network

Phytol. (1995), 130, 447-459 Sensitivity of seedlings of black cherry {Prunus serotina Ehrh The response of seedlings of black cherry {Prunus serotina Ehrh.) to ozone was evaluated in Great Smoky sensitive. Black cherry seedlings are shown to be among the most sensitive to elevated ozone of the 21 tree

Neufeld, Howard S.

149

The Influence of Glomus mosseae on Tylenchulus semipenetrans-Infected and Uninfected Citrus limon Seedlings.  

PubMed

Greenhouse studies have shown that when rough lemon (Citrus limon) seedlings infected with TyIenchulus semipenetrans were transplanted into soil infested with Glomus mosseae, the mycorrhizal fungus infection increased seedling growth compared to nonntycorrhizal seedlings. Tylenchulus semipenetrans significantly suppressed seedling growth below that of mycorrhizal seedlings. Histological observations of nematode-free mycorrhizal roots showed that hyphae penetrated the epidermis and invaded the cortex, giving rise to arbuscules and vesicles. Nematode infection sites in T. semipenetrans-infected roots grown in soil infested with G. mosseae did not show evidence of vesicle development in the cortex but did show arbuscule development. PMID:19300642

O'Bannon, J H; Inserra, R N; Nemec, S; Vovlas, N

1979-07-01

150

HOST-PATHOGEN INTERACTION OF SUGARBEET SEEDLINGS WITH RHIZOCTONIA SOLANI  

Technology Transfer Automated Retrieval System (TEKTRAN)

The progress curve of seedling damping-off caused by Rhizoctonia solani showed three distinct stages - an initial rapid disease progress stage, an intermediate stationary phase, and a final decline and death phase, in the compatible interaction. Both virulent and avirulent fungal isolates initiated ...

151

Effects of gravel mulch on emergency of galleta grass seedlings  

Microsoft Academic Search

Gravel mulches show promise as effective material on the US Dept. of Energy Nevada Test Site for stabilizing erosive soils and aiding plant establishment by conserving soil water. A greenhouse study was implemented to determine the effects of gravel mulch on seedling emergence and soil water, and optimal depths of gravel for various native plant species. Greenhouse flats were sown

V. K. Winkel; J. C. Medrano; M. D. Walo

1993-01-01

152

Predicting Seedling Emergence Using Soil Moisture and Temperature Sensors  

Microsoft Academic Search

Hydrothermal time models are often used to predict seed germination rates. In this study, soil water potential data from three resistance-type sensors (Colman cells, Watermark brand sensors, and Delmhorst gypsum blocks) and from a time-domain reflectometry (TDR) probe (Campbell Scientific 615) were input into a hydrothermal time model to predict seedling emergence in a growth chamber experiment for six desert

Jeffrey R. Taylor; Bruce A. Roundy; Phil S. Allen; Susan E. Meyer

153

Nitrogen effects on seed germination and seedling growth  

Microsoft Academic Search

Recent evidence associates the persistence of invasive plant species with disturbance and fluctuations in distinct forms of mineral N in soils. We conducted soil and hydroponic experi- ments to investigate the influence of N form and availability on germination and seedling development of 2 invasive annual grasses, cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) and 6 perennial grasses, blue- bunch

THOMAS A. MONACO; CHARLES T. MACKOWN; DOUGLAS A. JOHNSON; THOMAS A. JONES; JEANETTE M. NORTON; JAY B. NORTON; MARGARET G. REDINBAUGH

2003-01-01

154

N dynamics in the rhizosphere of Pinus ponderosa seedlings  

Microsoft Academic Search

Transformations of inorganic N were studied in microcosms containing Pinus ponderosa seedlings. We assessed the potential for immobilization and mineralization of NH4+ in soils collected from adjacent to coarse, fine and young roots and in soil more than 5 mm from any root. Rates of mineralization and immobilization of NH4+ in soils collected from adjacent to roots were >50% higher

Jeanette M. Norton; Mary K. Firestone

1996-01-01

155

Germination and seedling survival in fens undergoing succession  

Microsoft Academic Search

We studied mechanisms of vegetation change in fens subject to succession from open water to floating mats and finally herbaceous rich-fens. Earlier research showed that these systems are characterized by transient seed banks. Our main question was whether seedlings of later successional fen stages are already present in earlier stages, remaining subordinate in the vegetation until conditions become suitable for

Tom Van den Broek; Boudewijn Beltman

2006-01-01

156

Light Response of Native and Introduced Miscanthus sinensis Seedlings  

E-print Network

Light Response of Native and Introduced Miscanthus sinensis Seedlings David P. Matlaga, Lauren D. Quinn, Adam S. Davis, and J. Ryan Stewart* The Asian grass Miscanthus sinensis (Poaceae) is being populations. Nomenclature: Eulaliagrass; Miscanthus sinensis Anderss. Key words: Biomass allocation, light

Sims, Gerald K.

157

Optimized Preparation and Determination of Pea Seedling Diamine Oxidase  

Microsoft Academic Search

The level of diamine oxidase in pea seedling stems has been determined as a function of time after germination in both etiolated and non-etiolated plants. The maximum amount of enzyme per plant is obtained between 11 and 13 days. The amount of activity per gram of tissue appears to be proportional to the rate of growth. We describe an efficient

Michael D. Kluetz; Karlis Adamsons; James E. Flynn Jr

1980-01-01

158

Protein phosphorylation differs significantly among ontogenetic phases in Malus seedlings  

PubMed Central

Background Although protein phosphorylation is an important post-translational modification affecting protein function and metabolism, dynamic changes in this process during ontogenesis remain unexplored in woody angiosperms. Methods Phosphorylated proteins from leaves of three apple seedlings at juvenile, adult vegetative and reproductive stages were extracted and subjected to alkaline phosphatase pre-treatment. After separating the proteins by two-dimensional gel electrophoresis and phosphoprotein-specific Pro-Q Diamond staining, differentially expressed phosphoproteins were identified by MALDI-TOF-TOF mass spectrometry. Results A total of 107 phosphorylated protein spots on nine gels (three ontogenetic phases?×?three seedlings) were identified by MALDI-TOF-TOF mass spectrometry. The 55 spots of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) large-chain fragments varied significantly in protein abundance and degree of phosphorylation among ontogenetic phases. Abundances of the 27 spots corresponding to Rubisco activase declined between juvenile and reproductive phases. More extensively, phosphorylated ?-tubulin chain spots with lower isoelectric points were most abundant during juvenile and adult vegetative phases. Conclusions Protein phosphorylation varied significantly during vegetative phase change and floral transition in apple seedlings. Most of the observed changes were consistent among seedlings and between hybrid populations. PMID:24904238

2014-01-01

159

Seedling emergence of horseweed in no-till  

Technology Transfer Automated Retrieval System (TEKTRAN)

Density of horseweed is increasing in no-till cropping systems because horseweed seed is transported by wind and seedlings can establish from seeds lying on the soil surface. Also, horseweed has developed resistance to commonly-used herbicides, thus control tactics are often ineffective. This repo...

160

The vestigial root of dodder (Cuscuta pentagona) seedlings.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seedlings of dodder have no leaves nor cotyledons and the terminal root-like structure lasts only a few days before death. Structural and biochemical studies indicate that the terminal appendage of the dodder, although differentiated from the shoot, has few characteristics of root tissue. The root...

161

Burst of ethylene upon horizontal placement of tomato seedlings  

NASA Technical Reports Server (NTRS)

Seedlings of Lycopersicon esculentum Mill. cv Rutgers emit a pulse of ethylene during the first 2 to 4 minutes following horizontal placement. Because this burst appears too rapid and brief to be mediated by increase in net activity of 1-aminocyclopropane-1-carboxylic acid synthase, it might result form accelerated transformation of vacuolar 1-aminocyclopropane-1-carboxylic acid to ethylene.

Harrison, M.; Pickard, B. G.

1984-01-01

162

Inhibitory effects of monoterpenes on seed germination and seedling growth.  

PubMed

Monoterpenes, the chemical constituents of essential oils found in plants, are known biologically active compounds. The present study was conducted to investigate the inhibitory effects of 30 monoterpenes including monoterpene hydrocarbons and oxygenated monoterpenes on seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus under laboratory conditions. The monoterpenes were applied at contents of 10 and 20 microl for liquid compounds and 10 and 20 microg for solid compounds. The results show that most of the monoterpenes significantly inhibited seed germination and seedling growth of the tested plants. Oxygenated monoterpenes including beta-citronellol, nerol and terpinen-4-ol completely inhibited seed germination and seedling growth of all tested plants. Their inhibitory effects were also stronger than that of the herbicide 2,4-D. In general, monoterpenes were less effective against seed germination and seedling growth of C. album as compared with R. crispus and A. retroflexus. Phytotoxic effects of monoterpene hydrocarbons were found to be lower than those of oxygenated monoterpenes. The alcohol derivatives of oxygenated monoterpenes were also found to be more phytotoxic as compared with their acetate derivatives. Based on the present results, it can be concluded that the oxygenated monoterpenes can be used as potential bio-herbicides. PMID:17542486

Kordali, Saban; Cakir, Ahmet; Sutay, Sunay

2007-01-01

163

WEED SEEDLING EMERGENCE AND MICROCLIMATE IN A TROPICAL ENVIRONMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tropic ageratum (Ageratum conyzoides) is an important annual weed in tropical cropping systems. Better and more timely strategies for its control might be developed through a more thorough understanding of its emergence behavior. Seedling emergence of tropic ageratum was monitored periodically and s...

164

Growth responses and adaptations of Fraxinus pennsylvanica seedlings to flooding  

Microsoft Academic Search

Flooding induced several physiological and morphological changes in Fraxinus pennsylvanica seedlings, with stomatal closure among the earliest responses. Subsequent changes included: reduction in dry weight increment of roots, stems, and leaves; formation of hypertrophied lenticles and production of adventitious roots on submerged portions of the stem above the soil line; leaf necrosis; and leaf abscission. After 15 days of stomatal

A. R. Sena Gomes; T. T. Kozlowski

1980-01-01

165

Cytokinin activity in Citrus seedlings colonized by mycorrhizal fungi  

E-print Network

Cytokinin activity in Citrus seedlings colonized by mycorrhizal fungi R.K. Dixon* School of roots by vesicular-arbus- cular mycorrhizal fungi or the result of improved mineral nutrition (Van fungi; and 2) isolate cytokinins with demon- strated biological activity. Materials and Methods Five

Paris-Sud XI, Université de

166

Original article Photosynthesis and shoot water status of seedlings  

E-print Network

Original article Photosynthesis and shoot water status of seedlings from different oak species — Stress effects induced on shoot photosynthesis and leaf water status by root hypoxia due. Predawn leaf water potential remained high in all cases, in- dicating that reductions in photosynthesis

Boyer, Edmond

167

[Characterization of growth-promoting rhizobacteria in Eucalyptus nitens seedlings].  

PubMed

Rhizospheric and endophytic bacteria were isolated from the rizosphere and root tissue of Eucalyptus nitens. The objective of this work was to evaluate their capacity to promote growth in seedlings of the same species under greenhouse conditions. The isolates that improved seedling growth were identified and characterized by their capacity to produce indoleacetic acid (IAA), solubilize phosphates and increase 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. One hundred and five morphologically different strains were isolated, 15 of which promoted E. nitens seedling growth, significantly increasing the height (50%), root length (45%) as well as the aerial and root dry weight (142% and 135% respectively) of the plants. Bacteria belonged to the genus Arthrobacter, Lysinibacillus, Rahnella and Bacillus. Isolates A. phenanthrenivorans 21 and B. cereus 113 improved 3.15 times the emergence of E. nitens after 12 days, compared to control samples. Among isolated R. aquatilis, 78 showed the highest production of IAA (97.5±2.87?g/ml) in the presence of tryptophan and the highest solubilizer index (2.4) for phosphorus, while B. amyloliquefaciens 60 isolate was positive for ACC deaminase activity. Our results reveal the potential of the studied rhizobacteria as promoters of emergence and seedling growth of E. nitens, and their possible use as PGPR inoculants, since they have more than one mechanism associated with plant growth promotion. PMID:25576419

Angulo, Violeta C; Sanfuentes, Eugenio A; Rodríguez, Francisco; Sossa, Katherine E

2014-01-01

168

Recruitment Limitation, Seedling Performance and Persistence of Exotic Tree Monocultures  

Microsoft Academic Search

Many native plant communities are replaced by exotic monocultures that may be successional stages or persistent community types. We surveyed a stand of Sapium sebiferum (Chinese Tallow Tree) that replaced tallgrass prairie in Texas and performed experiments with seeds and seedlings to determine the contributions of recruitment limitation and natural enemy release to allowing such a forest type to persist

Evan Siemann; William E. Rogers

2006-01-01

169

Seeds and Seedling Establishment of Wyoming Big Sagebrush  

Microsoft Academic Search

Success with Wyoming sagebrush (Artemisia tridentata ssp. wyomingensis) depends on good seed vigor, and rapid seedling development. These characteristics are influenced by harvesting, processing, storing, and sowing. In this paper we discuss research findings related to those activities: (1) It appears that Wyoming big sagebrush growing on the western edge of the Great Plains might hold viable seed longer into

D. T. Booth; Y. Bai

170

Effects of arbuscular mycorrhizae on water stress tolerance of big sagebrush seedlings  

SciTech Connect

Reestablishment of Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) on mined lands has been difficult in the past even though it is widespread in the western US. Its reestablishment on mined lands has recently become law where wildlife is one of the post-mining land uses and it represented the primary premining shrub species. One hypothesis thought to contribute to its difficult reestablishment is the reduce lack of mycorrhizae inoculum present in the disturbed topsoil and the resulting effect on the seedling`s ability to extract water from the soil under the arid/semiarid climate of this region. A greenhouse study was conducted to evaluate the effect of mycorrhizae on sagebrush seedling water stress tolerance. Seedling ages evaluated ranged from 30 to 150 days. Seedling survival was greater for mycorrhizal seedlings compared to non-mycorrhizal seedlings when soil moisture tension was {minus}2.5 to {minus}3.8 MPa. At all ages, the degree of soil dryness necessary to cause sagebrush seedling mortality was significantly greater for mycorrhizal than non-mycorrhizal seedlings. Seedling age and mycorrhizal infection exhibited a significant statistical interaction; suggesting that as the sagebrush seedling aged, the benefits of arbuscular mycorrhizae (AM) increased the plants water stress tolerance. These findings lead the authors to conclude that topsoil management that prevents/reduces the loss of AM inoculum in the topsoil will significantly enhance the success of sagebrush establishment on mined lands.

Schuman, G.E.; Stahl, P.D.; Williams, S.E.; Frost, S.M. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Plant, Soil and Insect Sciences

1998-12-31

171

[Effects of gap size on seedling natural regeneration in artificial Pinus tabulaeformis plantation].  

PubMed

To clarify the effects of gap size created by thinning on the seedling natural regeneration in artificial Pinus tabulaeformis plantation, a plot investigation was conducted to study the ecological factors and the age structure, height, diameter, length of needles, and dry biomass of roots, stems, and needles of 1-10 year-old seedlings in different habitats, and a path analysis was made on the environmental factors affecting the seedling regeneration. Obvious differences were observed in the ecological factors in different size gaps and slope aspects. There lacked of above 3 year-old seedlings in understory and of above 7 year-old seedlings in small gap, and the seedlings of 5 and 6 year-old were lesser in big gap. The 1-10 year-old seedlings could be divided into 3 development phases, i. e. , 1-3 year-old, 4-7 year-old, and 8-10 year-old seedlings, among which, 1-3 year-old seedlings were critical for the establishment and growth of the population. The growth situation of the seedlings in different habitats was in order of big gap in shady slope > big gap in sunny slope > small gap in sunny slope > small gap in shady slope > understory in sunny slope > understory in shady slope. Path analysis showed light intensity had decisive positive effects on the seedling number of different development phases, shrub coverage had decisive negative effects on the seedling number of 4-7 year-old and 8-10 year-old phases, whereas humus dry mass had negative effects on the seedling number of 4-7 year-old but positive effects on the seedling number of 8-10 year-old. It was suggested that in the management of artificial P. tabulaeformis plantation, relatively high intensity thinning combined with shrub clearing should be adopted to provide favorable conditions for the sustainable development of P. tabulaeformis population. PMID:23431773

Han, Wen-Juan; Yuan, Xiao-Qing; Zhang, Wen-Hui

2012-11-01

172

Seedling occurrence in alpine treeline conifers: A case study from the central Rocky Mountains, USA  

NASA Astrophysics Data System (ADS)

Information concerning the occurrence of very young (1- to 10-year-old) tree seedlings in the alpine treeline ecotone is rare. Seedling occurrence of the dominant conifers Picea engelmannii and Abies lasiocarpa was measured in the treeline ecotone of the Medicine Bow Mountains, Wyoming (central Rocky Mountains, USA), an area composed of elongated tree islands separated by open meadows (ribbon forest) that grade into the closed forest. No seedlings were found on the windward sides of tree islands, while a mean of 0.6 seedlings.m -2 occurred on the leeward (downward) sides. These values compared to the 4.2 seedlings.m -2 in the closed forest. In addition, a strong correspondence was found between snowpack depth and seedling abundance, with depths that were either too shallow (< 0.5 m) or too deep (> 1.5 m) associated with fewer or no seedlings. A. lasiocarpa seedlings made up much less of the overall seedling population in the ribbon forest (6 %) than in the closed forest (22 %). Seedling establishment in this portion of the alpine treeline ecotone appears to be occurring at a low rate that differs between the two dominant species and may be strongly influenced by wind-driven snow accumulation patterns.

Hättenschwiler, Stephan; Smith, William K.

1999-05-01

173

Effects of invasive rats and burrowing seabirds on seeds and seedlings on New Zealand islands.  

PubMed

Rats (Rattus rattus, Rattus norvegicus, Rattus exulans) are important invaders on islands. They alter vegetation indirectly by preying on burrowing seabirds. These seabirds affect vegetation through nutrient inputs from sea to land and physical disturbance through trampling and burrowing. Rats also directly affect vegetation though consumption of seeds and seedlings. Seedling communities on northern New Zealand islands differ in composition and densities among islands which have never been invaded by rats, are currently invaded by rats, or from which rats have been eradicated. We conducted experimental investigations to determine the mechanisms driving these patterns. When the physical disturbance of seabirds was removed, in soils collected from islands and inside exclosures, seedling densities increased with seabird burrow density. For example, seedling densities inside exclosures were 10 times greater than those outside. Thus the negative effects of seabirds on seedlings, by trampling and uprooting, overwhelm the potentially beneficial effects of high levels of seed germination, seedling emergence, and possibly seed production, which result from seed burial and nutrient additions. Potential seedling density was reduced on an island where rats were present, germination of seeds from soils of this island was approximately half that found on other islands, but on this island seedling density inside exclosures was 7 times the density outside. Although the total negative effects of seabirds and rats on seedling densities are similar (reduced seedling density), the differences in mechanisms and life stages affected result in very different filters on the plant community. PMID:19921273

Grant-Hoffman, Madeline N; Mulder, Christa P H; Bellingham, Peter J

2010-04-01

174

Why Seedlings Die: Linking Carbon and Water Limitations to Mechanisms of Mortality During Establishment in Conifer Seedlings  

NASA Astrophysics Data System (ADS)

BACKGROUND Recent ecophysiological studies aimed at explaining adult tree mortality during drought have examined the carbon (C)-exhaustion compared to the hydraulic-failure hypotheses for death. Prolonged drought leads to durations of stomatal closure (and thus limited C gain), which could result in long periods of negative C balance and fatal reductions in whole-plant C reserves (i.e., available non-structural carbohydrates ["NSC"]). Alternatively, C reserves may not decrease much but could become increasingly inaccessible to sink tissues in long dry-periods due to impediments to translocation of photosynthate (e.g., through disruption of hydrostatic pressure flow in phloem). As C reserves decline or become inaccessible, continued maintenance respiration has been hypothesized to lead to exhaustion of NSC after extended durations of drought, especially in isohydric plant species. On the other hand, hydraulic failure (e.g., catastrophic xylem embolisms) during drought may be the proximate cause of death, occurring before true C starvation occurs. Few studies have investigated specifically the mechanism(s) of tree death, and no published studies that we know of have quantified changes in NSC during mortality. EXPERIMENTAL DESIGN AND HYPOTHESES We conducted two studies that investigated whole-tree and tissue-specific C relations (photosynthetic C gain, respiration, dry-mass gain, and NSC pools) in Pinus flexilis seedlings during the initial establishment phase, which is characterized by progressive drought during summer. We measured survival, growth and biomass allocation, and C-balance physiology (photosynthetic C-gain and chlorophyll fluorescence, respiration C-use, and NSC concentrations) from germination to mortality. We hypothesized that 1) stomatal and biochemical limitations to C gain would constrain seedling survival (through inadequate seasonal C-balance), as has been shown for conifer seedlings near alpine treeline; 2) hydraulic constraints (embolisms and/or reduced hydraulic conductance), associated with roots unable to escape the seasonal drying front in the soil, would limit seedling survival at least as much as C-balance dysfunction; and 3) seedling mortality would not be due to exhaustion of whole-plant NSC, as suggested by appreciable NSC in dead conifer seedlings reported in alpine treeline studies. RESULTS AND INTERPRETATIONS Preliminary results suggest that photosynthesis, fluorescence, and whole-tree NSC remained high until mortality, when plant water potentials decreased below -5 MPa. As seedlings approached mortality, NSC concentrations (both soluble sugars and starch) in roots decreased from ~9% to <3% of dry-mass. In aboveground tissues, NSC concentrations also declined initially (from ~12% to 3% of dry-mass), but then increased in needles (up to 8% dry-mass) and especially stems (up to 16% dry-mass), suggesting impediments to phloem-translocation in stems. Thus, seedling death could not be directly attributed to dysfunction of C-balance physiology, or exhaustion of NSC at the whole-plant level. We propose that hydraulic failure was likely the proximate cause of mortality under the conditions we evaluated, and drought-induced inhibition of NSC transport to roots may ultimately undermine the ability of seedlings to tap progressively deeper water sources during summer drying.

Reinhardt, K.; Germino, M. J.; Kueppers, L. M.; Mitton, J.; Castanha, C.

2012-12-01

175

Relationship between seedling and mature vegetation on the hilly-gullied Loess Plateau.  

PubMed

Seedling is an indispensable stage in plant cycle life, and seedling survival is important during natural vegetation restoration, especially on the Loess Plateau. In 2007, we selected 4 plots of Artemisia scoparia communities (ASC) and 4 plots of Artemisia gmelinii + Artemisia giraldii communities (AGC), examined seedling richness, diversity during the rainy season, and examined mature vegetation richness, coverage, and frequency in August. The results showed that seedlings density of ASC were 29 n m(-2), 33 n m(-2), 20 n m(-2) and 31 n m(-2) in July to October respectively, and that of AGC were 14 n m(-2), 12 n m(-2), 6 n m(-2) and 9 n m(-2) respectively; A. scoparia seedlings represented 53.2% of the total seedlings in ASC, the dominant species in AGC only account for less than 5% of the total seedlings. Most of the seedlings found were belonged to Compositae, Leguminoseae and Gramineae; 80% of seedlings in ASC were mainly comprised of A. scoparia and Lespedeza davurica, while in AGC that consisted of more than 6 species, such as L. davurica, Sophora viciifolia, Dracocephalum moldavicaand, A. gmelinii, Patrinia heterophylla, Heteropappus altaicus so on. Sørensen similarity index between monthly seedlings was approximately 0.47 in ASC and 0.35 in AGC; Sørensen similarity index between seedlings and mature vegetation ranged from 0.18 to 0.34 in ASC, and varied from 0.26 to 0.39 in AGC. These results suggested that seedling establishment would be a bottleneck for natural vegetation restoration when seed supply and seedling emergence were possible. PMID:24701385

Jia, Yan-Feng; Jiao, Ju-Ying; Wang, Ning

2013-01-01

176

The role of genetic and chemical variation of Pinus sylvestris seedlings in influencing slug herbivory.  

PubMed

This study investigated the genetic and chemical basis of resistance of Pinus sylvestris seedlings to herbivory by a generalist mollusc, Arion ater. Using feeding trials with captive animals, we examined selective herbivory by A. ater of young P. sylvestris seedlings of different genotypes and correlated preferences with seedling monoterpene levels. We also investigated the feeding responses of A. ater to artificial diets laced with two monoterpenes, Delta(3)-carene and alpha-pinene. Logistic regression indicated that two factors were the best predictors of whether seedlings in the trial would be consumed. Individual slug variation (replicates) was the most significant factor in the model; however, alpha-pinene concentration (also representing beta-pinene, Delta(3)-carene and total monoterpenes due to multicollinearity) of needles was also a significant factor. While A. ater did not select seedlings on the basis of family, seedlings not eaten were significantly higher in levels of alpha-pinene compared to seedlings that were consumed. We also demonstrated significant genetic variation in alpha-pinene concentration of seedlings between different families of P. sylvestris. Nitrogen and three morphological seedling characteristics (stem length, needle length and stem diameter) also showed significant genetic variation between P. sylvestris families. Artificial diets laced with high (5 mg g(-1) dry matter) quantities of either Delta(3)-carene or alpha-pinene, were eaten significantly less than control diets with no added monoterpenes, supporting the results of the seedling feeding trial. This study demonstrates that A. ater selectively feed on P. sylvestris seedlings and that this selection is based, in part, on the monoterpene concentration of seedlings. These results, coupled with significant genetic variation in alpha-pinene concentration of seedlings and evidence that slug herbivory is detrimental to P. sylvestris fitness, are discussed as possible evidence for A. ater as a selective force on the evolution of defensive chemistry in P. sylvestris. PMID:17180371

O'Reilly-Wapstra, Julianne M; Iason, Glenn R; Thoss, Vera

2007-05-01

177

A technique for collection of exudate from pea seedlings  

NASA Technical Reports Server (NTRS)

Ethylenediaminetetraacetic acid (EDTA), at concentrations higher than 1.0 millimolar, is phytotoxic to etiolated seedlings of Pisum sativum. Substantial vascular exudation from pea epicotyls could be obtained without tissue damage at 0.5 millimolar EDTA if the solution was buffered at pH 7.5 with sodium N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid. Treated seedlings exuded 950 micrograms (leucine equivalents) of ninhydrin-positive material per day and 870 micrograms (glucose equivalents) of anthrone-positive material per day. Amino acid analysis showed the exudate to have glutamine as the major amido nitrogen containing compound and sucrose was shown to be the major sugar. Radiolabeled tryptophan and sucrose applied to cotyledons were transferred through the epicotyl and into the collection medium. The pH profile for exudation shows half maximal exudation at pH 7.2, indicating the promotion of exudation by EDTA is probably not due simply to Ca2+ chelation.

Hanson, S. D.; Cohen, J. D.; Bandurski, R. S. (Principal Investigator)

1985-01-01

178

Phytochrome-controlled extension growth of Avena sativa L. seedlings  

Microsoft Academic Search

The effects of continuous red and far-red light and of brief light pulses on the growth kinetics of the mesocotyl, coleoptile, and primary leaf of intact oat (Avena sativa L.) seedlings were investigated. Mesocotyl lengthening is strongly inhibited, even by very small amounts of Pfr, the far-red light absorbing form of phytochrome (e.g., by [Pfr]˜0.1% of total phytochrome, established by

P. Schopfer; K.-H. Fidelak; E. Schäfer

1982-01-01

179

Plant regeneration from seedling explants of Juncus effusus  

Microsoft Academic Search

An in vitro plant regeneration method for Juncuseffusus L. was established. Six to eight day old in vitro grown seedlings, cultured on Murashige and Skoog medium supplemented with benzyladenine (BA), 2-isopentenyladenine (2iP), or kinetin, showed multiple shoot regeneration within 4 weeks. Among the three cytokinins, BA and 2iP induced the highest (88 and 86%, respectively) regeneration frequency, while no significant

K. S Sarma; S. M. D Rogers

2000-01-01

180

Antioxidant responses of rice seedlings to salinity stress  

Microsoft Academic Search

The possible involvement of activated oxygen species in the mechanism of damage by NaCl stress was studied in leaves of four varieties of rice (Oryza sativa L.) exhibiting different sensitivities to NaCl. The 3-week-old rice seedlings were subjected to 0, 6 and 12 dS m?1 salinity levels for 1-week after which differences in antioxidant capacities and possible correlation, growth rate

Maribel L Dionisio-Sese; Satoshi Tobita

1998-01-01

181

Allelopathic potential of ground cover species on Pinus resinosa seedlings  

Microsoft Academic Search

Summary Water extracts of foliage ofAster macrophyllus, Lonicera tatarica, Solanum dulcamara, Solidago gigantea, Prunus serotina, andRubus idaeus var.strigosus, collected from the ground vegetation of a red pine (Pinus resinosa Ait.) plantation, were tested for potential allelopathic effects on seed germination, radicle elongation, and growth of red pine seedlings. Seed germination was not significantly affected by extracts, but radicle elongation of

R. J. Norby; T. T. Kozlowski

1980-01-01

182

Amelioration of chilling stress by triadimefon in cucumber seedlings  

Microsoft Academic Search

Cucumber (Cucumis satvus L.) seeds were imbibed in distilled water (control) and 10 mg l-1 triadimefon (TDM) for 10 h and then grown in a plant growth chamber with a light\\/dark temperature of 28\\/20 °C and a photoperiod of 14 h with a light intensity of 60 µmol m-2 s-1. 14-day-old seedlings were exposed to chilling stress with a light\\/dark

Zhaozhong Feng; Anhong Guo; Zongwei Feng

2003-01-01

183

Testing control of saltcedar seedlings using fall flooding  

Microsoft Academic Search

Because germination requirements of the exotic saltcedar (Tamarix ramosissima) and native cottonwood (Populus deltoides subsp. wislizenii) are similar, efforts to establish cottonwoods often result in concurrent establishment of saltcedars. We evaluated the success\\u000a of fall flooding to reduce saltcedar seedling density in the Rio Grande floodplain of central New Mexico, USA. We also evaluated\\u000a the effects of flooding on cottonwood

Matthew D. Sprenger; Loren M. Smith; John P. Taylor

2001-01-01

184

Rodent seed predation and seedling recruitment in mesic grassland  

Microsoft Academic Search

Seedling recruitment of two grasses (Arrhenatherum elatius and Festuca rubra) and two herbs (Centaurea nigra and Rumex acetosa) was measured in areas with and without rodents to which seeds of each species were sown at three seed densities (1000, 10,000\\u000a and 50,000 seeds m?2) in two seasons (spring and autumn 1995). Seed removal was measured for 10-day periods and the

G. R. Edwards; M. J. Crawley

1999-01-01

185

Morphogenic capability of Gentiana kurroo Royle seedling and leaf explants  

Microsoft Academic Search

Experiments have been carried out on seedling and primary leaf explants of Gentiana kurroo Royle. Morphogenic capacities of cotyledons, hypocotyls and roots were investigated using MS (1962) medium supplemented with\\u000a 4.64 ?M kinetin and 2.26, 4.52 or 9.04 ?M 2,4-D. Percentage of callusing explants for each combination was inversely proportional\\u000a to numbers of obtained embryos. Cotyledons showed the highest morphogenic capabilities. To

Agnieszka Fiuk; Jan J. Rybczy?ski

2008-01-01

186

Tree Seedling Production Systems in Northern Mindanao, Philippines  

Microsoft Academic Search

This paper examines seedling production systems for small-scale forestry in northern Mindanao, particularly the constraints\\u000a and opportunities to sustain the operation of smallholder nurseries. Various types of nurseries were identified to examine\\u000a issues and concerns operators face, and data collected through a survey of nursery operators, discussion with government and\\u000a NGO personnel, and literature review. Many smallholders in northern Mindanao

Agustin R. Mercado Jr; Caroline Duque-Piñon

2008-01-01

187

Effect of paclobutrazol on abscisic acid levels in wheat seedlings  

Microsoft Academic Search

Contradictory results have been reported for the effects of triazoles on abscisic acid (ABA) levels in plants. Paclobutrazol\\u000a reduced the height, fresh weight, and ABA levels of wheat seedlings. The magnitude of the inhibitory effect of paclobutrazol\\u000a on ABA levels was dependent on the length of time after application. ABA levels in plants as determined by gas chromatography-selected\\u000a ion monitoring-mass

J. G. Buta; D. W. Spaulding

1991-01-01

188

Paclobutrazol protects wheat seedlings from injury due to waterlogging  

Microsoft Academic Search

Wheat (Triticum aestivum L.) seeds were imbibed for 18 h in 40 mM KCl solution containing either distilled water or 100 mg l-1 paclobutrazol (PBZ, a triazole) and then air dried. Seeds were germinated in a greenhouse and one set of seedlings was grown under non-stressed conditions. Another three sets were stressed by waterlogging at three different stages when the

Jinelle A. Webb; R. A. Fletcher

1996-01-01

189

Enantioselective separation and phytotoxicity on rice seedlings of paclobutrazol.  

PubMed

The environmental significance of enantioselectivity in chiral insecticides and herbicides has been widely studied. However, little information is currently available on the enantioselective behavior of chiral plant growth regulators. In this study, paclobutrazol enantiomers were resolved and prepared by chiral high-performance liquid chromatography with a Sino-chiral OJ column. The relationship among absolute configuration, optical activity and circular dichroism of paclobutrazol enantiomers was established. The enantioselective behavior of paclobutrazol, including enantioselective effect of paclobutrazol on the growth of rice seedlings and cyanobacteria and enantioselective loss of paclobutrazol in rice seedling growth media, in rice culture system was studied. The (2S,3S)-(-)-enantiomer was almost 3.1 times more active than the (2R,3R)-(+)-enantiomer toward shoot growth as measured by 7 day EC50 values. Enantioselectivity could not be determined with respect to root growth of rice seedlings because a typical dosage response was not observed in the range of the concentrations studied. The dissipation of paclobutrazol in rice growth medium is not enantioselective. Enantiomers and diastereoisomer of paclobutrazol all facilitated the growth of cyanobacteria, which increase the effectiveness of rice biofertilizers. The (2S,3S)-(-)-enantiomer showed stronger stimulatory activity on Microcystis aeruginosa cyanobacteria than the (2R,3R)-(+)-enantiomer, whereas the latter was a more potent stimulator of Anabaena sp. growth. These observations indicate that application of the (2S,3S)-(-)-enantiomer of paclobutrazol and Microcystis aeruginosa in rice cultivation is a good strategy for improving rice seedling performance. PMID:21395310

Zhang, Anping; Xie, Xuemei; Liu, Weiping

2011-04-27

190

Turnover of dhurrin in green sorghum seedlings. [Sorghum bicolor  

SciTech Connect

The turnover of dhurrin in green seedlings of Sorghum bicolor (Linn) Moench var Redland x Greenleaf, Sudan 70 has been investigated using glyphosate and pulse-labeling studies with {sup 14}C-tyrosine and ({sup 14}C)shikimic acid. The rate of dhurrin breakdown was 4.8 nanomoles per hour in the shoot and 1.4 nanomoles per hour in the root. The rate of dhurrin accumulation in the shoot of 4- to 5-day-old seedlings was high but decreased with age until at the peak period of dhurrin accumulation, the rates of dhurrin synthesis and breakdown were equal. Using a first order equation (an approximation) the rate of dhurrin synthesis (which equals accumulation plus breakdown rates) was 17.4 nanomoles per hour in the shoot and 4.1 nanomoles per hour in the root. In both tissues, the breakdown rate was between 27 and 34% of their synthetic capacity within the experimental period. Dhurrin synthesis in green sorghum seedlings occurred in both the light and dark photoperiods but was faster in the dark period. The result is discussed in relation to the possible metabolic roles of the turnover.

Adewusi, S.R.A. (Obafemi Awolowo Univ., Ile-Ife (Nigeria))

1990-11-01

191

Organic Matter Loading Affects Lodgepole Pine Seedling Growth  

NASA Astrophysics Data System (ADS)

Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.

Wei, Xiaohua; Li, Qinglin; Waterhouse, M. J.; Armleder, H. M.

2012-06-01

192

Organic matter loading affects lodgepole pine seedling growth.  

PubMed

Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability. PMID:22476669

Wei, Xiaohua; Li, Qinglin; Waterhouse, M J; Armleder, H M

2012-06-01

193

Effects of gravel mulch on emergency of galleta grass seedlings  

SciTech Connect

Gravel mulches show promise as effective material on the US Dept. of Energy Nevada Test Site for stabilizing erosive soils and aiding plant establishment by conserving soil water. A greenhouse study was implemented to determine the effects of gravel mulch on seedling emergence and soil water, and optimal depths of gravel for various native plant species. Greenhouse flats were sown with seeds of nine species of native grasses, forbs, and shrubs. The flats were then treated with a variety of mulch treatments including, no mulch, a 1-cm layer of soil over seeds, and 2 to 3-cm and 4 to 5-cm layers of 3 to 25-mm mixed gravel. Superimposed over these treatments were 3 irrigation treatments. Seedling density data was collected daily, and soil water was monitored daily with the gravimetric method. This study showed that under a variety of soil water conditions, a 2--3 cm gravel layer may aid emergence of galleta grass. Results from this study also demonstrated that a deeper layer of gravel (4--5 cm) prohibits emergence, probably because it acts as a physical barrier to the seedlings. Galleta grass emergence can be used as a model for how other species might respond to these seedbed and irrigation treatments, provided they have adequate germination and are exposed to similar environmental conditions.

Winkel, V.K.; Medrano, J.C.; Stanley, C.; Walo, M.D.

1993-02-01

194

A Chitosan Induced 9-Lipoxygenase in Adelostemma gracillimum Seedlings  

PubMed Central

Oxylipins generated by the lipoxygenase (LOX) pathway play an important role in plant defense against biotic and abiotic stress. In chitosan-treated Adelostemma gracillimum seedlings, obvious accumulation of 9-LOX-derived oxylipins, namely 9,10,11-trihydroxy-12-octadecenoic acid, was detected. Using degenerate primers, a LOX-specific fragment putatively encoding LOX was obtained by RT-PCR, and a 2.9-kb full-length cDNA named AgLOX1 was isolated by RACE from chitosan-induced A. gracillimum seedlings. Genomic Southern analysis implied that there was only one copy of AgLOX1 in the A. gracillimum genome. AgLOX1 was expressed in Escherichia coli and the recombinant protein was partially purified. The enzyme converted linoleic and linolenic acids almost exclusively to their 9-hydroperoxides. AgLOX1 encoded a 9-lipoxygenase. Northern blot analysis indicated that chitosan-induced AgLOX1 transcript accumulation peaked at 8 h after initiation of treatment, whereas trihydroxy derivatives accumulation was highest at 24 h after elicitation. Results showed that chitosan-induced AgLOX1 encoded a 9-lipoxygenase potentially involved in the defense response through 9-LOX pathway leading to biosynthesis of antimicrobial compounds in A. gracillimum seedlings. PMID:22312270

Li, Jing; Zhao, Pei-Ji; Ma, Chang-Le; Zeng, Ying

2012-01-01

195

The significance of glucosinolates for sulfur storage in Brassicaceae seedlings  

PubMed Central

Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation. PMID:25566279

Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; De Kok, Luit J.

2014-01-01

196

Purine Synthesis and Catabolism in Soybean Seedlings 1  

PubMed Central

The ureides, allantoin and allantoic acid, are the major nitrogenous substances transported within the xylem of N2-fixing soybeans (Glycine max L. Merr. cv Amsoy 71). The ureides accumulated in the cotyledons, roots and shoots of soybean seedlings inoculated with Rhizobium or grown in the presence of 10 millimolar nitrate. The patterns of activity for uricase and allantoinase, enzymes involved in ureide synthesis, were positively correlated with the accumulation of ureides in the roots and cotyledons. Allopurinol and azaserine inhibited ureide production in 3-day-old cotyledons while no inhibition was observed in the roots. Incubation of 4-day-old seedlings with [14C]serine indicated that in the cotyledons ureides arose via de novo synthesis of purines. The source of ureides in both 3- and 4-day-old roots was probably the cotyledons. The inhibition of ureide accumulation by allopurinol but not azaserine in 8-day-old cotyledons suggested that ureides in these older cotyledons arose via nucleotide breakdown. Incubation of 8-day-old plants with [14C]serine suggested that the roots had acquired the capability to synthesize ureides via de novo synthesis of purines. These data indicate that both de novo purine synthesis and nucleotide breakdown are involved in the production of ureides in young soybean seedlings. PMID:16663743

Polayes, Deborah A.; Schubert, Karel R.

1984-01-01

197

Endophytic fungi reduce leaf-cutting ant damage to seedlings.  

PubMed

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (E(high)) or low (E(low)) densities of endophytes. The E(high) seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E(low) treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E(low) relative to E(high) seedlings and had a tendency to recruit more ants to E(low) plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

Bittleston, L S; Brockmann, F; Wcislo, W; Van Bael, S A

2011-02-23

198

Growth response of Pinus densiflora seedlings inoculated with three indigenous ectomycorrhizal fungi in combination.  

PubMed

Pinus densiflora seedlings were inoculated with three indigenous ectomycorrhizal fungi (Cenococcum geophilum, Rhizopogon roseolus and Russula densifolia) in single-, two-, and three-species treatments. After 8 months, the colonization rates of each ectomycorrhizal species, seedling growth and the nutrition were assessed in each treatment. P. densiflora seedlings inoculated with different ECM species composition showed an increase in height and basal diameter and improved seedling root and shoot nutrition concentrations compared to control treatment. Generally, combined inoculation had a more positive influence on the seedlings than the single inoculation. The three-species inoculation presented the highest growth and basal diameter and concentration of most nutrients except potassium. In conclusion, the results provided strong evidence for benefits of combined inoculation with the indigenous ectomycorrhizal fungi on P. densiflora seedlings under controlled conditions. PMID:24031742

Dalong, M; Luhe, W; Guoting, Y; Liqiang, M; Chun, L

2011-07-01

199

Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays  

NASA Technical Reports Server (NTRS)

Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

Moore, R.; McClelen, C. E.

1985-01-01

200

Effect of Simulated Acid Rain on Bursaphelenchus xylophilus Infection of Pine Seedlings  

PubMed Central

White, Scots, and Austrian 3-year-old pine seedlings were treated with conditions simulating acid rain and inoculated with the white pine specific pathotype of Bursaphelenchus xylophilus, VPSt-1. Oleoresin concentration increased slightly and carbohydrate concentration decreased in all seedlings treated with simulated acid rain (SAR). The changes were significantly increased after inoculation of SAR-treated white and Scots pine seedlings with VPSt-1. Wilting was delayed and nematode reproduction decreased in SAR-treated white pine seedlings inoculated with VPSt-1. SAR-treated Austrian pine seedlings were resistant to VPSt-1, but SAR-treated Scots pine seedlings lost tolerance to VPSt-1 and wilted 50-60 days after inoculation. PMID:19290259

Bolla, R. I.; Fitzsimmons, K.

1988-01-01

201

Survival of planted tupelo seedlings in F- and H-Area tree-kill zones  

SciTech Connect

Swamp tupelo seedlings were planted in four areas which experienced previous tree mortality at the seeplines of the F- and H-Area Seepage Basins. The sites represented a range in severity of impact and stage of recovery. Seedlings were planted in February of 1994 and followed through the first growing season in the field. Survival on all sites through the first growing season was excellent, with greater than 92% of the seedlings still alive. Most seedlings appeared healthy with few external signs of stress. The performance of the seedlings will be followed in subsequent years to determine the physical state of the soil environment on seedling growth. Hopefully, the results will indicate that artificial reforestation can begin on similarly impacted sites prior to the beginning of natural revegetation of the site.

Nelson, E.A.; Rogers, V.A.

1995-01-01

202

The Effects of Seed Mass on Germination, Seedling Emergence, and Early Seedling Growth of Eastern White Pine ( Pinus strobus L.)  

Microsoft Academic Search

Half-sib seed of several eastern white pine (Pinus strobus L.) families was used to examine seed mass effects on laboratory germination, and seedling emergence and growth under moderate\\u000a and low light (47 and 13% full sunlight) in a greenhouse. Percent germination and speed of germination under laboratory conditions\\u000a were not related to seed mass among half-sib families or multi-family seedlots

William C. Parker; Thomas L. Noland; Andrée E. Morneault

2006-01-01

203

Early postfire seed dispersal, seedling establishment and seedling mortality of Pinus coulteri (D. Don) in central coastal California, USA  

Microsoft Academic Search

Seedling recruitment in many highly serotinous populations of Pinus coulteri on California's central coast depends almost entirely on periodic, stand-replacing fire. Compared to serotinous pines of the Mediterranean Basin, little detailed information is available on the postfire demography of California closed-cone pines, including P. coulteri. In September 1996 a wildfire burned the 760-ha American Canyon Research Natural Area (RNA). Using

Mark Borchert; Matthew Johnson; David S. Schreiner; Stephen B. Vander Wall

2003-01-01

204

Analysis of phytochrome kinetics in light-grown Avena sativa L. seedlings  

Microsoft Academic Search

The phytochrome content, the rate of phytochrome accumulation after a light\\/dark transition and the rate of phytochrome destruction after a 1.5 d reaccumulation period in darkness were measured in light grown Avena sativa L. seedlings. The results using spectrophotometrical methods (Norflurazon treated seedlings) and the radio-immunoassay (RIA) (green seedlings) were almost identical. The rate of phytochrome synthesis was analysed by

K. Gottmann; E. Schäfer

1983-01-01

205

Biosynthesis of theanine (?-ethylamino- l-glutamic acid) in seedlings of Camellia sinensis  

Microsoft Academic Search

Theanine (?-glutamylethylamide) is the most abundant free amino acid in tea seedlings, and is distributed in cotyledons, shoots and roots. Theanine was synthesised from 15N-labelled (NH4)2SO4, glutamic acid and alanine and from 14C-labelled ethylamine in all parts of seedlings. When (15NH4)2SO4 was supplied to intact seedlings in liquid culture, incorporation of 15N into theanine in roots was greater than in

Wei-Wei Deng; Shinjiro Ogita; Hiroshi Ashihara

2008-01-01

206

The role of cotyledon metabolism in the establishment of quinoa ( Chenopodium quinoa ) seedlings growing under salinity  

Microsoft Academic Search

A growth chamber experiment was conducted to assess the effect of salinity on emergence, growth, water status, photosynthetic\\u000a pigments, osmolyte accumulation, and ionic content of quinoa seedlings (Chenopodium quinoa). The aim was to test the hypothesis that quinoa seedlings are well adapted to grow under salinity due to their ability to\\u000a adjust the metabolic functionality of their cotyledons. Seedlings were

Ana María C. Ruffino; Mariana Rosa; Mirna Hilal; Juan A. González; Fernando E. Prado

2010-01-01

207

Controlling herbaceous competition in pasture planted with loblolly pine seedlings. Forest Service research note  

SciTech Connect

Three treatments designed to control herbaceous vegetation competing with loblolly pine (Pinus taeda L.) seedlings planted in grazed and ungrazed pasture were tested. Effects of the treatments on seedling survival and growth during the first 3 years after planting were determined. The treatments were directed application of herbicides (glyphosate in the first 2 years and hexazinone in the third year), rotary mowing, and mulching with pine straw around individual pine seedlings.

Haywood, J.D.

1995-09-01

208

Observations on Root Disease of Container Whitebark Pine Seedlings treated with Biological Controls  

Microsoft Academic Search

I observed that whitebark pine (Pinus albicaulis Engelm. [Pinaceae]) germinants treated with biological controls, one commercially available (Trichoderma harzianum strain T-22), and the other being studied for potential efficacy (Fusarium oxysporum isolate Q12), experienced less seedling mortality caused by root disease than did a non-treated control. Seedlings treated with the biological controls and non-symptomatic seedlings in the control treatment had

R Kasten Dumroese

2008-01-01

209

Effects of ammonium and nitrate on growth and nitrogen uptake by mycorrhizal Douglas-fir seedlings  

Microsoft Academic Search

Summary In a greenhouse pot study, mycorrhizal and non-mycorrhizal Douglas-fir seedling were grown in a forest soil amended with clays and ammonium or nitrate fertilizer. Mycorrhizal seedlings grew taller, increased root and shoot dry weight more, and accumulated more nitrogen and phosphorus than non-mycorrhizal seedlings. Mycorrhizal effects were most pronounced in the nitrate treatment. Ammonium enhancement of phosphorus uptake was

Caroline S. Bledsoe; R. J. Zasoski

1983-01-01

210

Inter organ comparison of amylases and starch content in mungbean seedlings  

Microsoft Academic Search

During seedling growth of mungbean in dark, depletion of cotyledonary starch is reflected by an increase in starch content\\u000a of root and shoot. With progress of seedling growth, amylolytic activity increases in all organs i.e. cotyledons, shoots and roots. A rapid turnover of starch in shoots and roots has been proposed. Amylase activity of seedlings\\u000a was in the order of

Narinder Kaur; Prabhdeep Kaur; Anil K. Gupta

2001-01-01

211

Grazing on regeneration sites encourages pine seedling growth. Forest Service research paper (Final)  

SciTech Connect

Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the seedlings were significantly taller, with longer leaders with season-long grazing than without grazing. Treatment comparisons for plant group and non-plant percent cover differed only for litter and bare soil, but cover and composition of bottlebrush squirreltail (Elymus elymoides (Raf.) Swezey) were greater without grazing.

Ratliff, R.D.; Denton, R.G.

1995-12-31

212

Occurrence of ectomycorrhizae on ericaceous and coniferous seedlings grown in soils from the Oregon Coast Range.  

E-print Network

??Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests… (more)

Smith, Jane E. (Jane Elizabeth)

1993-01-01

213

Photosynthesis, water relations and mortality in Abies lasiocarpa seedlings during natural establishment.  

PubMed

Few studies have investigated the ecophysiology of natural seedling establishment in forest trees not associated with anthropogenic disturbance. Photosynthesis and water relations measurements were made on one- through four-year-old seedlings of Abies lasiocarpa Nutt. (subalpine fir) establishing naturally in an understory environment. First (current)-year seedlings generally had only cotyledons, whereas most second-year seedlings had both cotyledons and primary leaves. Mortality was high (> 60%) in first-year seedlings with the greatest mortality (> 90%) measured at the more open, sun-exposed sites within the understory. Seedling mortality was negligible after the first year of growth at shaded microsites and after the second year of growth at sunny microsites. Photosynthetic CO(2) uptake at light saturation was considerably lower in first-year than in fourth-year seedlings (0.6 micromol m(-2) s(-1) versus 1.7 micromol m(-2) s(-1)) and occurred at lower solar irradiance (240 micromol m(-2) s(-1) versus 600 micromol m(-2) s(-1) of photosynthetically active radiation). Differences in photosynthetic capacity were due to differences in both stomatal and non-stomatal limitations to CO(2) uptake. Carbon dioxide assimilation in first- and second-year seedlings was 28 and 29%, respectively, of the mean value measured for fourth-year seedlings. Although first-year seedlings had low transpiration rates, their water use efficiency (photosynthesis/transpiration) was less than half that of fourth-year seedlings and their water potentials were lower than those of all other age classes (0.46 mol CO(2) mmol(-1) H(2)O and -3.0 MPa, respectively). The stomatal limitation to CO(2) uptake was approximately 21% in first- and second-year seedlings, and increased to 39% in fourth-year seedlings. Intercellular CO(2) concentrations were greater in first- and second-year seedlings (255 and 250 microl l(-1), respectively) than in third- and fourth-year seedlings (203 and 186 microl l(-1), respectively). Thus, abrupt increases in water status and photosynthetic capacity after the first or second year of growth appear crucial for survival to maturity. Moreover, differences in temperature and water relations according to microsite may be major factors determining seedling establishment and, thus, the distributional and successional patterns observed for adult trees of Abies lasiocarpa. PMID:14972895

Cui, M; Smith, W K

1991-01-01

214

What do seedlings die from and what are the implications for evolution of seed size?  

E-print Network

frequency- and density-dependent mortality among seedlings estab- lishing in experimentally created gaps in calcareous grassland in Oxfordshire, England and concluded that the evidence supported the assumptions

Moles, Angela

215

Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants.  

PubMed

Common mycorrhizal networks (CMNs) influence competition between plants, but reports regarding their precise effect are conflicting. We studied CMN effects on phosphorus (P) uptake and growth of seedlings as influenced by various disruptions of network components. Tomato (Solanum lycopersicon) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of (32)P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre-established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed improved growth. Solitary seedlings growing in a network patch that had been severed from the CMN also grew much better than seedlings of the corresponding CMN. Interspecific and size-asymmetric competition between plants may be amplified rather than relaxed by CMNs that transfer P to large plants providing most carbon and render small plants P deficient. It is likely that grazing or senescence of the large plants will alleviate the network-induced suppression of seedling growth. PMID:23738787

Merrild, Marie P; Ambus, Per; Rosendahl, Søren; Jakobsen, Iver

2013-10-01

216

Ames Research Center views of Oats, Slash-Pine and Mung bean seedlings STS-3  

NASA Technical Reports Server (NTRS)

Young oat seedlings are shown in a ground laboratory after being flown into space aboard the Space Shuttle Columbia on STS-3 in March of 1982. All plants were part of the experimental Plant Growth Unit. They appear to have grown to look similar to the control seedlings on earth. A few small roots can be seen growing upward from the soil (33915); Young slash-pine seedlings are shown upon returning from the STS-3 mission (33916); Mung bean seedlings are shown after their return from space aboard the STS-3 (37917).

1982-01-01

217

Effects of ectomycorrhizae removal on survival and growth of loblolly pine seedlings with pisolithus or natural ectomycorrhizae on an upland site in South Carolina. Progress report  

SciTech Connect

This study was undertaken to ascertain the significance of mechanical loss of ectomycorrhizae formed by Pisolithus tinctorius or naturally occurring fungi encountered during lifting of nursery seedlings to the capacity of these seedlings to regenerate roots, survive, and grow. Seedlings were planted in January 1981. Seedlings with Pisolithus ectomycorrhizae formed in the nursery can tolerate more removal of ectomycorrhizae than routine nursery seedlings with natural ectomycorrhizae. However, seedlings in both ectomycorrhizal condition groups were severely impacted by removal of ectomycorrhizae. 1 table.

Marx, D.H.

1982-01-01

218

Fuel reduction at a Spanish heathland by prescribed fire and mechanical shredding: effects on seedling emergence.  

PubMed

Traditional heathland burning has declined in Spain, leading to fuel accumulation and fuel reduction treatments have become common for severe wildfire hazard reduction. These methods need to maintain the botanical composition of those shrub communities. Prescribed fire has been widely used in the past, but we need to compare mechanical fuel reduction with prescribed fire because it is easier and safer to carry out in a wide range of weather conditions. This information could be particularly useful in flammable ecosystems all over the world where traditional anthropogenic burning has declined. In this study, we compared the effects of prescribed burning and mechanical shredding on the seedling emergence and its relation to the mature vegetation in a fire-prone heathland dominated by Erica australis L. and Pterospartum tridentatum (L.) Willk., in Galicia (NW Spain). We combined a greenhouse experiment with periodic field inventories of seedling emergence. In the greenhouse study, the seedling emergence was significantly higher in the soil samples after burning (383 seedlings m(-2)) than in samples before burning (242 seedlings m(-2)). In contrast, there was no significant difference in seedling density before and after mechanical shredding (243 compared with 261 seedlings m(-2)). Also, the number of seedlings that emerged after burning was significantly higher than that emerged after mechanical shredding. The maximum temperatures at the soil organic layer surface during burning were significantly and positively related to the density of Halimium lasianthum ssp. alyssoides and P. tridentatum seedlings. In the field study, the observed seedling density was very low both after prescribed burning and mechanical shredding. There was a high degree of similarity between emerged seedlings and mature vegetation in both the treated and in the untreated soils, which was probably a consequence of the dominance of resprouting species. Some consequences for the management of these shrublands are also discussed. PMID:24036096

Fernández, Cristina; Vega, José A; Fonturbel, Teresa

2013-11-15

219

Following isotopes in pulse-chase enriched aspen seedlings  

NASA Astrophysics Data System (ADS)

One method to quantitatively trace biogeochemical fluxes through ecosystems, such as organic matter decomposition, is to use plant material enriched with stable isotopes. However, as plant macromolecules are known to vary in their rate of formation and decomposition, both the enrichment levels and the location of enrichment within the plant material should be characterized prior to decomposition and tracing studies. Aspen (Populus tremuloides Michx.) is a common tree species with a diverse organic matter chemical structure found in the western Canadian boreal forest. This study used a multi pulse and multi chase enrichment of stable isotopes (15N and 13C) on aspen seedlings to determine the seedling enrichment, isotope movement among plant tissues and translocation of isotopes within plant macromolecules e.g., carbohydrates and lignin. As expected, all tissues experienced increased enrichment with multiple pulses. An initial enrichment with 13C was observed in the leaves followed by translocation to the stems and roots while the 15N moved upward from the roots to leaves. The macromolecular chemistry of the organic carbon was further characterized using 13C solid state nuclear magnetic resonance spectroscopy. After the initial two hour chase period enrichment of the O-alkyl type (carbohydrate) carbon within the leaves was identified, followed by redistribution to more complex carbon compounds after the one week chase period. Root and stem tissues did not show the same pattern. Rather, changes in 13C enrichment were observed in shifting ethyl and methyl alkyl (lipid) carbon peak intensities for the stem samples while roots did not preferentially allocate 13C to a specific macromolecule. These results confirm that stable isotope enrichment of plants was non-uniform across macromolecules and tissue types. Enrichment of aspen seedlings was therefore dependant on the pulse-chase sequence used.

Norris, C. E.; Wasylishen, R. E.; Landhäusser, S.; Quideau, S. A.

2011-12-01

220

Physiological and transplanting performance of Quercus ilex L. (holm oak) seedlings grown in nurseries with different winter conditions  

E-print Network

Physiological and transplanting performance of Quercus ilex L. (holm oak) seedlings grown winter conditions affected cold hardiness and other functional attributes relevant for transplanting have higher stress resistance, vigour, and transplanting performance than the seedlings cultivated

Villar-Salvador, Pedro

221

Water transfer via ectomycorrhizal fungal hyphae to conifer seedlings.  

PubMed

Little is known about water transfer via mycorrhizal hyphae to plants, despite its potential importance in seedling establishment and plant community development, especially in arid environments. Therefore, this process was investigated in the study reported in this paper in laboratory-based tripartite mesocosms containing the shrub Arctostaphylos viscida (manzanita) and young seedlings of sugar pine (Pinus lambertiana) and Douglas-fir (Pseudotsuga menziesii). The objectives were to determine whether water could be transported through mycorrhizal symbionts shared by establishing conifers and A. viscida and to compare the results obtained using two tracers: the stable isotope deuterium and the dye lucifer yellow carbohydrazide. Water containing the tracers was added to the central compartment containing single manzanita shrubs. The fungal hyphae were then collected as well as plant roots from coniferous seedlings in the other two compartments to determine whether water was transferred via fungal hyphae. In addition, the length of the hyphae and degree of mycorrhizal colonisation were determined. Internal transcribed spacer-restriction fragment length polymorphism (ITS-RFLP) analysis was used to identify the fungal species involved in dye (water) transfer. Results of the stable isotope analysis showed that water is transferred via mycorrhizal hyphae, but isotopically labelled water was only detected in Douglas-fir roots, not in sugar pine roots. In contrast, the fluorescent dye was transported via mycorrhizal hyphae to both Douglas-fir and sugar pine seedlings. Only 1 of 15 fungal morphotypes (identified as Atheliaceae) growing in the mesocosms transferred the dye. Differences were detected in the water transfer patterns indicated by the deuterium and fluorescent dye tracers, suggesting that the two labels are transported by different mechanisms in the same hyphae and/or that different fungal taxa transfer them via different routes to host plants. We conclude that both tracers can provide information on resource transfer between fungi and plants, but we cannot be sure that the dye transfer data provide accurate indications of water transfer rates and patterns. The isotopic tracer provides more direct indications of water movement and is therefore more suitable than the dye for studying water relations of plants and their associated mycorrhizal fungi. PMID:17333298

Plamboeck, Agneta H; Dawson, Todd E; Egerton-Warburton, Louise M; North, Malcolm; Bruns, Thomas D; Querejeta, José Ignacio

2007-07-01

222

Diamine oxidase of Lathyrus sativus seedlings. Purification and properties  

Microsoft Academic Search

Diamine oxidase (EC 1.4.3.6) was purified from 5-day-old etiolated seedlings ofLathyrus sativus by MnCl2 treatment, (NH4)2SO4 and acetone fractionations, DEAE-Sephadex chromatography followed by gel filtration on Sephadex G-200. A single step purification\\u000a of the enzyme was achieved by using an immunoaffinity column, wherein rabbit antibodies to the homogeneous diamine oxidase\\u000a were coupled to CNBr-activated Sepharose. The enzyme thus obtained was

M. R. Suresh; P. R. Adiga

1979-01-01

223

Characterization of Rhizoctonia isolates associated with damping-off and crown rot of rooibos seedlings  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia species were reported to be an important component of the complex involved in damping-off of rooibos (Aspalathus linearis) seedlings and cause severe crown rot of seedlings in nurseries. However, no information is available on the anastomosis groups (AGs) of Rhizoctonia associated with d...

224

Interaction between a Dark Septate Endophytic Isolate from Dendrobium sp. and Roots of D. nobile Seedlings  

Microsoft Academic Search

Interactions between an isolate of dark septate endophytes (DSE) and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subtropical forest. The fungus formed typical orchid mycorrhiza in aseptic co-culture with D. nobile seedlings on modified Murashige-Skoog (MMS) medium. Anatomic observations of the infected roots showed that

Xiao-Qiang Hou; Shun-Xing Guo

2009-01-01

225

Field tests of denatonium benzoate to reduce seedling damage by pocket gophers ( Thomomys talpoides Rich.)  

Microsoft Academic Search

The repellency of a bitter compound, denatonium benzoate, to reduce pocket gopher damage to conifer seedlings was tested in two independent field trials in Oregon and Idaho. In the Oregon trial (1992 to 1993), treatments included a denatonium benzoate tablet placed in-ground with the seedling roots; a tablet plus denatonium benzoate foliar spray applied to both roots and foliage; and

Gary W. Witmer; Michael J. Pipas; John C. Bucher

1998-01-01

226

Carbohydrate storage enhances seedling shade and stress tolerance in a neotropical forest  

Microsoft Academic Search

Summary 1 To survive in forest understoreys, seedlings must depend on carbohydrate reserves when they experience negative carbon balance imposed by occasional light reduction and tissue loss to herbivores and diseases. We present the first experimental evidence in support of this hypothesis, using seven woody neotropical species. 2 We transplanted seedlings that had recently expanded their first photosynthetic cotyledon or

JONATHAN A. MYERS; KAORU KITAJIMA

2007-01-01

227

Seed Germination and Seedling Emergence of Three Annuals Growing on Desert Sand Dunes in China  

Microsoft Academic Search

? Background and Aims Information on the initial growth characteristics of annuals found in Chinese deserts is very limited. The aim of this study was to investigate seed germination and interactive effects of irrigation and seed burial depth in sand on seedling emergence and seedling survival in three annuals (Agriophyllum squarrosum, Bassia dasyphylla and Aristida adscensionis) commonly growing on sand

KAZUO T OBE; L IPING Z HANG

228

Seed Germination and Seedling Emergence of Three Annuals Growing on Desert Sand Dunes in China  

Microsoft Academic Search

? Background and Aims Information on the initial growth characteristics of annuals found in Chinese deserts is very limited. The aim of this study was to investigate seed germination and interactive effects of irrigation and seed burial depth in sand on seedling emergence and seedling survival in three annuals (Agriophyllum squarrosum, Bassia dasyphylla and Aristida adscensionis) commonly growing on sand

KAZUO TOBE; LIPING ZHANG; KENJI OMASA

2005-01-01

229

Earthworm-mediated maternal effects on seed germination and seedling growth in three annual plants  

Microsoft Academic Search

Many ecological studies have pointed out maternal effects in plants and shown that plant maternal environment influences germination of their seed and subsequent seedling growth. However, few have tested for maternal effects induced by soil macroorganisms. We tested whether two earthworm species (Aporrectodea caliginosa and Lumbricus terrestris) trigger such maternal effects on seed germination and seedling growth of three plant

Kam-Rigne Laossi; Diana-Cristina Noguera; Sébastien Barot

2010-01-01

230

Seedling occurrence in alpine treeline conifers: A case study from the central Rocky Mountains, USA  

Microsoft Academic Search

Information concerning the occurrence of very young (1- to 10-year-old) tree seedlings in the alpine treeline ecotone is rare. Seedling occurrence of the dominant conifers Picea engelmannii and Abies lasiocarpa was measured in the treeline ecotone of the Medicine Bow Mountains, Wyoming (central Rocky Mountains, USA), an area composed of elongated tree islands separated by open meadows (ribbon forest) that

Stephan Hättenschwiler; William K. Smith

1999-01-01

231

Prediction of Leaf Area in Individual Leaves of Cherrybark Oak Seedlings (Quercus pagoda Raf.)  

Microsoft Academic Search

The prediction of leaf area for cherrybark oak (eerm pagoda Raf.) seedlings is important for studying the physiology of the species. Linear and polynomial models involving leaf length, width, fresh weight, dry weight, and internodal length were tested independently and collectively to predict leaf area. Twenty-nine cherrybark oak seedlings were grown in a greenhouse for one growing season and a

Yanfei Guo; Brian Lockhart; John Hodges

232

Potential Impact of Climatic Change on Tropical Rain Forest Seedlings and Forest Regeneration  

Microsoft Academic Search

Tropical rain forests are dynamic and continually regenerating by growth of seedlings up from the forest floor into canopy gaps that form on a cycle of usually a century of more in length. Changes in seedling establishment, survival, and release in gaps could thus change canopy species composition for a long time. Of likely climatic changes, evidence is presented that

T. C. Whitmore

1998-01-01

233

Conifer seedling distribution and survival in an alpine-treeline ecotone  

Microsoft Academic Search

The importance of seedling establishment to the position ofalpine-treeline is recognized, yet little is known about factorsaffecting the survival of seedlings of treeline conifers during their initialyears of growth and establishment. This establishment period may have thegreatest mortality of all life stages until death of mature trees by disease orfire. Spatial and temporal patterns in the distribution and survival ofseedlings

Matthew J. Germino; William K. Smith; A. Catherine Resor

2002-01-01

234

A TEST OF MUTUAL AID IN COMMON MYCORRHIZAL NETWORKS: ESTABLISHED VEGETATION NEGATES BENEFIT IN SEEDLINGS  

Microsoft Academic Search

By acquiring symbiosis from the mycelium supported by neighboring plants, seedlings become connected to a common mycorrhizal network (CMN). Although the main- tenance of a CMN may lead to mutual benefit among the neighboring plants, the benefits may be unequally distributed if the plants differ in their sink strength for the shared resources in the CMN. Hence, seedlings may not

M.-M. Kytöviita; M. Vestberg; J. Tuomi

2003-01-01

235

Contribution of cotyledons to seedling dry weight and development in Medicago falcata L  

Microsoft Academic Search

Three experiments are reported, two of which involved cotyledon excision, to elucidate seedling developmental strategy of a North China rangeland legume, Medicago falcata. Early loss of cotyledons was fatal, with data indicating a possible hormonal?type signal from cotyledons to initiate first leaf expansion. Cotyledons made a substantive photosynthetic contribution for some 28 days from imbibition, but high seedling relative growth

Hongxiang Zhang; Yi Wu; Cory Matthew; Daowei Zhou; Ping Wang

2008-01-01

236

Arrested succession in logging gaps: is tree seedling growth and survival limiting?  

Microsoft Academic Search

Thirty years after selective timber harvest in the Kibale National Park, Uganda, many abandoned logging gaps are dominated by Acanthus pubescens, and show little forest recovery. To examine if this arrested successional state was caused by limited tree seedling growth and survival, we planted seedlings of four forest tree species (Albizia gran- dibracteata, Mimusops bagshawei, Prunus africana and Uvariopsis congensis

John R. Paul; April M. Randle; Colin A. Chapman; Lauren J. Chapman

2004-01-01

237

Osmoregulation, solute distribution, and growth in soybean seedlings having low water potentials  

Microsoft Academic Search

Soybean (Glycine max (L.) Merr.) seedlings osmoregulate when the supply of water is limited around the roots. The osmoregulation involves solute accumulation (osmotic adjustment) by the elongating region of the hypocotyls. We investigated the relationship between growth, solute accumulation, and the partitioning of solutes during osmoregulation. Darkgrown seedlings were transplanted to vermiculite containing 1\\/8 (0.13 x) the water of the

R. F. Meyer; J. S. Boyer

1981-01-01

238

ANATOMY OF THE SEED AND SEEDLING OF SPARTINA ALTERNIFLORA LOIS (POACEAE)  

EPA Science Inventory

Members of the genus Spartina are dominant macrophytes in many salt marshes of North and South America, Europe, and Africa. Although the genus is of great ecological importance, seeds and seedlings of its 16 species have not been described. he seed and seedling of an American spe...

239

Fall fertilization enhanced nitrogen storage and translocation in Larix olgensis seedlings  

E-print Network

loading of deciduous forest nursery seedlings is of special interest because of foliage abscission use efficiency Á Deciduous forest seedling Á Nitrogen storage Á Nutrient translocation Introduction and varied translocation patterns. For non-deciduous seed- lings in the nursery, fall fertilization typically

240

Study on substrates selection for container seedling breeding of Platycladus orientalis  

Microsoft Academic Search

Using peat, straw powder, organic fertilizer, sand, perlite and vermiculite as substrate materials, mixed with dif- ferent proportions to make different substrate formulations, this paper studied substrates selection for con- tainer-grow-seedling breeding of Platycladus orientalis ac- cording to the test of the seedling's growth performance and physical properties of different substrates. The result showed that the emergence rate of young

Bing Cao; Jianan Hou; Lihua Song

2011-01-01

241

Photosynthesis and leaf longevity in alder, birch and ash seedlings grown under different nitrogen levels  

E-print Network

photosynthetic rates and leaf longevity of deciduous broad-leaved tree seedlings in relation to the anatomicalPhotosynthesis and leaf longevity in alder, birch and ash seedlings grown under different nitrogen regulated strictly with an artificially illumi- nated chamber (Koike, 1987). Leaf temperature was kept

Paris-Sud XI, Université de

242

OIKOS 98: 385392, 2002 Herbivory on Acacia seedlings in an East African savanna  

E-print Network

OIKOS 98: 385­392, 2002 Herbivory on Acacia seedlings in an East African savanna Margaret T. Shaw on Acacia seedlings in an East African savanna. ­ Oikos 98: 385­392. Trees critically affect the functioning of savanna ecosystems through their effects on nutrient cycling, water availability, and patterns of space

243

The effect of light on metabolism of IAA in maize seedlings  

Microsoft Academic Search

Carbon 14-labelled indole-3-acetic acid (IAA) was fed to segments of shoots of Zea mays seedlings grown in light or dark to find the effect of light on IAA metabolism. The seedling parts coleoptile, with enclosed leaf, and mesocotyl were also used to examine differences in IAA metabolism between tissue types. The rate of metabolite formation as a function of time

Eva Zelená

2000-01-01

244

-Establishment of Norway spruce seedlings -681 Journal of Vegetation Science 7: 681-684, 1996  

E-print Network

- Establishment of Norway spruce seedlings - 681 Journal of Vegetation Science 7: 681-684, 1996 abandoned for half a century and are sur- rounded by Picea abies (Norway spruce) forests. The causes of inhibition of establishment of Norway spruce seedlings in the meadows were tested experimentally

Leps, Jan "Suspa"

245

Integration of light and abscisic acid signaling during seed germination and early seedling development  

E-print Network

Integration of light and abscisic acid signaling during seed germination and early seedling, The Netherlands, and approved January 31, 2008 (received for review November 13, 2007) Seed germination (ABA) both regulate seed germination and seedling development, although how light and ABA signals

Deng, Xing-Wang

246

Testing low-quality urban composts for agriculture: germination and seedling performance of plants  

Microsoft Academic Search

Two urban composts, one very coarse, low in organic matter but mature, and the other particulated, high in organic matter but not well stabilized, were tested. Germination ‘in vitro’ and in soil of cress, ryegrass and sunflower seeds, seedling performance (root, shoot and sheath lengths) and seedling composition (in soil) of ryegrass were evaluated. Other organic composts, including a vermi-compost,

J. M. Murillo; F. Cabrera; R. López; P. Martín-Olmedo

1995-01-01

247

Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil  

PubMed Central

Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an “ashbed effect”). PMID:25339968

Tng, David Y. P.; Janos, David P.; Jordan, Gregory J.; Weber, Ellen; Bowman, David M. J. S.

2014-01-01

248

Growth response and nutrient utilization of Casuarina equisetifolia seedlings inoculated with bioinoculants under tropical nursery conditions  

Microsoft Academic Search

We investigated the role of tetrapartite associations between an arbuscular mycorrhizal (AM) fungus (Glomus geosporum), phosphate solubilizing bacteria (Paenibacillus polymyxa), Frankia and Casuarina equisetifolia on growth, nutrient acquisition, nutrient utilization and seedling quality of C. equisetifolia. Seedlings of C. equisetifolia were grown in an Alfisol soil and inoculated with G. geosporum, P. polymyxa and Frankia either individually or in combinations.

Thangavelu Muthukumar; Karuthamuthu Udaiyan

2010-01-01

249

Phenotypic plasticity in seedling defense strategies: compensatory growth and chemical induction  

Microsoft Academic Search

Phenotypic plasticity in growth (leading to compensation) and secondary chemical production (leading to induction) in response to herbivory are key defense strategies in adult plants, but their role in seedling defense remains unclear. A pair of greenhouse studies was conducted to investigate compensation and induction in seedlings and juvenile plants, using Plantago lanceolata (Plantaginaceae) and the specialist buckeye caterpillar Junonia

Kasey E. Barton

2008-01-01

250

Effects of slug herbivory on the seedling establishment of two montane Asteraceae species  

Microsoft Academic Search

Seedling establishment as the life stage transition most sensitive to herbivory might be impossible even if the herbivory losses suffered by adult plants of the same species are tolerable. We tested the hypothesis that herbivory impedes seedling establishment of two montane Asteraceae species on their lower altitudinal distribution border.In a submontane meadow in the Harz Mountains, Germany, the montane grassland

Ulrich Scheidel; Helge Bruelheide

2005-01-01

251

Impact of seed and seedling predation by small rodents on early regeneration establishment of black spruce  

Microsoft Academic Search

Black spruce (Picea mariana (Mill.) BSP) postdispersal seed and juvenile seedling predation by small ro- dents (Peromyscus maniculatus (Wagner), Clethrionomys gapperi (Vigor), and Phenacomys intermedius (Merriam)) was assessed in three boreal habitats over a 2-year period using an extensive exclosure-control experiment. Small rodent relative abundance was measured during six periods using snap trapping. We found that seed and juvenile seedling

Mathieu Côté; Jean Ferron; Réjean Gagnon

2003-01-01

252

Influence of soil mixing and sterilization on growth and nutrient uptake of black walnut seedlings  

Microsoft Academic Search

The effects of soil mixing (disturbance) and sterilization on nutrient solubility and uptake, and on growth of potted black walnut seedlings in forest and field soils were studied under glasshouse conditions. Seedlings were grown for 16 weeks in soils that were either disturbed or undisturbed only, and in combination with two methods of sterilization.Both pre? and post?harvest soil data showed

Felix Ponder Jr

1981-01-01

253

Variation among black walnut seedling families in resistance to competition and allelopathy  

Microsoft Academic Search

Summary Of three environmental variables affecting black walnut seedling establishment, moisture stress overshadowed the effects of fescue leachate and fertilizer. Interactions between moisture stress and family and between fescue leachate and moisture stress for both seedling height and dry weight suggested that selection for tolerance to moisture stress is possible, whereas progress from selecting for resistance to fescue leachate would

George Rink; J. W. VAN SAMBEEK

1985-01-01

254

Association with mature plants protects seedlings from predation in an arid grassland shrub, Gutierrezia microcephala  

Microsoft Academic Search

Survivorship of Gutierrezia microcephala (Compositae) seedlings was studied in an undisturbed arid grassland and in experimental plots where various components of the natural vegetation were removed following seed germination. The major causes of seedling mortality were herbivore damage from the specialist grasshopper, Hesperotettix viridis, and drought stress associated with competition from established plants. The relative intensity of these mortality factors

Matthew A. Parker

1982-01-01

255

Release of naturally established white pine seedlings from competition: An objective field index  

Microsoft Academic Search

Gap cutting has been recently prescribed in Quebec to favor the regeneration of midtolerant species such as white pine. However, this new practice may lead to increased competition, jeopardizing the survival of established seedlings. One important question, therefore, is how much care will be required to ensure that the seedlings will reach the sapling stage. More importantly, a practical field

P. a Nolet; D. a Bouffard; F.a b Lorenzetti

2006-01-01

256

Energy biomass tree seedling production study. Fuels from woody biomass. Progress report, September 1978-January 1980  

SciTech Connect

The research to date has centered around the establishment of baseline growing conditions for a number of species of tree seedlings, primarily deciduous hardwoods. As these baseline conditions were established for each specie, the shoot and root environments were manipulated in an attempt to establish techniques to increase seedling growth and reduce production times. Seedlings were outplanted in an attempt to establish baseline survival rates for seedlings grown in totally controlled environments. Studies to determine the optimum container for tree seedling production have been run and will continue as other containers are identified and made available. The most significant of the research results has been in the maximization of seedling growth. Seedling production times have been decreased in some species by as much as 50% under the baseline production times. Controlled environment production techniques provide for plant densities as high as 144 seedlings per square foot of growing space. Investigations of growing media indicate a significant species specific responses. Preliminary results of outplanting indicate survival rates as high as 90% plus.

Foote, K.R.

1980-03-01

257

Influence of paclobutrazol on water consumption and plant performance of Arbutus unedo seedlings  

Microsoft Academic Search

The purpose of this study was to examine the effect of paclobutrazol on the water consumption, plant water relations, gas exchange and development of strawberry tree seedlings (Arbutus unedo L.), to evaluate water resource management. Seedlings (8cm in height) were subjected to a single drench of 60 or 100mg of paclobutrazol and pot-grown in a greenhouse for 4 months. Untreated

Alejandra Navarro; M Sánchez-Blanco; Sebastián Bañon

2007-01-01

258

Salt stress limitation of seedling recruitment in a salt marsh plant community  

Microsoft Academic Search

Seedling recruitment in salt marsh plant communities is generally precluded in dense vegetation by competition from adults, but is also relatively rare in disturbance-generated bare space. We examined the constraints on seedling recruitment in New England salt marsh bare patches. Under typical bare patch conditions seed germination is severely limited by high substrate salinities. We examined the germination requirements of

Scott W. Shumway; Mark D. Bertness

1992-01-01

259

Fungus gnat feeding and mechanical wounding inhibit Pythium aphanidermatum infection of geranium seedlings.  

PubMed

ABSTRACT A series of laboratory tests were conducted to investigate potential effects of fungus gnat (Bradysia impatiens) feeding damage on susceptibility of geranium seedlings (Pelargonium x hortorum) to infection by the root rot pathogen Pythium aphanidermatum. Effects were compared with those from similar tests in which the seedlings were mechanically wounded by severing the root tip with a scalpel. Assays of geranium seedlings in petri dishes revealed a pronounced negative fungus gnat-Pythium interaction, with exposure to fungus gnat larvae 24 h prior to inoculation with P. aphanidermatum zoospores resulting in up to 47% fewer seedling deaths than would have been expected if the two agents had acted independently. Similar results were observed when seedlings were subjected to mechanical wounding 24 h prior to zoospore inoculation. In contrast, no interaction occurred when seedlings were mechanically wounded immediately prior to inoculation. The degree of plant damage inflicted by the feeding activities of the larval fungus gnats had no significant effect on the combined damage from fungus gnats and Pythium in petri dishes. Ancillary studies showed that Pythium development on V8 agar was not inhibited by the presence of fungus gnat-associated microorganisms, nor were seedlings inoculated with these microbes less susceptible to Pythium infection. The precise mechaism or mechanisms underlying the observed interactions were not elucidated; however, the results strongly suggest that both fungus gnat feeding and mechanical wounding activated systemic defenses that made the seedlings more resistant to Pythium infection. PMID:19900009

Braun, S E; Sanderson, J P; Nelson, E B; Daughtrey, M L; Wraight, S P

2009-12-01

260

Oak Seedling Establishment in Relation to Environmental Factors at Annadel State Park1  

E-print Network

Oak Seedling Establishment in Relation to Environmental Factors at Annadel State Park1 Stephen J. Barnhart Joe R. McBride Peter Warner2 Abstract: As part of an ongoing study of oak ecology in Sonoma County, California, we have begun to evaluate various environmental factors relative to oak seedling establishment

Standiford, Richard B.

261

Seedling recruitment of Chamaecyparis obtusa and Sciadopitys verticillata in different microenvironments in an old-growth Sciadopitys verticillata forest  

Microsoft Academic Search

Seedling recruitment ofChamecyparis obtusa andSciadopitys verticillata in different microenvironments in an old-growthS. verticillata forest was studied for five years. Exposed mineral soil beneath a gap, which was newly created by a typhoon, supported the\\u000a best seedling emergence forC. obtusa. S. verticillata seemed to require no specific microenvironment for its seedling emergence. Mortality of seedlings was higher for both species\\u000a beneath

Shin-Ichi Yamamoto

1988-01-01

262

Colonization with Hebeloma crustuliniforme increases water conductance and limits shoot sodium uptake in white spruce ( Picea glauca ) seedlings  

Microsoft Academic Search

White spruce [Picea glauca (Moench) Voss] seedlings were inoculated with Hebeloma crustuliniforme and treated with 25 mM NaCl to examine the effects of salinized soil and mycorrhizae on root hydraulic conductance and growth. Mycorrhizal seedlings had significantly greater shoot and root dry weights, number of lateral branches and chlorophyll content than non-mycorrhizal seedlings. Salt treatment reduced seedling growth in both

Tawfik M. Muhsin; Janusz J. Zwiazek

2002-01-01

263

Seedling Populations Produced by Colored-leaf Genotypes of Japanese Barberry (Berberis thunbergii DC.) Contain Seedlings with Green Leaf Phenotype1  

Microsoft Academic Search

The leaf color of seedling populations derived from ornamental genotypes of Japanese barberry ( Berberis thunbergii DC.) was evaluated to determine whether nursery selections of this important landscape plant could be expected to produce green-leaf progeny or seedlings with leaf color resembling the purple-leaf or yellow-leaf parent. This is a compelling inquiry since nearly all B. thunbergii plants found within

Jonathan M. Lehrer; Mark H. Brand; Jessica D. Lubell

2006-01-01

264

Forty years of inoculating seedlings with truffle fungi: past and future perspectives.  

PubMed

The first commercialization of seedlings inoculated with truffle fungi occurred in 1973. Over the last 40 years, considerable progress has been made relative to quality control for inoculated seedlings. A recently published paper by Andrés-Alpuente and colleagues (Mycorrhiza 24:29-37, 2014) reviewed and tested the different methods of mycorrhization assessment currently used in Europe. The aim of this paper is to augment their findings by adding information to the discussion about the most important steps in seedling quality control. Additionally, the history of seedlings inoculated with truffles, procedures currently used in France for seedling control quality, and a reflection on future research aimed at increasing truffle production will be presented. PMID:24989673

Murat, Claude

2015-01-01

265

An elicitor in caterpillar oral secretions that induces corn seedlings to emit chemical signals attractive to parasitic wasps  

Microsoft Academic Search

Regurgitate of corn-fed beet armyworm (BAW) caterpillars,Spodoptera exigua, when applied to damaged sites of corn (Zea mays) seedlings, causes the release of relatively large amounts of terpenes by the seedlings several hours later. This plant response could be induced by merely placing the cut stem of seedlings in a solution of BAW regurgitate for 12 hr, a response that could

Ted C. J. Turlings; Philip J. McCall; Hans T. Alborn; James H. Tumlinson

1993-01-01

266

Microclimate, freezing tolerance, and cold acclimation along an elevation gradient for seedlings of the Great Basin Desert shrub, Artemisia tridentata  

Microsoft Academic Search

Vegetation, microclimate, seedling frequency, freezing tolerance, and cold acclimation were compared for seedlings of Artemisia tridentata collected from 1775, 2175, and 2575 m elevation in the eastern Sierra Nevada, California. Data were used to test the hypothesis that ecotypic differences in stress physiology are important for seedling survival along gradients from desert to montane ecosystems. The vegetation canopy cover and

Michael E Loik; Sean P Redar

2003-01-01

267

Root dipping of conifer seedlings shows little benefit in the northern Rocky Mountains. Forest Service research paper  

SciTech Connect

In the growth chamber, in the greenhouse, and in field studies, root dipping of bareroot lodgepole pine, ponderosa pine, Douglas-fir, and Engelmann spruce seedlings did not improve seedling survival, shoot growth, or root growth under dry soil conditions. Seedling root growth varied with tree species, soil type, and type of rood dip.

Sloan, J.P.

1994-07-01

268

Identification of Calonectria colhounii Associated with Basal Stem Rot on Blueberry Seedlings Imported from the United States of America  

PubMed Central

Basal stem rot symptoms were found on blueberry seedlings imported from the United States of America in 2008. The fungus obtained from the diseased seedlings was identified as Calonectria colhounii based on morphological and molecular characteristics. The consignments of the blueberry seedlings infected with C. colhounii were destroyed to prevent introduction of the fungus to Korea. PMID:23956678

Jeon, Nak Beom; Kim, Wan Gyu; Park, Myung Soo; Hyun, Ik-Hwa; Heo, Noh-Youl

2010-01-01

269

[Effects of waterlogging on ecophysiological characteristics of Salix variegate seedlings].  

PubMed

Salix variegate, a widely distributed species along the riverbank in Three Gorges Reservoir area, plays an important role in soil conservation and riverbank stabilization. Waterlogging from April to May was simulated in 2006 to test the adapting ability and mechanism of S. variegate seedlings to water environment change resulted from the construction of Three Gorges Project. The results showed that under waterlogging, all of the S. variegate seedlings could survive, but their maximum photosynthesis (Pmax), transpiration rate (Tr), water use efficiency (WUE), and stomatal conductance (Gs) decreased significantly with the prolongation of waterlogging. In the early period of waterlogging (20 days), these indices changed little, with the Pmax and Tr decreased by 18.5% and 2.2%, respectively, compared with the control. After 30 days, Pmax and Tr decreased by 53.4% and 23.7%, respectively, and then, kept stable. The contents of chlorophyll and carotenoid and their ratio decreased significantly with the prolongation of waterlogging, while the ratio of chlorophyll a to b increased significantly. The ratio of chlorophyll to carotenoid ranged in 4.873-6.883, and that of chlorophyll a to b ranged in 2.855-3.912. Adventitious roots were developed after waterlogging, which would benefit the oxygen supply for the plants. It was suggested that S. variegate had good adaptability to waterlogging, and could be used as a pioneer species in the restoration of degraded water-level fluctuation zone. PMID:18808013

Chen, Fang-Qing; Guo, Cheng-Yuan; Wang, Chuan-Hua; Xu, Wen-Nian; Fan, Da-Yong; Xie, Zong-Qiang

2008-06-01

270

Insecticides and arable weeds: effects on germination and seedling growth.  

PubMed

The decline of many arable weed species in Northern Europe has been attributed to the intensification of modern agriculture and in particular, increasing pesticide use. In this study, we examined the effect of two insecticides, dimethoate and deltamethrin, on the germination and seedling growth of six arable weed species. Although germination was unaffected by insecticide application, seedling growth of four species was decreased by exposure to deltamethrin (Capsella bursa-pastoris and Poa annua), dimethoate (Agrostemma githago), or by both insecticides together (Urtica urens). While increased herbicide use, seed cleaning, and changing sowing times may be of primary importance in explaining the reduction of northern Europe's arable weed flora, our results indicate that insecticide use may also be a contributory factor. Moreover, those species that exhibit apparent tolerance of the insecticides tested, particularly the grass Avena fatua, may benefit from continued insecticide use. The ability to tolerate these agrochemicals, in tandem with reduced herbivory and competition from plants, whose growth is reduced by insecticide application, is likely to confer a significant competitive advantage on insecticide-resistant weed species. PMID:16385742

Hanley, M E; Whiting, M D

2005-05-01

271

Mycorrhizal effects on potassium fluxes by northwest coniferous seedlings.  

PubMed

In ectomycorrhizae, the relative abilities of mycobiont and host plant to take up and store inorganic nutrients are not easily determined due to the intimate physical relationship of the two components forming the association. Since compartmental analysis of solute elution can estimate cellular compartment pool sizes and unidirectional fluxes across membranes, we have used this method to study ectomycorrhizal coniferous roots. Rubidium-86, used as a tracer for potassium, was loaded into and eluted from intact roots of nonmycorrhizal and mycorrhizal (with the fungus Hebeloma crustuliniformme [Bull.: St. Amans Quél] Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), western hemlock (Tsuga heterophylla [Raf.] Sarg.) and Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings.Mycorrhizas significantly increased (86)Rb uptake rates while decreasing the amount of (86)Rb released to the external solution. Using compartmental analysis, the flux data suggest that the primary mycorrhizal effects were to increase inward potassium fluxes across the fungal tonoplast and to decrease potassium efflux across the fungal tonoplast, as compared with nonmycorrhizal seedling roots. The result was greater potassium storage, presumably in the fungal vacuole. The three coniferous species responded differently to fungal infection with respect to potassium fluxes. Both cytoplasmic and vacuolar fluxes for mycorrhizal hemlock were 2-fold greater than for spruce and 3-fold greater than for Douglas fir. These results demonstrate the usefulness of compartmental analysis for study of ion fluxes in intact mycorrhizal root systems and suggest that the fungal tonoplast may be the site for regulation of potassium fluxes in these coniferous roots. PMID:16663971

Rygiewicz, P T; Bledsoe, C S

1984-12-01

272

Mycorrhizal Effects on Potassium Fluxes by Northwest Coniferous Seedlings 1  

PubMed Central

In ectomycorrhizae, the relative abilities of mycobiont and host plant to take up and store inorganic nutrients are not easily determined due to the intimate physical relationship of the two components forming the association. Since compartmental analysis of solute elution can estimate cellular compartment pool sizes and unidirectional fluxes across membranes, we have used this method to study ectomycorrhizal coniferous roots. Rubidium-86, used as a tracer for potassium, was loaded into and eluted from intact roots of nonmycorrhizal and mycorrhizal (with the fungus Hebeloma crustuliniformme [Bull.: St. Amans Quél] Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), western hemlock (Tsuga heterophylla [Raf.] Sarg.) and Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings. Mycorrhizas significantly increased 86Rb uptake rates while decreasing the amount of 86Rb released to the external solution. Using compartmental analysis, the flux data suggest that the primary mycorrhizal effects were to increase inward potassium fluxes across the fungal tonoplast and to decrease potassium efflux across the fungal tonoplast, as compared with nonmycorrhizal seedling roots. The result was greater potassium storage, presumably in the fungal vacuole. The three coniferous species responded differently to fungal infection with respect to potassium fluxes. Both cytoplasmic and vacuolar fluxes for mycorrhizal hemlock were 2-fold greater than for spruce and 3-fold greater than for Douglas fir. These results demonstrate the usefulness of compartmental analysis for study of ion fluxes in intact mycorrhizal root systems and suggest that the fungal tonoplast may be the site for regulation of potassium fluxes in these coniferous roots. PMID:16663971

Rygiewicz, Paul T.; Bledsoe, Caroline S.

1984-01-01

273

Dynamic hydrolase activities precede hypersensitive tissue collapse in tomato seedlings.  

PubMed

Hydrolases such as subtilases, vacuolar processing enzymes (VPEs) and the proteasome play important roles during plant programmed cell death (PCD). We investigated hydrolase activities during PCD using activity-based protein profiling (ABPP), which displays the active proteome using probes that react covalently with the active site of proteins. We employed tomato (Solanum lycopersicum) seedlings undergoing synchronized hypersensitive cell death by co-expressing the avirulence protein Avr4 from Cladosporium fulvum and the tomato resistance protein Cf-4. Cell death is blocked in seedlings grown at high temperature and humidity, and is synchronously induced by decreasing temperature and humidity. ABPP revealed that VPEs and the proteasome are not differentially active, but that activities of papain-like cysteine proteases and serine hydrolases, including Hsr203 and P69B, increase before hypersensitive tissue collapse, whereas the activity of a carboxypeptidase-like enzyme is reduced. Similar dynamics were observed for these enzymes in the apoplast of tomato challenged with C. fulvum. Unexpectedly, these challenged plants also displayed novel isoforms of secreted putative VPEs. In the absence of tissue collapse at high humidity, the hydrolase activity profile is already altered completely, demonstrating that changes in hydrolase activities precede hypersensitive tissue collapse. PMID:24890496

Sueldo, Daniela; Ahmed, Ali; Misas-Villamil, Johana; Colby, Tom; Tameling, Wladimir; Joosten, Matthieu H A J; van der Hoorn, Renier A L

2014-08-01

274

Cryopreservation affects ROS-induced oxidative stress and antioxidant response in Arabidopsis seedlings.  

PubMed

Plant recovery status after cryopreservation by vitrification had a negative relationship to the oxidative stress induced by reactive oxygen species (ROS). Arabidopsis thaliana seedlings germinated for 48h or 72h with different survival tolerances were examined at five steps of cryopreservation, to determine the role of ROS (O2(-), H2O2 and OH) and antioxidant systems (SOD, POD, CAT, AsA and GSH) in cryo-injury. In addition, the effects of the steps on membrane lipid peroxidation were studied using malondialdehyde (MDA) as an indicator. The results indicated that H2O2-induced oxidative stress at the steps of dehydration and rapid warming was the main cause of cryo-injury of 48-h seedlings (high survival rate) and 72-h seedlings (no survival). The H2O2 was mainly generated in cotyledons, shoot tips and roots of seedlings as indicated by Amplex Red staining. Low survival of 72-h seedlings was associated with severe membrane lipid peroxidation, which was caused by increased OH generation activity and decreased SOD activity. The antioxidant-related gene expression by qRT-PCR and physiological assays suggested that the antioxidant system of 48-h seedlings were activated by ROS, and they mounted a defense against oxidative stress. A high level of ROS led to the weakening of the antioxidant system of 72-h seedlings. Correlation analysis indicated that enhanced antioxidant enzymes activities contributed to the high survival rate of 48-h seedlings, which could reflect by cryopreservation of antioxidant mutant seedlings. This model system indicated that elevated CAT activity and AsA content were determinants of cryogenic stress tolerance, whose manipulation could improve the recovery of seedlings after cryopreservation. PMID:25489814

Chen, Guan-Qun; Ren, Li; Zhang, Jie; Reed, Barbara M; Zhang, Di; Shen, Xiao-Hui

2015-02-01

275

Influence of Litter and Weather on Seedling Recruitment in a Mixed Oak–Pine Woodland  

PubMed Central

The effects of regular litter removal and annual variation in temperature and precipitation on seedling recruitment of species differing in their seed size and mode of dispersal were studied in a 16?year (1984–1999) experiment in a mixed oak–pine wood in southern Poland. Litter was the most important factor in determining spatial variability in seedling recruitment, whereas differences in climatic conditions among years, especially temperature fluctuations in late winter and early spring, determined the temporal variability in seedling recruitment. Compared with control plots, significantly more new individuals of bryophytes and seedlings as well as a number of new species of vascular plants were noted in the litter?removal plots over the 16?year study. Litter strongly impeded seedling emergence of small?seeded species. The negative effect of litter on seedling recruitment of large?seeded species and the recruitment of new shoots in species growing clonally was much weaker. There was a significant positive correlation between the numbers of seedlings in the litter?removal and control plots and temperatures in January to March. In the litter?removal plots this mainly affected small?seeded species. Seedling recruitment was less consistently related to variation in precipitation. Positive relationships were found only between the number of seedlings of large?seeded species in the litter?removal plots and precipitation in July of the current year and in September of the previous year, and between the number of seedlings in the control plots and precipitation in September and November of the previous year. PMID:12197522

DZWONKO, ZBIGNIEW; GAWRO?SKI, STEFAN

2002-01-01

276

Can NPK fertilizers enhance seedling growth and mycorrhizal status of Tuber melanosporum-inoculated Quercus ilex seedlings?  

PubMed

Although successful cultivation of the black truffle (Tuber melanosporum) has inspired the establishment of widespread truffle orchards in agricultural lands throughout the world, there are many unknowns involved in proper management of orchards during the 6-10 years prior to truffle production, and there are conflicting results reported for fertilizer treatments. Here, we systematically evaluate the combined effects of nitrogen, phosphorous, and potassium with different doses of each element, applied to either foliage or roots, on plant growth parameters and the mycorrhizal status of outplanted 3-year-old seedlings in five experimental Quercus ilex-T. melanosporum orchards. Fertilization did not significantly improve seedling aboveground growth, but the plants treated with the fertilizer 12-7-7 applied to the roots (HNr) displayed longer field-developed roots. Only the fertilizer with the highest dose of K (10-6-28) applied to the foliage (HKf) increased the probability of fine root tip colonization by T. melanosporum in field-developed roots. However, the plants treated with the same fertilizer applied to the soil (HKr) presented the highest probability for colonization by other competing mycorrhizal soil fungi. Potassium seems to have an important role in mycorrhizal development in these soils. Apart from T. melanosporum, we found 14 ectomycorrhizal morphotypes, from which seven were identified to species level, three to genus, two to family, and two remained unidentified by their morphological characteristics and DNA analyses. PMID:20033737

Suz, Laura M; Martín, María P; Fischer, Christine R; Bonet, José A; Colinas, Carlos

2010-06-01

277

Ethanolamide Oxylipins of Linolenic Acid Can Negatively Regulate Arabidopsis Seedling Development[C][W  

PubMed Central

N-Acylethanolamines (NAEs) are fatty-acid derivatives with potent biological activities in a wide range of eukaryotic organisms. Polyunsaturated NAEs are among the most abundant NAE types in seeds of Arabidopsis thaliana, and they can be metabolized by either fatty acid amide hydrolase (FAAH) or by lipoxygenase (LOX) to low levels during seedling establishment. Here, we identify and quantify endogenous oxylipin metabolites of N-linolenoylethanolamine (NAE 18:3) in Arabidopsis seedlings and show that their levels were higher in faah knockout seedlings. Quantification of oxylipin metabolites in lox mutants demonstrated altered partitioning of NAE 18:3 into 9- or 13-LOX pathways, and this was especially exaggerated when exogenous NAE was added to seedlings. When maintained at micromolar concentrations, NAE 18:3 specifically induced cotyledon bleaching of light-grown seedlings within a restricted stage of development. Comprehensive oxylipin profiling together with genetic and pharmacological interference with LOX activity suggested that both 9-hydroxy and 13-hydroxy linolenoylethanolamides, but not corresponding free fatty-acid metabolites, contributed to the reversible disruption of thylakoid membranes in chloroplasts of seedling cotyledons. We suggest that NAE oxylipins of linolenic acid represent a newly identified, endogenous set of bioactive compounds that may act in opposition to progression of normal seedling development and must be depleted for successful establishment. PMID:24151297

Keereetaweep, Jantana; Blancaflor, Elison B.; Hornung, Ellen; Feussner, Ivo; Chapman, Kent D.

2013-01-01

278

90sr uptake by 'pinus ponderosa' and 'pinus radiata' seedlings inoculated with ectomycorrhizal fungi  

SciTech Connect

In the study, the authors inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi; inoculated and nonincoculated (control) seedlings were compared for their ability to remove Sr90 from an organic growth medium. Seedlings were grown for 3 months in a growth chamber in glass tubes containing 165 cu cm of sphagnum peat moss and perlite and, except in the controls, the fungal inoculum. After 3 months, 5978 Bq of Sr90 in 1 ml of sterile, distilled, deionized water was added. Seedlings were grown for an additional month and then harvested. P. ponderosa seedlings that were inoculated with ectomycorrhizal fungi accumulated 3.0-6.0% of the Sr90; bioconcentration ratios ranged from 98-162. Inoculated P. radiata seedlings accumulated 6.0-6.9% of the Sr90; bioconcentration ratios ranged from 88-133. Noninoculated P. ponderosa and P. radiata seedlings accumulated only 0.6 and 0.7% of the Sr90 and had bioconcentration ratios of 28 and 27, respectively.

Entry, J.A.; Rygiewicz, P.T.; Emmingham, W.H.

1994-01-01

279

N2-fixation and seedling growth promotion of lodgepole pine by endophytic Paenibacillus polymyxa.  

PubMed

We inoculated lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) with Paenibacillus polymyxa P2b-2R, a diazotrophic bacterium previously isolated from internal stem tissue of a naturally regenerating pine seedling to evaluate biological nitrogen fixation and seedling growth promotion by this microorganism. Seedlings generated from pine seed inoculated with strain P2b-2R were grown for up to 13 months in a N-limited soil mix containing 0.7 mM available N labeled as Ca((15)NO3)2 to facilitate detection of N2-fixation. Strain P2b-2R developed a persistent endophytic population comprising 10(2)-10(6) cfu g(-1) plant tissue inside pine roots, stems, and needles during the experiment. At the end of the growth period, P2b-2R had reduced seedling mortality by 14 % and (15)N foliar N abundance 79 % and doubled foliar N concentration and seedling biomass compared to controls. Our results suggest that N2-fixation by P. polymyxa enhanced growth of pine seedlings and support the hypothesis that plant-associated diazotrophs capable of endophytic colonization can satisfy a significant proportion of the N required by tree seedlings growing under N-limited conditions. PMID:23420205

Anand, Richa; Grayston, Susan; Chanway, Christopher

2013-08-01

280

Herbivory and seedling performance in a fragmented temperate forest of Chile  

NASA Astrophysics Data System (ADS)

Forest fragmentation alters plant-animal interactions, including herbivory. Relying manipulative experiments, we test if the reduction in insect herbivory associated with forest fragmentation translates into increased seedling growth and survival of three tree common species ( Aristotelia chilensis, Cryptocarya alba and Persea lingue) in forest fragments and continuous forests in coastal Maulino forest, central Chile. Furthermore, we test if after protecting seedlings from herbivorous insects, plant performance is increased regardless of forest fragmentation. Nursery grown seedlings were transplanted into four forest fragments and a continuous forest during 2002. Insects, important herbivores in this forest, were excluded from half the seedlings by repeated applications of insecticides. Compared to continuous forests, in forest fragments, herbivory was reduced in all three species, seedling growth was greater in A. chilensis and C. alba but not in P. lingue, and survivorship was unaffected by herbivory or fragmentation in all three species. Protecting seedlings from insects reduced herbivory in the continuous forest to similar levels attained in the forest fragments. No change in herbivory results from by protecting seedlings in forest fragments. These results confirm that insects are important herbivores in the Maulino forest and also support the hypothesis that fragmentation can have strong indirect effects on plant communities as mediated through trophic interactions.

Simonetti, Javier A.; Grez, Audrey A.; Celis-Diez, Juan L.; Bustamante, Ramiro O.

2007-11-01

281

Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurringbirch and hemlock seedlings.  

PubMed

Coarse woody debris (CWD)is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF)and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediatedeffects on seedling dynamics. In hemlock-dominatedstands, we characterized ECMF communities associated with eastern hemlock (Tsuga canadensis (L.) Carr) and yellow birch (Betula alleghaniensis Britt) seedling pairs growing on CWD. Seedling foliage and CWD were analyzed chemically, and seedling growth, canopy cover, and canopy species determined. Thirteen fungal taxa, 12 associated with birch, and 6 with hemlock, were identified based on morphology and ITS sequencing. Five species were shared by co-occurringbirch and hemlock, representing 75 % of ectomycorrhizal root tips. Rarified ECMF taxon richness per seedling was higher on birch than hemlock. Nonmetric multidimensional scaling revealed significant correlations between ordination axes, the mutually exclusive ECMF Tomentella and Lactarius spp., foliar N and K, CWD pH, and exchangeable Ca and Mg. Seedlings colonized by Lactarius and T. sublilacina differed significantly in foliar K and N, and CWD differed in exchangeable Ca and Mg. CWD pH and nutrient concentrations were low but foliar macro-nutrientconcentrations were not. We hypothesize that the dominant ECMF are adapted to low root carbohydrate availability typical in shaded environments but differ in their relative supply of different nutrients. PMID:25091153

Poznanovic, Sarah K; Lilleskov, Erik A; Webster, Christopher R

2015-02-01

282

Varying impacts of cervid, hare and vole browsing on growth and survival of boreal tree seedlings.  

PubMed

The negative impacts of mammalian herbivores on plants have been studied quite extensively, but typically with only a single herbivore species at a time. We conducted a novel comparison of the browsing effects of voles, hares and cervids upon the growth and survival of boreal tree seedlings. This was done by excluding varying assemblages of these key mammalian herbivores from silver birch, Scots pine and Norway spruce seedlings for 3 years. We hypothesised that the pooled impacts of the herbivores would be greater than that of any individual group, while the cervids would be the group with the strongest impact. Growth of birch seedlings advanced when cervids were excluded whereas growth of seedlings accessible to cervids was hindered. Survival of all seedlings was lowest when they were accessible to voles and voles plus hares, whereas cervids seemed not to influence seedling survival. Our results show that the impact of herbivores upon woody plants can be potent in the boreal forests, but the mechanism and strength of this link depends on the tree and herbivore species in question. Risk of abated stand regeneration appears highest for the deciduous birch, though there is need for seedling protection also in coniferous stands. The clear cervid-mediated growth limitation of birch also indicates potential for a trophic cascade effect by mammalian top predators, currently returning to boreal ecosystems. PMID:24036931

Lyly, Mari; Klemola, Tero; Koivisto, Elina; Huitu, Otso; Oksanen, Lauri; Korpimäki, Erkki

2014-01-01

283

Role of Potassium and Malate in Nitrate Uptake and Translocation by Wheat Seedlings 1  

PubMed Central

Wheat seedlings (Triticum vulgare) treated with 1 mm KNO3 or NaNO3, in the presence of 0.2 mm CaSO4, were compared during a 48-hour period with respect to nitrate uptake, translocation, accumulation and reduction; cation uptake and accumulation; and malate accumulation. Seedlings treated with KNO3 absorbed and accumulated more nitrate, had higher nitrate reductase levels in leaves but less in roots, accumulated 17 times more malate in leaves, and accumulated more of the accompanying cation than seedlings treated with NaNO3. Within seedlings of each treatment, changes in nitrate reductase activity and malate accumulation were parallel in leaves and in roots. Despite the great difference in malate accumulation, leaves of the KNO3-treated seedlings had only slightly greater levels of phosphoenolpyruvate carboxylase than leaves of NaNO3-treated seedlings. NADP-malic enzyme levels increased only slightly in leaves and roots of both KNO3- and NaNO3-treated seedlings. The effects of K+ and Na+ on all of these parameters can best be explained by their effects on nitrate translocation, which in turn affects the other parameters. In a separate experiment, we confirmed that phosphoenolpyruvate carboxylase activity increased about 2-fold during 36 hours of KNO3 treatment, and increased only slightly in the KCl control. PMID:16660606

Blevins, Dale G.; Barnett, Neal M.; Frost, William B.

1978-01-01

284

Seasonal differences in needle gas exchange between mature branches and seedlings of Pinus ponderosa  

SciTech Connect

In 1990, an interactive study was initiated to understand the differing physiological and morphological response of mature tissue and seedling tissue to stress. The study was conducted at the Air Pollution and Climate Change Exposure Facility in a Pinus ponderosa seed production orchard at the US Forest Service Tree Improvement Center in Chico, CA. The orchard consists of clonal trees and the authors have planted half-sibling seedlings which correspond to the mature clones which were measured. Both the mature trees and seedlings were regularly irrigated and fertilized. The result is that they have minimized the genetic and environmental differences that might otherwise influence the physiological differences between mature and seedling tissue. One of the physiological parameters which was measured was seasonal and diurnal gas exchange using a LICOR 6200. They measured gas exchange in November 1989, March, July, and October 1990. They found that throughout the year, all gas exchange components (eg. photosynthesis, transpiration, stomatal conductance) were significantly greater for seedling tissue. Photosynthetic differences were greater during early October, with diurnal mean rates of 1.1 {mu}mol m{sup {minus}2}s{sup {minus}1} and 0.5 {mu}mol m{sup {minus}2}s{sup {minus}1} for seedling and mature tissue, respectively. Transpiration differences were greater during early October, with diurnal mean rates of 2.2 mmol m{sup {minus}2}2{sup {minus}1} and 1.2 mmol m{sup {minus}2}s{sup {minus}1} for seedling and mature tissue, respectively. Finally, gas exchange differences between seedling and mature tissue were greater for current needles than one-year old needles. The results of this study demonstrate that gas exchange differences between seedling and mature tissue observed in the field may be the result of inherent physiological differences, and not merely genetic and environmental differences.

Houpis, J.L.J.; Anderson, P.D. (Lawrence Livermore National Lab., CA (United States))

1991-05-01

285

Interactions between seedlings of Agave deserti and the nurse plant Hilaria rigida  

SciTech Connect

Seedlings of the succulent crassulacean acid metabolism (CAM) plant Agave deserti in the northwestern Sonoran Desert were found only in sheltered microhabitats, nearly all occurring under the canopy of a desert bunchgrass, Hilaria rigida. Apparently because soil surface temperatures can reach 71{degree}C in exposed areas, seedlings were generally located near the center or on the northern side of this nurse plant. Both species have shallow root systems, about half of the roots of H. rigida and all those for seedlings of A. deserti occurring above soil depths of 0.08 m. To examine competition for water between the nurse plant and an associated seedling, a three-dimensional model for root water uptake was developed. Predicted pre-dawn soil water potentials at the mean root depth and total shoot transpiration agreed well with field measurements. Simulated annual water uptake by a seedling of A. deserti was reduced {approx}50% when the seedling was moved from an exposed location to the center of the nurse plant. Shading by the nurse plant reduced total daily photosynthetically active radiation (PAR) by up to 74% compared with an exposed seedling. On the other hand, soil nitrogen under the canopy of H rigida was 60% higher than in exposed locations. Assuming that the effects of nitrogen, temperature, PAR, and soil water on net CO{sub 2} uptake are multiplicative, the predicted net CO{sub 2} uptake by a seedling of A. deserti under the nurse plant was only {approx}45% of that for an exposed seedling.

Franco, A.C.; Nobel, P.S. (Univ. of California, Los Angeles (USA))

1988-12-01

286

Mapping Salinity Tolerance during Arabidopsis thaliana Germination and Seedling Growth  

PubMed Central

To characterize and dissect genetic variation for salinity tolerance, we assessed variation in salinity tolerance during germination and seedling growth for a worldwide sample of Arabidopsis thaliana accessions. By combining QTL mapping, association mapping and expression data, we identified genomic regions involved in salinity response. Among the worldwide sample, we found germination ability within a moderately saline environment (150 mM NaCl) varied considerable, from >90% among the most tolerant lines to complete inability to germinate among the most susceptible. Our results also demonstrated wide variation in salinity tolerance within A. thaliana RIL populations and identified multiple genomic regions that contribute to this variation. These regions contain known candidate genes, but at least four of the regions contain loci not yet associated with salinity tolerance response phenotypes. Our observations suggest A. thaliana natural variation may be an underutilized resource for investigating salinity stress response. PMID:21857956

DeRose-Wilson, Leah; Gaut, Brandon S.

2011-01-01

287

Growth Responses and Adaptations of Fraxinus pennsylvanica Seedlings to Flooding.  

PubMed

Flooding induced several physiological and morphological changes in Fraxinus pennsylvanica seedlings, with stomatal closure among the earliest responses. Subsequent changes included: reduction in dry weight increment of roots, stems, and leaves; formation of hypertrophied lenticels and production of adventitious roots on submerged portions of the stem above the soil line; leaf necrosis; and leaf abscission. After 15 days of stomatal closure as a result of flooding, stomata began to reopen progressively until stomatal aperture was similar in flooded and unflooded plants. Adventitious roots began to form at about the time stomatal reopening began. As more adventitious roots formed, elongated, and branched, the stomata opened further. The formation of adventitious roots was an important adaptation for flooding tolerance as shown by the high efficiency of adventitious roots in absorption of water and in high correlation between the production of adventitious roots and stomatal reopening. PMID:16661419

Gomes, A R; Kozlowski, T T

1980-08-01

288

Growth responses and adaptations of Fraxinus pennsylvanica seedlings to flooding  

SciTech Connect

Flooding induced several physiological and morphological changes in Fraxinus pennsylvanica seedlings, with stomatal closure among the earliest responses. Subsequent changes included: reduction in dry weight increment of roots, stems, and leaves; formation of hypertrophied lenticles and production of adventitious roots on submerged portions of the stem above the soil line; leaf necrosis; and leaf abscission. After 15 days of stomatal closure as a results of flooding, stomata began to reopen progressively until stomata aperture was similar in flooded and unflooded plants. Adventitious roots began to form at about the time stomatal reopening began. As more adventitious roots formed, elongated, and branched, the stomata opened further. The formation of adventitious roots was in important adaptation for flooding tolerance as shown by the high efficiency of adventitious roots in absorption of water and in high correlation between the production of adventitious roots and stomatal reopening. 6 figures, 2 tables.

Sena Gomes, A.R.; Kozlowski, T.T.

1980-01-01

289

The structure of the stem endodermis in etiolated pea seedlings  

NASA Technical Reports Server (NTRS)

Differentiation of the endodermis was examined in third internodes of etiolated Pisum sativum L. cv. Alaska seedlings. The endodermis in young internodes contains large, sedimented amyloplasts; in older internodes, a casparian strip differentiates and the endodermis becomes depleted of starch except for the proximal region of the stem, which retains sedimented amyloplasts and remains graviresponsive. Sedimentation occurs in the hook but does not occur consistently until cells reach the base of the hook, where the axis becomes vertical, rapid cell elongation starts, and amyloplast diameter increases substantially. Contact between endoplasmic reticulum and amyloplasts was observed. Endoplasmic reticulum is not distributed polarly with respect to gravity. No symplastic or apoplastic blockages exist in the endodermis at the level of the stem where lateral gradients may be established during tropic curvature.

Sack, F. D.

1987-01-01

290

Correlations between polyamine ratios and growth patterns in seedling roots  

NASA Technical Reports Server (NTRS)

The levels of putrescine, cadaverine, spermidine and spermine were determined in seedling roots of pea, tomato, millet and corn, as well as in corn coleoptiles and pea internodes. In all roots, putrescine content increased as elongation progressed, and the putrescine/spermine ratio closely paralleled the sigmoid growth curve up until the time of lateral root initiation. Spermidine and spermine were most abundant near the apices and declined progressively with increasing age of the cells. In the zone of differentiation of root hairs in pea roots, putrescine rose progressively with increasing age, while cadaverine declined. In both pea internodes and corn coleoptiles, the putrescine/spermidine ratio rises with increasing age and elongation. Thus, a block in the conversion of the diamine putrescine to the triamine spermidine may be an important step in the change from cell division to cell elongation.

Shen, H. J.; Galston, A. W.

1985-01-01

291

Carbon allocation and morphology of cherrybark oak seedlings and sprouts under three light regimes  

Microsoft Academic Search

– \\u000a \\u000a • Continued problems in regenerating oak forests has led to a need for more basic information on oak seedling biology.\\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • In the present study, carbon allocation and morphology were compared between cherrybark oak (Quercus pagoda Raf.) seedlings and sprouts at 1-Lag grown in full, 47%, and 20% sunlight.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • Results indicated that cherrybark oak seedling carbon

Brian Roy Lockhart; Emile S. Gardiner; John D. Hodges; Andrew W. Ezell

2008-01-01

292

Cellular ultrastructure and net photosynthesis of apple seedlings under iron stress  

Microsoft Academic Search

Iron deficiency was induced in apple seedlings (Malus domestica Borkh.) grown in solution culture. Severity of leaf chlorosis increased when seedlings were grown in nutrient solutions containing 0.13 ppm Fe at pH 6.5; no Fe at pH 5.5; no Fe at pH 6.5, and no Fe at pH 7.8. Seedlings grown in solutions containing 1.3 ppm Fe at pH 5.5

Zhou Hou Ji; R. F. Korcak; W. P. Wergin; F. Fan; M. Faust

1984-01-01

293

Interaction of light and gravitropism with nutation of hypocotyls of Arabidopsis thaliana seedlings  

NASA Technical Reports Server (NTRS)

Etiolated seedlings of Arabidopsis thaliana nutated under conditions of physiological darkness while about ten percent of monitored individuals exhibited regular elliptical nutation, circumnutation. Pre-irradiation with red light prevented occurrence of circumnutation without having an effect on the average rate of the nutational movement. Phototropic response of seedlings to unilateral blue light appeared to be superimposed over nutation. Throughout gravitropism, some seedlings continued to exhibit nutation suggesting that these two processes are independently controlled. Based on these results, we suggest that nutation in Arabidopsis probably is not controlled by the mechanism predicted by the theory of gravitropic overshoots.

Orbovic, V.; Poff, K. L.

1997-01-01

294

Interaction between hydrotropism and gravitropism in seedling roots  

NASA Astrophysics Data System (ADS)

Roots display positive hydrotropism in response to a moisture gradient, which could play a role in avoiding drought stress. Because roots also respond to other stimuli such as gravity, touch and light and exhibit gravitropism, thigmotropism and phototropism, respectively, their growth orientation is determined by interaction among those tropisms. We have demonstrated the interaction between hydrotropism and gravitropism. For example, 1) agravitropic roots of pea mutant strongly respond to a moisture gradient and show positive hydrotropism by overcoming gravitropism, 2) in wild type pea roots hydrotropism is weak but pronounced when rotated on clinostat, 3) cucumber roots are positively gravitropic on the ground but become hydrotropic in microgravity, and 4) maize roots change their growth direction depending on the intensities of both gravistimulation and hydrostimulation. Here we found that Arabidopsis roots could display strong hydrotropism by overcoming gravitropism. It was discovered that amyloplasts in the columella cells are rapidly degraded upon exposure to a moisture gradient. Thus, degradation of amyloplasts could reduce the responsiveness to gravity, which could pronounce the hydrotropic response. In hydrotropically stimulated roots of pea seedlings, however, we could not observe a rapid degradation of amyloplasts in the columella cells. These results suggest that mechanism underlying the interaction between hydrotropism and gravitropism differs among plant species. To further study the molecular mechanism of hydrotropism and its interaction with gravitropism, we isolated unique mutants of Arabidopsis of which roots showed either ahydrotropism, reduced hydrotropism or negative hydrotropic response and examined their gravitropism, phototropism, waving response, amyloplast degradation and elongation growth. Based on the characterization of hydrotropic mutants, we will attempt to compare the mechanisms of the two tropisms and to clarify their cross talk for controlling the directional growth of seedling roots.

Kobayashi, A.; Takahashi, A.; Yamazaki, Y.; Kakimoto, Y.; Higashitani, A.; Fujii, N.; Takahashi, H.

295

How do riparian woody seedlings survive seasonal drought?  

PubMed

In semi-arid regions, a major population limitation for riparian trees is seedling desiccation during the dry season that follows annual spring floods. We investigated the stress response of first-year pioneer riparian seedlings to experimental water table declines (0, 1 and 3 cm day(-1)), focusing on the three dominant cottonwood and willows (family Salicaceae) in California's San Joaquin Basin. We analyzed growth and belowground allocation response to water stress, and used logistic regression to determine if these traits had an influence on individual survival. The models indicate that high root growth (>3 mm day(-1)) and low shoot:root ratios (<1.5 g g(-1)) strongly predicted survival, but there was no evidence that plants increased belowground allocation in response to drawdown. Leaf ?(13)C values shifted most for the best-surviving species (net change of +3.5 per mil from -30.0 ± 0.3 control values for Goodding's willow, Salix gooddingii), implying an important role of increased water-use efficiency for surviving water stress. Both S. gooddingii and sandbar willow (S. exigua) reduced leaf size from controls, whereas Fremont cottonwood (Populus fremontii) sustained a 29% reduction in specific leaf area (from 13.4 to 9.6 m(2) kg(-1)). The functional responses exhibited by Goodding's willow, the more drought-tolerant species, may play a role in its greater relative abundance in dry regions such as the San Joaquin Basin. This study highlights the potential for a shift in riparian forest composition. Under a future drier climate regime or under reduced regulated river flows, our results suggest that willow establishment will be favored over cottonwood. PMID:20480183

Stella, John C; Battles, John J

2010-11-01

296

Two Approaches to Evaluate Drought Tolerance in Maize: Seedling Stress Response and Epicuticular Wax Accumulation  

E-print Network

and epicuticular wax accumulation as predictors of drought tolerance. The seedling screening method measured germination, survival and recovery percentages after a series of drought cycles in a greenhouse environment. Eight inbred lines had significantly (P < 0...

Meeks, Meghyn

2010-12-02

297

Annals of Botany 79: 111120, 1997 Mechanisms of Phosphorus Acquisition for Ponderosa Pine Seedlings  

E-print Network

# , climate change, growth analysis, oxalate, Pinus ponderosa, ponderosa pine, phosphorus uptake, rhizosphereAnnals of Botany 79: 111­120, 1997 Mechanisms of Phosphorus Acquisition for Ponderosa Pine conditions, act antagonistically on phosphorus acquisition of ponderosa pine, seedlings were grown

DeLucia, Evan H.

298

Hydroperoxide lyase products, hexanal, hexenal and nonenal, inhibit soybean seedling growth  

SciTech Connect

Hexanal, a product of hydroperoxide lyase, inhibited the germination and growth of soybean seeds. Hexanal was continuously delivered to germinating seeds as a vapor dissolved in air with a flow-through system (100 ml/min). Only 0.8 {mu}g hexanal/ml air was required to inhibit seedling growth by 50%; nearly 100% inhibition occurred with a dose of 1.8 {mu}g hexanal/ml air. In the absence of hexanal brown spots were often visible on the seedlings, but at sublethal doses of hexanal, the seedlings were largely devoid of these spots. The relative toxicity of three hydroperoxide lyase products, hexanal, trans-2-hexanal and trans-2-nonenal, were compared with a Petri-dish bioassay. The order of toxicity against seedling growth was hexenal>hexanal>nonenal.

Gardner, H.W.; Dornbos, D.L. Jr. (Dept. of Agriculture, Peoria, IL (USA))

1989-04-01

299

Chloroplast Fe(III) chelate reductase activity is essential for seedling viability under iron  

E-print Network

in alkaline soil, fro7 seedlings show severe chlorosis and die without setting seed unless watered with high under iron-limiting conditions. metal homostasis FRO Arabidopsis alkaline soil photosynthesis

300

Light and temperature differentially colimit subalpine fir and Engelmann spruce seedling  

E-print Network

spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) seedling croissance de semis d'épinette (Picea engelmannii Parry ex Engelm.) et de sapin (Abies lasiocarpa (Hook

Massicotte, Hugues

301

Multiple Phytochrome-Interacting bHLH Transcription Factors Repress Premature Seedling Photomorphogenesis in Darkness  

Technology Transfer Automated Retrieval System (TEKTRAN)

An important contributing factor to the success of terrestrial flowering plants in colonizing the land was the evolution of a developmental strategy, termed skotomorphogenesis, whereby postgerminative seedlings emerging from buried seed grow vigorously upward in the subterranean darkness toward the ...

302

Influence of fertilization on nutrient status and size of bare-root Pinus taeda L. seedlings  

E-print Network

The purpose of this study was to evaluate the influence of varying types and amounts of fertilizer on loblolly pine ( inns taeda L.) seedlings. Morphological traits as well as nutritional status were measured. A comparison of the effects of constant...

Wall, Margot Marie

2012-06-07

303

Use of TREGRO to simulate the effects of ozone on the growth of red spruce seedlings  

SciTech Connect

TREGRO, a model developed to simulate the growth of sapling red spruce (Picea rubens Sarg.), was parameterized to grow 2- to 3-yr-old seedlings. Results of the simulation compared favorably to actual growth of seedlings used in a field study of the effects of ozone and acidic precipitation on tree physiology and development. Furthermore, a 10-yr simulation produced a modeled tree that corresponded to saplings used in another field experiment. Additional simulations were conducted to compare predicted effects of ozone on seedling growth to those measured in controlled experiments. Based on the performance of the model, we believe TREGRO can be used effectively to simulate both seedling and sapling red spruce growth, and the potential effects of ozone on the development of the trees. 11 refs., 6 figs., 3 tabs.

Laurence, J.A.; Kohut, R.J.; Amundson, R.G. (Boyce Thompson Institute for Plant Research, Ithaca, NY (United States))

1993-08-01

304

Original article Growth and survival in Quercus ilex L. seedlings after  

E-print Network

coincided with a thick layer of the weed Amaranthus retroflexus L. (in the first dry season). Seedling couverture des adventices (Amaranthus retroflexus L.) au cours de la première année. Des effets signi

Boyer, Edmond

305

Factors affecting emergence and seedling vigor of kleingrass and Yuchi arrowleaf clover  

E-print Network

(Trifolium v siculosum Savi. ). Inoculation procedures included seed treatment with gum arabic (GA) only, GA and peat inoculum, and peat inoculum in. water. Seedling emergence from kleingrass seed seemed to be related more to genotype than to seed size... the style and format of the Agronomy Journal. seedling emergence, vigor, and nodulation of Yuchi arrowleaf clover (Trifolium vesiculosum Savi. ). REVIEW OF LITERATURE The Effects of Seedin De th and Soil Moisture on Seedlin Emer ence In practice, little...

Belkhiria, Mohsen Taoufik

1981-01-01

306

Evaluation of nitrogen content in cabbage seedlings using hyper-spectral images  

Microsoft Academic Search

Monitoring of nutrient status of crops is essential for better management of crop production. Nitrogen is one of the most\\u000a important elements in fertilizer for the growth and yield of vegetable crops. In this study, nitrogen content of cabbage seedlings\\u000a was evaluated using hyper-spectral images. Cabbage seedlings, cultured at five nitrogen fertilization levels, were planted\\u000a in the 128-cell plug trays

Chia-Tseng Chen; Suming Chen; Ching-Yin Wang; I-Chang Yang; Shih-Chieh Hsiao; Chao-Yin Tsai

2008-01-01

307

The effect of canopy gaps on growth and morphology of seedlings of rain forest species  

Microsoft Academic Search

Summary  Growth and morphology of seedlings of ten tropical rain forest species were studied at Los Tuxtlas, Mexico. Seedlings were\\u000a grown in three environmental conditions: the shaded forest understorey (FU, receiving 0.9–2.3% of the daily photosynthetic\\u000a photon flux, PF, above the canopy), a small canopy gap of approx. 50 m2 (SG, receiving 2.1–6.1% of daily PF), and a large canopy gap

J. Popma; F. Bongers

1988-01-01

308

Seed Size Effects on Seedling Emergence of Desert Psammophytes in China  

Microsoft Academic Search

To investigate the effects of seed size on the behavior of seeds and seedlings in sand, seedling emergence from sand was examined in Caragana korshinskii (Fabaceae; mean seed weight 65 mg) and Atraphaxis bracteata (Polygonaceae; mean seed weight 5.7 mg), two shrubs with nonphotoblastic seeds that grow on desert sand dunes in China. Seeds were sown at depths of 0 to 50 mm

Kazuo Tobe; Liping Zhang; Kenji Omasa

2007-01-01

309

Growth analysis of Quercus serrata seedlings within Miscanthus sinensis grass canopies differing in light availability  

Microsoft Academic Search

The effects of different light regimes on the survival, growth and morphology ofQuercus serrata seedlings were studied in canopies ofMiscanthus sinensis. The seedlings of various ages (0–3 yr) were grown in three light regimes: under a denseM. sinensis canopy (TG plot) receiving 2.5%–8.7% of full sunlight, under a relatively sparse canopy (SG plot) receiving 3.8%–16.1% of\\u000a light and in an

Yanhong Tang; Izumi WASI-nTANI; Takayoshi Tsuchiya; Hideo Iwaki

1990-01-01

310

Seed dispersal and seedling emergence in an old field community in central New York (USA)  

Microsoft Academic Search

Seed dispersal and seedling emergence of common taxa growing in a Solidago-dominated old field in central New York (USA) were monitored from May 1982 to June 1984. Over 3.5x104 seeds per m2 were captured on seed traps in each of the two years, with peaks occuring in July (due to Hieracium) and in November (due to Solidago). About 4.0x103 seedling\\/m2

W. F. Morris; P. L. Marks; C. L. Mohler; N. R. Rappaport; F. R. Wesley; M. A. Moran

1986-01-01

311

Seedling establishment in an epiphytic orchid: an experimental study of seed limitation  

Microsoft Academic Search

Will increased fruit and seed production in a severely pollination-limited orchid stimulate population growth? We tested whether safe sites for germination and seedling establishment are limiting for the twig epiphyte, Tolumnia variegata, by manipulating fruit set and monitoring subsequent seedling establishment for two seasons (1991–1992, 1992–1993). In the Cambalache Forest Reserve of Puerto Rico, we established 36 plots along a

J. D. Ackerman; A. Sabat; J. K. Zimmerman

1996-01-01

312

Differential responses of pea seedlings to indole acetic acid under manganese toxicity  

Microsoft Academic Search

Present study showed the responses of pea seedlings to exogenous indole acetic acid (IAA; 10 and 100 ?M) application under\\u000a manganese (Mn; 50, 100 and 250 ?M) toxicity. Manganese and 100 ?M IAA alone as well as in combination decreased growth of\\u000a pea seedlings compared to control. Moreover, some parameters of oxidative stress—hydrogen peroxide (H2O2) and malondialdehyde (MDA) were also increased by single

Savita Gangwar; Vijay Pratap Singh; Sheo Mohan Prasad; Jagat Narayan Maurya

2011-01-01

313

Modulation of manganese toxicity in Pisum sativum L. seedlings by kinetin  

Microsoft Academic Search

In the present study, the effects of kinetin (KN; 10 and 100?M) application under manganese toxicity (Mn; 50, 100 and 250?M) were investigated, on growth, photosynthetic pigments, total protein, total nitrogen, ammonium (NH4+) content, NH4+ assimilating enzymes and antioxidant system in pea seedlings. The exposure of pea seedlings to Mn and 100?M of KN alone and in combination, caused decrease

Savita Gangwar; Vijay Pratap Singh; Sheo Mohan Prasad; Jagat Narayan Maurya

2010-01-01

314

Competitive Effects of Various Grasses and Forbs on Ponderosa Pine Seedlings  

Microsoft Academic Search

Competition between ponderosa pine seedlings and various grasses and forbs was studied on :I site in northern Arizona burned in 1982 by a wildfire. Two-year- old pine seedlings were planted in 3.05 x 3.05 m plots in April 1983, followed by the sowing of grass and forb seeds on the same plots in July 1983 after summer rains had begun.

KATHERINE J. ELLIOTT; ALAN S. WHITE

315

Effects of Salinity and Specific Ions on Seedling Emergence and Growth of Onions  

E-print Network

TR-2008-319 Effects of Salinity and Specific Ions on Seedling Emergence and Growth of Onions S. Miyamoto, I. Martinez and G. Niu Texas AgriLife Research and Extension Center El Paso, Texas August... 2008 Effects of Salinity and Specific Ions on Seedling Emergence and Growth of Onions A Research Report Submitted to American Water Works Association U.S. Bureau of Reclamation and El Paso Water Utilities in Partial...

Miyamoto, S.; Martinez, I.; Niu, G.

316

Effects of flow pattern on riparian seedling recruitment on sandbars in the Wisconsin River, Wisconsin, USA  

Microsoft Academic Search

In riparian ecosystems, river flow is the dominant driver influencing ecological process and pattern, including the recruitment\\u000a of riparian tree species. In a four-year field study (1997–2000) of seedling recruitment on sandbars in the Wisconsin River,\\u000a I evaluated the hypothesis that the timing of seed dispersal and river flow interact to determine the annual composition of\\u000a pioneer tree seedling cohorts.

Mark D. Dixon

2003-01-01

317

Evaluating Chemical Indices of Growing Media for Nursery Production of Quercus rubra Seedlings  

Microsoft Academic Search

We evaluated suitability of chemical indices of three media formulations or substrates (A, B, and C) consisting of composted pine bark, coconut coir pith, sphagnum peatmoss,processedbarkash,andperliteinvariedproportionsforgrowingnorthernred oak (Quercus rubra L.) seedlings. These substrates were ranked according to their ability to promote seedling growth. The low-yielding substrate (A) was devoid of pine bark and perlite and the medium-yielding substrate (B) contained

K. Francis Salifu; Michael A. Nicodemus; Douglass F. Jacobs; Anthony S. Davis

2006-01-01

318

Efficient generation of 2 E-hexenal by a hydroperoxide lyase from mung bean seedlings  

Microsoft Academic Search

2E-hexenal was generated with a high molar conversion rate by the incubation of a hydroperoxide lyase containing extract from mung bean seedlings and its substrate, 13-hydroperoxy-9Z, 11E, 15Z-octadecatrienoic acid (13-HPOT). Various parameters affected the yield of 2E-hexenal and the conversion rate: hydroperoxide lyase activity was especially, pronounced in seedlings older than 10 days. The cleavage of 13-HPOT by a solubilized

B. Rehbock; D. Gan?er; R. G. Berger

1998-01-01

319

Chilling stress suppresses chloroplast development and nuclear gene expression in leaves of mung bean seedlings  

Microsoft Academic Search

Etiolated leaves of 28°C-dark-grown mung bean (Vigna radiata L. cv. 2937) seedlings fail to turn green after being shifted to a light and cold environment. At the visible phenotypic level, incapability of leaf greening is the only failure event for the de-etiolation of mung bean seedlings at low temperature. Ultrastructural studies revealed that chloroplast development was completely suppressed by chilling

Ming-Tzong Yang; Shu-Ling Chen; Chu-Yung Lin; Yih-Ming Chen

2005-01-01

320

Raffinose in seedlings of winter vetch ( Vicia villosa Roth.) under osmotic stress and followed by recovery  

Microsoft Academic Search

During germination of winter vetch (Vicia villosa Roth.) seeds, the degradation of raffinose family oligosaccharides and galactosyl pinitols occurred faster in axis than in\\u000a cotyledons. After 7 days of germination, all ?-d-galactosides disappeared and the soluble carbohydrates in seedling tissues consisted of d-pinitol, sucrose, fructose, glucose and myo-inositol. Osmotic stress caused by incubation of seedlings in PEG 8000 solution (?0.5, ?1.0,

Les?aw B. Lahuta; Ryszard J. Górecki

2011-01-01

321

Induction by thidiazuron of somatic embryogenesis in intact seedlings of peanut  

Microsoft Academic Search

In planta differentiation of somatic embryos was induced in seedlings of peanut (Arachis hypogaea L.) obtained from mature seeds germinated on a medium supplemented with thidiazuron (TDZ: N-phenyl-N1- (1,2,3 thiadiazol-yl)urea). At optimum levels of TDZ (10 µM), all germinating seeds produced embryogenic seedlings, and somatic embryos developed in the apical region and on the surface of cotyledons and hypocotyls. These

Praveen K. Saxena; Kamal A. Malik; R. Gill

1992-01-01

322

Thidiazuron-Induced High-Frequency Shoot Regeneration from Root Region of Robinia pseudoacacia L. Seedlings  

Microsoft Academic Search

High-frequency regeneration of shoots was achieved at root region of seedlings of Robinia pseudoacacia L. cultured from seeds on medium supplemented with thidiazuron (TDZ, 1.0 µM). The roots of intact seedlings proliferated and formed a compact callus followed by differentiation of numerous shoots. Corresponding cultures on benzylaminopurine-containing medium exhibited much weaker response. Hypocotyl segments also formed shoots at a lower

M. Hosseini-Nasr; A. Rashid

2003-01-01

323

Effects of nitrate on nitrogen fixation and growth of black locust (Robinia pseudoacacia L. ) seedlings  

SciTech Connect

N fertilization may affect the growth of black locust via effects on N fixation (NF) and N metabolism energy costs. This work examined the effects of nitrate (n) on NF and growth of black locust seedlings (BLS). Two experiments examined the effects of n on acetylene reduction, nodule biomass (NB), and n reductase activity of families using nodulated seedlings. Two additional experiments examined the effects of n using functional growth analysis. Nitrate was enriched with [sup 15]N and seedling N was partitioned into n and atmospheric N sources. Nitrate fertilization affected both NF and growth of BLS. High concentrations of n decreased both NB and activity. Nitrate additions generally increase total plant growth. Adjustments for seedling size via allometric principles are necessary to correctly interpret treatment effects on NF. Without such adjustments, n fertilization and family effects on general seedling growth confound analysis. Nitrate fertilization decreased NF primarily by decreasing dry matter partitioning to nodules. Low concentrations of n resulted in higher total seedling NB. Once, it was thought that low levels of soil N are needed to stimulate nodule growth and NF. Allometric analysis clearly indicated that low concentrations of n did not affect nodule growth directly but did so by increasing general seedling growth. Growth analyses were conducted to correct for confounding effects of differential plant size and internal N concentration resulting from different rates of n fertilization. These analyses showed that n fertilization increased BLS growth both by increasing seedling internal N concentrations and by increasing N productivity. The latter indicates that n utilization is more energy efficient than NF. High levels of n reductase activity were observed in leaves of BLS given n. Differences in energy costs might be partly attributable to photo-reduction of n and/or nitrite in the leaves.

Johnsen, K.H.

1990-01-01

324

Pine and spruce seedling growth and mycorrhizal infection after inoculation with plant growth promoting Pseudomonas strains  

Microsoft Academic Search

Pine and spruce seeds were inoculated with antibiotic-resistant plant growth promoting fluorescent Pseudomonas strains Sm3-RN, Ss2-RN and Sw5-RN for evaluation of bacterial root colonization and seedling growth responses under greenhouse conditions. Mycorrhizal inoculum was introduced to seedling containers by placing 2 cc of forest floor soil around seeds at the time of sowing. Mycorrhizal roots were detected on 39% of

Masahiro Shishido; Daniel J. Petersen; Hugues B. Massicotte; Christopher P. Chanway

1996-01-01

325

Adaptive responses of Acer ginnala, Pyrus ussuriensis and Prunus davidiana seedlings to soil moisture stress  

Microsoft Academic Search

One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moisture contents (75.0%, 61.1%, 46.4% and\\u000a 35.4%). The results showed that net photosynthesis rate (NPR), transpiration rate (TR) and stomatal conductance (Sc) of seedlings\\u000a of the three species decreased

Wang Qing-cheng; Sun Zhi-hu; Zhang Yan-dong

2003-01-01

326

Early selection of loblolly pine based on genotype x fertilization interaction of seedlings  

E-print Network

EARLY SELECTION OF LOBLOLLY PINE BASED ON GENOTYPE x FERTILIZER INTERACTION OF SEEDLINGS A Thesis by DOROTHY ELAINE M:LLER Submitted to the Graduate College of Texas A&M Oniversity in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1982 Major Subject: Forestry EARLY SELECTION OF LOBLOLLY PINE BASED ON GENOTYPE x FERTILIZER INTERACTION OF SEEDLINGS A Thesis by DOROTHY ELAINE MILLER Approved as to style and content by: (C ' an f Committee) (Member...

Miller, Dorothy Elaine

2012-06-07

327

New Plant Growth Regulators Protect Photosynthesis and Enhance Growth Under Drought of Jack Pine Seedlings  

Microsoft Academic Search

.   To determine whether natural plant growth regulators (PGRs) can enhance drought tolerance and the competitive ability of\\u000a transplanted seedlings, 1.5-year-old jack pine (Pinus banksana Lamb.) seedlings were treated with homobrassinolide, salicylic acid, and two polyamines, spermine and spermidine, triacontanol,\\u000a abscisic acid (ABA), and the synthetic antioxidant, Ambiol. PGRs were fed into the xylem for 7 days and plants were

L. R. Rajasekaran; T. J. Blake

1999-01-01

328

Foliar anthocyanin accumulation may be a useful indicator of hardiness in eucalypt seedlings  

Microsoft Academic Search

Anthocyanin as an indicator of seedling hardiness was tested in field trials at 350m above sea level (a.s.l.) (Watson’s Block with Eucalyptus globulus Labill. and E. nitens [Deane and Maiden] Maiden) and at 700m a.s.l. (Moory Rd. with E. nitens only). Nutrients were withheld (nutrient-deprived) or added (nutrient-loaded) to seedlings in the nursery and shaded or non-shaded in the field.

D. C Close; C. L Beadle; M Battaglia

2004-01-01

329

Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress  

Microsoft Academic Search

The modulation of primary nitrogen metabolism by hypoxic stress was studied in young Medicago trunca- tula seedlings. Hypoxic seedlings were characterized by the up-regulation of glutamate dehydrogenase 1 (GDH1) and mitochondrial alanine aminotransferase (mAlaAT), and down-regulation of glutamine synthe- tase 1b (GS1b), NADH-glutamate synthase (NADH- GOGAT), glutamate dehydrogenase 3 (GDH3), and isocitrate dehydrogenase (ICDH) gene expression. Hypoxic stress severely inhibited

Anis M. Limami; Gaelle Glevarec; Claudie Ricoult; Jean-Bernard Cliquet; Elisabeth Planchet

2008-01-01

330

Influence of temperature on respiration of excised tissues from citrus seedlings  

E-print Network

INFLUENCE OF TEMPERATURE ON RESPIRATION OF EXCISED TISSUFS FROM CITRUS SEEDLINGS A Thesis by ASCENSION PEYNADO Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1970 Major Subject: Plant Physiology INI'LUENCE OF TK'PERATURE ON RESPIRATION OF EXCISED TISSUES FROM CITRUS SEEDLINGS A Thesis by ASCENSION PEYNADO Approved as to style and content by: (Head of Department) /. d (Member) Pdmberf...

Peynado, Ascension

2012-06-07

331

Comparative transcription profiling analyses of maize reveals candidate defensive genes for seedling resistance against corn earworm  

Microsoft Academic Search

As maize seedlings germinate into the soil, they encounter an environment teeming with insects seeking rich sources of nutrition.\\u000a Maize presumably has developed a number of molecular mechanisms to ensure survival at the beginning of its life cycle. Comparative\\u000a transcription analysis using microarrays was utilized to document the expression of a number of genes with potential defensive\\u000a functions in seedling

Eric T. JohnsonPatrick; Patrick F. Dowd; Z. Lewis Liu; Richard O. Musser

2011-01-01

332

Responses of Fraxinus excelsior seedlings to grass-induced above- and below-ground competition  

Microsoft Academic Search

The competitive interactions between woody seedlings and herbaceous vegetation have received increasing interest in recent\\u000a years. However, little is known about the relative contributions and underlying mechanisms of above- and below-ground competition\\u000a between species. We used a novel experimental approach to assess the responses of Fraxinus excelsior seedlings to different combinations of root and shoot competition imposed by the grass

Juliette M. G. Bloor; Paul W. Leadley; Laure Barthes

2008-01-01

333

Long-term variability in seed size and seedling establishment of Maianthemum bifolium  

Microsoft Academic Search

Relatively few studies conducted in natural plants populations focus on the relationship between seed size and their germination\\u000a ability and seedling establishment. Maianthemum bifolium is a perennial herb that spreads vegetatively through rhizomatous growth and reproduces through seeds. However, this species\\u000a is characterized as seed and microsite limited, and under undisturbed conditions seedlings are not noted. The studies were\\u000a conducted

Igor Kosi?ski

2008-01-01

334

Seedling establishment in a dynamic sedimentary environment: a conceptual framework using mangroves  

PubMed Central

1. Vegetated biogeomorphic systems (e.g. mangroves, salt marshes, dunes, riparian vegetation) have been intensively studied for the impact of the biota on sediment transport processes and the resulting self-organization of such landscapes. However, there is a lack of understanding of physical disturbance mechanisms that limit primary colonization in active sedimentary environments. 2. This study elucidates the effect of sediment disturbance during the seedling stage of pioneer vegetation, using mangroves as a model system. We performed mesocosm experiments that mimicked sediment disturbance as (i) accretion/burial of plants and (ii) erosion/excavation of plants of different magnitudes and temporal distribution in combination with water movement and inundation stress. 3. Cumulative sediment disturbance reduced seedling survival, with the faster-growing Avicennia alba showing less mortality than the slower-growing Sonneratia alba. The presence of the additional stressors (inundation and water movement) predominantly reduced the survival of S. alba. 4. Non-lethal accretion treatments increased shoot biomass of the seedlings, whereas non-lethal erosion treatments increased root biomass allocation. This morphological plasticity in combination with the abiotic disturbance history determined how much maximum erosion the seedlings were able to withstand. 5. Synthesis and applications. Seedling survival in dynamic sedimentary environments is determined by the frequency and magnitude of sediment accretion or erosion events, with non-lethal events causing feedbacks to seedling stability. Managers attempting restoration of mangroves, salt marshes, dunes and riparian vegetation should recognize sediment dynamics as a main bottleneck to primary colonization. The temporal distribution of erosion and accretion events has to be evaluated against the ability of the seedlings to outgrow or adjust to disturbances. Our results suggest that selecting fast-growing pioneer species and measures to enhance seedling growth or temporary reduction in sediment dynamics at the restoration site can aid restoration success for vegetated biogeomorphic ecosystems. PMID:23894211

Balke, Thorsten; Webb, Edward L; van den Elzen, Eva; Galli, Demis; Herman, Peter M J; Bouma, Tjeerd J

2013-01-01

335

Estimating dispersibility of Acer , Fraxinus and Tilia in fragmented landscapes from patterns of seedling establishment  

Microsoft Academic Search

Relative dispersibility of Tilia americana L., Acer saccharum Marsh. and Fraxinus pennsylvanica Marsh, was inferred from the ratio among species-specific regression coefficients (ß) computed from seedling density-distance plots. Density counts were made in spatially-uniform old fields adjacent to single seed sources or monotypic fencerows. Resultant seedling shadow curves approximate the negative exponential form expected for many seeds (log y=a-ßX). This

W. Carter Johnson

1988-01-01

336

Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings  

Microsoft Academic Search

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25, 44 and\\u000a 100 plants·m?2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height\\u000a and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf,

Wei Huan-yong; Wang Yang; Wang Zhen-yue; Yan Xiu-feng

2005-01-01

337

Antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings  

Microsoft Academic Search

This study measured the responses of different anti-oxidants in 2-year-old birch (Betula pendula Roth) seedlings subjected to simulated acid rain (pH 4.0) and heavy metals (CuNi), applied alone or in combination for 2 months. The applied concentrations of pollutants did not significantly affect seedling biomass or total glutathione levels. Acid rain alone increased superoxide dismutase (SOD) activity both in leaves

Julia Koricheva; Sashwati Roy; John A. Vranjic; Erkki Haukioja; Patrick R. Hughes; Osmo Hänninen

1997-01-01

338

Forest soil community responses to plant growth-promoting rhizobacteria and spruce seedlings  

Microsoft Academic Search

The influence of plant-growth-promoting rhizobacteria (PGPR) and spruce seedlings on the composition and activity of forest\\u000a soil microbial communities was studied in a microcosm experiment in which sterile, sand-filled 25mm×150mm glass tubes were\\u000a treated with a forest soil suspension containing Bacillus or Pseudomonas PGPR and 2-week-old spruce seedlings. Eighteen weeks after treatments were established, bacterial, actinomycete and fungal\\u000a population sizes

M. Shishido; C. P. Chanway

1998-01-01

339

Ectomycorrhizal development on pine by Pisolithus tinctorius in bare-root and container seedling nurseries  

Microsoft Academic Search

Vegetative inoculum of Pisolithus tinctorius (Pt) with carbon:nitrogen (C:N) ratios between 22 and 70 produced by Sylvan Spawn Laboratories were compared to inoculum produced by research methods in Athens, GA, in-forming ectomycorrhizae on pine in bare-root seedling nurseries in South Carolina and Indiana, and on seedlings in microplots and containers in Georgia. Nonleached Sylvan Spawn inoculum with C:N ratios of

Donald H. Marx; Charles E. Cordell; Stephen B. Maul; John L. Ruehle

1989-01-01

340

Inhibitions of cotton seedling growth by volatile ketones emitted by cover crop residues  

Microsoft Academic Search

Low-input, sustainable agriculture (LISA) systems can include soil incorporation of residues of weeds and legume cover crop species. However, both seed germination and seedling growth of crops, including cotton (Gossypium hirsutum L.), are inhibited by volatile organic compounds emitted by these residues during decomposition. A cotton seedling-growth assay was used to demonstrate that C4 through C9 ketones released by decomposing

Judith M. Bradow

1993-01-01

341

Inheritance of grain sorghum seedling characters and their linkage with specific chromosomes using trisomics  

E-print Network

preparation of this manuscript. TABLE OF CONTENTS Page I INTRODUCTION. . . II LITERATURE REVIEW. III MATERIALS AND METHODS. Materials Seedling genetic (g) stocks Primary trisomics Procedures Selfed genetic stocks 'Trisonic X genetic stock crosses.... IV EXPERItiENTAL RESULTS. 12 Seedling Genetic Stocks. Segregation ratios 12 12 Descriptions. 12 Trisomic X Genetic Stock Crosses. 23 Linkage of genes controlling chlorophyll deficient characters 23 Linkage of genes controlling coleoptile...

Hanna, Wayne William

1968-01-01

342

A life cycle assessment case study for walnut tree ( Juglans regia L.) seedlings production  

Microsoft Academic Search

Purpose  High-quality wood production is based on both natural forestry populations and dedicated tree plantations, also mentioned\\u000a as industrial plantations. The establishment of dedicated plantations needs high-quality seedlings, often grown in a nursery,\\u000a having specific genetic and morphological features. From seed gathering to final selling, the growth of the seedlings needs\\u000a human interventions and specific inputs such as fertilizers, pesticides, substrates,

Daniele Cambria; Domenico Pierangeli

343

Seedling disease of sorghum [Sorghum bicolor (L.) Moench]: epidemiology, etiology and resistance  

E-print Network

SEEDLING DISEASE OF SORGHUM [SORGHUM BICOLOR (L. ) MOENCH]: EPIDEMIOLOGY, ETIOLOGY AND RESISTANCE A Thesis by GREGORY ALLAN FORBES Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1984 Major Subject: Plant Pathology SEEDLING DISEASE OF SORGHUM [SORGHUM BICOLOR (L. ) MOENCH]: EPIDEMIOLOGY, ETIOLOGY AND RESISTANCE A Thesis GREGORY ALLAN FORBES Approved as to style and content by: 3 Dr. R...

Forbes, Gregory Allan

1984-01-01

344

The effect of paclobutrazol on the growth and uptake of Ca and K by apple seedlings  

Microsoft Academic Search

Addition of paclobutrazol (PP333) at 0.2 ppm to a nutrient solution in which 11?month?old apple seedlings were growing reduced terminal growth, fresh weight increase (FWI), transpiration and Ca and K uptake per seedling. Total root surface area was not affected by PP333 treatment. Reduced Ca uptake preceded the reduction in transpiration and FWI. In the case of K these changes

Dariusz Swietlik; Stephen S. Miller

1984-01-01

345

Competition for soil water between annual plants and blue oak ( Quercus douglasii ) seedlings  

Microsoft Academic Search

We examined the competitive effects of two annual species on soil water potential and blue oak (Quercus douglasii Hook & Arn.) seedling growth and water relations. Two densities of the annual grass Bromus diandrus (Roth.) (100\\/dm2, 3.6\\/dm2) and one density of the annual forb Erodium botrys (Cav.) (3.6\\/dm2) comprised plant neighborhoods around the oak seedlings grown in 1 m deep

D. R. Gordon; J. M. Menke; K. J. Rice

1989-01-01

346

Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments  

PubMed Central

Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves. PMID:25630843

Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

2015-01-01

347

Resource availability and repeated defoliation mediate compensatory growth in trembling aspen (Populus tremuloides) seedlings.  

PubMed

Plant ecologists have debated the mechanisms used by plants to cope with the impact of herbivore damage. While plant resistance mechanisms have received much attention, plant compensatory growth as a type of plant tolerance mechanisms has been less studied. We conducted a greenhouse experiment to evaluate compensatory growth for trembling aspen (Populus tremuloides) seedlings under varying intensities and frequencies of simulated defoliation, with or without nutrient enriched media. For the purpose of this study, changes in biomass production and non-structural carbohydrate concentrations (NSC) of roots and leaves were considered compensatory responses. All defoliated seedlings showed biomass accumulation under low defoliation intensity and frequency, regardless of resource availability; however, as defoliation intensity and frequency increased, compensatory growth of seedlings was altered depending on resource availability. Seedlings in a resource-rich environment showed complete compensation, in contrast responses ranged from undercompensation to complete compensation in a resource-limited environment. Furthermore, at the highest defoliation intensity and frequency, NSC concentrations in leaves and roots were similar between defoliated and non-defoliated seedlings in a resource-rich environment; in contrast, defoliated seedlings with limited resources sustained the most biomass loss, had lower amounts of stored NSC. Using these results, we developed a new predictive framework incorporating the interactions between frequency and intensity of defoliation and resource availability as modulators of plant compensatory responses. PMID:25083352

Erbilgin, Nadir; Galvez, David A; Zhang, Bin; Najar, Ahmed

2014-01-01

348

Bird predation enhances tree seedling resistance to insect herbivores in contrasting forest habitats.  

PubMed

According to the associational resistance hypothesis, neighbouring plants are expected to influence both the insect herbivore communities and their natural enemies. However, this has rarely been tested for the effects of canopy trees on herbivory of seedlings. One possible mechanism responsible for associational resistance is the indirect impact of natural enemies on insect herbivory, such as insectivorous birds. But it remains unclear to what extent such trophic cascades are influenced by the composition of plant associations (i.e. identity of 'associated' plants). Here, we compared the effect of bird exclusion on insect leaf damage for seedlings of three broadleaved tree species in three different forest habitats. Exclusion of insectivorous birds affected insect herbivory in a species-specific manner: leaf damage increased on Betula pendula seedlings whereas bird exclusion had no effect for two oaks (Quercus robur and Q. ilex). Forest habitat influenced both the extent of insect herbivory and the effect of bird exclusion. Broadleaved seedlings had lower overall leaf damage within pine plantations than within broadleaved stands, consistent with the resource concentration hypothesis. The indirect effect of bird exclusion on leaf damage was only significant in pine plantations, but not in exotic and native broadleaved woodlands. Our results support the enemies hypothesis, which predicts that the effects of insectivorous birds on insect herbivory on seedlings are greater beneath non-congeneric canopy trees. Although bird species richness and abundance were greater in broadleaved woodlands, birds were unable to regulate insect herbivory on seedlings in forests of more closely related tree species. PMID:21811874

Giffard, Brice; Corcket, Emmanuel; Barbaro, Luc; Jactel, Hervé

2012-02-01

349

[Soil nutrient status of pure birch and larch plantations based on their seedlings bioassay].  

PubMed

One-year-old birch (Betula platyphylla) and larch (Larix olgensis) seedlings were respectively planted in pots with the soils taken from 35-year-old pure birch and larch plantations, and the seedlings growth, biomass increment, foliar nutrient content, and soil nutrient status were monitored, aimed to evaluate the fertility levels of the two soils and the possible interspecific interaction in mixed larch-birch forest. Birch soil had significantly higher contents of total N and available N than larch soil, while larch soil had significantly higher contents of total P, available P, and total K than birch soil (P < 0.05). In the first growth season, the height and collar diameter growth and the biomass accumulation of birch seedlings growing on birch soil were 69%, 52%, and 65% (P < 0.05) higher than those growing on larch soil, and the larch seedlings also had 12%, 8%, and 37% gains of the indices, respectively. The foliar N concentration of both larch and birch seedlings growing on birch soil was higher than that on larch soil, while the foliar P concentration was higher when the seedlings were growing on larch soil than on birch soil. The birch soil had higher content of available N because of the higher litterfall, while the larch soil had greater available P because of the higher P mobilizing effect. It was predicted that in mixed birch-larch forest, the complementary interaction of soil N and P could benefit the growth of the two tree species. PMID:22097360

Liu, Zhong-ling; Wang, Qing-cheng; Sun, Xin-xin

2011-08-01

350

Seed germination and seedling growth of two Pseudobombax species (Malvaceae) with contrasting habitats from Brazilian Cerrado.  

PubMed

Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas. PMID:22208102

Mendes-Rodrigues, Clesnan; Oliveira, Paulo Eugênio; Ranal, Marli Aparecida

2011-12-01

351

Influence of microhabitat on seedling survival and growth of the mediterranean seagrass posidonia oceanica (l.) Delile  

NASA Astrophysics Data System (ADS)

Early life history phases are crucial stages limiting species distribution and abundance, thus influencing assemblage composition in marine benthic environments. In seagrass systems the period between seed germination and establishment is one of the most vulnerable phases for plant development. This study analyzes the influence of microhabitat structure, in terms of substrate nature and algal canopy, on the persistence and growth over two years of seedlings of Posidonia oceanica, the dominant Mediterranean seagrass. Long time persistence of seedlings only occurred on microhabitats providing vegetated rocky substrates, with a maximum value of 81% on rock covered by Cystoseira spp. No seedling was found on unvegetated sand and gravel after the first year. Seedling growth resulted increased on rock covered by Halopteris spp. and Dilophus spp. than on rock covered by Cystoseira spp. Results suggest that high canopy onto a stable substrate enhances seedling persistence, probably because these allow the best anchorage by roots while hampering water flow. In contrast, turf algal cover promotes better seedling growth, possibly through higher light irradiance and nutrient availability. Our findings support the view that the understanding of the factors controlling early life processes is a necessary prerequisite for the comprehension of seagrass species distribution patterns, colonization and recovery potentials, which, in turn, can guide sound strategies for seagrass management and restoration.

Alagna, Adriana; Fernández, Tomás Vega; Terlizzi, Antonio; Badalamenti, Fabio

2013-03-01

352

Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments.  

PubMed

Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves. PMID:25630843

Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

2015-01-01

353

A spaceflight experiment for the study of gravimorphogenesis and hydrotropism in cucumber seedlings.  

PubMed

Seedlings of Cucurbitaceae plants form a protuberance, termed peg, on the transition zone between hypocotyl and root. Our spaceflight experiment verified that the lateral positioning of a peg in cucumber seedlings is modified by gravity. It has been suggested that auxin plays an important role in the gravity controlled positioning of a peg on the ground. Furthermore, cucumber seedlings grown in microgravity developed a number of the lateral roots that grew towards the water containing substrate in the culture vessel, whereas on the ground they oriented perpendicular to the primary root growing down. The response of the lateral roots in microgravity was successfully mimicked by clinorotation of cucumber seedlings on the three dimensional clinostat. However, this bending response of the lateral roots was observed only in an aeroponic culture of the seedlings but not in solid medium. We considered the response of the lateral roots in microgravity and on clinostat as positive hydrotropism that could easily be interfered by gravitropism on the ground. This system with cucumber seedlings is thus a useful model of spaceflight experiment for the study of the gravimorphogenesis, root hydrotropism and their interaction. PMID:11543179

Takahashi, H; Mizuno, H; Kamada, M; Fujii, N; Higashitani, A; Kamigaichi, S; Aizawa, S; Mukai, C; Shimazu, T; Fukui, K; Yamashita, M

1999-12-01

354

Hydraulic redistribution of water from Pinus ponderosa trees to seedlings: evidence for an ectomycorrhizal pathway.  

PubMed

While there is strong evidence for hydraulic redistribution (HR) of soil water by trees, it is not known if common mycorrhizal networks (CMN) can facilitate HR from mature trees to seedlings under field conditions. Ponderosa pine (Pinus ponderosa) seedlings were planted into root-excluding 61-microm mesh barrier chambers buried in an old-growth pine forest. After 2 yr, several mature trees were cut and water enriched in D(2)O and acid fuchsin dye was applied to the stumps. Fine roots and mycorrhizal root tips of source trees became heavily dyed, indicating reverse sap flow in root xylem transported water from stems throughout root systems to the root hyphal mantle that interfaces with CMN. Within 3 d, D(2)O was found in mesh-chamber seedling foliage > 1 m from source trees; after 3 wk, eight of 10 mesh-chamber seedling stem samples were significantly enriched above background levels. Average mesh-chamber enrichment was 1.8 x greater than that for two seedlings for which the connections to CMN were broken by trenching before D(2)O application. Even small amounts of water provided to mycorrhizas by HR may maintain hyphal viability and facilitate nutrient uptake under drying conditions, which may provide an advantage to seedlings hydraulically linked by CMN to large trees. PMID:18298435

Warren, Jeffrey M; Brooks, J Renée; Meinzer, Frederick C; Eberhart, Joyce L

2008-01-01

355

Maternal influences on seed mass effect and initial seedling growth in four Quercus species  

NASA Astrophysics Data System (ADS)

Seed mass represents the reserves available for growth in the first stages of plant establishment. Variation in seed mass is an important trait which may have consequences for growth and survival of seedlings. Three mechanisms have been proposed to explain how seed mass influences seedling development: the reserve use effect, the metabolic effect and the seedling-size effect. Few studies have evaluated at the same time the three hypotheses within species and none have evaluated the effect of the mother trees. We studied four Quercus species by selecting five mother trees per species. Seeds were sown in a glasshouse and the use of seed reserves, seedling growth and morphology were measured. Considering all mothers of the same species together, we did not find the reserve effect for any species, the metabolic effect was observed in all species except for Quercus suber, and the seedling-size effect was matched for all the species. Within species, maternal origin modified the studied relationships and thus the studied mechanisms as we did not observe seed mass effects on all mothers from each species. Moreover, the metabolic effect was not found in any mother of Quercus ilex and Quercus faginea. We concluded that a maternal effect can change seed mass relationships with traits related to seedling establishment. The conservation of this high intra-specific variability must be considered to guarantee species performance in heterogeneous environments and in particular in the current context of climate change.

González-Rodríguez, Victoria; Villar, Rafael; Navarro-Cerrillo, Rafael M.

2011-01-01

356

The effects of host defence elicitors on betacyanin accumulation in Amaranthus mangostanus seedlings.  

PubMed

The effect of elicitors associated with host defence on betacyanin accumulation in Amaranthus mangostanus seedlings was investigated. Under the conditions of the experiments, betacyanin accumulation was generally enhanced by light. Methyl jasmonate (MeJA) treatment increased betacyanin synthesis in a concentration-dependent response. Seedlings treated with ethylene as 5mM Ethephon also had elevated levels of betacyanin. In contrast, salicylic acid (SA) and H(2)O(2) treatments had no influence on betacyanin contents in light or dark. Combined MeJA with Ethephon or H(2)O(2) had an additive effect on betacyanin accumulation in dark-grown seedlings. However, a decline was recorded in light-grown seedlings. Moreover, an antagonistic effect on betacyanin synthesis was found when MeJA and SA were added simultaneously. Our results indicate that betacyanin content in A. mangostanus seedlings can be upregulated by MeJA and ethylene. Both additive and antagonistic effects in regulating betacyanin synthesis in A. mangostanus seedlings were observed between MeJA and other elicitors. PMID:23442611

Cao, Shifeng; Liu, Ting; Jiang, Yueming; He, Shenggen; Harrison, Dion K; Joyce, Daryl C

2012-10-15

357

Two Novel Techniques to Screen Abies Seedlings for Resistance to the Balsam Woolly Adelgid, Adelges piceae  

PubMed Central

Since its introduction into the Southern Appalachians in the 1950s, the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae), has devastated native populations of Fraser fir, Abies fraseri (Pursh) Poir. (Pinales: Pinaceae), and has become a major pest in Christmas tree plantations requiring expensive chemical treatments. Adelges piceae—resistant Fraser fir trees would lessen costs for the Christmas tree industry and assist in the restoration of native stands. Resistance screening is an important step in this process. Here, four studies directed toward the development of time— and cost—efficient techniques for screening are reported. In the first study, three methods to artificially infest seedlings of different ages were evaluated in a shade—covered greenhouse. Two—year—old seedlings had much lower infestation levels than 7 year—old seedlings. Placing infested bark at the base of the seedling was less effective than tying infested bark to the seedling or suspending infested bolts above the seedling. Although the two latter techniques resulted in similar densities on the seedlings, they each have positive and negative considerations. Attaching bark to uninfested trees is effective, but very time consuming. The suspended bolt method mimics natural infestation and is more economical than attaching bark, but care must be taken to ensure an even distribution of crawlers falling onto the seedlings. The second study focused on the density and distribution of crawlers falling from suspended bolts onto paper gridded into 7.6 × 7.6 cm cells. Crawler density in a 30 cm band under and to each side of the suspended bolt ranged from 400 to over 3000 crawlers per cell (1 to 55 crawlers per cm2). In the third study, excised branches from 4 year—old A. fraseri and A. vetchii seedlings were artificially infested with A. piceae to determine whether this technique may be useful for early resistance screening. The excised A. fraseri branches supported complete adelgid development (crawler to egg—laying adult), and very little adelgid development occurred on A. vetchii branches. The fourth study compared infestation levels and gouting response on excised versus intact branches of 4 year—old A. fraseri seedlings from three different seed sources, and excised branches from 4 year—old and 25 year—old trees. There were no differences in infestation levels between excised versus intact branches nor in very young versus mature trees; gouting response was observed only on intact branches. PMID:22239164

Newton, Leslie; Frampton, John; Monahan, John; Goldfarb, Barry; Hain, Fred

2011-01-01

358

Two novel techniques to screen Abies seedlings for resistance to the balsam woolly adelgid, Adelges piceae.  

PubMed

Since its introduction into the Southern Appalachians in the 1950s, the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae), has devastated native populations of Fraser fir, Abies fraseri (Pursh) Poir. (Pinales: Pinaceae), and has become a major pest in Christmas tree plantations requiring expensive chemical treatments. Adelges piceae-resistant Fraser fir trees would lessen costs for the Christmas tree industry and assist in the restoration of native stands. Resistance screening is an important step in this process. Here, four studies directed toward the development of time- and cost-efficient techniques for screening are reported. In the first study, three methods to artificially infest seedlings of different ages were evaluated in a shade-covered greenhouse. Two-year-old seedlings had much lower infestation levels than 7 year-old seedlings. Placing infested bark at the base of the seedling was less effective than tying infested bark to the seedling or suspending infested bolts above the seedling. Although the two latter techniques resulted in similar densities on the seedlings, they each have positive and negative considerations. Attaching bark to uninfested trees is effective, but very time consuming. The suspended bolt method mimics natural infestation and is more economical than attaching bark, but care must be taken to ensure an even distribution of crawlers falling onto the seedlings. The second study focused on the density and distribution of crawlers falling from suspended bolts onto paper gridded into 7.6 × 7.6 cm cells. Crawler density in a 30 cm band under and to each side of the suspended bolt ranged from 400 to over 3000 crawlers per cell (1 to 55 crawlers per cm²). In the third study, excised branches from 4 year-old A. fraseri and A. vetchii seedlings were artificially infested with A. piceae to determine whether this technique may be useful for early resistance screening. The excised A. fraseri branches supported complete adelgid development (crawler to egg-laying adult), and very little adelgid development occurred on A. vetchii branches. The fourth study compared infestation levels and gouting response on excised versus intact branches of 4 year-old A. fraseri seedlings from three different seed sources, and excised branches from 4 year-old and 25 year-old trees. There were no differences in infestation levels between excised versus intact branches nor in very young versus mature trees; gouting response was observed only on intact branches. PMID:22239164

Newton, Leslie; Frampton, John; Monahan, John; Goldfarb, Barry; Hain, Fred

2011-01-01

359

Effects of nitrogen source and defoliation on growth and biological dinitrogen fixation of Gliricidia sepium seedlings.  

PubMed

Effects of four N sources and two defoliation treatments on growth and nitrogenase activity of Gliricidia sepium (Jacq.) Walp seedlings were studied in a greenhouse. All nutrients were supplied in irrigation water to the sterile growing medium. The N sources were: (1) 100 mg l(-1) of N supplied as NO(3) (-) (high-NO(3) (-)), (2) 50 mg l(-1) of N supplied as NO(3) (-) and inoculation with Rhizobium spp. medium-NO(3) (-)), (3)100 mg l(-1) of N supplied as NH(4)NO(3), and (4) inoculation with Rhizobium spp without mineral N (N(2)). At 35 weeks after sowing, mean total biomass was 130.5, 50.5, 22.9 and 17.4 g seedling(-1) in the NH(4)NO(3), N(2), medium-NO(3) (-) and high-NO(3) (-) treatments, respectively. The root/shoot ratio was high in all of the N treatments (1.73-2.77) because the seedlings had big taproots. The medium-NO(3) (-) treatment completely inhibited nodulation, whereas seedlings in the N(2) treatment were profusely nodulated. At 32 weeks after sowing, groups of seedlings in the N(2) and high-NO(3) (-) treatments were subjected to 50 or 100% defoliation. Closed-chamber acetylene reduction assays of intact root systems were conducted to compare nitrogenase activity at 7, 14 and 28 days after defoliation (DAD). At 7 and 14 DAD, nitrogenase activity of completely and partially defoliated seedlings was about 10 and 60%, respectively, of that of undefoliated controls. At 28 DAD, nitrogenase activity of completely defoliated seedlings was twice the predefoliation value, whereas nitrogenase activity of partially defoliated seedlings was only 87% of the predefoliation value. Recovery of nitrogenase activity was strongly correlated with foliage regrowth in the completely defoliated seedlings, but not in the partially defoliated seedlings. Abundant belowground C and N reserves in the large taproot probably contributed to the rapid recovery from defoliation. Accumulation of belowground biomass may also improve defoliation tolerance of mature trees. PMID:12651524

Nygren, Pekka; Vaillant, Victor; Desfontaines, Lucienne; Cruz, Pablo; Domenach, Anne Marie

2000-01-01

360

The effect of sodium and ouabain on the influx of potassium into the seedlings of Arachis hypogea L., and the determination of trace quantities of sodium in seeds and seedling parts by non-destructive thermal neutron activation analysis  

E-print Network

THE EFFECT OF BODILESS AVD OUABAIN ON THE INFLUE OF POTASSIUM INTO THE SEEDLINGS OF ARACHIS HYPOGEA L, AND THE DETERMINATION OF TRACE OUANTITIES OF SODIUM IN SEEDS AND SEEDLING PARTS BY NON-DESTRUCTIVE THEW1AL NEUTFON ACTIVATION ANALYSIS A... AND OUABAIN ON THE INFLUX OF POTASSIUM INTO THE SEEDLINGS OF ARACHIS HYPOGEA L. , AND THE DETERMINATION OF TRACE QUANTITIES OF SODIUM IN SEEDS AND SEEDLING PARTS BY NON-DESTRUCTIVE THERMAL NEUTRON ACTIVATION ANALYSIS A Thesis by JAGAT SINGH App oved...

Singh, Jagat

1968-01-01

361

Early selection for chip quality and dry matter content in potato seedling populations in greenhouse or screenhouse  

Microsoft Academic Search

Summary  The possibilities of selecting individual seedlings and seedling populations for dry matter content and chip colour were examined.\\u000a Tuber glucose content as measured with Reflocheck Glucose test strips was strongly correlated with the colour of the chips,\\u000a but Gluko-Test strips were less reliable.\\u000a \\u000a Glasshouse and field determinations of both the dry matter content and the glucose content of the seedling

A. E. F. Neele; K. M. Louwes

1989-01-01

362

Local and regional variation in hemlock seedling establishment in forests of the upper Great Lakes region, USA  

Microsoft Academic Search

Successful tree regeneration requires both successful seedling establishment and subsequent survival and growth sufficient to ensure recruitment. We examined patterns of initial seedling establishment in randomly selected stands of eastern hemlock (Tsuga canadensis) distributed across northern Wisconsin and eastern Upper Michigan. In 1990, we counted all hemlock seedlings (defined as 4–29cm tall) and sampled substrate conditions in two 7×7m quadrats

Thomas P. Rooney; Donald M. Waller

1998-01-01

363

Survival of plains cottonwood ( Populus deltoides subsp. Monilifera ) and saltcedar ( Tamarix ramosissima ) seedlings in response to flooding  

Microsoft Academic Search

We examined the response of first year saltcedar (Tamarix ramosissima) and plains cottonwood (Populus deltoides subsp.monilifera) seedlings to flooding in fall (25 days) and spring (28 days) using potgrown plants (12–18 individuals\\/26.5-liter pot). Seedlings\\u000a were initially counted in all pots prior to fall treatment. Survival was calculated as the proportion of seedlings in cach\\u000a pot still alive following spring treatment.

Douglas N. Gladwin; James E. Roelle

1998-01-01

364

Light affects the chloroplast ultrastructure and post-storage photosynthetic performance of watermelon (Citrullus lanatus) plug seedlings.  

PubMed

Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] plug seedlings were stored at 15°C in the light at a photosynthetic photon flux density of 15 µmol·m(-2)·s(-1) or in darkness for 6 days, to evaluate their chloroplast ultrastructure, and associated photosynthetic characteristics. Storage in the dark caused swelling, disordered granal arrangement, and starch grain disappearance in the chloroplasts. In contrast, the chloroplasts stored in the light were relatively normal. As a result, the light-stored seedlings had a significantly higher chlorophyll content, Fv/Fm, and Pn than did dark-stored seedlings. Regardless of whether the seedlings were stored in light or darkness, the Gs and Ls of the seedlings significantly decreased, while the Ci obviously increased when the Pn decreased after 6 days of storage. This result suggests that the decreased Pn is not solely a stomatal effect, as the effects on the chloroplasts contributed to this photosynthetic inhibition. Six days after transplanting, seedlings that were stored in the light or darkness for 2 or 4 days showed complete recovery of chloroplast ultrastructure, chlorophyll content, Fv/Fm, Gs and Pn. When the storage period increased to 6 days, the dark-stored seedlings had a significantly lower Fv/Fm and Pn than the light-stored and control seedlings 6 days after transplanting, which was mainly ascribed to incomplete recovery of chloroplast ultrastructure. Furthermore, the light-stored seedlings exhibited a significantly higher shoot dry weight during storage and a higher percentage dry weight increase after transplanting than the dark-stored seedlings. These effects were enhanced by prolonged storage (4 to 6 days). This study demonstrated that dim light during storage is beneficial for maintaining chloroplast ultrastructure as well as photosynthetic efficiency in watermelon seedlings, thus contributing to the rapid recovery of post-storage photosynthetic performance, which ensures the transplant quality of the seedlings after removal from storage. PMID:25340859

Duan, Qingqing; Jiang, Wu; Ding, Ming; Lin, Ye; Huang, Danfeng

2014-01-01

365

Effect of co-inoculations of native PGPR with nitrogen fixing bacteria on seedling traits in Prosopis cineraria.  

PubMed

Prosopis cineraria significantly contribute to sand dune stabilization, soil fertility rejuvenation and is an integral component of agro-forestry systems in arid regions of India. Effect of different rhizobacterial seed treatments on seed germination and seedling traits in two genotypes of P. cineraria (HPY-1) and (FG-1) were tested. Observations on seed germination (%) and seedling traits viz., root length (cm), shoot length (cm), seedling weight (g) and seedling length of different treatments were recorded. Whereas, germination index (GI), seedling vigour index (SVI) and root/shoot length ratio were derived from the observed data. The scarification treatment with sulphuric acid for 10 minutes substantially enhanced germination from < 20% to 80-82% in control treatments. Treatments with co-inoculations of Bacillus licheniformis and Sinorhizobium kostiense or S. saheli supported the maximum seed germination and seedling growth and vigour. The maximum germination per cent (92.5%), seedling length (10.94 cm), seedling vigour index (10.12) and germination index (7.97) were recorded with treatment (V2T6) wherein seeds of high pod yielding genotype were co-inoculated with Bacillus licheniformis and S. kostiense. The higher positive correlations of seedling length v/s shoot length followed by SVI v/s seedling length, SVI v/s root length and seedling length v/s root length is a fair indicative of inter dependency of these characteristics. Higher R2 values of root length v/s shoot length followed by that of SVI v/s GI indicates that a regression line fits the data well and future outcomes of observed seedling traits are likely to be predicted by the model. PMID:25204069

Singh, S K; Pancholy, Anjly; Jindal, S K; Pathak, Rakesh

2014-09-01

366

Fine-scale spatial heterogeneity and seed size determine early seedling survival in a desert perennial shrub ( Ericameria nauseosa: Asteraceae)  

Microsoft Academic Search

In heterogenous landscapes, seeds settle in some microsites more readily than others, independently of whether those microsites\\u000a are suitable for germination and subsequent growth, and survival of seedlings. Wild seeds and seedlings of Ericameria\\u000a nauseosa var. oreophila in the sand-dune ecosystem near Mono Lake, California show both concordance and conflict in where seeds are retained and\\u000a where seedlings flourish. Using

Rebecca Balogh Benard; Catherine A. Toft

2008-01-01

367

Trigonelline accumulation in leaves of Panicum virgatum seedlings.  

PubMed

Panicum virgatum is a dominant, native, perennial species found in the tallgrass prairie. In this study, we report the biosynthesis and accumulation of trigonelline (TRG) in leaves of P. virgatum in response to water-deficit stress. Once established, half of the seedlings underwent a drought stress treatment while the other half were watered daily (control). Relative water content (RWC) and trigonelline (TRG) concentrations were determined. RWC showed an interaction between moisture treatment and time, in which upland cultivars had the highest mean RWC compared with the lowland cultivars. The moisture treatments showed a significant difference in TRG concentration across all P. virgatum cultivars, which ranged from 0.5-31.8 microg/gFW(-1). There was a divergence in TRG accumulation between upland and lowland cultivars in relation to RWC. This study is the first to report TRG accumulation in the grass P. virgatum, and to test for differences in TRG with respect to water-deficit stress among cultivars. The effect of soil moisture levels on cultivars may be important in making an informed selection and the response of P. virgatum and other dominant grasses should be considered as a potential filter in tallgrass prairies for restoration. Physiological markers such as TRG and RWC can aid in this decision making process. PMID:25233598

Schwartz, Lauren M; Wooda, Andrew J; Gibson, David J

2014-08-01

368

Rhizobacteria of Cotton and Their Repression of Seedling Disease Pathogens  

PubMed Central

During the 1983 field season, the rhizobacteria (including organisms from rhizosphere soil and the root rhizoplane) of cotton plants at one location in Mississippi were inventoried at different plant growth stages. Isolates (1,000) were identified to the genus level and characterized for repression of Pythium ultimum and Rhizoctonia solani. Cotton seedlings were initially colonized by bacteria of many different genera, and populations quickly reached 108 CFU/g of root tissue. As the season progressed, the bacterial populations declined as root mass increased and the roots became more woodlike in consistency. Fluorescent pseudomonads were the most numerous gram-negative rhizobacterial isolates of those that were randomly collected and identified, and they provided the largest number of isolates with fungal repressive activity. Several other gram-negative bacterial genera were recovered throughout the growing season, and some gram-positive bacteria were also isolated routinely, but at lower numbers. There was no correlation between the proportion of rhizobacterial isolates that possessed fungal repressive activity and the plant growth stage from which the isolates were obtained. Approximately twice as many bacterial isolates demonstrated fungal repression in the agar assay compared with the inplanta assay, and isolates were found more frequently with fungal repressive activity against P. ultimum than against R. solai. PMID:16348043

Hagedorn, C.; Gould, W. D.; Bardinelli, T. R.

1989-01-01

369

Polyamines in rice seedlings under oxygen-deficit stress  

SciTech Connect

Incubation of 3-d-old seedlings of Oryza sativa L. cv Arborio under anaerobic conditions, leads to a large increase in the titer of free putrescine while aerobic incubation causes a slight decrease. After 2 days, the putrescine level is about 2.5 times greater without oxygen than in air. The rice coleoptile also accumulates a large amount of bound putrescine and, to a lesser extent, spermidine and spermine (mainly as acid-soluble conjugates). Accumulation of conjugates in the roots is severely inhibited by the anaerobic treatment. Feeding experiments with labeled amino acids showed that anoxia stimulates the release of {sup 14}CO{sub 2} from tissues fed with ({sup 14}C)arginine and that arginine is the precursor in putrescine biosynthesis. After 2 d of anoxia, the activity of arginine decarboxylase was 42% and 89% greater in coleoptile and root, respectively, than in the aerobic condition. The causes of the differences in polyamine metabolism in anoxic coleoptiles and roots are discussed.

Reggiani, R.; Hochkoeppler, A.; Bertani, A. (A.N.R., Milano (Italy))

1989-11-01

370

Coronatine alleviates water deficiency stress on winter wheat seedlings.  

PubMed

With the aim to determine whether coronatine (COR) alleviates drought stress on wheat, two winter wheat (Triticum aestivum L.) cultivars, ChangWu134 (drought-tolerant) and Shan253 (drought-sensitive) were studied under hydroponic conditions. Seedlings at the three-leaf stage were cultured in a Hoagland solution containing COR at 0.1 microM for 24 h, and then exposed to 20% polyethylene glycol 6000 (PEG-6000). Under simulated drought (SD), COR increased the dry weight of shoots and roots of the two cultivars significantly; the root/shoot ratio also increased by 30% for Shan253 and 40% for ChangWu134. Both cultivars treated with COR under SD (0.1COR+PEG) maintained significantly higher relative water content, photosynthesis, transpiration, intercellular concentration of CO(2) and stomatal conductance in leaves than those not treated with PEG. Under drought, COR significantly decreased the relative conductivity and malondialdehyde production, and the loss of 1,1-diphenyl-2-picrylhydrazyl scavenging activity in leaves was significantly alleviated in COR-treated plants. The activity of peroxidase, catalase, glutathione reductase and ascorbate peroxidase were adversely affected by drought. Leaves of plants treated with COR under drought produced less abscisic acid (ABA) than those not treated. Thus, COR might alleviate drought effects on wheat by reducing active oxygen species production, activating antioxidant enzymes and changing the ABA level. PMID:20590992

Li, Xiangwen; Shen, Xuefeng; Li, Jianmin; Eneji, Anthony Egrinya; Li, Zhaohu; Tian, Xiaoli; Duan, Liusheng

2010-07-01

371

The effects of methyl bromide alternatives on soil and seedling microbial populations, weeds, and seedling morphology in Oregon and Washington forest tree nurseries  

Technology Transfer Automated Retrieval System (TEKTRAN)

Six fumigant treatments were evaluated at two forest tree nurseries in Oregon and one forest tree nursery in Washington for their effects on soil microbial populations, weeds, and seedling morphology during a 2-year study. Fusarium commune, F. oxysporum, Gibberella fujikuroi complex, P. irregulare,...

372

The Effects of Large Terrestrial Mammals on Seed Fates, Hoarding, and Seedling Survival in a Costa Rican Rain Forest.  

E-print Network

??Terrestrial mammals affect numerous aspects of plant demography, colonization, and community structure in Neotropical forests. Granivorous mammals destroy seeds via seed predation and seedlings through… (more)

Kuprewicz, Erin Kathleen

2010-01-01

373

Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L  

NASA Technical Reports Server (NTRS)

The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

Ng, Y. K.; Moore, R.

1985-01-01

374

Saturated humidity accelerates lateral root development in rice (Oryza sativa L.) seedlings by increasing phloem-based auxin transport.  

PubMed

Auxin transport plays a significant role modifying plant growth and development in response to environmental signals such as light and gravity. However, the effect of humidity on auxin transport is rarely documented. It is shown here that the transport of labelled indole-3-acetic acid (IAA) from the shoot to the root is accelerated in rice (Oryza sativa L. ssp. indica cv. IR8) seedlings grown under saturated humidity (SH-seedlings) compared with plants grown under normal humidity (NH-seedlings). The development of lateral roots in SH-seedlings was greatly enhanced compared with NH-seedlings. Removal of the shoot from SH-seedlings reduced the density of lateral roots, and the application of IAA to the cut stem restored the lateral root density, while the decapitation of NH-seedlings did not alter lateral root development. Phloem-based auxin transport appeared responsible for enhanced lateral root formation in SH-seedlings since (i) the rate of IAA transport from the shoot to the root tip was greater than 3.5 cm h-1 and (ii) naphthylphthalamic acid (NPA)-induced reduction of polar auxin transport in the shoot did not influence the number of lateral roots in SH-seedlings. It is proposed that high humidity conditions accelerate the phloem-based transport of IAA from the leaf to the root, resulting in an increase in the number of lateral roots. PMID:17383991

Chhun, Tory; Uno, Yuichi; Taketa, Shin; Azuma, Tetsushi; Ichii, Masahiko; Okamoto, Takashi; Tsurumi, Seiji

2007-01-01

375

Development of ectomycorrhizae on containerized sweet birch and European alder seedlings for planting on low quality sites  

SciTech Connect

A study was initiated to assess the potential of Pisolithus tinctorius as an ectomycorrhizal associate of containerized sweet birch (Betula lenta) and European alder (Alnus glutinosa) seedlings and to determine the effect of this fungal symbiont on seedling growth. In a test of sweet birch and European alder grown in Leach tubes, P. tinctorius formed abundant ectomycorrhizae on sweet birch when introduced via a vegetative mycelial inoculum. Cenococcum geophilum, originating from sclerotia present in the potting medium, and Thelephora terrestris, introduced via wind-borne propagules, formed ectomycorrhizae on the sweet birch seedlings inoculated with P. tinctorius and on the sweet birch control seedlings. C. geophilum also formed ectomycorrhizae on the inoculated and control European alder seedlings, but an inoculation with P. tinctorius did not result in the formation of P. tinctorius ectomycorrhizae on this host. Sweet birch seedlings infected with P. tinctorius had a greater dry weight, height, root collar diameter, and volume and a lower shoot/root ratio than the sweet birch control seedlings, and European alder seedlings with abundant C. geophilum ectomycorrhizae exhibited a similar improvement in growth in comparison with European alder with lesser C. geophilum infections. The inoculation of containerized sweet birch and European alder seedlings in the nursery with the appropriate ectomycorrhizal symbiont may facilitate the establishment of these species on harsh sites such as surface mine spoils. 57 references, 3 tables.

Walker, R.F.; West, D.C.; McLaughlin, S.B.

1982-01-01

376

Constraints on tree seedling establishment in montane grasslands of the Valles Caldera, New Mexico.  

PubMed

Montane and subalpine grasslands are prominent, but poorly understood, features of the Rocky Mountains. These communities frequently occur below reversed tree lines on valley floors, where nightly cold air accumulation is spatially coupled with fine soil texture. We used field experiments to assess the roles of minimum temperature, soil texture, grass competition, and ungulate browsing on the growth, photosynthetic performance, and survival of transplanted ponderosa pine (Pinus ponderosa) seedlings at 32 sites straddling such reversed tree lines in the Valles Caldera National Preserve (VCNP) of the Jemez Mountains, New Mexico (USA). Seedling growth increased most strongly with increasing nighttime minimum temperatures away from the valley bottoms; seedlings experiencing the coldest temperatures on the caldera floor exhibited stunted needles and often no measurable height growth. Based on the chlorophyll fluorescence ratios PhiPSII and Fv/Fm, we found that low minimum temperatures, low soil moisture, and fine soil texture all contributed to photoinhibition. Neighboring herbs had only minor negative effects on seedlings. We found no effect of ungulates, but golden-mantled ground squirrels (Spermophilus lateralis) caused substantial seedling mortality. Second-year seedling survival was highest on sandy soils, and third-year survival was highest at sites with higher minimum temperatures. We conclude that differential tree seedling establishment driven by low minimum temperatures in the valley bottoms is the primary factor maintaining montane grasslands of the VCNP, although this process probably operated historically in combination with frequent surface fire to set the position of the tree line ecotone. As at alpine tree lines, reversed tree lines bordering montane and subalpine grasslands can represent temperature-sensitive boundaries of the tree life form. PMID:18481534

Coop, Jonathan D; Givnish, Thomas J

2008-04-01

377

Flooding and SO/sub 2/ stress interaction in Betula papyrifera and B. nigra seedlings  

SciTech Connect

The effects of flooding of soil for 5 weeks and fumigation of shoots with 0.35 ppm SO/sub 2/ for 30 hours, alone and in combination, were studied on Betula papyrifera Marsh. (paper birch) and Betula nigra L. (river birch) seedlings. B. papyrifera, an upland species, was adversely affected by flooding more severely than B. nigra, a lowland species. Symptoms of flooding injury in both species included stomatal closure, chlorosis, deterioration of root systems, and greatly reduced dry matter accumulation. Flooding induced formation of hypertrophied lenticels and adventitious roots in B. nigra but not B. papyrifera seedlings. Seedlings of both species recovered 1 to 2 wk after flooding ended and continued growing at a faster rate than unflooded seedlings, thereby partially or completely compensating for the growth-inhibiting effects of flooding. Fumigation with SO/sub 2/ at the end of the flooding period induced partial stomatal closure, injury to leaves, and reductions in mean relative growth rates in both species. Stomatal conductance and SO/sub 2/ uptake in B. nigra seedlings were reduced 40 to 45 percent by flooding, respectively, and consequently SO/sub 2/ caused less visible injury (17 vs. 44 percent of leaf area) and less growth inhibition (0 vs. 26 percent in mean relative root growth rate) in flooded than in unflooded seedlings. Stomatal conductance and SO/sub 2/ uptake were reduced even more in flooded B. papyrifera (75 and 77 percent, respectively), yet flooded and unflooded seedlings were similarly affected by SO/sub 2/. Flooding stress apparently affected mechanisms of pollution avoidance and pollution tolerance differently in the two species.

Norby, R.J.; Kozlowski, T.T.

1983-12-01

378

Flooding and SO/sub 2/ stress interaction in Betula papyrifera and B. nigra seedlings  

SciTech Connect

The effects of flooding of soil for 5 weeks and fumigation of shoots with 0.35 ppm SO/sub 2/ for 30 hours, alone and in combination, were studied on Betula papyrifera Marsh. (paper birch) and Betula nigra L. (river birch) seedlings. B. papyrifera, an upland species, was adversely affected by flooding more severely than B. nigra, a lowland species. Symptoms of flooding injury in both species included stomatal closure, chlorosis, deterioration of root systems, and greatly reduced dry matter accumulation. Flooding induced formation of hypertrophied lenticels and adventitious roots in B. nigra but not B. papyrifera seedlings. Seedlings of both species recovered 1 to 2 wk after flooding ended and continued growing at a faster rate than unflooded seedlings, thereby partially or completely compensating for the growth-inhibiting effects of flooding. Fumigation with SO/sub 2/ at the end of the flooding period induced partial stomatal closure, injury to leaves, and reductions in mean relative growth rates in both species. Stomatal conductance and SO/sub 2/ uptake in B. nigra seedlings were reduced 40 and 45% by flooding, respectively, and consequently SO/sub 2/ caused less visible injury (17 vs. 44% of leaf area) and less growth inhibition (0 vs. 26% in mean relative root growth rate) in flooded than in unflooded seedlings. Stomatal conductance and SO/sub 2/ uptake were reduced even more in flooded B. papyrifera (75 and 77%, respectively), yet flooded and unflooded seedlings were similarly affected by SO/sub 2/. Flooding stress apparently affected mechanisms of pollution avoidance and pollution tolerance differently in the two species.

Norby, R.J.; Kozlowski, T.T.

1983-01-01

379

Early selection of black spruce seedlings and global change: Which genotypes should we favor  

SciTech Connect

The effects of both soil fertility and predicted changes in climate on growth of different families of black spruce, Picea mariana (Mill.) B.S.P., during the first growing season was studied. The results were used to examine whether reforestation programs should consider changing their preferred family lines in anticipation of altered performance given global climate change. We grew seedlings of 16 open-pollinated maternal families of black spruce under phytotron conditions simulating present and mid-21st century climatic conditions during the growing season. The realistic, simulated future climate included both elevated CO[sub 2] levels and seasonally appropriate increases in mean daily temperature. To explore the dependence of climatic responses on site quality, seedlings were irrigated with solutions having either 5 or 100 mg/L of nitrogen. The lower nitrogen level represents a poor site for black spruce growth and survival, but the higher level provides ample nitrogen. We also recorded seed size for each seedling to evaluate the degree to which maternal investments might buffer responses to future climate and fertility during the first year on the seedbed. Seedling survival and growth increase both under the future climate regime and with nitrogen fertilization. The two factors interacted synergistically, with nitrogen enrichment significantly enhancing the positive effects of the future climate regime. Nitrogen-poor conditions, however, did not preclude a positive seedling response to the future climate. Our results indicate that seedling survival and height growth are highly dependent upon initial seed mass, seed germination, and seedling, survival and growth, but their relative performances did not vary significantly among the treatments. These results suggest that black spruce families selected for rapid growth under present conditions will also do well in the future, at least in terms of early establishment and performance on sites regenerated by seeding.

Wang, Z.M.; Lechowicz, M.J.; Potvin, C. (McGill Univ., Montreal (Canada))

1994-08-01

380

Herbivory of tropical rain forest tree seedlings correlates with future mortality.  

PubMed

Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies. PMID:20462123

Eichhorn, Markus P; Nilus, Reuben; Compton, Stephen G; Hartley, Sue E; Burslem, David F R P

2010-04-01

381

Ability of ellagic acid to alleviate osmotic stress on chickpea seedlings.  

PubMed

Seed germination and growth of seedlings are critical phases of plant life that are adversely affected by various environmental cues. Water availability is one of the main factors that limit the productivity of many crops. This study was conducted to assess the changes in the sensitivity of chickpea seedlings to osmotic stress by prior treatment of chickpea seeds with a low concentration (50 ppm) of ellagic acid. Ellagic acid was isolated and purified from Padina boryana Thivy by chromatographic techniques. After ellagic acid treatment, seeds were germinated for 10 days under different osmotic potentials (0, -0.2, -0.4, -0.6 and -0.8 MPa) of polyethylene glycol (PEG) solutions. Ellagic acid treatment accelerated the germination and seedling growth of chickpea under osmotic stress conditions. Consistent with the accelerated growth, ellagic acid-treated seedlings also showed a significant increase in the total antioxidant capacity (FRAP) as well as an increase in the compatible solutes (proline and glycine betaine) content. Additionally, treated seedlings revealed lower lipid peroxidation levels (MDA), electrolyte leakage (EL) and H2O2. Flavonoid and reduced glutathione (GSH) content, and the activity of antioxidant enzymes [catalase (CAT), peroxidase (POX), superoxide dismutase (SOD), glutathione reductase (GR)] and enzymes of the shikimic acid pathway [phenylalanine ammonia lyase (PAL) and chalcone synthase (CHS)] all showed a remarkable increase with ellagic acid pretreatment compared to untreated seedlings especially under mild osmotic stress values (-0.2 and -0.4 MPa). These results suggested that treatment with ellagic acid could confer an increased tolerance of chickpea seedlings to osmotic stress, through reducing levels of H2O2 and increasing antioxidant capacity. PMID:23938205

Abu El-Soud, Walid; Hegab, Momtaz Mohamed; AbdElgawad, Hamada; Zinta, Gaurav; Asard, Han

2013-10-01

382

Basal Transcription Factor 3 Plays an Important Role in Seed Germination and Seedling Growth of Rice  

PubMed Central

BTF3 has been recognized to be involved in plant growth and development. But its function remains mostly unknown during seed germination and seedling stage. Here, we have analyzed OsBTF3-related sequences in Oryza sativa L. subspecies, japonica, which resembles with the conserved domain of a nascent polypeptide associated complex (NAC) with different homologs of OsBTF3 and human BTF3. Inhibition of Osj10gBTF3 has led to considerable morphological changes during seed germination and seedling growth. Germination percentage was not influenced by the application of GA3, ABA, and NaCl but all concentrations caused wild-type (WT) seeds to germinate more rapidly than the RNAi (Osj10gBTF3Ri) transgenic lines. Seedling inhibition was more severe in the Osj10gBTF3Ri seedlings compared with their WT especially when treated with 100 or 200??M GA3; 50% reduction in shoots was observed in Osj10gBTF3Ri seedlings. The expression of Osj3g1BTF3, Osj3g2BTF3 and Osj10gBTF3 was primarily constitutive and generally modulated by NaCl, ABA, and GA3 stresses in both Osj10gBTF3Ri lines and WT at the early seedling stage, suggesting that Osj3g1BTF3 and Osj10gBTF3 are much similar but different from Osj3g2BTF3 in biological function. These results show that OsBTF3 plays an important role in seed germination and seedling growth gives a new perception demonstrating that more multifaceted regulatory functions are linked with BTF3 in plants. PMID:24971328

Wang, Wenyi; Xu, Mengyun; Wang, Ya

2014-01-01

383

Seedling Responses to Water Pulses in Shrubs with Contrasting Histories of Grassland Encroachment  

PubMed Central

Woody plant encroachment into grasslands has occurred worldwide, but it is unclear why some tree and shrub species have been markedly more successful than others. For example, Prosopis velutina has proliferated in many grasslands of the Sonoran Desert in North America over the past century, while other shrub species with similar growth form and life history, such as Acacia greggii, have not. We conducted a glasshouse experiment to assess whether differences in early seedling development could help explain why one species and not the other came to dominate many Sonoran Desert grasslands. We established eight watering treatments mimicking a range of natural precipitation patterns and harvested seedlings 16 or 17 days after germination. A. greggii had nearly 7 times more seed mass than P. velutina, but P. velutina emerged earlier (by 3.0±0.3 d) and grew faster (by 8.7±0.5 mg d?1). Shoot mass at harvest was higher in A. greggii (99±6 mg seedling?1) than in P. velutina (74±2 mg seedling?1), but there was no significant difference in root mass (54±3 and 49±2 mg seedling?1, respectively). Taproot elongation was differentially sensitive to water supply: under the highest initial watering pulse, taproots were 52±19 mm longer in P. velutina than in A. greggii. Enhanced taproot elongation under favorable rainfall conditions could give nascent P. velutina seedlings growth and survivorship advantages by helping reduce competition with grasses and maintain contact with soil water during drought. Conversely, A. greggii's greater investment in mass per seed appeared to provide little return in early seedling growth. We suggest that such differences in recruitment traits and their sensitivities to environmental conditions may help explain ecological differences between species that are highly similar as adults and help identify pivotal drivers of shrub encroachment into grasslands. PMID:24475263

Woods, Steven R.; Archer, Steven R.; Schwinning, Susan

2014-01-01

384

Salt stress-induced seedling growth inhibition coincides with differential distribution of serotonin and melatonin in sunflower seedling roots and cotyledons.  

PubMed

Indoleamines regulate a variety of physiological functions during the growth, morphogenesis and stress-induced responses in plants. Present investigations report the effect of NaCl stress on endogenous serotonin and melatonin accumulation and their differential spatial distribution in sunflower (Helianthus annuus) seedling roots and cotyledons using HPLC and immunohistochemical techniques, respectively. Exogenous serotonin and melatonin treatments lead to variable effect on hypocotyl elongation and root growth under NaCl stress. NaCl stress for 48?h increases endogenous serotonin and melatonin content in roots and cotyledons, thus indicating their involvement in salt-induced long distance signaling from roots to cotyledons. Salt stress-induced accumulation of serotonin and melatonin exhibits differential distribution in the vascular bundles and cortex in the differentiating zones of the primary roots, suggesting their compartmentalization in the growing region of roots. Serotonin and melatonin accumulation in oil body rich cells of salt-treated seedling cotyledons correlates with longer retention of oil bodies in the cotyledons. Present investigations indicate the possible role of serotonin and melatonin in regulating root growth during salt stress in sunflower. Effect of exogenous serotonin and melatonin treatments (15 ?M) on sunflower seedlings grown in the absence or presence of 120 mM NaCl substantiates their role on seedling growth. Auxin and serotonin biosynthesis are coupled to the common precursor tryptophan. Salt stress-induced root growth inhibition, thus pertains to partial impairment of auxin functions caused by increased serotonin biosynthesis. In seedling cotyledons, NaCl stress modulates the activity of N-acetylserotonin O-methyltransferase (HIOMT; EC 2.1.1.4), the enzyme responsible for melatonin biosynthesis from N-acetylserotonin. PMID:24799301

Mukherjee, Soumya; David, Anisha; Yadav, Sunita; Baluška, František; Bhatla, Satish Chander

2014-12-01

385

Endoreduplication in the germinating embryo and young seedling is related to the type of seedling establishment but is not coupled with superoxide radical accumulation.  

PubMed

During germination, the embryo axis elongates and the radicle emerges through the surrounding structures of the seed. However, this elongation is not even along the axis, and it has been suggested that the region responsible for radicle protrusion is related to the type of subsequent seedling establishment. Eleven epigeal- and five hypogeal-type species were selected to study endoreduplication, a process coupled with cell elongation, in the radicle, hypocotyl-radicle transition zone, hypocotyl, and cotyledons of dry and germinating seeds, and in seedlings after radicle protrusion. Flow cytometry was used to establish the proportions of nuclei with different DNA contents, the mean C-value, and the (?>2C)/2C ratio. Additionally, a nitroblue tetrazolium chloride test was applied to the embryos/seedlings in the dry state and during and after germination to localize superoxide radical (O2(•-)) accumulation, which has been suggested to play a role in cell elongation. Endoreduplication intensity varied in different species, in the embryo/seedling regions, and with the type of seedling establishment. In most of the cases, it was highest in the transition zone of epigeal species and in the hypocotyl in hypogeal species. O2(•-) was invariably produced during germination in the radicle, and additionally in the transition zone at the time of radicle protrusion; thus, it was not coupled with endoreduplication, and most probably played a role in defence against biotic and abiotic environmental stresses. These results provide information to aid in the selection of the most suitable plant material for molecular research on germination and for monitoring seed priming. PMID:24863437

Rewers, Monika; Sliwinska, Elwira

2014-08-01

386

Respiration and Alternative Oxidase in Corn Seedling Tissues during Germination at Different Temperatures  

PubMed Central

Respiration rates of Zea mays L. seedling tissues grown at 30 and 14°C were measured at 25°C at different stages of seedling growth. Accumulation of heat units was used to define the developmental stages to compare respiration between the two temperatures. At both temperatures, respiration rates of most tissues were highest at the youngest stages, then declined with age. Respiration rates of mesocotyl tissue were the most responsive to temperature, being nearly twofold higher when grown at 14 compared to 30°C. Alternative pathway respiration increased concomitantly with respiration and was higher in mesocotyls grown in the cold. When seedlings were started at 30 then transferred to 14°C, the increase in alternative pathway respiration due to cold was not observed unless the seedlings were transferred before 2 days of growth. Seedlings transferred to 14°C after growth at 30°C for 2 days had the same alternative oxidase capacity as seedlings grown at 30°C. Seedlings grown at 14°C for 10 to 12 days, then transferred to 30°C, lost alternative pathway respiratory capacity over a period of 2 to 3 days. Western blots of mitochondrial proteins indicated that this loss of capacity was due to a loss of the alternative oxidase protein. Some in vitro characteristics of mitochondria were determined. The temperature optimum for measurement of alternative oxidase capacity was 15 to 20°C. At 41°C, very little alternative oxidase was measured, i.e., the mitochondrial oxygen uptake was almost completely sensitive to cyanide. This inactivation at 41°C was reversible. After incubation at 41°C, the alternative oxidase capacity measured at 25°C was the similar to when it was measured at that temperature directly. Isolated mitochondria lost alternative oxidase capacity at the same rate when incubated at 41°C as they did when incubated at 25°C. Increasing the supply of electrons to isolated mitochondria increased the degree of engagement of the alternative pathway, whereas lower temperature decreased the degree of engagement. Lower temperatures did not increase the degree of engagement of the pathway in intact tissues. We interpret these observations to indicate that the greater capacity of alternative oxidase in cold-grown seedlings is a consequence of development at these low temperatures which results in elevated respiration rates. Low temperature itself does not cause greater capacity or engagement of the alternative oxidase in mitochondria that have developed under warm temperatures. Our hypothesis would be that the low growth temperatures require the seedlings to have a higher respiration rate for some reason, e.g., to prevent the accumulation of a toxic metabolite, and that the alternative pathway functions in that respiration. Images Figure 2 PMID:16667345

Stewart, Cecil R.; Martin, Barry A.; Reding, Linda; Cerwick, Sharon

1990-01-01

387

Accumulation of cesium-137 and strontium-90 in ponderosa pine and monterey pine seedlings  

SciTech Connect

Because Pinus ponderosa (Dougl.ex Laws) and P. radiata (D.Don) have exceptionally fast growth rates and their abscised needles are not readily dispersed by wind, these species may be valuable for removing radioisotopes from contaminated soils. P. ponderosa and P. radiata seedlings were tested for their ability to accumulate Cesium 137 and Strontium 90--characteristic radioisotopes of nuclear fallout--from contaminated soil. All seedlings were grown for 3 months in cu cm of sphagnum peat moss:perlite (1:1 V:V) in a growth chamber. In experiment 1, seedling accumulation of 137 CS and 90 Sr after 1 month of exposure was measured. In experiment 2, seedling accumulation of the radioisotopes during different-length exposures was measured. Experiment 3 measured seedling accumulation of CS 137 and SR 90 at different concentrations of the radioisotopes in the growth medium. Accumulation of CS 137 and SR 90 by both species increased with increasing concentration in the growth medium and correlated curvilinearly with radioisotope concentration in the growth medium. (Copyright (c) 1993, Environmental Quality.)

Entry, J.A.; Rygiewicz, P.T.; Emmingham, W.H.

1993-01-01

388

[Effects of exogenous silicon on physiological characteristics of cucumber seedlings under ammonium stress].  

PubMed

The present study evaluated the effects of exogenous silicon on growth and physiological characteristics of hydroponically cultured cucumber seedlings under ammonium stress. The results showed that the growth, especially the aerial part growth of cucumber seedlings cultured with ammonium were significantly inhibited than those with nitrate, especially after treatment for 10 d, the aerial part fresh mass of cucumber seedlings were reduced 6.17 g per plant. The accumulation of reactive oxygen species (ROS) was also promoted in cucumber seedlings under ammonium, and the contents of O2*- and H2O2 were significantly increased in cucumber leaves. With the exogenous silicon treatment, the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) were significantly improved, the ability to remove reactive oxygen species was enhanced, the contents of O2*- and H2O2 were significantly reduced in cucumber leaves, decreasing the reactive oxygen damage to the cell membrane, and the ratio of electrolyte leakage and the content of MDA in cucumber leaves. Also, with exogenous silicon treatment, the plasma membrane and activity of vacuolar membrane H(+)-ATP was significantly increased, transport capacity of intracellular proton was improved, and the level of ammonium in cucumber body was significantly reduced, thereby reducing the toxicity of ammonium. In conclusion, exogenous silicon could relieve ammonium stress, by increasing the antioxidant enzyme activity, H(+)-ATP activity, and decreasing the ammonium content in cucumber seedlings. PMID:25129941

Gao, Qing-Hai; Wang, Ya-Kun; Lu, Xiao-Min; Jia, Shuang-Shuang

2014-05-01

389

Expression of stress-related genes in zebrawood (Astronium fraxinifolium, Anacardiaceae) seedlings following germination in microgravity  

PubMed Central

Seeds of a tropical tree species from Brazil, Astronium fraxinifolium, or zebrawood, were germinated, for the first time in microgravity, aboard the International Space Station for nine days. Following three days of subsequent growth under normal terrestrial gravitational conditions, greater root length and numbers of secondary roots was observed in the microgravity-treated seedlings compared to terrestrially germinated controls. Suppression subtractive hybridization of cDNA and EST analysis were used to detect differential gene expression in the microgravity-treated seedlings in comparison to those initially grown in normal gravity (forward subtraction). Despite their return to, and growth in normal gravity, the subtracted library derived from microgravity-treated seedlings was enriched in known microgravity stress-related ESTs, corresponding to large and small heat shock proteins, 14-3-3-like protein, polyubiquitin, and proteins involved in glutathione metabolism. In contrast, the reverse-subtracted library contained a comparatively greater variety of general metabolism-related ESTs, but was also enriched for peroxidase, possibly indicating the suppression of this protein in the microgravity-treated seedlings. Following continued growth for 30 days, higher concentrations of total chlorophyll were detected in the microgravity-exposed seedlings. PMID:24688295

Inglis, Peter W.; Ciampi, Ana Y.; Salomão, Antonieta N.; Costa, Tânia da S.A.; Azevedo, Vânia C.R.

2014-01-01

390

Low root reserve accumulation during drought may lead to winter mortality in poplar seedlings.  

PubMed

Climate models suggest that more frequent drought events of greater severity and length, associated with climate change, can be expected in the coming decades. Although drought-induced tree mortality has been recognized as an important factor modulating forest demography at the global scale, the mechanisms underlying drought-induced tree mortality remain contentious. Above- and below-ground growth, gas exchange, water relations and carbon reserve accumulation dynamics at the organ and whole-plant scale were quantified in Populus tremuloides and P. balsamifera seedlings in response to severe drought. Seedlings were maintained in drought conditions over one growing and one dormant winter season. Our experiment presents a detailed description of the effect of severe drought on growth and physiological variables, leading to seedling mortality after an extended period of drought and dormancy. After re-watering following the dormant period, drought-exposed seedlings did not re-flush, showing that the root system had died off. The results of this study suggest a complex series of physiological feedbacks between the measured variables in both Populus species. Further, they reveal that reduced reserve accumulation in the root system during drought decreases the conversion of starch to soluble sugars in roots, which may contribute to the root death of drought-exposed seedlings during the dormant season by compromising the frost tolerance of the root system. PMID:23347066

Galvez, David A; Landhäusser, S M; Tyree, M T

2013-04-01

391

Presowing seed treatment with melatonin protects red cabbage seedlings against toxic copper ion concentrations.  

PubMed

One of the targets of modern plant physiology is to identify tools for improving seed germination and plant growth under unfavorable environmental conditions. Seeds of Brassica oleracea rubrum were pretreated with melatonin at concentrations: 1, 10, and 100 microM using a hydropriming method. Air-dried seeds of each experimental variants that were nonpretreated (control), hydroprimed (H) or hydroprimed with melatonin (HM1, HM10, and HM100) were germinated in darkness for 3 days at 25 degrees C. Young seedlings were then transferred to the light and grown for an additional 5 days. Both germination and growth tests were performed in water and in CuSO(4) water solutions in concentrations of 0.5 and 1 mM. H, HM1 and HM10 improved seed germination both in water and in the presence of Cu(2+). One or 10 microM melatonin eliminated the inhibitory effect of the 0.5 mM metal concentration on the fresh weight of seedlings. HM100 had a negative effect; thus seed germination was lower and seedlings had poor establishment. The toxic effect of Cu(2+) manifested by membrane peroxidation and DNA endoreplication blocking in the seedlings grown from nontreated (control) and H seeds was not observed in the seedlings grown from HM1 and HM10 seeds; in contrast, HM100 enhanced the toxic effect of Cu(2+). PMID:18205729

Posmyk, Ma?gorzata M; Kuran, Hanna; Marciniak, Kazimierz; Janas, Krystyna M

2008-08-01

392

Optimizing the calcium content of a copolymer acrylamide gel matrix for dark-grown seedlings  

NASA Technical Reports Server (NTRS)

A copolymer acrylamide acrylate gel was investigated as the sole root matrix for dark-grown seedlings of soybean (Glycine max Merr. 'Century 84'). Increasing Ca2+ in the hydrating solution of the hydrogel from 1 to 10 mM decreased its water-holding capacity from 97 to 46 mL g-1, yet water potential of the medium remained high, sufficient for normal plant growth at all Ca2+ concentrations tested. Elongation rate of dark-grown soybean seedlings over a 54-hour period was 0.9, 1.5, and 1.8 mm h-1 with 1.0, 2.5, or 5.0 mM Ca2+, respectively, but did not increase with further increases in Ca2+ concentration. Further study revealed that Na+ was released from the hydrogel medium and was taken up by the seedlings as Ca2+ increased in the medium. In dry hypocotyl tissue, sodium content correlated negatively with calcium content. Despite the presence of Na+ in the hydrogel, seedling growth was normal when adequate Ca2+ was added in the hydrating solution. Acrylamide hydrogels hold good potential as a sole growth matrix for short-term experiments with dark-grown seedlings without irrigation.

Myers, P. N.; Mitchell, C. A.

1998-01-01

393

Physio-anatomic aspects on the initial growth of Guazuma ulmifolia Lam. seedlings.  

PubMed

This paper aimed to evaluate the initial growth of "mutambo" seedlings in different conditions of light intensity and treatments with gibberellic acid (GA). The seedlings were kept under full sun and 50% of shading. Sixty days after the emergence, seedlings were sprayed with: 1) 100 mg L(-1) GA(3); 2) 200 mg L(-1) GA(3); 3) control. At the end of the appraisals, seedlings height under 50% of shading was compared to the height that were growing under full sun with 200 mg L(-1) GA. Stem diameter was lower under shading. Leaf area did not vary among the treatments, but the root system growth was higher under full sun and did not vary among GA levels. The number of stomata, trichomes and epidermal cells on adaxial and abaxial sides was higher under full sun. Total dry masses of leaf and root were highe runder full sun and with 200 mg L(-1) GA application. "Mutambo" seedlings presented a higher initial growth under full sun, although with a lower height, diameter, and lenght of the largest root and total dry masses of leaf and root were higher. A concentration with 200 mg L(-1) promoted a higher growth. PMID:21670888

Scalon, Silvana P Q; Pereira, Heloisa H G; Glaeser, Daniele F; Silva, Jocemar J; Betoni, Roseli; Mussury, Rosilda M

2011-06-01

394

[Impacts of digging Phascolosoma esculenta on the growth of mangrove Avicennia marina seedlings: a simulation study].  

PubMed

Digging Phascolosoma esculenta to increase income is one of the main causes leading to the degradation of China mangroves. In order to understand the impact mechanisms of digging P. esculenta on the mangrove growth and to select indicators to evaluate the mangrove health, a simulative study was conducted to clarify the impacts of digging depth, radian, and frequency on the growth of 1-year old Avicennia marina seedlings, with the indices seedling height, basal diameter, single leaf area, specific leaf area, total biomass, and dead root dry mass measured. The results showed that digging activities decreased the increment of seedling height and basal diameter, single leaf area, specific leaf area, and total biomass significantly, and increased the dead root dry mass markedly. Digging depth and radian had obvious effects on the growth of A. marina seedlings, but digging frequency had minor effects. When the digging depth was < 5 cm, digging radian was < 240 degrees, and digging frequency was < 2 times per month, the damage to the seedlings was slighter; but when the digging depth was > 5 cm, the damage was quite serious. PMID:22803458

He, Qin-Fei; Fan, Hang-Qing; Mo, Zhu-Cheng; Wang, Xin; Shen, Wen-Hui

2012-04-01

395

[Effects of coat and sowing depth on seed germination and early seedling growth of Quercus wutaishanica].  

PubMed

Under shade environment in glasshouse, the effects of seed coat and sowing depth (0, 2, 5, 10 or 15 cm) on seed germination and early seedling growth of Quercus wutaishanica were studied. Seed coat had obvious inhibiting effects on the germination of Q. wutaishanica seeds. The germination percentage of uncoated seeds increased significantly, averagely by 19.4% at different sowing depths. The germination index and vigor index were increased significantly and the germination was speeded in the peeling treatment. The germination percentages of uncoated and coated seeds were the highest at the sowing depth of 2 cm with 78.9% and 62.2%, respectively. The germination index and vigor index were the highest at the sowing depth of 2 cm, while the coefficient of rate of germination were the highest at the sowing depth of 5 cm. Leaf area per seedling and dry mass of seedlings increased significantly in the peeling treatment compared with those in the unpeeling treatment, but specific root length decreased significantly. The shoot height in the peeling and unpeeling treatments were the highest at the sowing depth of 5 cm with 13.8 and 14.2 cm, respectively. With the increasing of sowing depth, the basal stem diameter of seedlings increased, but tap-root length, number of lateral root and maximum of lateral root all decreased. Sowing depth had little influence on dry mass of seedlings. PMID:24765842

Yan, Xing-Fui; Qiu, Zhi-Hu; Zhang, Qiang; Zhang, Kao-Wen; Zhou, Yun-Feng

2014-01-01

396

Influence of germination date on Dioon edule (Zamiaceae) seedling tolerance to water stress.  

PubMed

Dioon edule seedling mortality is mostly attributed to dehydration by prolonged drought, even when they present xeromorphic characteristics like the adult plants. The effect of germination date (GD) and soil water deficit on seedling tolerance to water stress was assessed. The seedlings germinated and grown from mature seeds every month from December to April GD were selected to evaluate the leaf area, photosynthetic pigment content, crassulacean acid metabolism (CAM) activity, stomatal conductance (gs) and leaflet anatomy at soil water potential (?s) of 0.0 MPa (day 1), -0.1 MPa (day 40), -1.0 MPa (day 90), -1.5 MPa (day 130), and a control (0.0 MPa at day 130) to recognize differences due to leaf development. The seedlings shifted from C3 to CAM cycling when exposed to water stress at ?s of -1.0 MPa, like adult plants. The March-April GD seedlings with undeveloped sclerified hypodermis and stomata, presented reduced leaf area, lower Chlorophyll a/b ratio, higher CAM activity and midday partial stomatal closure when reached ?s of -1.0 MPa. These have higher probability of dehydration during severe drought (February-April) than those of the December-February GD with similar ?s. Plants used for restoration purposes must have full leaf development to increase the survival. PMID:24500792

Yáñez-Espinosa, Laura; Flores, Joel; Rodríguez Millán, Paulina S; Rubio Méndez, Gabriel

2014-05-01

397

Light intensity alters the extent of arsenic toxicity in Helianthus annuus L. seedlings.  

PubMed

The present study is aimed at assessing the extent of arsenic (As) toxicity under three different light intensities-optimum (400 ?mole photon m(-2) s(-1)), sub-optimum (225 ?mole photon m(-2) s(-1)), and low (75 ?mole photon m(-2) s(-1))-exposed to Helianthus annuus L. var. DRSF-113 seedlings by examining various physiological and biochemical parameters. Irrespective of the light intensities under which H. annuus L. seedlings were grown, there was an As dose (low, i.e., 6 mg kg(-1) soil, As1; and high, i.e., 12 mg kg(-1) soil, As2)-dependent decrease in all the growth parameters, viz., fresh mass, shoot length, and root length. Optimum light-grown seedlings exhibited better growth performance than the sub-optimum and low light-grown seedlings; however, low light-grown plants had maximum root and shoot lengths. Accumulation of As in the plant tissues depended upon its concentration used, proximity of the plant tissue, and intensity of the light. Greater intensity of light allowed greater assimilation of photosynthates accompanied by more uptake of nutrients along with As from the medium. The levels of chlorophyll a, b, and carotenoids declined with increasing concentrations of As. Seedlings acquired maximum Chl a and b under optimum light which were more compatible to face As1 and As2 doses of As, also evident from the overall status of enzymatic (SOD, POD, CAT, and GST) and non-enzymatic antioxidant (Pro). PMID:24699829

Yadav, Geeta; Srivastava, Prabhat Kumar; Singh, Vijay Pratap; Prasad, Sheo Mohan

2014-06-01

398

Carbon and nitrogen gain during the growth of orchid seedlings in nature.  

PubMed

For germination and establishment, orchids depend on carbon (C) and nutrients supplied by mycorrhizal fungi. As adults, the majority of orchids then appear to become autotrophic. To compare the proportional C and nitrogen (N) gain from fungi in mycoheterotrophic seedlings and in adults, here we examined in the field C and N stable isotope compositions in seedlings and adults of orchids associated with ectomycorrhizal and saprotrophic fungi. Using a new highly sensitive approach, we measured the isotope compositions of seedlings and adults of four orchid species belonging to different functional groups: fully and partially mycoheterotrophic orchids associated with narrow or broad sets of ectomycorrhizal fungi, and two adult putatively autotrophic orchids associated exclusively with saprotrophic fungi. Seedlings of orchids associated with ectomycorrhizal fungi were enriched in (13) C and (15) N similarly to fully mycoheterotrophic adults. Seedlings of saprotroph-associated orchids were also enriched in (13) C and (15) N, but unexpectedly their enrichment was significantly lower, making them hardly distinguishable from their respective adult stages and neighbouring autotrophic plants. We conclude that partial mycoheterotrophy among saprotroph-associated orchids cannot be identified unequivocally based on C and N isotope compositions alone. Thus, partial mycoheterotrophy may be much more widely distributed among orchids than hitherto assumed. PMID:24444001

Stöckel, Marcus; T?šitelová, Tamara; Jersáková, Jana; Bidartondo, Martin I; Gebauer, Gerhard

2014-04-01

399

Exploring the Natural Variation for Seedling Traits and Their Link with Seed Dimensions in Tomato  

PubMed Central

The success of germination, growth and final yield of every crop depends to a large extent on the quality of the seeds used to grow the crop. Seed quality is defined as the viability and vigor attribute of a seed that enables the emergence and establishment of normal seedlings under a wide range of environments. We attempt to dissect the mechanisms involved in the acquisition of seed quality, through a combined approach of physiology and genetics. To achieve this goal we explored the genetic variation found in a RIL population of Solanum lycopersicum (cv. Moneymaker) x Solanum pimpinellifolium through extensive phenotyping of seed and seedling traits under both normal and nutrient stress conditions and root system architecture (RSA) traits under optimal conditions. We have identified 62 major QTLs on 21 different positions for seed, seedling and RSA traits in this population. We identified QTLs that were common across both conditions, as well as specific to stress conditions. Most of the QTLs identified for seedling traits co-located with seed size and seed weight QTLs and the positive alleles were mostly contributed by the S. lycopersicum parent. Co-location of QTLs for different traits might suggest that the same locus has pleiotropic effects on multiple traits due to a common mechanistic basis. We show that seed weight has a strong effect on seedling vigor and these results are of great importance for the isolation of the corresponding genes and elucidation of the underlying mechanisms. PMID:22952841

Willems, Leo A. J.; van Heusden, Adriaan W.; Ligterink, Wilco; Hilhorst, Henk W. M.

2012-01-01

400

N-Acylethanolamine Metabolism Interacts with Abscisic Acid Signaling in Arabidopsis thaliana Seedlings[W][OA  

PubMed Central

N-Acylethanolamines (NAEs) are bioactive acylamides that are present in a wide range of organisms. In plants, NAEs are generally elevated in desiccated seeds, suggesting that they may play a role in seed physiology. NAE and abscisic acid (ABA) levels were depleted during seed germination, and both metabolites inhibited the growth of Arabidopsis thaliana seedlings within a similar developmental window. Combined application of low levels of ABA and NAE produced a more dramatic reduction in germination and growth than either compound alone. Transcript profiling and gene expression studies in NAE-treated seedlings revealed elevated transcripts for a number of ABA-responsive genes and genes typically enriched in desiccated seeds. The levels of ABI3 transcripts were inversely associated with NAE-modulated growth. Overexpression of the Arabidopsis NAE degrading enzyme fatty acid amide hydrolase resulted in seedlings that were hypersensitive to ABA, whereas the ABA-insensitive mutants, abi1-1, abi2-1, and abi3-1, exhibited reduced sensitivity to NAE. Collectively, our data indicate that an intact ABA signaling pathway is required for NAE action and that NAE may intersect the ABA pathway downstream from ABA. We propose that NAE metabolism interacts with ABA in the negative regulation of seedling development and that normal seedling establishment depends on the reduction of the endogenous levels of both metabolites. PMID:17766402

Teaster, Neal D.; Motes, Christy M.; Tang, Yuhong; Wiant, William C.; Cotter, Matthew Q.; Wang, Yuh-Shuh; Kilaru, Aruna; Venables, Barney J.; Hasenstein, Karl H.; Gonzalez, Gabriel; Blancaflor, Elison B.; Chapman, Kent D.

2007-01-01

401

The mitochondrial folylpolyglutamate synthetase gene is required for nitrogen utilization during early seedling development in arabidopsis.  

PubMed

Investigations into the biochemical processes and regulatory mechanisms of nitrogen (N) utilization can aid in understanding how N is used efficiently in plants. This report describes a deficiency in N utilization in an Arabidopsis (Arabidopsis thaliana) transfer DNA insertion mutant of the mitochondrial folylpolyglutamate synthetase gene DFC, which catalyzes the conjugation of glutamate residues to the tetrahydrofolate during folate synthesis. The mutant seedlings displayed several metabolic changes that are typical of plant responses to low-N stress, including increased levels of starch and anthocyanin synthesis as well as decreased levels of soluble protein and free amino acid, as compared with those in wild-type seedlings when external N was sufficient. More striking changes were observed when dfc seedlings were grown under N-limited conditions, including shorter primary roots, fewer lateral roots, higher levels of glycine and carbon-N ratios, and lower N content than those in wild-type seedlings. Gene expression studies in mutant seedlings revealed altered transcript levels of several genes involved in folate biosynthesis and N metabolism. The biochemical and metabolic changes also suggested that N assimilation is drastically perturbed due to a loss of DFC function. The observation that elevated CO(2) partly rescued the dfc phenotypes suggests that the alterations in N metabolism in dfc may be mainly due to a defect in photorespiration. These results indicate that DFC is required for N utilization in Arabidopsis and provide new insight into a potential interaction between folate and N metabolism. PMID:23129207

Jiang, Ling; Liu, Yanyan; Sun, Hong; Han, Yueting; Li, Jinglai; Li, Changkun; Guo, Wenzhu; Meng, Hongyan; Li, Sha; Fan, Yunliu; Zhang, Chunyi

2013-02-01

402

Comparative analysis of different methods for evaluating quality of Quercus ilex seedlings inoculated with Tuber melanosporum.  

PubMed

The quality of seedlings colonized by Tuber melanosporum is one of the main factors that contributes to the success or failure of a truffle crop. Truffle cultivation has quickly grown in European countries and elsewhere, so a commonly shared seedling evaluation method is needed. Five evaluation methods are currently published in the literature: three are used in Spain and two in France and Italy. Although all estimate the percentage colonization by T. melanosporum mycorrhizae, they do it in different ways. Two methods also estimate total number of mycorrhizae per seedling. Most are destructive. In this work, ten batches of holm oak seedlings inoculated with T. melanosporum from two different nurseries were evaluated by means of the five methods noted above. Some similarity was detected between the percentages of T. melanosporum mycorrhizae estimated by each method but not in their ability to assess the suitability of each batch. We discuss the advantages and disadvantages for each method and suggest approaches to reach consensus within the truffle culture industry for certifying mycorrhizal colonization by T. melanosporum and seedling quality. PMID:24522843

Andrés-Alpuente, Antonio; Sánchez, Sergio; Martín, María; Aguirre, Angel Javier; Barriuso, Juan J

2014-04-01

403

The combined effects of Pseudomonas fluorescens and Tuber melanosporum on the quality of Pinus halepensis seedlings.  

PubMed

The ecological, economic and social values of the ectomycorrhizal fungi of the black truffle found in the rural Mediterranean are well known. The inoculation of Pinus halepensis seedlings with mycorrhizal fungi and rhizobacteria can improve the morphology and physiology of the seedlings and benefit the regeneration of arid regions and the reintroduction of inocula of mycorrhizal fungi into these areas. Some rhizobacteria can improve the establishment and functioning of ectomycorrhizal symbiosis. In this study, seedlings of P. halepensis were inoculated with the mycorrhizal fungus Tuber melanosporum and the rhizobacteria Pseudomonas fluorescens CECT 844 under non-limiting greenhouse conditions. Five months after inoculation, we analysed the growth, water parameters (osmotic potential at saturation, osmotic potential at turgor loss and modulus of elasticity), concentrations of mycorrhizal colonies, nutrient concentration and nutrient contents (N, P, K, Ca, Mg and Fe) in roots and aerial parts of the seedlings. Subsequently, tests were performed to estimate the root growth potentials. None of the treatments changed the water parameters or growth potentials of the roots. The inoculations improved the growth and nutrient uptake of the seedlings, although the combination of P. fluorescens CECT 844 and T. melanosporum did not generally lead to a significant improvement over the positive effects of a simple inoculation of T. melanosporum; however, the addition of P. fluorescens CECT 844 did double the rate of the mycorrhization of T. melanosporum. These results may be promising for enhancing the cultivation of truffles. PMID:22068563

Dominguez, J A; Martin, A; Anriquez, A; Albanesi, A

2012-08-01

404

Local Adaptation Enhances Seedling Recruitment Along an Altitudinal Gradient in a High Mountain Mediterranean Plant  

PubMed Central

Background and Aims Germination and seedling establishment, which are critical stages in the regeneration process of plant populations, may be subjected to natural selection and adaptive evolution. The aims of this work were to assess the main limitations on offspring performance of Silene ciliata, a high mountain Mediterranean plant, and to test whether local adaptation at small spatial scales has a significant effect on the success of establishment. Methods Reciprocal sowing experiments were carried out among three populations of the species to test for evidence of local adaptation on seedling emergence, survival and size. Studied populations were located at the southernmost margin of the species' range, along the local elevation gradient that leads to a drought stress gradient. Key Results Drought stress in summer was the main cause of seedling mortality even though germination mainly occurred immediately after snowmelt to make the best use of soil moisture. The results support the hypothesis that species perform better at the centre of their altitudinal range than at the boundaries. Evidence was also found of local adaptation in seedling survival and growth along the whole gradient. Conclusions The local adaptation acting on seedling emergence and survival favours the persistence of remnant populations on the altitudinal and latitudinal margins of mountain species. In a global warming context, such processes may help to counteract the contraction of this species' ranges and the consequent loss of habitat area. PMID:17307775

Giménez-Benavides, Luis; Escudero, Adrián; Iriondo, José M.

2007-01-01

405

Combined effects of lead and acid rain on photosynthesis in soybean seedlings.  

PubMed

To explore how lead (Pb) and acid rain simultaneously affect plants, the combined effects of Pb and acid rain on the chlorophyll content, chlorophyll fluorescence reaction, Hill reaction rate, and Mg(2+)-ATPase activity in soybean seedlings were investigated. The results indicated that, when soybean seedlings were treated with Pb or acid rain alone, the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, and maximal photochemical efficiency (F(v)/F(m)) were decreased, while the initial fluorescence (F 0) and maximum quantum yield (Y) were increased, compared with those of the control. The combined treatment with Pb and acid rain decreased the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, F(v)/F(m), and Y and increased F 0 in soybean seedlings. Under the combined treatment with Pb and acid rain, the two factors showed additive effects on the chlorophyll content in soybean seedlings and exhibited antagonistic effects on the Hill reaction rate. Under the combined treatment with high-concentration Pb and acid rain, the two factors exhibited synergistic effects on the Mg(2+)-ATPase activity, F 0, F v/F m, as well as Y. In summary, the inhibition of the photosynthetic process is an important physiological basis for the simultaneous actions of Pb and acid rain in soybean seedlings. PMID:25069575

Hu, Huiqing; Wang, Lihong; Liao, Chenyu; Fan, Caixia; Zhou, Qing; Huang, Xiaohua

2014-10-01

406

Physiological aspects underlying the improved outplanting performance of Pinus pinaster Ait. seedlings associated with ectomycorrhizal inoculation.  

PubMed

Mycorrhizal inoculation of conifer roots is a key strategy to optimize establishment and performance of forest tree species under both natural and cultivated conditions and also to mitigate transplantation shock. However, despite being a common practice, inoculation in outdoor nursery conditions has been poorly studied. Here, we have evaluated effectiveness of four fungal species (Lactarius deliciosus, Lactarius quieticolor, Pisolithus arhizus, and Suillus luteus) in the production of mycorrhizal Pinus pinaster seedlings in an outdoor commercial nursery and their ability to improve seedling physiology and field performance. All inoculated seedlings showed a significant increase in growth at the end of the nursery stage and these differences remained after 3 years of growth in the field. Differences observed in the content of malondialdehyde, total chlorophyll, carotenoids, anthocyanins, and phenolic compounds from needles of mycorrhizal and control seedlings may reflect a different sensitivity to photo-oxidative damage. We conclude that ectomycorrhizal inoculation improves adaptability to changeable growing conditions of an outdoor nursery and produces a higher quality nursery stock, thereby enhancing seedling performance after planting. PMID:23674120

Sanchez-Zabala, Joseba; Majada, Juan; Martín-Rodrigues, Noemí; Gonzalez-Murua, Carmen; Ortega, Unai; Alonso-Graña, Manuel; Arana, Orats; Duñabeitia, Miren K

2013-11-01

407

Climate Change Alters Seedling Emergence and Establishment in an Old-Field Ecosystem  

PubMed Central

Background Ecological succession drives large-scale changes in ecosystem composition over time, but the mechanisms whereby climatic change might alter succession remain unresolved. Here, we asked if the effects of atmospheric and climatic change would alter tree seedling emergence and establishment in an old-field ecosystem, recognizing that small shifts in rates of seedling emergence and establishment of different species may have long-term repercussions on the transition of fields to forests in the future. Methodology/Principal Findings We introduced seeds from three early successional tree species into constructed old-field plant communities that had been subjected for 4 years to altered temperature, precipitation, and atmospheric CO2 regimes in an experimental facility. Our experiment revealed that different combinations of atmospheric CO2 concentration, air temperature, and soil moisture altered seedling emergence and establishment. Treatments directly and indirectly affected soil moisture, which was the best predictor of seedling establishment, though treatment effects differed among species. Conclusions The observed impacts, coupled with variations in the timing of seed arrival, are demonstrated as predictors of seedling emergence and establishment in ecosystems under global change. PMID:20976104

Classen, Aimée T.; Norby, Richard J.; Campany, Courtney E.; Sides, Katherine E.; Weltzin, Jake F.

2010-01-01

408

Involvement of phytochrome A in suppression of photomorphogenesis in rice seedling grown in red light.  

PubMed

Plants have evolved a remarkable capacity to track and respond to fluctuations of light quality and intensity that influence photomorphogenesis facilitated through several photoreceptors, which include a small family of phytochromes. Rice seedlings grown on germination paper in red light for 48 h having their shoot bottom exposed had suppressed photomorphogenesis and were deficient in chlorophyll. Seedlings grown under identical light regime having their shoot bottom covered were green and accumulated chlorophyll. Further, etiolated seedlings with their shoot bottom exposed, when grown in 4 min red/far-red cycles for 48 h, accumulated chlorophyll demonstrating the reversal of suppression of photomorphogenesis by far-red light. It implicates the involvement of phytochrome. Immunoblot analysis showed the persistence of photolabile phytochrome A protein for 48 h in seedlings grown in red light with their shoot bottom exposed, suggesting its involvement in suppression of photomorphogenesis. This was further corroborated in phyA seedlings that turned green when grown in red light having their shoot bottom exposed. Calmodulin (CaM) antagonist N-(6-aminohexyl)-5-chloro-1-napthalene sulphonamide or trifluoperazine substantially restored photomorphogenesis both in the wild type (WT) and phyA demonstrating the involvement of CaM-dependent kinases in the down-regulation of the greening process. Results demonstrate that red light-induced suppression of photomorphogenesis, perceived in the shoot bottom, is a red high irradiance response of PhyA. PMID:23495675

Roy, Ansuman; Sahoo, Dinabandhu; Tripathy, Baishnab C

2013-12-01

409

Evaluation of nitrogen content in cabbage seedlings using hyper-spectral images  

NASA Astrophysics Data System (ADS)

Monitoring of nutrient status of crops is essential for better management of crop production. Nitrogen is one of the most important elements in fertilizer for the growth and yield of vegetable crops. In this study, nitrogen content of cabbage seedlings was evaluated using hyper-spectral images. Cabbage seedlings, cultured at five nitrogen fertilization levels, were planted in the 128-cell plug trays and grown in a phytotron at National Taiwan University. The images, ranged from 410 to 1090 nm, of cabbage seedlings were analyzed by a hyper-spectral imaging system consisting of CCD cameras with liquid crystal tunable filters (LCTF), which was developed in this study. The digital images of seedling canopies were processed including image segmentation, gray level calibration and absorbance conversion. Models including modified partial least square regression (MPLSR), step-wise multi-linear regression (SMLR) and artificial neural network with cross-learning strategy (ANN-CL) were developed for the determination of the nitrogen content in cabbage seedlings. The three significant wavelengths derived from SMLR model are 470, 710, and 1080; and the best result is obtained by ANN-CL model, in which r c=0.89, SEC=6.41 mg/g, r v=0.87, and SEV=6.96 mg/g. The ANN-CL model is more suitable for the remote sensing in precision agriculture applications because not only its model accuracy but also only 3 wavelengths are needed.

Chen, Suming; Chen, Chia-Tseng; Wang, Ching-Yin; Yang, I.-Chang; Hsiao, Shih-Chieh

2007-09-01

410

Gibberellin mediates the development of gelatinous fibres in the tension wood of inclined Acacia mangium seedlings  

PubMed Central

Background and Aims Gibberellin stimulates negative gravitropism and the formation of tension wood in tilted Acacia mangium seedlings, while inhibitors of gibberellin synthesis strongly inhibit the return to vertical growth and suppress the formation of tension wood. To characterize the role of gibberellin in tension wood formation and gravitropism, this study investigated the role of gibberellin in the development of gelatinous fibres and in the changes in anatomical characteristics of woody elements in Acacia mangium seedlings exposed to a gravitational stimulus. Methods Gibberellin, paclobutrazol and uniconazole-P were applied to the soil in which seedlings were growing, using distilled water as the control. Three days after the start of treatment, seedlings were inclined at 45 ° to the vertical and samples were harvested 2 months later. The effects of the treatments on wood fibres, vessel elements and ray parenchyma cells were analysed in tension wood in the upper part of inclined stems and in the opposite wood on the lower side of inclined stems. Key Results Application of paclobutrazol or uniconazole-P inhibited the increase in the thickness of gelatinous layers and prevented the elongation of gelatinous fibres in the tension wood of inclined stems. By contrast, gibberellin stimulated the elongation of these fibres. Application of gibberellin and inhibitors of gibberellin biosynthesis had only minor effects on the anatomical characteristics of vessel and ray parenchyma cells. Conclusions The results suggest that gibberellin is important for the development of gelatinous fibres in the tension wood of A. mangium seedlings and therefore in gravitropism. PMID:24043495

Nugroho, Widyanto Dwi; Nakaba, Satoshi; Yamagishi, Yusuke; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

2013-01-01

411

An endogenous growth pattern of roots is revealed in seedlings grown in microgravity.  

PubMed

In plants, sensitive and selective mechanisms have evolved to perceive and respond to light and gravity. We investigated the effects of microgravity on the growth and development of Arabidopsis thaliana (ecotype Landsberg) in a spaceflight experiment. These studies were performed with the Biological Research in Canisters (BRIC) hardware system in the middeck region of the space shuttle during mission STS-131 in April 2010. Seedlings were grown on nutrient agar in Petri dishes in BRIC hardware under dark conditions and then fixed in flight with paraformaldehyde, glutaraldehyde, or RNAlater. Although the long-term objective was to study the role of the actin cytoskeleton in gravity perception, in this article we focus on the analysis of morphology of seedlings that developed in microgravity. While previous spaceflight studies noted deleterious morphological effects due to the accumulation of ethylene gas, no such effects were observed in seedlings grown with the BRIC system. Seed germination was 89% in the spaceflight experiment and 91% in the ground control, and seedlings grew equally well in both conditions. However, roots of space-grown seedlings exhibited a significant difference (compared to the ground controls) in overall growth patterns in that they skewed to one direction. In addition, a greater number of adventitious roots formed from the axis of the hypocotyls in the flight-grown plants. Our hypothesis is that an endogenous response in plants causes the roots to skew and that this default growth response is largely masked by the normal 1?g conditions on Earth. PMID:21970704

Millar, Katherine D L; Johnson, Christina M; Edelmann, Richard E; Kiss, John Z

2011-10-01

412

Tolerance to Cadmium of Agave lechuguilla (Agavaceae) Seeds and Seedlings from Sites Contaminated with Heavy Metals  

PubMed Central

We investigated if seeds of Agave lechuguilla from contaminated sites with heavy metals were more tolerant to Cd ions than seeds from noncontaminated sites. Seeds from a highly contaminated site (Villa de la Paz) and from a noncontaminated site (Villa de Zaragoza) were evaluated. We tested the effect of Cd concentrations on several ecophysiological, morphological, genetical, and anatomical responses. Seed viability, seed germination, seedling biomass, and radicle length were higher for the non-polluted site than for the contaminated one. The leaves of seedlings from the contaminated place had more cadmium and showed peaks attributed to chemical functional groups such as amines, amides, carboxyl, and alkenes that tended to disappear due to increasing the concentration of cadmium than those from Villa de Zaragoza. Malformed cells in the parenchyma surrounding the vascular bundles were found in seedlings grown with Cd from both sites. The leaves from the contaminated place showed a higher metallothioneins expression in seedlings from the control group than that of seedlings at different Cd concentrations. Most of our results fitted into the hypothesis that plants from metal-contaminated places do not tolerate more pollution, because of the accumulative effect that cadmium might have on them. PMID:24453802

Méndez-Hurtado, Alejandra; Rangel-Méndez, René; Flores, Joel

2013-01-01

413

Expression of stress-related genes in zebrawood (Astronium fraxinifolium, Anacardiaceae) seedlings following germination in microgravity.  

PubMed

Seeds of a tropical tree species from Brazil, Astronium fraxinifolium, or zebrawood, were germinated, for the first time in microgravity, aboard the International Space Station for nine days. Following three days of subsequent growth under normal terrestrial gravitational conditions, greater root length and numbers of secondary roots was observed in the microgravity-treated seedlings compared to terrestrially germinated controls. Suppression subtractive hybridization of cDNA and EST analysis were used to detect differential gene expression in the microgravity-treated seedlings in comparison to those initially grown in normal gravity (forward subtraction). Despite their return to, and growth in normal gravity, the subtracted library derived from microgravity-treated seedlings was enriched in known microgravity stress-related ESTs, corresponding to large and small heat shock proteins, 14-3-3-like protein, polyubiquitin, and proteins involved in glutathione metabolism. In contrast, the reverse-subtracted library contained a comparatively greater variety of general metabolism-related ESTs, but was also enriched for peroxidase, possibly indicating the suppression of this protein in the microgravity-treated seedlings. Following continued growth for 30 days, higher concentrations of total chlorophyll were detected in the microgravity-exposed seedlings. PMID:24688295

Inglis, Peter W; Ciampi, Ana Y; Salomão, Antonieta N; Costa, Tânia da S A; Azevedo, Vânia C R

2014-03-01

414

Purification and properties of chlorophyllase from greened rye seedlings.  

PubMed

1. Chlorophyllase [EC 3.1.1.14] was extracted from the acetone-dried powder of the chloroplasts of greened rye seedlings with 1% cholate, and purified 870-fold with a yield of about 30%. The purification procedure was composed of fractionations with acetone and ammonium sulfate, and hydrophobic chromatography on a phenyl-Sepharose CL-4B column. 2. The purified enzyme was pure as analyzed by molecular-sieve chromatography and isoelectric electrophoresis. It had an isoelectric point of 4.5 and a molecular weight of 39,000. 3. The purified enzyme was stable at pH 6-9 and 4 degrees C. At pH 7.5, it was stable in the presence and absence of 30% acetone. However, at 30 degrees C, it was not stable above a 10% concentration of acetone. 4. The purified enzyme hydrolyzed chlorophylls a and b from spinach into chlorophyllides a and b and phytols, respectively; and bacteriochlorophyll a from Rhodospirillum rubrum into bacteriochlorophyllide a and a derivative of phytol, possibly all-trans-geranylgeraniol. The hydrolysis rates were stimulated to their maxima in the presence of 30% acetone; maximum stimulation was about 50% with bacteriochlorophyll a and about 400% with chlorophyll a. 5. At pH 7.5 and 30 degrees C in the presence of 30% acetone, the Km values and specific activities were 12 microM and 480 nmol . min-1 . mg-1 for chlorophylls a, and 4 microM and 170 nmol . min-1 . mg-1 for R. rubrum bacteriochlorophyll a, respectively. PMID:6819291

Tanaka, K; Kakuno, T; Yamashita, J; Horio, T

1982-12-01

415

Water Relation Parameters of Embryogenic Cultures and Seedlings of Larch  

PubMed Central

Changes in the water relations parameters of developing somatic embryogenic and xygotic European larch (Larix decidua) were studied. Water release curves were generated by suspending tissue samples over unsaturated NaCl solutions until they reached vapor equilibration with the surrounding air. Twenty solutions were used whose water potentials ranged from ?0.05 to ?10 MPa. Water release curves were obtained by plotting paired values of tissue relative water content (RWC) and solution potential. Curves were derived for embryonic larch at various stages of development and for hypocotyls and roots from germinated zygotic and somatic embryos. The ability to resist dehydration increased markedly with development. Stage 1 tissue, which consisted of clusters of loosely associated nonchlorophyllous cells, had extremely low bulk elastic modulus (?) (1.91 MPa) and apoplastic water content (A) (0.023), relatively high osmotic potential (??) (?0.53 MPa), and lost turgor at 0.56 RWC. In contrast, mature embryoids with primary roots, hypocotyl, and cotyledons (stage 3) had an almost 4-fold increase in A (0.089), significantly higher ? (3.49 MPa), and lower ?? (?0.88 MPa) and lost turgor at 0.66 RWC. Hypocotyl tissue from germinated somatic embryos lost turgor at 0.74 RWC and had higher ?, A, and solute accumulation than pregerminated tissue. Hypocotyl tissue resisted dehydration more strongly than root tissue, and differences between root and hypocotyl water relation parameters were more pronounced in xygotic than in somatic seedlings. Highest dehydration resistance was in zygotic hypocotyls. The characterization of the water relations of tissue cultures should allow the development of more consistent and reliable desiccation protocols to induce maturation of embryos and produce synchronously germinating seed. PMID:16653121

Livingston, Nigel J.; von Aderkas, Patrick; Fuchs, Edgar E.; Reaney, Martin J. T.

1992-01-01

416

Development of Enzymes in the Cotyledons of Watermelon Seedlings 1  

PubMed Central

Changes in hypocotyl length, cotyledon weight, lipid content, chlorophyll content, and capacity for photosynthesis have been described in seedlings of Citrullus vulgaris, Schrad. (watermelon) growing at 30 C under various light treatments. Corresponding changes in the levels of 19 enzymes in the cotyledons are described, with particular emphasis on enzymes of microbodies, since during normal greening, enzymes of the glyoxysomes are lost and those of leaf peroxisomes appear. In complete darkness enzymes of the glyoxysomes reach a peak at 4 days and decline as the fat is depleted. Enzymes of mitochondria and of glycolytic pathways also peak at 4 to 5 days and either remain unchanged or decline to a lesser extent. Exposure to light at 4 days, when the cotyledons emerge, results in a selectively greater destruction of enzymes of the glyoxylate cycle; chlorophyll synthesis and capacity for photosynthesis increase in parallel, and there is a striking increase in the activities of chloroplast enzymes and in those of the leaf peroxisomes, hydroxypyruvate reductase and glycolate oxidase. The reciprocal changes in enzymes of the glyoxysomes and of leaf peroxisomes can be temporally dissociated, since even after 10 days in darkness, when malate synthetase and isocitrate lyase have reached very low levels, hydroxypyruvate reductase and glycolate oxidase increase strikingly on exposure to light and the cotyledons become photosynthetic. Furthermore, the parallel development of enzymes of leaf peroxisomes and functional chloroplasts is not immutable, since hydroxypyruvate reductase and glycolate oxidase activity can be elicited in darkness following a 5-minute exposure to light at day 4 while chlorophyll does not develop under these conditions. PMID:16658299

Kagawa, T.; McGregor, D. I.; Beevers, Harry

1973-01-01

417

Effects of O/sub 2/ concentration on rice seedlings  

SciTech Connect

The ability of rice, wheat, and oat seedlings to germinate and grow as the O/sub 2/ concentration was lowered to zero was compared. The germination of rice was completely unaffected by O/sub 2/ supply, whereas that of oats and wheat was strongly retarded at levels below 5% O/sub 2/. In contrast to the coleoptiles of oats and wheat and to roots of all three species where growth was progressively diminished as the O/sub 2/ concentration was lowered, that of the rice coleoptile was progressively increased. However, the dry weight and content of protein, sugars, and cellulose were all depressed in the rice coleoptile in anoxia, and the levels of several respiratory enzymes, particularly those of mitochondria, were also much lower than those of the coleoptiles grown in air. In 1% O/sub 2/, the growth of the rice coleoptile was similar to that in air. The effect of ethanol concentration on germination and growth of rice was measured. Coleoptile growth was reduced when the ethanol concentration exceeded 40 millimolarity, and root growth was somewhat more sensitive. Coleoptiles of all three species grown in air were transferred to N/sub 2/ and ethanol accumulation was measured over 24 hours. The rate of ethanol accumulation in oats was close to that in rice, and in all three species the amounts of ethanol lost to the surrounding medium were those expected from simple diffusion from the tissue. The ability of the rice coleoptile to grow in anoxia is apparently not due to a particularly low rate of ethanol formation or to unusual ethanol tolerance. Any explanation of the success of rice in anoxia must encompass the much lower rate of ATP synthesis than that in air and account for the biochemical deficiencies of the coleoptile.

Alpi, A.; Beevers, H.

1983-01-01

418

Effects of Chemical Treatments upon Photosynthetic Parameters in Soybean Seedlings  

PubMed Central

The effects of various chemical treatments upon photosynthesis, soluble leaf protein, CO2 compensation point, and leaf light transmission in soybean, Glycine max (L.) Merr., seedlings were examined following varying response periods after application at 14 to 17 days postemergence. The compounds N6-benzyladenine (BA), 2-(4-chlorophenoxy)-2-methylpropanoic acid (CPMP), (4-chlorophenoxy)acetic acid (CPA), rhodanine-N-acetic acid (RAA), and 2,3,5-triiodobenzoic acid (TIBA) significantly increased soluble protein and decreased senescence, measured by leaf light transmission, at CO2 concentrations below the compensation point in a survival chamber. All compounds except BA significantly decreased transmission values under ambient atmospheric conditions. In statistically significant experiments, applications of 3.49 millimolar CPMP increased net photosynthesis on a leaf area basis by an average of 14.4% at all trifoliolate positions with increases generally requiring response periods of 12 days or longer. RAA at 1.31 and 2.61 millimolar increased net photosynthesis by 19 to 36% following 13-day response periods. CPMP and other compounds tested had no effect upon the CO2 compensation point after 4- to 8-day response periods. The effects of CPMP and RAA upon net photosynthesis and soluble protein appeared to involve a combined stimulation of protein synthesis and an antisenescent effect. There were no indications that any of the photosynthetic changes observed resulted from direct differential effects upon ribulose bisphosphate carboxylase-oxygenase. The assays for soluble protein and light transmission responded more consistently to the chemicals than did photosynthesis. PMID:16663948

Manning, David T.; Chen, Tsong Meng; Campbell, Andrew J.; Tolbert, N. E.; Smith, E. Wayne

1984-01-01

419

Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees  

PubMed Central

Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

2007-01-01

420

Effect of nursery nitrogen application of bare-root Larix olgensis seedlings on growth, nitrogen uptake and initial field performance.  

PubMed

Nursery nitrogen application has been used to improve seedling quality. The technique has received little attention with bare-root seedlings and their subsequent field performance on weed competition sites. Our research objective was to examine responses of one- and two- year-old bare-root Olga Bay larch (Larix olgensis Henry) seedlings to nursery nitrogen supplements and subsequent one-year field performance on a competitive site. The fertilizer levels (kg N ha(-1)) were 0 (control), 60 (conventional fertilization, 60 C), 120 (additional nitrogen applied two times, 120 L), 180 (additional nitrogen applied three times, 180 L) and N were applied in increments of 30 kg ha(-1 )at 15-day interval to maintain a base nutrient level Although pre-planting morphological attributes and nitrogen status of one-year-old (la) seedlings were more sensitive to 60 C than for two-year-old (2a) seedlings, the conventional application failed to enhance their field survival (15.6% vs 17.8%), relative height growth (89.0% vs 79.6%), and relative diameter growth (17.0% vs 22.9%). The la seedlings' field survival (15.6% for 0, 17.8% for 60 C) and 2a seedlings' relative height growth rate (11.0% for 0, 8.9% for 60 C) were not increased significantly until they were provided the 120 L (survival of 23.3% for la, relative height growth rate of 15.0% for 2a). According to pre-planting attributes and field performance, optimum nursery nitrogen application was 120 L for the 2a seedlings and 180 L for la seedlings. Except for component nitrogen concentration, pre-planting morphological attributes and component N content for the 2a seedlings were as much 3.3 to 37.7 times that of la seedlings. In conclusion, the contrasting survival of poor (15.6%-28.9%) for la seedlings and high (84.4%-91.1%) for 2a seedlings indicated that additional nitrogen fertilizer would not equal the benefits of an another year's growth in the nursery. Successful reforestation could not be fulfilled by la seedlings regardless of their prenutrients. An alternative technique for sites with competing vegetation was to apply 120 kg N ha(-1) in the nursery during July and August on 2a seedlings. PMID:24006811

Li, Guo Lei; Zhu, Yan; Liu, Yong; Jiang, Le; Shi, Wenhui; Liu, Jiajia; Wang, Jiaxi; Cheng, Zhongqian

2013-01-01

421

Interaction between root lesion nematode Pratylenchus vulnus and two species of Fusarium on growth and development of maple seedlings.  

PubMed

Producing healthy seedlings and distributing them to far areas, is one of the most important factor for developing forests. Because of easy planting, rapid growth and good wood quality, Acer velutinum is the most useful species, among the softwood and hardwood trees. Growth and development of the nurseries were effected by different pests and diseases, the nematodes are one of these agents. They are not actively surveyed in the forest nurseries in Iran. On a survey of maple seedling in the forest nurseries Pratylenchus vulnus, Fusarium solani and F. oxysporum were identified. The interaction between these two fungi and nematode were studied in randomized complete block design with four replications and six treatments. For mass production and multiplication of the nematodes, they were sterilized with Streptomycin Sulfate, they were reared on carrot disc culture. The nematodes were then added to each pot. The results showed a highly significant difference (p = 0.01) between different treatments. In the treatment with nematodes alone growth of seedlings was minimum and population density of nematodes in soil and root tissue was maximum. In this treatments 75% of seedlings were died and seedling average height were 2.25 cm. In the treatments with nematode and fungi together the population of nematodes were decreased and the growth of seedlings were increased, in comparison with nematode alone. F. oxysporum showed more antagonistic effect on nematodes than F. solani. In the nematode + F. oxysporum treatment, 25% of seedlings were died and seedling average height was 12.75 cm. In the nematode + F. solani treatment, 50% of seedlings were died and the seedling average height was 5.5 cm. This is the first report of pathogenecity of Pratylenchus vulnus and its interaction whit fungi on maple seedlings in Iran. PMID:12696440

Kheiri, A; Borhani, A; Okhovat, M; Pourjam, E

2002-01-01

422

Arbuscular mycorrhizal fungi enhance photosynthesis, water use efficiency, and growth of frankincense seedlings under pulsed water availability conditions.  

PubMed

Under drought conditions, arbuscular mycorrhizal (AM) fungi alter water relationships of plants and improve their resistance to drought. In a factorial greenhouse experiment, we tested the effects of the AM symbiosis and precipitation regime on the performance (growth, gas exchange, nutrient status and mycorrhizal responsiveness) of Boswellia papyrifera seedlings. A continuous precipitation regime was imitated by continuous watering of plants to field capacity every other day during 4 months, and irregular precipitation by pulsed watering of plants where watering was switched every 15 days during these 4 months, with 15 days of watering followed by 15 days without watering. There were significantly higher levels of AM colonization under irregular precipitation regime than under continuous precipitation. Mycorrhizal seedlings had higher biomass than control seedlings. Stomatal conductance and phosphorus mass fraction in shoot and root were also significantly higher for mycorrhizal seedlings. Mycorrhizal seedlings under irregular watering had the highest biomass. Both a larger leaf area and higher assimilation rates contributed to higher biomass. Under irregular watering, the water use efficiency increased in non-mycorrhizal seedlings through a reduction in transpiration, while in mycorrhizal seedlings irregular watering increased transpiration. Because assimilation rates increased even more, mycorrhizal seedlings achieved an even higher water use efficiency. Boswellia seedlings allocated almost all carbon to the storage root. Boswellia seedlings had higher mass fractions of N, P, and K in roots than in shoots. Irregular precipitation conditions apparently benefit Boswellia seedlings when they are mycorrhizal. Electronic supplementary material The online version of this article (doi:10.1007/s00442-012-2258-3) contains supplementary material, which is available to authorized users. PMID:22286084

Birhane, Emiru; Sterck, Frank J; Fetene, Masresha; Bongers, Frans; Kuyper, Thomas W

2012-08-01

423

Effects of ectomycorrhizae removal on survival and growth of loblolly pine seedlings with pisolithus or natural ectomycorrhizae on an upland site in South Carolina. Progress report  

SciTech Connect

This study was undertaken to ascertain the significance of physiological stress caused by mechanical loss of specific ectomycorrhizae (as done by seedling lifting machines) to the capacity of pine seedlings to regenerate roots, survive, and grow.

Marx, D.H.

1984-01-01

424

Effects of ectomycorrhizae removal on survival and growth of loblolly pine seedlings with Pisolithus or natural ectomycorrhizae on an upland site in South Carolina  

SciTech Connect

This study was undertaken to ascertain the significance of loss of ectomycorrhizae encountered during lifting of nursery seedlings to the capacity of the seedlings. Loblolly pine seedlings with abundant Pisolithus tinctorius (Pt) or naturally occurring (NI) ectomycorrhizae were nursery grown. Seedlings from the 2 groups were graded to similar sizes and either 100, 66, 33 or 0% of the ectomycorrhizae were removed to simulate degrees of roughness in machine handling of seedlings. The 8 treatments were outplanted on an upland site in a complete randomized plot design. Although the results are only preliminary at this time, they do indicate that seedlings with intact Pt ectomycorrhizae survive better, regenerate more roots, and initiate more height growth than seedlings with their roots stripped to different degrees. Generally, seedlings with Pt ectomycorrhizae are doing better than those with NI ectomycorrhizae. 1 table.

Marx, D.H.

1981-01-01

425

Air pollutants affect the relative growth rate of hardwood seedlings. Forest service research paper (final)  

SciTech Connect

One-year-old seedlings of yellow-poplar (Liriodendron tulipifera), eastern cottonwood (Populus deltoides), and white ash (Fraxinus americana) were divided into four groups. One group Served as the control, and the other groups were fumigated for 12 hours per day with either 0.1 ppm O3, 0.2 ppm SO2, or 0.1 ppm O3 plus 0.2 ppm SO2. Two or three seedlings of each species were harvested twice a week for 6 weeks, and leaf area and new growth weight were determined. Data on leaf area and new growth were transformed to natural logarithms and fitted with a linear regression model. Relative growth rate was positive in all species-treatment combinations, but varied with fumigation treatment. Relative leaf area growth rate of the cottonwood and yellow-poplar seedlings was reduced by all three fumigation treatments. White ash growth was not analyzed because statistically significant differences were not found.

Jensen, K.F.

1981-01-01

426

A comparative field study of growth and survival of Sierran conifer seedlings  

SciTech Connect

This study is a comparison of seedling growth and survival of seven species of conifers that make up the mid-elevation Sierra Nevada mixed conifer forest--Abies concolor, Abies magnifica, Calocedrus decurrens, Pinus jeffreyi, Pinus lambertiana, Pinus ponderosa, and Sequoiadendron giganteum. The field experiment was designed to test the hypothesis that seedling demography is affected by the study species` relatively shade and drought tolerances. Six discrete treatments were created in the first experiment by using three elevations (1,600 m, 1,900, m, and 2,200 m) and two natural light levels (closed canopy shade and open gap sun) at each elevation. One or two-year old seedlings were planted in the ground in replicate plots in each treatment and followed for two growing seasons. Four responses were analyzed--survival, height growth, diameter growth, and mass growth (total mass as well as root mass and shoot mass separately).

Kern, R.A. [Duke Univ., Durham, NC (United States). Dept. of Botany] [Duke Univ., Durham, NC (United States). Dept. of Botany

1996-12-31

427

Interactive effects of cadmium and acid rain on photosynthetic light reaction in soybean seedlings.  

PubMed

Interactive effects of cadmium (Cd(2+)) and acid rain on photosynthetic light reaction in soybean seedlings were investigated under hydroponic conditions. Single treatment with Cd(2+) or acid rain and the combined treatment decreased the content of chlorophyll, Hill reaction rate, the activity of Mg(2+)-ATPase, maximal photochemical efficiency and maximal quantum yield, increased initial fluorescence and damaged the chloroplast structure in soybean seedlings. In the combined treatment, the change in the photosynthetic parameters and the damage of chloroplast structure were stronger than those of any single pollution. Meanwhile, Cd(2+) and acid rain had the interactive effects on the test indices in soybean seedlings. The results indicated that the combined pollution of Cd(2+) and acid rain aggravated the toxic effect of the single pollution of Cd(2+) or acid rain on the photosynthetic parameters due to the serious damage to the chloroplast structure. PMID:22182775

Sun, Zhaoguo; Wang, Lihong; Chen, Minmin; Wang, Lei; Liang, Chanjuan; Zhou, Qing; Huang, Xiaohua

2012-05-01

428

Coincidence of biophoton emission by wheat seedlings during simultaneous, transcontinental germination tests.  

PubMed

Measurements of spontaneous ultra-weak light (biophoton) emission from native Brazilian and German wheat seedlings in three simultaneous series of germination tests are presented, two run in Germany and one in Brazil. Seedlings in both countries presented semi-circadian rhythms of emission that were in accordance with the local lunisolar gravimetric tidal acceleration, as did seeds which had been transported from Brazil to Germany. The simultaneity of the photon emission patterns in all tests argues for the lunisolar tide and its rhythmic variations as regulators of the natural rhythm of photon emission. However, seedlings from seed samples transported from Brazil to Germany showed, in addition, a temporary disturbance within the emission periodicity which may indicate a possible short-term acclimatization to the new location. PMID:23011402

Gallep, Cristiano M; Moraes, Thiago A; Dos Santos, Samuel R; Barlow, Peter W

2013-06-01

429

Phytotoxic and genotoxic effects of silver nanoparticles exposure on germinating wheat seedlings.  

PubMed

We investigated the effects of 1 and 10 mg L(-1) AgNPs on germinating Triticum aestivum L. seedlings. The exposure to 10 mg L(-1) AgNPs adversely affected the seedling growth and induced morphological modifications in root tip cells. TEM analysis suggests that the observed effects were due primarily to the release of Ag ions from AgNPs. To gain an increased understanding of the molecular response to AgNP exposure, we analyzed the genomic and proteomic changes induced by AgNPs in wheat seedlings. At the DNA level, we applied the AFLP technique and we found that both treatments did not induce any significant DNA polymorphisms. 2DE profiling of roots and shoots treated with 10 mg L(-1) of AgNPs revealed an altered expression of several proteins mainly involved in primary metabolism and cell defense. PMID:24973586

Vannini, Candida; Domingo, Guido; Onelli, Elisabetta; De Mattia, Fabrizio; Bruni, Ilaria; Marsoni, Milena; Bracale, Marcella

2014-08-15

430

[Effects of light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut seedling leaves].  

PubMed

Abstract: This study explored the effects of different light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut (Qinhua 6) seedling leaves. The results showed that, compared with natural light, blue light (445-470 nm) could significantly improve the specific leaf area (SLA), chlorophyll a/b value and carotenoid content of peanut seedlings. Meanwhile, the net photosynthetic rate, stomatal conductance, and transpiration rate were higher, the intercellular CO2 content was lower, and the photosynthetic efficiency was improved significantly under blue light. Red light (610-660 nm) could improve the chlorophyll content significantly, and reduce SLA, chlorophyll a/b value and carotenoid content, with a lower photosynthetic efficiency than natural light. Green light (515-520 nm) and yellow light (590-595 nm) were not conducive to photosynthetic pigment accumulation of leaves, and significantly inhibited leaf photosynthesis of peanut seedlings. PMID:24830249

Yan, Meng-Meng; Wang, Ming-Lun; Wang, Hong-Bo; Wang, Yue-Fu; Zhao, Chang-Xing

2014-02-01

431

Photosynthetic Independence of Light-induced Anthocyanin Formation in Zea Seedlings 1  

PubMed Central

Results are reported which support the view that the photosynthetic photosystems are not involved in the high irradiance response (HIR) phenomenon of light-dependent anthocyanin biosynthesis in dark-grown Zea mays L. seedlings. A negative correlation between change in greening rates and change in light-dependent anthocyanin accumulation rates with age was demonstrated. Lack of chlorophyll synthesis in a strain of maize possessing a temperature-sensitive lesion for chlorophyll synthesis could not be correlated with light-induced anthocyanin accumulation. Furthermore, seedlings totally lacking photosynthetic capabilities, either due to a genetic lesion or to excision of all photosynthetic tissue, had an enhanced rate of photoinduced anthocyanin formation. This evidence indicates that the HIR results in the initiation of processes that are in competition with chloroplast development for substrate in normal, intact seedlings. PMID:16659449

Duke, Stephen O.; Fox, Sue B.; Naylor, Aubrey W.

1976-01-01

432

A LOW COST, HIGH ACCURACYOPTICAL FLOW METHOD FOR MEASURING 2D AND 3D CORN SEEDLING GROWTH  

E-print Network

A LOW COST, HIGH ACCURACYOPTICAL FLOW METHOD FOR MEASURING 2D AND 3D CORN SEEDLING GROWTH: THEORY propose the use of optical flow as a means of accurately measuring 2D and 3D growth of young corn­ cal flow method for the use in (accurately) measuring young corn seedling growth. The 2D plant motion

Barron, John

433

Development of red oak seedlings using plastic shelters on hardwood sites in West Virginia. Forest Service research paper (Final)  

SciTech Connect

Plastic shelters were used to grow red oak seedlings on good-to-excellent Appalachian hardwood growing sites in north central West Virginia. Preliminary results indicate that shelters have the potential to stimulate development of red oak seedlingheight growth, especially if height growth continues once the seedling tops are above the 5-foot-tall shelters.

Smith, H.C.

1993-04-01

434

Summary Drought stress is the main cause of mortality of holm oak (Quercus ilex L.) seedlings in forest plantations. We  

E-print Network

Summary Drought stress is the main cause of mortality of holm oak (Quercus ilex L.) seedlings in forest plantations. We therefore assessed if drought hardening, applied in the nursery at the end of the growing season, enhanced the drought toler- ance and transplanting performance of holm oak seedlings

Villar-Salvador, Pedro

435

Intraspecific variation in the response to CO 2 enrichment in seeds and seedlings of Plantago lanceolata L  

Microsoft Academic Search

Four genotypes of P. lanceolata were grown to maturity at combinations of two levels of atmospheric CO2 concentrations and two temperature conditions. Seed weight was determined, and seed germination and seedling growth were measured for the progeny of each genotype under the same environmental conditions. Overall, high CO2 levels decreased seed weight, increased germination percentage and rate, and increased seedling

Renata D. Wulff; Helen Miller Alexander

1985-01-01

436

Incident Irradiance and Cupric Hydroxide Container Treatment Effects on Early Growth and Development of Container-grown Pawpaw Seedlings  

Microsoft Academic Search

The North American pawpaw (Asimina triloba (L.) Dunal) has great potential as a fruit crop or as a landscape plant. The influence of incident irradiance on pawpaw seedling growth and development in containers was examined in the greenhouse and outdoors. Root spiraling can be a problem for container-grown pawpaw seedlings; therefore, the influence of paint containing cupric hydroxide (Cu(OH) 2)

Kirk W. Pomper; Desmond R. Layne; Snake C. Jones

2002-01-01

437

Effects of water deficit stress and recovery on the root water relations of trembling aspen ( Populus tremuloides) seedlings  

Microsoft Academic Search

Aspen (Populus tremuloides Michx.) seedlings were grown in sand culture and subjected to mild and severe water deficit stress by withholding watering. Severely-stressed seedlings were also rewatered for 24 h to determine the effects of water deficit stress and stress recovery on root water flow properties. Both stress levels and stress recovery treatment reduced leaf stomatal conductance and shoot water

J. Aurea Siemens; Janusz J. Zwaizek

2003-01-01

438

Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide: their influence on some phenological and biochemical behaviors  

PubMed Central

Objective: To evaluate the effect of chitosan (CH) and hydrogen peroxide (H2O2) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology, the H2O2 presence, the catalase (CAT) activity, and the protein quantity. Methods: Seven groups of ten seeds for each maize variety were treated with CH (2% (20 g/L) and 0.2% (2 g/L)) or H2O2 (8 mmol/L) by coating, sprinkling, or both. Germination and seedling growth were measured. One month after germination, the presence of H2O2 in seedlings in the coated seed treatments was evaluated. Protein content and CAT activity were determined under all treatments. Results: H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize (QPM) variety. Seedlings had a higher emergence velocity under this treatment in both varieties. CH and H2O2 sprinklings did not have an effect on seedling phenology. Exogenous application of H2O2 promoted an increase of endogenous H2O2. CH and H2O2 seedling sprinkling increased the protein content in both maize varieties, while there was no significant effect on the CAT activity of treated seeds and seedlings. Conclusions: CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application. PMID:23365007

Lizárraga-Paulín, Eva-Guadalupe; Miranda-Castro, Susana-Patricia; Moreno-Martínez, Ernesto; Lara-Sagahón, Alma-Virginia; Torres-Pacheco, Irineo

2013-01-01

439

Effects of hardened wood ash on microbial activity, plant growth and nutrient uptake by ectomycorrhizal spruce seedlings  

Microsoft Academic Search

Plant growth, nutrient uptake, microbial biomass and activity were studied in pot systems containing spruce seedlings colonised with different ectomycorrhizal fungi from an ash-fertilised forest. The seedling root systems were enclosed in mesh bags inside an outer compartment containing crushed, hardened wood ash. Three different species of mycorrhizal fungi and a non-mycorrhizal control were exposed to factorial combinations of ash

Shahid Mahmood; Roger D Finlay; Ann-Mari Fransson; Håkan Wallander

2003-01-01

440

Growth response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima seedlings under different nitrogen and phosphorus concentrations  

Microsoft Academic Search

Treated effluent can potentially be used to restore riparian ecosystems to the many stream reaches in the south-western United States that have been dewatered. We undertook this study to determine how elevated nutrient levels in effluent influence riparian tree seedling performance. Seedlings of Fremont cottonwood (Populus fremontii), Goodding willow (Salix gooddingii), and exotic saltcedar (Tamarix ramosissima) were grown in a

Roy J. Marler; Juliet C. Stromberg; Duncan T. Patten

2001-01-01

441

Effects of Seedbed Density and Row Spacing on Growth and Nutrient Concentrations of Nuttall Oak and Green Ash Seedlings  

Microsoft Academic Search

SUMMARY Larger size and higher percentages of plantable 1-O and 2-O green ash (Fraxinus pennsylvanica Marsh.) and Nuttall oak (Quercus nuttallii Palmer) seedlings were produced in the wider spacing-lower density plots. Greater numbers of plantable seedlings were produced in the higher density plots. Spacing significantly affected diameters, heights, and percentages of plantable seed-

Harvey E. Kennedy

442

Impacts of mechanical site preparation on foliar nutrients of planted white spruce seedlings on mixed-wood  

E-print Network

Impacts of mechanical site preparation on foliar nutrients of planted white spruce seedlings nutrition of planted white spruce (Picea glauca (Moench) Voss) seedlings were examined at two mixed-wood boreal forest sites (Judy Creek, Fox Creek) in Alberta, Canada. The treatments included three types

Macdonald, Ellen

443

The Window of Desiccation Tolerance Shown by Early-Stage Germinating Seedlings Remains Open in the Resurrection Plant, Xerophyta viscosa  

PubMed Central

Resurrection plants are renowned for their vegetative desiccation tolerance (DT). While DT in vegetative tissues is rare in angiosperms, it is ubiquitous in mature orthodox seeds. During germination, seedlings gradually lose DT until they pass a point of no return, after which they can no longer survive dehydration. Here we investigate whether seedlings of the resurrection plant Xerophyta viscosa ever lose the capacity to establish DT. Seedlings from different stages of germination were dehydrated for 48 hours and assessed for their ability to recover upon rehydration. While a transient decline in the ability of X. viscosa seedlings to survive dehydration was observed, at no point during germination was the ability to re-establish DT completely lost in all seedlings. Pre-treatment of seedlings with PEG or sucrose reduced this transient decline, and improved the survival rate at all stages of germination. Additionally, we observed that the trait of poikilochlorophylly (or loss of chlorophyll) observed in adult X. viscosa leaves can be induced throughout seedling development. These results suggest that the window of DT seen in germinating orthodox seeds remains open in X. viscosa seedlings and that vegetative DT in Xerophyta species may have evolved from the ability to retain this program through to adulthood. PMID:24667896

Lyall, Rafe; Ingle, Robert A.; Illing, Nicola

2014-01-01

444

Anthocyanin formation in turnip seedlings ( Brassica rapa L.): Evidence for two light steps in the biosynthetic pathway  

Microsoft Academic Search

Summary In turnip seedlings, anthocyanin synthesis can be induced with light as soon as water uptake enables the seed coat to be removed. In very young seedlings the main site of production is in the cotyledons but this moves to the hypocotyl when the period of dark growth, before transfer to the light, is increased. The total amount of anthocyanin

Renate Grill; Daphne Vince

1964-01-01

445

INTEGRATING CONTINUOUS SOIL DEPTH DISTRIBUTIONS OF HYDROTHERMAL TIME, SEEDS, AND BURIAL TOLERANCES TO IMPROVE SEEDLING EMERGENCE MODELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Improvements in seedling emergence models may arise by accounting for variable and depth-specific accumulation of hydrothermal time in seed-bearing zones of soil, as well as tolerances of seed germination and seedling emergence in burial depth and, lastly, distribution of seed densities in soil, whi...

446

Development of ectomycorrhizae on containerized sweet birch and European alder seedlings for planting on low quality sites  

Microsoft Academic Search

A study was initiated to assess the potential of Pisolithus tinctorius as an ectomycorrhizal associate of containerized sweet birch (Betula lenta) and European alder (Alnus glutinosa) seedlings and to determine the effect of this fungal symbiont on seedling growth. In a test of sweet birch and European alder grown in Leach tubes, P. tinctorius formed abundant ectomycorrhizae on sweet birch

R. F. Walker; D. C. West; S. B. McLaughlin

1982-01-01

447

Seed Burial Physical Environment Explains Departures from Regional Hydrothermal Model of Giant Ragweed (Ambrosia trifida) Seedling Emergence  

E-print Network

Ragweed (Ambrosia trifida) Seedling Emergence in U.S. Midwest Adam S. Davis, Sharon Clay, John Cardina for explaining arable weed seedling emergence progress across wide regions. Nomenclature: Giant ragweed, Ambrosia trifida L. Key words: Abiotic influences on seed dormancy,hydrothermal time, nonlinear mixed effects

Sims, Gerald K.

448

THE IMPACTS ON SEEDLING ROOT GROWTH OF WATER AND SALINITY STRESS IN MAIZE (ZEA MAYS INDENTATA STURT.)  

Microsoft Academic Search

BILGIN, O., I. BASER, K. Z. KORKUT, A. BALKAN and N. SAGLAM, 2008. The impacts on seedling root growth of water and salinity stress in maize (Zea mays indentata Sturt.). Bulg. J. Agric. Sci., 14: 313-320 Effects of salinity and available water level at the seedling stage of dent corn variety were examined for some shoot and root characters. Two

O. BILGIN; I. BASER; K. Z. KORKUT; A. BALKAN; N. SAGLAM

2008-01-01

449

Stock Quality of Black Walnut (Juglans Nigra) Seedlings as Affected by Half-Sib Seed Source and Nursery Sowing Density  

E-print Network

375 Stock Quality of Black Walnut (Juglans Nigra) Seedlings as Affected by Half-Sib Seed Source identity, bareroot nursery production Abstract Morphological quality of black walnut (Juglans nigra L role of genetic selection in dictating morphological quality of nursery-grown black walnut seedlings

450

Effects of competition from young northern hardwoods on red pine seedling growth, nutrient use efficiency, and leaf morphology  

Microsoft Academic Search

Elliott, K.J. and White, AS., 1993. Effects of competition from young northern hardwoods on red pine seedling growth, nutrient use efficiency, and leaf morphology. For. Ecol. Manage., 57. 233- 255. The effects of competition from three northern hardwood tree species on red pine (Pinus resinosa Ait. ) seedlings were examined on two clear-cut sites in western Maine. We examined how

Katherine J. Elliott; A WHITE

1993-01-01

451

GENETIC MAPPING OF THE QCTS12 AND QCTS4 LOCI CONTROLLING M202 RICE SEEDLING RESPONSE TO LOW TEMPERATURES.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The California variety M202 exhibits good tolerance to low temperatures during the seedling stage of development. We have identified two major genetic loci, qCTS12 and qCTS4, which are involved in the low temperature tolerance of M202 seedlings. The qCTS12 locus, provides tolerance to cold-induced w...

452

Causes and consequences of unequal seedling production in forest trees: a case study in red oaks.  

PubMed

Inequality in reproductive success has important implications for ecological and evolutionary dynamics, but lifetime reproductive success is challenging to measure in long-lived species such as forest trees. While seed production is often used as a proxy for overall reproductive success, high mortality of seeds and the potential for trade-offs between seed number and quality draw this assumption into question. Parentage analyses of established seedlings can bring us one step closer to understanding the causes and consequences of variation in reproductive success. In this paper we demonstrate a new method for estimating individual seedling production and average percentage germination, using data from two mixed-species populations of red oaks (Quercus rubra, Q. velutina, Q. falcata, and Q. coccinea). We use these estimates to examine the distribution of female reproductive success and to test the relationship between seedling number and individual seed production, age, and growth rate. We show that both seed and seedling production are highly skewed, roughly conforming to zero-inflated lognormal distributions, rather than to the Poisson or negative-binomial distributions often assumed by population genetics analyses. While the number of established offspring is positively associated with mean annual seed production, a lower proportion of seeds from highly fecund individuals become seedlings. Our red oak populations also show evidence of trade-offs between growth rate and reproductive success. The high degree of inequality in seedling production shown here for red oaks, and by previous studies in other species, suggests that many trees may be more vulnerable to genetic drift than previously thought, if immigration in limited by fragmentation or other environmental changes. PMID:22764494

Moran, Emily V; Clark, James S

2012-05-01

453

Effects of soil enrichment, watering and seedling age on establishment of Mediterranean woody species  

NASA Astrophysics Data System (ADS)

Vegetation restoration in strongly degraded lands has inherent limitations. Among the most relevant limitations in Mediterranean Mountains are severe drought and stressful levels of irradiance during summer. Thus, it is common that seedlings planted in open ground incur high rates of early mortality. In the context of a project of restoration of a burned area in Southern Spain, we evaluate the efficiency of watering and enrichment with native soil, and the influence of seedling age on survival and growth of 9 late-successional tall shrubs and trees planted in open ground. We also explore how small-scale variation in environmental variables relates to establishment success. Our results show an overall positive effect of watering on the survival of planted seedlings, while the effects of enrichment with native soil and age of planted seedlings were species-specific. Seedling establishment varied markedly with the presence of ravines, which duplicated seedling survival. This suggests that ravines may be more easily restored, improving their role as corridors in landscape designs of restoration. Independently of the treatment applied, Rosa sp. and Crataegus monogyna, both fleshy-fruited species, had the highest rates of establishment. In conclusion, this study shows the viability of low aggressive restoration techniques to assist vegetation recovery in fire-degraded environments. Specifically, watering and planting in ravines should be considered where restoration practices are applied in areas lacking vegetation cover. Some species highly attractive for animal dispersers and of easy establishment ( Rosa sp. and Crataegus sp.) could be used to enhance spontaneous regeneration within and beyond corridors through increasing seed attraction and dissemination.

Siles, Gemma; Rey, Pedro J.; Alcántara, Julio M.; Bastida, Jesús M.; Herreros, Jose L.

2010-07-01

454

Temperature and saline stress on seedlings of Swietenia macrophylla: a comparative study.  

PubMed

Physical responses of plants to change in climatic factors like temperature, precipitation and abiotic factors like salinity intrusion may lead positive or negative effects. Some factor may promulgate growth while other may stunts their vigour. Present study seeks growth of a plantation species at its early stage of life towards elevated temperature and saline water stresses. Growth records of Swietenia macrophylla seedlings were enumerated by measuring height, collar diameter and leaf number development of the replicates growing at an environment-controlled plant growth chamber. One experimented with merely elevated temperature while other tries to find results of combined effect of elevated temperature (30, 32 and 34 degrees C) and saline (0.5, 1.5 and 2.5 g L(-1) NaCl) to said species seedlings. Seedling replicates showed diverse response to elevated temperature and saline irrigation at height, collar diameter and leaf number development. Results depict that elevated temperature alone might be positive for S. macrophylla seedlings, rather most favourable for its growth in height, however, collar diameter and leaf number may remain unaffected. Saline treatment along with higher temperature stresses may lead seedlings toward stunted or very low growth. As saline intensity increases, species growth tends to decrease proportionally. Elevated temperature aided with higher salinity may direct further under development of S. macrophylla seedlings which is distressing to plantation establishment of this species in sites which are vulnerable to salinity intrusion due to climate change. However, S. macrophylla may be a promising plantation species in drier part of the globe in near future. PMID:24506045

Rahman, M Siddiqur; Akter, S; Al-Amin, M

2013-12-01

455

Organ-coordinated response of early post-germination mahogany seedlings to drought.  

PubMed

Water deficit tolerance during post-germination stages is critical for seedling recruitment. In this work, we studied the effect of water deficit on morphological and biochemical responses in different organs of newly germinated mahogany (Swietenia macrophylla King) seedlings, a woody species that occurs in the Amazon rainforest. The root : shoot ratio increased under water deficit. The leaf number and water potential were not altered, although reductions in leaf area and stomatal conductance were observed. Osmotic potential became more negative in leaves of seedlings under severe stress. Water deficit increased fructose, glucose, sucrose and myo-inositol levels in leaves. Stems accumulated fructose, glucose and l-proline. Nitric oxide (NO) levels increased in the vascular cylinder of roots under severe stress while superoxide anion levels decreased due to augmented superoxide dismutase activity in this organ. Water deficit induced glutathione reductase activity in both roots and stems. Upon moderate or severe stress, catalase activity decreased in leaves and remained unaffected in the other seedling organs, allowing for an increase of hydrogen peroxide (H2O2) levels in leaves. Overall, the increase of signaling molecules in distinct organs-NO in roots, l-proline in stems and H2O2 and myo-inositol in leaves-contributed to the response of mahogany seedlings to water deficit by triggering biochemical processes that resulted in the attenuation of oxidative stress and the establishment of osmotic adjustment. Therefore, this body of evidence reveals that the development of newly germinated mahogany seedlings may occur in both natural habitats and crop fields even when water availability is greatly limited. PMID:24690672

Horta, Lívia P; Braga, Márcia R; Lemos-Filho, José P; Modolo, Luzia V

2014-04-01

456

[Effects of light intensity on Quercus liaotungensis seed germination and seedling growth].  

PubMed

This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability. PMID:22007441

Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao

2011-07-01

457

Auxin represses stomatal development in dark-grown seedlings via Aux/IAA proteins.  

PubMed

Stomatal development is tightly regulated through internal and external factors that are integrated by a complex signalling network. Light represents an external factor that strongly promotes stomata formation. Here, we show that auxin-resistant aux/iaa mutants, e.g. axr3-1, exhibit a de-repression of stomata differentiation in dark-grown seedlings. The higher stomatal index in dark-grown axr3-1 mutants when compared with the wild type is due to increased cell division in the stomatal lineage. Excessive stomata in dark-grown seedlings were also observed in mutants defective in auxin biosynthesis or auxin perception and in seedlings treated with the polar auxin transport inhibitor NPA. Consistent with these findings, exogenous auxin repressed stomata formation in light-grown seedlings. Taken together, these results indicate that auxin is a negative regulator of stomatal development in dark-grown seedlings. Epistasis analysis revealed that axr3-1 acts genetically upstream of the bHLH transcription factors SPCH, MUTE and FAMA, as well as the YDA MAP kinase cascade, but in parallel with the repressor of photomorphogenesis COP1 and the receptor-like protein TMM. The effect of exogenous auxin required the ER family of leucine-rich repeat receptor-like kinases, suggesting that auxin acts at least in part through the ER family. Expression of axr3-1 in the stomatal lineage was insufficient to alter the stomatal index, implying that cell-cell communication is necessary to mediate the effect of auxin. In summary, our results show that auxin signalling contributes to the suppression of stomatal differentiation observed in dark-grown seedlings. PMID:25063454

Balcerowicz, Martin; Ranjan, Aashish; Rupprecht, Laura; Fiene, Gabriele; Hoecker, Ute

2014-08-01

458

Acclimation to frost alters proteolytic response of wheat seedlings to drought.  

PubMed

A comparative examination of cysteine proteinases in winter wheat (Triticum aestivum L.) seedlings differing in sensitivity to frost and drought revealed many similarities and differences in response to water deprivation. Azocaseinolytic activity was enhanced under water deficiency, but the enhancement was significantly lower in the tolerant genotype (Kobra cultivar). On the contrary, acclimation of wheat seedlings at low temperature had no effect on the proteolytic activity of the tolerant cultivar and depressed the azocaseinolytic activity of the sensitive cultivar (Tortija). However, the observed depression of enzyme activity was fully reversible under dehydration. The content of soluble proteins was reduced in dehydrated non-acclimated and in acclimated seedlings of the frost-sensitive cultivar, but increased in acclimated seedlings of the tolerant cultivar. The cysteine proteinases were preferentially induced under water deficiency when assessment was based on the inhibitory effect of iodoacetate on azocasein hydrolysis. Separation of cysteine proteinases by SDS-PAGE containing gelatin as a substrate showed two bands with apparent molecular masses of 36 and 38 kDa in the sensitive cultivar, and a third band was detected (42 kDa) in the resistant cultivar. Water deficit and low temperature induced the new cysteine proteinases of molecular masses about 29, 33 and 42 kDa in sensitive non-acclimated seedlings. Polyclonal antibodies raised against Arabidopsis proteinase responsive to drought (RD21) cross-reacted with the protein in the 33 kDa region, and a slight signal was obtained in the 42 kDa region, but only in dehydrated seedlings acclimated to frost. Several polypeptides of molecular masses of 30, 22, 20 and 18 kDa were recognized by the Arabidopsis aleurain-like proteinase (AtALEU) antibodies. The results presented indicate that cysteine proteinases are potentially responsible for both low temperature and drought tolerance. PMID:20674076

Grudkowska, Ma?gorzata; Zagda?ska, Barbara

2010-11-01