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1

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

2

Bioactivities and compositional analyses of Cinnamomum essential oils from Nepal: C. camphora, C. tamala, and C. glaucescens.  

PubMed

This work examines the biological activity of essential oils of Cinnamomum camphora leaves, C. glaucescens fruit, and C. tamala root from Nepal. The oils were screened for phytotoxic activity against lettuce and perennial ryegrass, brine shrimp lethality, and antibacterial, antifungal, cytotoxic, insecticidal, and nematicidal activities. C. camphora leaf essential oil was phytotoxic to lettuce, antifungal to Aspergillus niger, and insecticidal, particularly toward midge and butterfly larvae, fruit flies, and fire ants. C. camphora oil was also toxic to brine shrimp and human breast tumor cells. C. glaucescens fruit essential oil showed notable nematicidal activity, as well as termiticidal and mosquito larvicidal activity. The root essential oil of C. tamala was toxic to mosquito larvae and fire ants. PMID:24555298

Satyal, Prabodh; Paudel, Prajwal; Poudel, Ambika; Dosoky, Noura S; Pokharel, Kiran Kumar; Setzer, William N

2013-12-01

3

Lipozyme RM IM-Catalyzed Acidolysis of Cinnamomum camphora Seed Oil with Oleic Acid To Produce Human Milk Fat Substitutes Enriched in Medium-Chain Fatty Acids.  

PubMed

In the present study, a human milk fat substitute (HMFS) enriched in medium-chain fatty acids (MCFAs) was synthesized through acidolysis reaction from Cinnamomum camphora seed oil (CCSO) with oleic acid in a solvent-free system. A commercial immobilized lipase, Lipozyme RM IM, from Rhizomucor miehei, was facilitated as a biocatalyst. Effects of different reaction conditions, including substrate molar ratio, enzyme concentration, reaction temperature, and reaction time were investigated using response surface methodology (RSM) to obtain the optimal oleic acid incorporation. After optimization, results showed that the maximal incorporation of oleic acid into HMFS was 59.68%. Compared with CCSO, medium-chain fatty acids at the sn-2 position of HMFS accounted for >70%, whereas oleic acid was occupied predominantly at the sn-1,3 position (78.69%). Meanwhile, triacylglycerol (TAG) components of OCO (23.93%), CCO (14.94%), LaCO (13.58%), OLaO (12.66%), and OOO (11.13%) were determined as the major TAG species in HMFS. The final optimal reaction conditions were carried out as follows: substrate molar ratio (oleic acid/CCSO), 5:1; enzyme concentration, 12.5% (w/w total reactants); reaction temperature, 60 °C; and reaction time, 28 h. The reusability of Lipozyme RM IM in the acidolysis reaction was also evaluated, and it was found that it could be reused up to 9 times without significant loss of activities. Urea inclusion method was used to separate and purify the synthetic product. As the ratio of HMFS/urea increased to 1:2, the acid value lowered to the minimum. In a scale-up experiment, the contents of TAG and total tocopherols in HMFS (modified CCSO) were 77.28% and 12.27 mg/100 g, respectively. All of the physicochemical indices of purified product were within food standards. Therefore, such a MCFA-enriched HMFS produced by using the acidolysis method might have potential application in the infant formula industry. PMID:25298236

Zou, Xian-Guo; Hu, Jiang-Ning; Zhao, Man-Li; Zhu, Xue-Mei; Li, Hong-Yan; Liu, Xiao-Ru; Liu, Rong; Deng, Ze-Yuan

2014-10-29

4

Antipathogenic Activities and Chemical Composition of Cinnamomum osmophloeum and Cinnamomum zeylanicum Leaf Essential Oils  

Microsoft Academic Search

In this study, inhibitory activities of leaf essential oils from Cinnamomum osmophloeum and Cinnamomum zeylanicum and their major constituents (trans-cinnamaldehyde and eugenol) against Rhizoctonia solani were investigated. Furthermore, the relationship between the antipathogenic activity and the chemical structure of trans-cinnamaldehyde and eugenol is discussed. Results demonstrated that leaf essential oils and their major constituents from C. osmophloeum and C. zeylanicum

Sen-Sung Cheng; Min-Jay Chung; Ying-Ju Chen; Shang-Tzen Chang

2011-01-01

5

Evaluation of Brine Shrimp Lethality of Cinnamomum Species  

Microsoft Academic Search

Cinnamomum species have long been used as spices. The preliminary bioactive constituent’s identification and brine shrimp lethality activities of ethanolic extracts of seven Cinnamomum species, viz., C. travancoricum, C. walaiwarense, C. wightii, C. verum, C. sulphuratum, C. riparium, and C. perrottetii were evaluated in this study. The results of cytotoxic activity of the bark extracts of seven Cinnamomum species were

Muthiah Maridass

2008-01-01

6

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

7

Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii.  

PubMed

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

2012-07-01

8

A Study of the Yield of Camphor and of Camphor Oil Obtained from the Laurus Camphora of Jamaica  

E-print Network

00107 LAWRENCE, KANSAS, Kay 15, 1910. In commerce we have various qualities of camphor, all coming from the Asiatic Orient. The prin­ cipal quality, and the most common, is the ordinary camphor from Formosa, China and Japan. This has the chemical... of the Laurus Camphora is less rich in camphor when these trees grow in Formosa, the Japanese will be justified in fearing competition against their camphor obtained from the toots and trunks of century old trees, not only on the part of synthetic camphor...

Weidlein, Edward Ray

1910-05-15

9

Mosquitocidal Activity of Leaf and Bark Essential Oils of Ceylon Cinnamomum zeylanicum  

Microsoft Academic Search

Mosquito control properties of essential oils of leaf and bark of Ceylon Cinnamomum zeylanicum Blume (Lauraceae) and their eight compounds were investigated against Culex quinquefasciatus, Anopheles tessellatus and Aedes aegypti. Cinnamomum zeylanicum bark oil showed good knock-down and mortality against A. tessellatus (LD50 0.33 ?g\\/mL) and C. quinquefasciatus (LD 0.66 ?g\\/mL) than leaf oil (LD 1.03 and 2.1 ?g\\/mL). Cinnamaldehyde

Radhika Samarasekera; Kosmulalage S. Kalhari; Indira S. Weerasinghe

2005-01-01

10

Macro-microscopic examination of leaves of Cinnamomum malabatrum (Burm. f.) Blume sold as Tamalapatra  

PubMed Central

Leaves of Cinnamomum tamala Nees & Eberm. (Lauraceae) commonly known as ‘Tamalapatra’ is a highly reputed commodity in drug and spice trade. Its adulteration with other leaf species belonging to genus Cinnamomum is found to be a common practice in India and other parts of the world. Thorough macroscopic and microscopic investigations are essential to differentiate them. Survey of South Indian crude drug markets revealed that in place of C. tamala some other leaves of Cinnamomum species are sold. Fresh leaves of various Cinnamomum species, including C. tamala, growing in south India were collected and studied to establish their correct identity. Leaves sold in markets of S. India under the name of Tamalapatra were subjected for detailed macro-microscopic evaluation including maceration and powder microscopy. Leaves of Cinnamomum malabatrum showed many distinguishing macro-microscopic characters, which will serve as markers to differentiate them from C. tamala the official source of Tamalapatra. Though macroscopy will serve the purpose of identification of the entire drug, microscopy had revealed the identity of the commercial substitute even in fragmented and powdered form. Macro-microscopic identity of C. malabatrum is established in comparison with the official drug, further chemical and biological studies may be confirmative in deciding the leaves as a substitute or adulterant. PMID:24250130

Sunil Kumar, K. N.

2013-01-01

11

Antibacterial activity of leaf essential oils and their constituents from Cinnamomum osmophloeum  

Microsoft Academic Search

The antibacterial activities of the essential oils from leaves of two Cinnamomum osmophloeum clones (A and B) and their chemical constituents were investigated in this study. The nine strains of bacteria, including Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus, were used in the antibacterial tests. Results

Shang-Tzen Chang; Pin-Fun Chen; Shan-Chwen Chang

2001-01-01

12

An evidence-based systematic review of cinnamon (Cinnamomum spp.) by the Natural Standard Research Collaboration.  

PubMed

An evidence-based systematic review of cinnamon (Cinnamomum spp.), including written and statistical analysis of scientific literature, expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing, by the Natural Standard Research Collaboration is discussed in this monograph. PMID:22432776

Ulbricht, Catherine; Seamon, Erica; Windsor, Regina C; Armbruester, Nicole; Bryan, J Kathryn; Costa, Dawn; Giese, Nicole; Gruenwald, Joerg; Iovin, Ramon; Isaac, Richard; Serrano, Jill M Grimes; Tanguay-Colucci, Shaina; Weissner, Wendy; Yoon, Heeja; Zhang, Jie

2011-12-01

13

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

14

[Supercritical carbon dioxide extraction of essential oil from Cinnamomum migao H. W. Li].  

PubMed

Essential oil from Cinnamomum migao H. W. Li. was extracted by supercritical fluid extraction (SFE) using carbon dioxide and a two-stage fractional separation system. The experiment was carried out under 306K-333K and 10-30 MPa. The influence of the process parameters were discussed. The GC-MS method was applied to analyze the components of these oils obtained by SFE. The result by SFE was better than that by stream distillation. PMID:12856468

Li, Tianxiang; Wang, Jingkang

2003-03-01

15

Insecticidal activities of leaf essential oils from Cinnamomum osmophloeum against three mosquito species  

Microsoft Academic Search

The larvicidal activities of leaf essential oils and their constituents from six chemotypes of indigenous cinnamon (Cinnamomum osmophloeum Kaneh.) trees were evaluated against three mosquito species. Results of larvicidal tests demonstrated that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde\\/cinnamyl acetate type had an excellent inhibitory effect against Aedes albopictus larvae, and their LC50 values in 24h were 40.8?g\\/ml

Sen-Sung Cheng; Ju-Yun Liu; Chin-Gi Huang; Yen-Ray Hsui; Wei-June Chen; Shang-Tzen Chang

2009-01-01

16

Composition, antimicrobial activity and in vitro cytotoxicity of essential oil from Cinnamomum zeylanicum Blume ( Lauraceae)  

Microsoft Academic Search

The essential oil from the bark of Cinnamomum zeylanicum Blume was analyzed by GC–MS and bioassays were carried out. Nine constituents representing 99.24% of the oil were identified by GC–MS. The major compounds in the oil were (E)-cinnamaldehyde (68.95%), benzaldehyde (9.94%) and (E)-cinnamyl acetate (7.44%). The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against

Mehmet Unlu; Emel Ergene; Gulhan Vardar Unlu; Hulya Sivas Zeytinoglu; Nilufer Vural

2010-01-01

17

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

18

Ovicidal and adulticidal activities of Cinnamomum zeylanicum bark essential oil compounds and related compounds against Pediculus humanus capitis (Anoplura: Pediculicidae)  

Microsoft Academic Search

The toxicity of cinnamon, Cinnamomum zeylanicum, bark essential oil compounds against eggs and adult females of human head louse, Pediculus humanus capitis, was examined using direct contact and vapour phase toxicity bioassays and compared with the lethal activity of their related compounds, benzyl alcohol, cinnamic acid, cinnamyl acetate, 4-hydroxybenzaldehyde and salicylaldehyde, as well as two widely used pediculicides, d-phenothrin and

Young-Cheol Yang; Hoi-Seon Lee; Si Hyeock Lee; J. Marshall Clark; Young-Joon Ahn

2005-01-01

19

Reforestation and Seedling Symbionts.  

National Technical Information Service (NTIS)

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

J. G. Mexal, R. K. Dixon

1990-01-01

20

Ovicidal and adulticidal activities of Cinnamomum zeylanicum bark essential oil compounds and related compounds against Pediculus humanus capitis (Anoplura: Pediculicidae).  

PubMed

The toxicity of cinnamon, Cinnamomum zeylanicum, bark essential oil compounds against eggs and adult females of human head louse, Pediculus humanus capitis, was examined using direct contact and vapour phase toxicity bioassays and compared with the lethal activity of their related compounds, benzyl alcohol, cinnamic acid, cinnamyl acetate, 4-hydroxybenzaldehyde and salicylaldehyde, as well as two widely used pediculicides, d-phenothrin and pyrethrum. In a filter-paper contact toxicity bioassay with female lice at 0.25 mg/cm(2), benzaldehyde was 29- and 27-fold more toxic than pyrethrum and d-phenothrin, respectively, as judged by median lethal time (LT(50)) values. Salicylaldehyde was nine and eight times more active than pyrethrum and d-phenothrin, respectively. Pediculicidal activity of linalool was comparable with that of d-phenothrin and pyrethrum. Cinnamomum bark essential oil was slightly less effective than either d-phenothrin or pyrethrum. Benzyl alcohol and (E)-cinnamaldehyde exhibited moderate pediculicidal activity. After 24h of exposure, no hatching was observed with 0.063 mg/cm(2) salicylaldehyde, 0.125 mg/cm(2) benzaldehyde, 0.5mg/cm(2)Cinnamomum bark essential oil, 1.0 mg/cm(2) (E)-cinnamaldehyde, and 1.0 mg/cm(2) benzyl cinnamate. Little or no ovicidal activity was observed with d-phenothrin or pyrethrum. In vapour phase toxicity tests with female lice, benzaldehyde and salicylaldehyde were much more effective in closed containers than in open ones, indicating that the mode of delivery of these compounds was largely due to action in the vapour phase. Neither d-phenothrin nor pyrethrum exhibited fumigant toxicity. Cinnamomum bark essential oil and test compounds described merit further study as potential pediculicides or ovicides for the control of P. h. capitis. PMID:16188263

Yang, Young-Cheol; Lee, Hoi-Seon; Lee, Si Hyeock; Clark, J Marshall; Ahn, Young-Joon

2005-12-01

21

Subcritical water extraction of flavoring and phenolic compounds from cinnamon bark (Cinnamomum zeylanicum).  

PubMed

Cinnamon bark (Cinnamomum zeylanicum) powder was treated with subcritical water at 150 and 200°C in a semi-continuous system at a constant flow rate (3 mL/min) and pressure (6 MPa). Major flavoring compounds, i.e., cinnamaldehyde, cinnamic acid, cinnamyl alcohol and coumarin, were extracted at lower recoveries than the extraction using methanol, suggesting that degradation of these components might occur during the subcritical water treatment. Caffeic, ferulic, p-coumaric, protocatechuic and vanillic acids were identified from the subcritical water treatment. Extraction using subcritical water was more effective to obtain these acids than methanol (50% v/v) in both number of components and recovery, especially at 200°C. Subcritical water treatment at 200°C also resulted in a higher total phenolic content and DPPH radical scavenging activity than the methanol extraction. The DPPH radical scavenging activity and total phenolic content linearly correlated but the results suggested that the extraction at 200°C might result in other products that possessed a free radical scavenging activity other than the phenolic compounds. PMID:22687781

Khuwijitjaru, Pramote; Sayputikasikorn, Nucha; Samuhasaneetoo, Suched; Penroj, Parinda; Siriwongwilaichat, Prasong; Adachi, Shuji

2012-01-01

22

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

23

Impact of decomposing Cinnamomum septentrionale leaf litter on the growth of Eucalyptus grandis saplings.  

PubMed

A pot experiment was performed to study the impact of decomposing Cinnamomum septentrionale leaf litter on the growth of Eucalyptus grandis saplings. The experimental design scheme was 0 (CK), 40 (A1), 80 (A2) and 120 g pot(-1) (A3) of E. grandis leaves, and changes in the volatile oil chemical composition during litter decomposition were assessed in the present study. The results showed that C. septentrionale leaf litter inhibited the growth of E. grandis saplings, as determined by the height, basal diameter and chlorophyll content, after 69 d (T1). Five months after transplantation (T2), the height growth rate of the E. grandis saplings increased and then gradually reduced (A1: 40 g pot(-1) > A2: 80 g pot(-1) > A3: 120 g pot(-1) > CK: 0 g pot(-1)). After eleven months (T3), the variations in the height and basal diameter were the same as observed at T2, and the inhibition on leaf, branch, root and stem biomass increased with increasing leaf litter content. Gas chromatography-mass spectrometry (GC-MS) was used to identify the volatile compound composition. The results indicated that the C. septentrionale original leaf litter (S1) contained thirty-one volatile compounds, but the treated leaf litter S2 (which was mixed with soil for eleven months to simultaneously plant E. grandis saplings) only possessed fourteen volatile compounds, releasing many secondary metabolites in the soil during decomposition. Most of the volatile compounds were alcohols, monoterpenoids, sesquiterpenes, alkanes, alkene, esters and ketones. Most of the allelochemicals of C. septentrionale might be released during the initial decomposing process, inhibiting the growth of other plants, whereas some nutrients might be released later, promoting the height growth of plants. In conclusion, decomposing C. septentrionale leaf litter release of many allelochemicals in the soil that significantly inhibit the growth of E. grandis. PMID:23835358

Huang, Weiwei; Hu, Tingxing; Chen, Hong; Wang, Qian; Hu, Hongling; Tu, Lihua; Jing, Liao

2013-09-01

24

VIRGINIA 4-H PINE SEEDLING  

E-print Network

are not tolerant of shade, so you will need to find an open area for planting. Seedlings will also need ________ Date planted ________ Date of first rain ________ Number of live trees on June 1 ________ on August 15 and coastal plain counties) White Pine (mountain and valley counties) Map of Planting Area Pine seedlings

Liskiewicz, Maciej

25

Simultaneous quantitative determination of cinnamaldehyde and methyl eugenol from stem bark of Cinnamomum zeylanicum Blume using RP-HPLC.  

PubMed

A simple, sensitive, and precise reversed-phase high performance liquid chromatographic (HPLC) method has been developed, validated and used for simultaneous quantitative determination of cinnamaldehyde and methyl eugenol from the methanolic extract of dried bark powder of Cinnamomum zeylanicum Blume (family Lauraceae). The ultrasonic extraction method was used for the extraction of these compounds. The reversed-phase HPLC analysis was carried out using a Intersil ODS-3V-C(18) (150 mm x 4.6 mm, 5 microm) column and a mobile phase comprising of methanol-acetonitrile-water in the volume ratio of 35:20:45, delivered at a flow rate of 1.0 cm(3)/min. The detection and quantitation of both the compounds was carried out at 221 nm. PMID:20056038

Gursale, Atish; Dighe, Vidya; Parekh, Guarang

2010-01-01

26

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.

27

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

28

In vitro antifungal, anti-elastase and anti-keratinase activity of essential oils of Cinnamomum, Syzygium- and Cymbopogon-species against Aspergillus fumigatus and Trichophyton rubrum  

Microsoft Academic Search

This study was aimed to evaluate effects of certain essential oils namely Cinnamomum verum, Syzygium aromaticum, Cymbopogon citratus, Cymbopogon martini and their major components cinnamaldehyde, eugenol, citral and geraniol respectively, on growth, hyphal ultrastructure and virulence factors of Aspergillus fumigatus and Trichophyton rubrum. The antifungal activity of essential oils and their major constituents was in the order of cinnamaldehyde>eugenol>geraniol=C. verum>citral>S.

Mohd Sajjad Ahmad Khan; Iqbal Ahmad

29

Effect of Cinnamon (Cinnamomum Cassia) intervention on Blood Glucose of Middle Aged Adult Male with Non Insulin Dependent Diabetes Mellitus (NIDDM)  

Microsoft Academic Search

The present study was conducted to find out the effect of oral administration of cinnamon (Cinnamomum cassia) on non insulin dependent diabetes mellitus (NIDDM) patients of Udaipur city (Rajasthan). Thirty type 2 diabetics were divided into two groups (15 in each) experimental and control group. Experimental group was supplemented with 2g cinnamon powder filled in capsules (4capsules\\/day\\/person) for 40 days.

Richa Soni; Vibha Bhatnagar

30

Cinnamomum cassia Essential Oil Inhibits ?-MSH-Induced Melanin Production and Oxidative Stress in Murine B16 Melanoma Cells  

PubMed Central

Essential oils extracted from aromatic plants exhibit important biological activities and have become increasingly important for the development of aromatherapy for complementary and alternative medicine. The essential oil extracted from Cinnamomum cassia Presl (CC-EO) has various functional properties; however, little information is available regarding its anti-tyrosinase and anti-melanogenic activities. In this study, 16 compounds in the CC-EO have been identified; the major components of this oil are cis-2-methoxycinnamic acid (43.06%) and cinnamaldehyde (42.37%). CC-EO and cinnamaldehyde exhibited anti-tyrosinase activities; however, cis-2-methoxycinnamic acid did not demonstrate tyrosinase inhibitory activity. In murine B16 melanoma cells stimulated with ?-melanocyte-stimulating hormone (?-MSH), CC-EO and cinnamaldehyde not only reduced the melanin content and tyrosinase activity of the cells but also down-regulated tyrosinase expression without exhibiting cytotoxicity. Moreover, CC-EO and cinnamaldehyde decreased thiobarbituric acid-reactive substance (TBARS) levels and restored glutathione (GSH) and catalase activity in the ?-MSH-stimulated B16 cells. These results demonstrate that CC-EO and its major component, cinnamaldehyde, possess potent anti-tyrosinase and anti-melanogenic activities that are coupled with antioxidant properties. Therefore, CC-EO may be a good source of skin-whitening agents and may have potential as an antioxidant in the future development of complementary and alternative medicine-based aromatherapy. PMID:24051402

Chou, Su-Tze; Chang, Wen-Lun; Chang, Chen-Tien; Hsu, Shih-Lan; Lin, Yu-Che; Shih, Ying

2013-01-01

31

Antifungal and antioxidative potential of oil and extracts derived from leaves of Indian spice plant Cinnamomum tamala.  

PubMed

Plant—based antimicrobials and antioxidants represent a vast untapped source for medicines and food supplements and hence have enormous therapeutic potential. Present work reports the fungicidal potential of Cinnamomum tamala Nees & Eberm (Lauraceae) leaf oil against five food spoilage and pathogenic fungi. In addition antioxidant efficacy of seven different solvent extracts derived from leaf was also evaluated using in vitro models. The oil demonstrated potent antifungal activity against Aspergillus niger, A. fumigatus, Candida albicans, Rhizopus stolonifer and Penicillium spp. in agar diffusion assay. Zone of inhibition ranged from 17-25 mm. The MFC values of oil against all the test fungi were found to be 230?g/ml. Phytochemicals present in C. tamala leaf were extracted in several solvents for assessing their effect in oxidative defense. The extracts exhibited appreciable antioxidant activity in ?-carotene bleaching assay and reducing power assay. The antioxidative activities of extracts were compared with the activities of standard antioxidant compounds BHA and ascorbic acid. Petroleum ether, ethanol, acetone and chloroform extracts exhibited about 30-67% antioxidant activity in ?-carotene bleaching assay. Aqueous and ethanol extracts exhibited better reducing power which increased gradually with increasing amount of the extract concentration showing dose dependent response. Results indicated that natural phytochemicals present in C. tamala leaf extracts have potential to prevent growth of food spoilage/pathogenic fungi. In addition they also have capability to mitigate the oxidative stress by antioxidant response. PMID:23273204

Pandey, A K; Mishra, A K; Mishra, A

2012-01-01

32

Identifying melanogenesis inhibitors from Cinnamomum subavenium with in vitro and in vivo screening systems by targeting the human tyrosinase.  

PubMed

Tyrosinase is known to be the first two and rate-limiting enzyme in the synthesis of melanin pigments responsible for colouring skin, hair and eyes. Tyrosinase inhibition is one major strategy used to treat hyperpigmentation. In human skin melanocytes, the cellular tyrosinase inhibition was examined by the conversion of l-tyrosine and oxidation of l-DOPA to dopaquinone. We evaluated the skin pigmentation inhibitor effects with both in vitro and in vivo systems to find skin-whitening agents without cytotoxic concerns. First, linderanolide B and subamolide A were isolated from the stems of Cinnamomum subavenium and exhibited mushroom tyrosinase inhibition. Then, these two herbal compounds were proved to have good pigmentation inhibitory abilities at low doses and demonstrated free cytotoxicities to normal human skin cells and zebrafish system. With molecular docking, in a virtual model of human tyrosinase, linderanolide B and subamolide A displayed meta(l) -coordinating interactions with Cu(2+) ions. The results obtained from biological assays showed that linderanolide B and subamolide A possessed anti-tyrosinase properties, which exhibited potential for application in medical cosmetology. PMID:21054558

Wang, Hui-Min; Chen, Chung-Yi; Wen, Zhi-Hong

2011-03-01

33

Antifungal effect of Allium tuberosum, Cinnamomum cassia, and Pogostemon cablin essential oils and their components against population of Aspergillus species.  

PubMed

Antifungal activity of Allium tuberosum (AT), Cinnamomum cassia (CC), and Pogostemon cablin (Patchouli, P) essential oils against Aspergillus flavus strains 3.2758 and 3.4408 and Aspergillus oryzae was tested at 2 water activity levels (aw : 0.95 and 0.98). Main components of tested essential oils were: allyl trisulfide 40.05% (AT), cinnamaldehyde 87.23% (CC), and patchouli alcohol 44.52% (P). The minimal inhibitory concentration of the plant essential oils against A. flavus strains 3.2758 and 3.4408 and A. oryzae was 250 ppm (A. tuberosum and C. cassia), whereas Patchouli essential oil inhibited fungi at concentration > 1500 ppm. The essential oils exhibited suppression effect on colony growth at all concentrations (100, 175, and 250 ppm for A. tuberosum; 25, 50, and 75 for C. cassia; 100, 250, and 500 for P. cablin essential oil). Results of the study represent a solution for possible application of essential oil of C. cassia in different food systems due to its strong inhibitory effect against tested Aspergillus species. In real food system (table grapes), C. cassia essential oil exhibited stronger antifungal activity compared to cinnamaldehyde. PMID:23647469

Kocevski, Dragana; Du, Muying; Kan, Jianquan; Jing, Chengjun; La?anin, Ines; Pavlovi?, Hrvoje

2013-05-01

34

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

35

Cinnamomum cassia Bark in Two Herbal Formulas Increases Life Span in Caenorhabditis elegans via Insulin Signaling and Stress Response Pathways  

PubMed Central

Background Proving the efficacy and corresponding mode of action of herbal supplements is a difficult challenge for evidence-based herbal therapy. A major hurdle is the complexity of herbal preparations, many of which combine multiple herbs, particularly when the combination is assumed to be vitally important to the effectiveness of the herbal therapy. This issue may be addressed through the use of contemporary methodology and validated animal models. Methods and Principal Findings In this study, two commonly used traditional herbal formulas, Shi Quan Da Bu Tang (SQDB) and Huo Luo Xiao Ling Dan (HLXL) were evaluated using a survival assay and oxidative stress biomarkers in a well-established C. elegans model of aging. HLXL is an eleven herb formula modified from a top-selling traditional herbal formula for the treatment of arthritic joint pain. SQDB consists of ten herbs often used for fatigue and energy, particularly in the aged. We demonstrate here that SQDB significantly extend life span in a C. elegans model of aging. Among all individual herbs tested, two herbs Cinnamomum cassia bark (Chinese pharmaceutical name: Cinnamomi Cortex, CIN) and Panax ginseng root (Chinese pharmaceutical name: Ginseng Radix, GS) significantly extended life span in C. elegans. CIN in both SQDB and HLXL formula extended life span via modulation of multiple longevity assurance genes, including genes involved in insulin signaling and stress response pathways. All the life-span-extending herbs (SQDB, CIN and GS) also attenuated levels of H2O2 and enhanced small heat shock protein expression. Furthermore, the life span-extending herbs significantly delayed human amyloid beta (A?)-induced toxicity in transgenic C. elegans expressing human A?. Conclusion/Significance These results validate an invertebrate model for rapid, systematic evaluation of commonly used Chinese herbal formulations and may provide insight for designing future evidence-based herbal therapy(s). PMID:20179756

Yu, Young-Beob; Dosanjh, Laura; Lao, Lixing; Tan, Ming; Shim, Bum Sang; Luo, Yuan

2010-01-01

36

Seedling demography in an alpine ecosystem.  

PubMed

Seedling establishment has long been believed to be rare on alpine tundra because of predicted life history trade-offs, the clonality of alpine species, and the harshness of the alpine climate. Contrary to the idea that seedlings are rare on alpine tundra, a 4-yr demographic study of seedlings at Niwot Ridge, Colorado, USA, found seedlings at high densities, particularly in wetter plant communities. Higher germination densities were associated with higher soil moistures both across communities and across time. Mortality of seedlings was highest in the first year and decreased in subsequent years. Species' abundances differed between seedling and adult populations. Many forbs that lacked vegetative reproduction were significantly more abundant among seedling populations, and many monocots and clonal forbs were more abundant among adult populations. In a comparison with published demographic rates, seedling recruitment and mortality rates of Niwot Ridge species fell above or within rates for a wide range of perennial species. Therefore, germination and seedling establishment stages are no more limiting to sexual reproduction in alpine plants than in other perennial plants. PMID:21659220

Forbis, Tara A

2003-08-01

37

Planting frozen conifer seedlings: Warming trends and effects on seedling performance  

Microsoft Academic Search

In temperate climates, conifer seedlings are often held in frozen storage (-2 °C) for extended periods and then placed in cool storage (+2 °C) so the root plug can thaw prior to outplanting. Two plug temperature treatments were used to test the hypothesis that thawing seedlings prior to outplanting may be unnecessary: seedlings were planted with frozen root plugs (‘frozen

C. M. Kooistra; J. D. Bakker

2002-01-01

38

Effects of Cinnamomum zeylanicum (Ceylon cinnamon) on blood glucose and lipids in a diabetic and healthy rat model  

PubMed Central

Objectives: To evaluate short- and long-term effects of Cinnamomum zeylanicum on food consumption, body weight, glycemic control, and lipids in healthy and diabetes-induced rats. Materials and Methods: The study was conducted in two phases (Phase I and Phase II), using Sprague-Dawley rats in four groups. Phase I evaluated acute effects on fasting blood glucose (FBG) (Groups 1 and 2) and on post-oral glucose (Groups 3 and 4) blood glucose. Groups 1 and 3 received distilled-water and Groups 2 and 4 received cinnamon-extracts. Phase II evaluated effects on food consumption, body weight, blood glucose, and lipids over 1 month. Group A (n = 8, distilled-water) and Group B (n = 8, cinnamon-extracts) were healthy rats, while Group C (n = 5, distilled-water) and Group D (n = 5, cinnamon-extracts) were diabetes-induced rats. Serum lipid profile and HbA1c were measured on D-0 and D-30. FBG, 2-h post-prandial blood glucose, body weight, and food consumption were measured on every fifth day. Results: Phase I: There was no significant difference in serial blood glucose values in cinnamon-treated group from time 0 (P > 0.05). Following oral glucose, the cinnamon group demonstrated a faster decline in blood glucose compared to controls (P < 0.05). Phase II: Between D0 and D30, the difference in food consumption was shown only in diabetes-induced rats (P < 0.001). Similarly, the significant difference following cinnamon-extracts in FBG and 2-h post-prandial blood glucose from D0 to D30 was shown only in diabetes-induced rats. In cinnamon-extracts administered groups, total and LDL cholesterol levels were lower on D30 in both healthy and diabetes-induced animals (P < 0.001). Conclusions: C. zeylanicum lowered blood glucose, reduced food intake, and improved lipid parameters in diabetes-induced rats. PMID:22518078

Ranasinghe, Priyanga; Perera, Sanja; Gunatilake, Mangala; Abeywardene, Eranga; Gunapala, Nuwan; Premakumara, Sirimal; Perera, Kamal; Lokuhetty, Dilani; Katulanda, Prasad

2012-01-01

39

Mycorrhizas on nursery and field seedlings of Quercus garryana.  

PubMed

Oak woodland regeneration and restoration requires that seedlings develop mycorrhizas, yet the need for this mutualistic association is often overlooked. In this study, we asked whether Quercus garryana seedlings in nursery beds acquire mycorrhizas without artificial inoculation or access to a mycorrhizal network of other ectomycorrhizal hosts. We also assessed the relationship between mycorrhizal infection and seedling growth in a nursery. Further, we compared the mycorrhizal assemblage of oak nursery seedlings to that of conifer seedlings in the nursery and to that of oak seedlings in nearby oak woodlands. Seedlings were excavated and the roots washed and examined microscopically. Mycorrhizas were identified by DNA sequences of the internal transcribed spacer region and by morphotype. On oak nursery seedlings, predominant mycorrhizas were species of Laccaria and Tuber with single occurrences of Entoloma and Peziza. In adjacent beds, seedlings of Pseudotsuga menziesii were mycorrhizal with Hysterangium and a different species of Laccaria; seedlings of Pinus monticola were mycorrhizal with Geneabea, Tarzetta, and Thelephora. Height of Q. garryana seedlings correlated with root biomass and mycorrhizal abundance. Total mycorrhizal abundance and abundance of Laccaria mycorrhizas significantly predicted seedling height in the nursery. Native oak seedlings from nearby Q. garryana woodlands were mycorrhizal with 13 fungal symbionts, none of which occurred on the nursery seedlings. These results demonstrate the value of mycorrhizas to the growth of oak seedlings. Although seedlings in nursery beds developed mycorrhizas without intentional inoculation, their mycorrhizas differed from and were less species rich than those on native seedlings. PMID:19139931

Southworth, Darlene; Carrington, Elizabeth M; Frank, Jonathan L; Gould, Peter; Harrington, Connie A; Devine, Warren D

2009-03-01

40

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

E-print Network

: 10.1899/07­073.1 Published online: 7 April 2009 Great house, poor food: effects of exotic leaf litter Abstract. Exotic plants have invaded the riparian zones of many streams worldwide, but their consequences Wales, Australia, the exotic tree camphor laurel (Cinnamomum camphora) has aggressively invaded riparian

Wisenden, Brian D.

41

Antigenotoxic effects of three essential oils in diploid yeast ( Saccharomyces cerevisiae) after treatments with UVC radiation, 8MOP plus UVA and MMS  

Microsoft Academic Search

Essential oils (EOs) extracted from medicinal plants such as Origanum compactum, Artemisia herba alba and Cinnamomum camphora are known for their beneficial effects in humans. The present study was undertaken to investigate their possible antigenotoxic effects in an eukaryotic cell system, the yeast Saccharomyces cerevisiae. The EOs alone showed some cytotoxicity and cytoplasmic petite mutations, i.e. mitochondrial damage, but they

F. Bakkali; S. Averbeck; D. Averbeck; A. Zhiri; D. Baudoux; M. Idaomar

2006-01-01

42

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-Jurgen

2007-01-01

43

Densities and Media Effect on Tomato Seedling Quality  

Microsoft Academic Search

The quality of tomato seedlings raised in 4 seedling densities (1,100\\/m2, 400\\/m2, 200\\/m2, 100\\/ m 2 ) and 2 kinds of media were compared. Decreasing seedling density markedly increased the seedling vigor, field survival rates and improved reproductive growth and fruit development. Vegetative vigor was evaluated according to an index based on relationships among seedling height, stem thickness, shoot and

Zhou Rui Jun

44

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...

45

Seedling growth and development on space shuttle  

Microsoft Academic Search

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

J. Cowles; R. Lemay; G. Jahns

1994-01-01

46

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.

47

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

48

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...

49

Method of pollination and heritability for seedling vigor in switchgrass  

E-print Network

on seed size because of its strong correlation with seedling vigor (Black, 1957; Townsend and Wilson, 1981; Knight, 1985). Evers (1999), compared the morphological seedling traits of arrowleaf (Trifolium vesiculosum Savi.), crimson (T. incarnatum L... on seed size because of its strong correlation with seedling vigor (Black, 1957; Townsend and Wilson, 1981; Knight, 1985). Evers (1999), compared the morphological seedling traits of arrowleaf (Trifolium vesiculosum Savi.), crimson (T. incarnatum L...

Ramirez de Leon, Hector

2005-08-29

50

Cinnamomum cassia bark produced by solid-state fermentation with Phellinus baumii has the potential to alleviate atopic dermatitis-related symptoms.  

PubMed

In order to evaluate whether the aqueous fraction of Cinnamomum cassia produced by solid?state fermentation with Phellinus baumii (afCc/Pb) inhibits atopic symptoms in vivo, its efficacy was evaluated in an animal model of 2,4?dinitrofluorobenzene (DNFB)?induced atopic dermatitis. Immune?related cells were quantified using hematoxylin and eosin staining, and phenotypic cytokines, enzymes and the expression of other proteins in the animal model were evaluated. The data revealed that afCc/Pb (100 µg/ml) exhibited strong anti?atopic activity, causing a significant 40% reduction in immune response, as shown by the extent of ear swelling, resulting from a decrease in the number of eosinophils in the skin tissues due to decreased matrix metalloproteinase?2 and interleukin?31 expression. These results collectively suggest that afCc/Pb has the potential to alleviate the symptoms of atopic dermatitis in a mouse model of DNFB?induced atopic dermatitis, and that it may be a valuable bioresource for the cosmetic/cosmeceutical industry. PMID:25406033

Shin, Yong-Kyu; Son, Hyeong-U; Kim, Jong-Myung; Heo, Jin-Chul; Lee, Sang-Han; Kim, Jong-Guk

2015-01-01

51

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

52

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

53

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

54

An outbreak of yellow mold of peanut seedlings in Texas  

Microsoft Academic Search

Yellow mold of peanut (Arachis hypogaea) seedlings caused by Aspergillus flavus was first observed during May 1984 in a commercial peanut farm in south Texas. The mold caused preemergence rotting of peanut seed and seedlings. On emerged seedlings the infection was largely restricted to cotyledons. The diseased plants were chlorotic, stunted, and leaflets were reduced in size with pointed tips

P. Subrahmanyam; D. H. Smith; R. A. Raber; E. Shepherd

1987-01-01

55

Seed mucilage improves seedling emergence of a sand desert shrub.  

PubMed

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

56

Alkaloid metabolism in wounded Catharanthus roseus seedlings  

Microsoft Academic Search

The effect of mechanical wounding on alkaloid metabolism was analyzed in Catharanthus roseus seedlings. Wounding induced an increase in ajmalicine accumulation, whereas catharanthine remained unaffected. A positive dual effect on vindoline was noticed. Short and mid-term effects were detected between 12 and 24 h after mechanical damage was inflicted, and apparently resulted from the accelerated transformation of the tabersonine intermediaries to vindoline.

Felipe Vázquez-Flota; Mildred Carrillo-Pech; Yereni Minero-García; María de Lourdes Miranda-Ham

2004-01-01

57

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...

58

Lectins in Castor Bean Seedlings 1  

PubMed Central

The amounts of the two lectins (ricin and Ricinus communis agglutinin) in tissues of castor bean seedlings were followed during germination and early growth. For measurement, lectins in extracts were separately eluted from Sepharose columns; an antibody to the agglutinin was also used to detect the lectins by immunodiffusion. The endosperm of the dry seed contains 3.5 mg total lectin (5.6% of the total seed protein), which declines by 50% by day 4 and more rapidly thereafter as the tissue is completely consumed. The cotyledons of the dry seed also contain lectins but the amounts are less than 1% of those in the endosperm, and, as in the endosperm, they are constituents of the albumin fraction of the isolated protein bodies. No lectins were detected in the green cotyledons of 10-day seedlings that had been exposed to light from day 5. The embryonic axes of 2-day seedlings contained very small amounts of lectins but they were not detectable in the aerial parts of seedlings grown for 3 weeks or in cells from endosperm grown in tissue culture. The ability of proteinases and glycosidases (isolated from endosperm of 4-day seedlings) to hydrolyze the lectins was examined. No hydrolysis of the two lectins was observed, but the subunits, separated by reduction with 2-mercaptoethanol, were hydrolyzed slowly by a proteinase and some release of mannose was observed in the presence of the glycosidases. Ricin was converted to its subunits by cysteine and an enzyme in an endosperm extract accelerated chain separation by glutathione. Images Fig. 3 PMID:16664561

Harley, Suzanne M.; Beevers, Harry

1986-01-01

59

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

60

Antiinflammatory effects of essential oil from the leaves of Cinnamomum cassia and cinnamaldehyde on lipopolysaccharide-stimulated J774A.1 cells.  

PubMed

Cassia oil (CO) from different parts of Cinnamomum cassia have different active components. Very few pharmacological properties of cassia leaf oil have been reported. This study investigated and compared effects of cassia leaf oil and cinnamaldehyde on lipopolysaccharide (LPS)-activated J774A.1 cells. Volatile compositions in cassia leaf oil were identified by gas chromatography-mass spectrometry (MS)/MS. Effects of CO and cinnamaldehyde on LPS-activated J774A.1 cells were investigated by determining nitric oxide (NO) production using Griess reaction assay; expression of pro-inflammatory cytokines, enzymes involve in inflammatory mediators; antiinflammatory cytokines, and iron exporter ferroportin1 (Fpn1) using reverse transcription-polymerase chain reaction; and production of tumor necrosis factor (TNF-?) and interleukin (IL)-10 using ELISA. The main component of CO was cinnamaldehyde. Both oils at 1-20 ?g/ml markedly inhibited NO production in LPS-activated J774A.1 cells with IC50 value of 6.1 ± 0.25 and 9.97 ± 0.35 ?g/ml, respectively. They similarly inhibited mRNA expression of pro-inflammatory cytokines and chemokines. These mediators included TNF-?, IL-1?, IL-6, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1? in LPS-activated cells. They also significantly decreased expression of inducible enzymes inducible nitric oxide synthase, cyclooxygenase-2, microsomal prostaglandin-E synthase-1. In the opposite way, they increased mRNA expression and the production of antiinflammatory cytokines IL-10 and transforming growth factor-?. In addition, they promoted the expression of Fpn1. These results demonstrated that inhibitory effects of cassia leaf oil from C. cassia mainly came from cinnamaldehyde. This compound not only inhibited inflammatory mediators but also activated antiinflammatory mediators in LPS-activated J774A.1 cells. It may also have an effect on iron regulatory proteins in activated macrophages. PMID:25364694

Pannee, Chinjarernpan; Chandhanee, Itthipanichpong; Wacharee, Limpanasithikul

2014-10-01

61

Regulation of growth in rice seedlings  

Microsoft Academic Search

Etiolated rice seedlings (Oryza sativa L.) exhibited marked morphological differences when grown in sealed containers or in containers through which air was passed\\u000a continuously. Enhancement of coleoptile and mesocotyl growth and inhibition of leaf and root growth in the sealed containers\\u000a (“enclosure syndrome”) were accompanied by accumulation of CO2 and C2H4 in and depletion of O2 from the atmosphere. Ethylene

Ilya Raskin; Hans Kende

1983-01-01

62

Early events in geotropism of seedling shoots  

NASA Technical Reports Server (NTRS)

Developments during the first ten minutes of geotropic stimulation in plant seedling shoots are reviewed. Topics include induction and curvature; early processes; the relationship between auxin, electric field, calcium, and differential growth; gravity reception leading to Went-Cholodny transport; and comparison of root and shoot. Early processes reviewed are sedimentation of amyloplasts, release of ethylene, rise of electrical and auxin asymmetry, redistribution of calcium, asymmetric vascular transport, increase in tendency to deposit callose, and simulation of putative exocytotic voltage transients.

Pickard, B. G.

1985-01-01

63

Zirconium induced physiological alterations in wheat seedlings  

Microsoft Academic Search

The effects of zirconium ascorbate (Zr-ASC), a water-soluble complex of Zr, were examined on wheat seedlings (Triticum aestivum L. cv. MV. 20). Hydroponically grown plants were exposed to 10, 33, 55, 100 and 550 µM Zr-ASC (Zr10, Zr33etc.). After 9 d of treatment inhibition of germination, retarded root and shoot growth, and increased activities of antioxidant enzymes (guaiacol peroxidase, ascorbate

M. Fodor; A. Hegedus; E. Stefanovits-Banyai

2005-01-01

64

Mineral Nutrient Requirements of Cucumber Seedlings 1  

PubMed Central

Mineral nutrient requirements for maximum growth rate of cucumber (Cucumis sativus L.) seedlings are estimated on the basis of three criteria. 1. The optimal weight proportions among the nutrients present in the seedlings. In relation to N = 100, close to 75 K, 13 P, 9 Ca, and 9 Mg are required. 2. The optimal ratio between the nitrogen sources NH4 and NO3 in the solution. The best growth is recorded with about equivalent amounts. Nitrate alone is also highly productive. Cucumber prefers nitrate and is sensitive to high ammonium concentrations. 3. The optimal total concentration in the solution corresponds to 200 to 300 milligrams of nitrogen per liter, with the proportions of the nutrients according to criterion 1. Simple growth methods are suggested in which the three criteria are fulfilled. Calcium, especially, is found to accumulate in older leaves. It is proposed that this is not an expression for a physiological requirement for calcium but a mechanism for deposition of excess uptake important in adaptation to calcareous soils. This mechanism also operates at low calcium uptake rates, causing deficiency in the young parts, despite relatively high contents in the old leaves. Cucumber is therefore interpreted to be an obligate calcicole. The results are discussed in relation to similar experiments with birch (Betula verrucosa Ehrh.) seedlings, a species able to grow on very acid soils. PMID:16658558

Ingestad, Torsten

1973-01-01

65

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...

66

Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana  

NASA Technical Reports Server (NTRS)

An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16 degrees about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6 degrees during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics.

Orbovic, V.; Poff, K. L.

1991-01-01

67

Uptake and distribution of trace metal elements in wheat seedlings  

Microsoft Academic Search

The uptake and distribution of eight metallic elements were examined in wheat seedlings for a period of 12 d with a radioactive\\u000a multitracer technique. The radioactive nuclides of the seedlings were simultaneously determined by ?-ray spectrometry. All\\u000a of the elements studied were taken up by the wheat seedlings and mainly accumulated in the roots. Only some elements were\\u000a transported to

Xiaorong Tan; Zhi Qin; Rongliang Zheng

2002-01-01

68

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

69

Habitat-related variation in seedling recruitment of Gentiana pannonica  

NASA Astrophysics Data System (ADS)

Differences in seedling recruitment of Gentiana pannonica were investigated between the primary (relict) and the secondary (semi-natural) forest-free habitats of the Bohemian Forest (870-1200 m a.s.l.) and of the Alps (1045-1935 m a.s.l.) to understand the factors promoting the seedling recruitment of G. pannonica and their importance for species distribution, population structure, and conservation. In the communities with adult plants of G. pannonica, we recorded environmental variables (the slope, the altitude, and the covers of bare ground, litter, and rocks), estimated parameters of the vegetation (the covers of herbs, bryophytes, and dwarf shrubs), and counted the seedlings of G. pannonica. In a field experiment, we investigated seedling survival under different soil moisture regimes. We also observed seasonal dynamics of seedling recruitment in permanent plots over the course of three years. In the primary habitats of both regions, G. pannonica grew in a relatively wide range of communities, and its seedlings occurred in each area. In the secondary habitats of the Bohemian Forest, a very low frequency of the seedlings was recorded. The number of seedlings increased with the covers of the moss layer and of bare soil and decreased with the cover of the herb layer, especially of graminoids. The seedling mortality was significantly lower in the plots with higher soil moistures, and the emergence of new-born seedlings was concentrated in the spring season, when the soil received a high water supply due to melting of snow. For the successful generative reproduction of G. pannonica, our findings highlight the critical importance of the microsites with low levels of competition and of sufficient soil moisture G. pannonica. It seems that because of the long-term lack of grazing disturbances, the structures of the secondary habitats of G. pannonica in the Bohemian Forest have become unfavourable for seedling establishment and generative reproduction of this threatened species.

Ekrtová, Ester; Košnar, Jan

2012-11-01

70

Heritable Chlorophyll Deficiencies in Seedling Cotton.  

E-print Network

of HorticwZture tr~ral Economics 5. W. BILSING, Ph. D., Professor of Ento- E. 0. POLLOCK, A. M., Assistant mology fessor of Agronomv F. A. BUECHEL, Ph. D., Professor of Age- W. L. STANGEL, M. S., Prof1 culturd Economics Antmal Husbandry (Swine) H. V... ............................................ Appendix. Tables 15-19 20 "--l1etin No. 333 August, 1925 been , rath erso no c acte' The I HERITABLE CHLOROPHYLL DEFICIENCIES IN SEEDLING COTTON G. N. Stroman and C. H. Mahoney Chlorophyll deficiencies have been found in certain individuals...

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

1925-01-01

71

Carbon Fixation and Partitioning in Coffee Seedlings Infested with Pratylenchuscoffeae  

Microsoft Academic Search

The objective was to study CO2 fixation and photoassimilate partition in coffee (Coffea arabica) seedlings infested with the lesion nematode Pratylenchus coffeae. Seedlings infested with 0, 1000 and 8000 Pratylenchus coffeae nematodes were exposed to 14CO2 and the incorporation and distribution of radioactivity were followed in the roots, stems and leaves. Fresh mass, pigments, soluble sugars, sucrose and specific radioactivity

Paulo Mazzafera; Roberto K. Kubo; Mário M. Inomoto

2004-01-01

72

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

73

Juvenile phase and growth of apple and pear seedlings  

Microsoft Academic Search

It was investigated whether and to what extent the duration of the juvenile phase of pear and apple seedlings is related to their vegetative growth. The juvenile phase was defined as the period in years that the seedling remains vegetative; the trunk diameter served as a measure of vegetative vigour. The following observations were made:

T. Visser

1964-01-01

74

Evolutionary Dynamics of Seed Size and Seedling Competitive Ability  

Microsoft Academic Search

We present a model for the evolutionary dynamics of seed size when there is a trade-off between seed size and seed number, and seedlings from large seeds are better competitors and have a higher precompetitive survival than seedlings from small seeds. We find that strong competitive asymmetry, high resource levels, and intermediate harshness of the precompetitive environment favor coexistence of

Stefan A. H. Geritz; Ed van der Meijden; Johan A. J. Metz

1999-01-01

75

Insecticides and Arable Weeds: Effects on Germination and Seedling Growth  

Microsoft Academic Search

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

M. E. Hanley; M. D. Whiting

2005-01-01

76

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

77

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

78

Uptake of Seeds Secondary Metabolites by Virola surinamensis Seedlings  

PubMed Central

The major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis were monitored by GC-MS during germination and seedling development. The role as carbon source for seedling development was indicated considering that both classes of compounds were similarly consumed in the seeds and that no selective consumption of compounds could be detected. PMID:22505921

Kato, Massuo Jorge; Yoshida, Massayoshi; Lopes, Norberto Peporine; da Silva, Denise Brentan; Cavalheiro, Alberto Jose

2012-01-01

79

Blue oak seedlings may be older than they look  

E-print Network

Blue oak seedlings may be older than they look Ralph L. Phillips u Neil K. McDougald o Richard B. Standiford William E.Frost A 4-year study indicates that na- tive blue oak seedlings are prob- ably much the year of above- average rainfall. Blue oak (Quercusdouglasii)trees are a valuable economic and aesthetic

Standiford, Richard B.

80

Resources and Assistance Available for Planting Hardwood Seedlings  

E-print Network

a successful tree planting involves several steps, ideally starting almost a year before the seedlings of a successful tree planting program is obtaining professional advice and assistance to help plan and implementResources and Assistance Available for Planting Hardwood Seedlings FNR-226 Lenny D. Farlee

81

Effectiveness and Mechanisms of Hydrogen Sulfide Adsorption by Camphor-derived Biochar  

Microsoft Academic Search

The characteristics and mechanisms of hydrogen sulfide (H2S) adsorption on a biochar through pyrolysis at various temperatures (100 °C to 500 °C) were investigated. The biochar used in the current study was derived from the camphor tree (Cinnamomum camphora). The samples were ground and sieved to produce particle sizes of 0.4 mm to 1.25 mm, 0.3 mm to 0.4 mm,

Guofeng Shang; Guoqing Shen; Tingting Wang; Qin Chen

2012-01-01

82

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

83

Neural network recognition of the conifer seedling root collar  

NASA Astrophysics Data System (ADS)

In recent work, we have demonstrated a prototype machine vision seedling inspection system which shows strong promise for automating production-line grading. Precise morphological measurements and accurate grade assignment require reliable identification of the seedling root collar location. The large variability of seedling morphology makes automatic root collar location the most challenging aspect of machine vision seedling inspection. This function is currently achieved using a heuristic algorithm which relies on many operator-controlled parameters to extract root collar location cues based on seedling shape. Artificial intelligence techniques, specifically, neural networks, have yielded excellent performance in similar pattern recognition applications. Neural networks were developed to locate the seedling root collar in digital images acquired by a machine vision inspection system. Several neural network architectures and input feature sets are evaluated. Input features consist of those used by the heuristic algorithm, plus additional features extracted from each line in the seedling image. The performance of several neural networks was superior to that of the heuristic algorithm. Good performance was achieved by networks which used local (single line) features along with normalized line number as inputs. A hierarchical network which took inputs from 15 lines over a 140-mm window provided improved performance in one case. The best networks identified the root collar location with an average error of less than 1 mm and an error standard deviation of 12 mm.

Rigney, Michael P.; Kranzler, Glenn A.

1996-12-01

84

Phytochrome-Mediated Phototropism in De-Etiolated Seedlings 1  

PubMed Central

Phototropic responses to broadband far red (FR) radiation were investigated in fully de-etiolated seedlings of a long-hypocotyl mutant (lh) of cucumber (Cucumis sativus L.), which is deficient in phytochrome-B, and its near isogenic wild type (WT). Continuous unilateral FR light provided against a background of white light induced negative curvatures (i.e. bending away from the FR light source) in hypocotyls of WT seedlings. This response was fluence-rate dependent and was absent in the lh mutant, even at very high fluence rates of FR. The phototropic effect of FR light on WT seedlings was triggered in the hypocotyls and occurred over a range of fluence rates in which FR was very effective in promoting hypocotyl elongation. FR light had no effect on elongation of lh-mutant hypocotyls. Seedlings grown in the field showed negative phototropic responses to the proximity of neighboring plants that absorbed blue (B) and red light and back-reflected FR radiation. The bending response was significantly larger in WT than in lh seedlings. Responses of WT and lh seedlings to lateral B light were very similar; however, elimination of the lateral B light gradients created by the proximity of plant neighbors abolished the negative curvature only in the case of lh seedlings. More than 40% of the total hypocotyl curvature induced in WT seedlings by the presence of neighboring plants was present after equilibrating the fluence rates of B light received by opposite sides of the hypocotyl. These results suggest that: (a) phytochrome functions as a phototropic sensor in de-etiolated plants, and (b) in patchy canopy environments, young seedlings actively project new leaves into light gaps via stem bending responses elicited by the B-absorbing photoreceptor(s) and phytochrome. PMID:16652942

Ballare, Carlos L.; Scopel, Ana L.; Radosevich, Steven R.; Kendrick, Richard E.

1992-01-01

85

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.

86

Environmental factors in relation to seedling necroses of cotton  

E-print Network

seed* ling disease complex is considered to include fungal decay of planted seed before germination, pro-emergence damping-off, post-emergence damping-off and seedling root rot* In the present paper pre-emergence damping-off is defined as loss... small lesions is probably common. Seedling root rot may involve any part or all of the root system, with wilting or death of aerial parts in accordance with the extent of root damage* Neal (26) reported a striking aftermath of seedling root rot...

Das, Gopinath

2013-10-04

87

Molecular dissection of seedling-vigor and associated physiological traits in rice  

Microsoft Academic Search

seedling-vigor is important for crop establishment. There have been reported quantitative trait locus (QTL) analyses on seedling-vigor related morphological traits. However, physiological understanding of these detected QTLs is rather limited. In this study, we employed a recombinant inbred population to detect QTLs for seedling-vigor traits and physiological traits related to seedling-vigor. Germination rate and seedling growth were measured to quantify

K. Cui; S. Peng; Y. Xing; C. Xu; S. Yu; Q. Zhang

2002-01-01

88

Water relations in Azospirillum -inoculated wheat seedlings under osmotic stress  

Microsoft Academic Search

Azospirillum has been shown to improve coleoptile growth in seedlings growing in darkness under osmotic stress. However, the changes in water relations that may occur in this experimental system have not yet been studied. Two-centimetre long Triticum aestivum cv. Buck PucarÆ and Triticum durum cv. Balcarceæo-INTA seedlings were inoculated with viable or autoclaved (control) Azospirillum brasilense Sp. 245 bacteria, at

Cecilia M. Creus; Rolando J. Sueldo; Carlos A. Barassi

1998-01-01

89

Effect of Gibberellic Acid on Hypocotyl Growth of Lettuce Seedlings  

Microsoft Academic Search

GIBBERELLINS are physiologically defined by their ability to induce shoot elongation in certain dwarf plants and they have been demonstrated in various plant extracts using dwarf maize plants1 and dwarf peas2-4 as assay material. Other assay material includes leaf sections of wheat seedlings2 and sections of cucumber tendrils5. A convenient method employed by Murakami6 involves the use of rice seedlings.

B. Frankland; P. F. Wareing

1960-01-01

90

Recruitment of Thalassia testudinum seedlings into physically disturbed seagrass beds  

Microsoft Academic Search

Thalassia testudinum seedling recruitment, survival, and growth were examined within physically disturbed seagrass beds in the Florida Keys. Two separate studies were conducted. In the first, a large-scale study, T. testudinum seedlings were surveyed and collected from a large seagrass disturbance (1560 m 2 ), 4.8 yr after the initial impact from a motor-vessel grounding. In the second, a smaller-scale

Paula E. Whitfield; W. Judson Kenworthy; Michael J. Durako; Kamille K. Hammerstrom; Manuel F. Merello

2004-01-01

91

Seed and seedling morphology of two species of Euphorbia (Euphorbiaceae)  

Microsoft Academic Search

Morphology of the seeds and seedlings ofEuphorbia hirta andE. thymifolia are described. In both the species, the seeds are endospermous, exotegmic, more or less oblong and obtusely tetragonal. The\\u000a testa is only two-layer thick, collapsing when dry; the tegmen is made up of a single layer of macrosclereids with occluded\\u000a lumen. The early developmental pattern of the seedlings in both

Jose K Mangaly; K Swarupanandan; P V Madhusoodan

1979-01-01

92

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

93

[Growth of epiphytic and soil yeasts on wheat seedlings].  

PubMed

Colonization of wheat seedlings by epiphytic (Rhodotorula glutinis) and soil (Lipomyces starkeyi) yeasts was studied by scanning electron microscopy. Epiphytic yeast cells dominated on the plant surface. Soil yeast cells were randomly distributed among both the zones of a seedling and the particles of an inorganic substrate. It has been found that epiphytic yeast strains can readily grow on the surface of a plant. PMID:561879

Guzeva, I S; Guzev, V S; Bab'eva, I P; Zviagintsev, D G

1977-01-01

94

Ethylene and the Growth of Rice Seedlings 1  

PubMed Central

Etiolated whole rice seedlings enclosed in sealed vials produced ethylene at a rate of 0.9 picomole per hour per seedling. When 2-centimeter-long shoots were subdivided into 5-millimeter-long sections, the sections containing the tip of the shoot evolved 37% of the total ethylene with the remaining 63% being produced along a gradient decreasing to the base of the shoot. The tip of the coleoptile also had the highest level of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid and of the ethylene-forming enzyme activity. Ethylene is one of the factors controlling coleoptile elongation. Decapitation of the seedling reduced ethylene evolution to one-third its original level and inhibited coleoptile growth. In short-term experiments, the growth rate of decapitated seedlings was restored to almost that of intact seedlings by application of ethylene at a concentration of 10 microliters per liter. Apart from ethylene, O2 also participates in the control of coleoptile growth. When rice seedlings were grown in a gas mixture of N2 and O2, the length of the coleoptiles reached a maximum at a concentration of 2.5% O2. Lower and higher concentrations of O2 reduced coleoptile growth. The effect of exogenous ethylene on coleoptile growth was also O2 dependent. PMID:16664369

Satler, Sergio O.; Kende, Hans

1985-01-01

95

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

96

Lignification in young plant seedlings grown on earth and aboard the Space Shuttle  

NASA Technical Reports Server (NTRS)

The Space Shuttle era has provided an opportunity for investigators to conduct experiments in a microgravity environment. Two Shuttle flights, STS-3 and STS-51F, each contained an experiment designed principally to determine whether young plant seedlings exposed to microgravity had reduced lignin content in comparison to seedlings grown at one gravity. Three different plant species, pine, oats, and mung beans, were exposed for eight days to the microgravity environment of the Shuttle. The lignin content of in-flight seedlings was less than the control seedlings in all seven sets of seedlings included in these two experiments. In five sets of seedlings, the reduction in lignin content in flight seedlings ranged from 6 to 24 percent and was statistically significant. In addition, the activity of two enzymes involved in lignin synthesis, phenylalanine ammonia lyase and peroxidase, were significantly reduced in pine seedlings. It was therefore concluded that microgravity, as perceived by young plant seedlings, results in reduced lignin synthesis.

Cowles, Joe R.; Lemay, R.; Jahns, G.; Scheld, W. H.; Peterson, C.

1989-01-01

97

Beneficial effect of spider presence on seedling recruitment of the tropical rainforest tree Dipteryx oleifera (Fabaceae).  

PubMed

This research presents evidence showing that: (1) lower arthropod herbivory correlates with seedling survival, and (2) spider presence correlates with lower arthropod herbivory, seedling growth, and seedling survival of the tropical rainforest tree species Dipteryx oleifera in eastern Nicaragua. The study was conducted from January 2005 to January 2006 in a 6.37 ha permanent plot established in 2002. Seedling height, spider behavior and presence on seedlings, and percentage of leaf area lost due to arthropod herbivory were measured. Arthropod herbivory was assessed from digital photographs of each seedling within the permanent plot. Seedling fate was followed in order to determine its correlation with spider presence, initial seedling size, and arthropod herbivory. A GLM showed that seedling survival correlated negatively with lower levels of arthropod herbivory (<20%), while seedlings with higher levels of herbivore damage experienced mortalities close to 100%. Results from another GLM suggests that seedling mean height (aprox. 8 cm) would be increased by approximately 1.5 cm for each year that spiders were present on seedlings and would be decreased 0.75 cm in height for each percent unit of arthropod herbivory. We also report a trend toward lower arthropod herbivory in seedlings colonized by spiders with aggressive traits, presumably because more aggressive spiders better defended seedlings against herbivorous arthropods than less aggressive spiders. PMID:19928475

Ruiz, Javier; Ingram-Flóres, Cherryl; Boucher, Douglas H; Chaves, Luis F

2009-09-01

98

Conifer seedling nursery worker exposure to glyphosate.  

PubMed

This study addresses the measurements of glyphosate exposure received by 14 workers employed at two tree nurseries. The applicators, weeders, and scouts monitored all wore normal work clothing, which for applicators was a protective suit, rubber gloves and boots. Measurements were made of the glyphosate that was dislodged from conifer seedlings during water rinses taken twice weekly from May through August. Only 1 of these 78 dislodgeable residue samples were positive for glyphosate. Nine cotton gauze patches were attached to the clothing of each worker one day per week during this same period. Hand washes were taken on the same day that patches were worn. Most patches and hand washes from applicators and weeders contained measurable amounts of glyphosate. Analyses of individual patches showed that the body portions receiving the highest exposure were ankles and thighs. For scouts only 1 of 23 hand washes contained glyphosate. To provide a measure of the exposure occurring via all exposure routes (dermal, ingestion, and inhalation) an analysis was made of the total urine excreted. For most workers a daily total urine collection was made for 12 consecutive weeks. Urine analysis, the biological monitoring tool used to assess the total amount absorbed via all avenues, did not reveal any positive samples. The lower limit of method validation for glyphosate in the urine samples was 0.01 micrograms/ml. High rainfall, or irrigation as needed, in conjunction with normal field dissipation avenues and worker training were cited as contributing factors for the low amounts of glyphosate exposure found.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1554254

Lavy, T L; Cowell, J E; Steinmetz, J R; Massey, J H

1992-01-01

99

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

100

The effect of light on the gravimorphogenesis of cucumber seedlings.  

PubMed

Light affects the responses of plants to gravity. For example, light is inhibitory to the gravimorphogenesis of cucumber seedlings, peg formation. We have suggested that auxin regulates peg formation by stimulating the expression of auxin-inducible genes including CsACS1 that encodes key enzyme in ethylene synthesis. We also have hypothesized that ethylene promotes the development of peg in cucumber seedlings. To understand how light inhibits peg formation, we examined the effects of light on the auxin-induced peg formation, the expression of auxin-inducible genes and ethylene production in cucumber seedlings. Number of seedlings that produced a peg in response to applied IAA was significantly decreased by exposure to light compared with that in the dark. In addition, exposure of seedlings to light decreased mRNA accumulation of CsACS1 and ethylene production. However ethylene application did not compensate the inhibition of peg formation by light. These results suggest that light blocks auxin-mediated step(s) including CsACS1 expression for the initiation of peg formation. PMID:14676363

Saito, Yuko; Fujii, Nobuharu; Takahashi, Hideyuki

2003-10-01

101

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

102

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

103

Effects of Different Sources of Fertilizer Nitrogen on Growth and Nutrition of Western Hemlock Seedlings.  

National Technical Information Service (NTIS)

Twelve different nitrogen (N) fertilizer treatments were tested on potted western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings. Fertilizers affected soil N and pH, and growth and foliar chemical composition of seedlings. Urea plus N-Serve and sulfu...

M. A. Radwan, D. S. DeBell

1980-01-01

104

Selection on Seedling Emergence Timing and Size in an Annual Plant (common sunflower, Helianthus annuus (Asteraceae))  

E-print Network

• Premise: Variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. To explore the adaptive significance of seedling ...

Kristen, Mercer L.; Alexander, Helen M.; Snow, Allison A.

2011-06-01

105

Tree shelters and weed control enhance growth and survival of natural blue oak seedlings  

E-print Network

1997. Tree shelters: An alternative for oak regeneration.oak stands, with con- siderable numbers of seedlings and treestree shelter types on microclimate and seedling performance of Oregon white oak and

2011-01-01

106

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

107

Sulfometuron methyl influences seedling growth and leaf function of three conifer species  

Microsoft Academic Search

Seedling growth and gas exchange responses were measured for two potted seedling trials testing herbicide phytotoxicity to\\u000a three important tree species of the Inland Northwest, USA. Media-filled pots were treated with sulfometuron methyl (Oust®) in varying concentrations and planted with seedlings of Larix occidentalis Nutt., Pseudotsuga menziesii var. glauca (Beissn.) Franco, and Pinus monticola Dougl. ex D. Don. Seedlings were

Nathan D. Robertson; Anthony S. Davis

108

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

109

Stress indications in copper- and nickel-exposed Scots pine seedlings  

Microsoft Academic Search

Scots pine nursery seedlings were planted in pots, five seedlings per treatment, and placed in an experimental field at the University of Oulu in northern Finland at the beginning of June 1997. Copper and nickel sulphates were mixed with forest mineral soil before seedling planting. The metal levels ranged from 0 to 25 mg Ni kg?1 dry soil and 0

E Kukkola; P Rautio; S Huttunen

2000-01-01

110

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

111

Ecological significance of root tip rotation for seedling establishment of Oryza sativa L  

Microsoft Academic Search

How plant seeds secure root penetration into soil to obtain good seedling establishment is one of the basic ecological problems. In this study, seminal root growth was investigated to clarify the cause of varietal difference of seedling establishment in direct seeding of rice in flooded paddy fields, with special reference to root tip rotation. In a field experiment, seedling establishment

Naoto Inoue; Teruo Arase; Motoyuki Hagiwara; Takahisa Amano; Taiichi Hayashi; Ryoichi Ikeda

1999-01-01

112

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

113

Effect of fire on survival and growth of Acer rubrum and Quercus seedlings  

Microsoft Academic Search

Controlled ground fires had a significant effect on survival and growth of 1- to 2-year-old seedlings of Acer rubrum, Quercus rubra and Quercus alba. In addition, although not statistically significant, seedling survival of fire was higher at lower than at higher fuel loading levels. Seedlings of Q. rubra survived fire better than those of A. rubrum. This superior survival was

Julie A Huddle; Stephen G Pallardy

1999-01-01

114

Abiotic and biotic drivers of seedling survival in a hurricane-impacted tropical forest  

E-print Network

and cyclones, which open the forest canopy, causing dramatic changes in understorey light conditions likely shape seedling dynamics, which in turn will contribute to patterns of forest recovery. 2. We of the understorey and linked seedling dynamics to changes in canopy openness and seedling density, and to spatial

115

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

Microsoft Academic Search

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\\u000a responses of A. ater to

Julianne M. O’Reilly-Wapstra; Glenn R. Iason; Vera Thoss

2007-01-01

116

Light activation of vindoline biosynthesis does not require cytomorphogenesis in Catharanthus roseus seedlings  

Microsoft Academic Search

Upon illumination, the cotyledons of Catharanthus roseus seedlings readily synthesise vindoline from late biosynthetic intermediates, which accumulate in etiolated seedlings. The cellular localisation of tryptophan decarboxylase (TDC) and desacetoxyvindoline 4-hydroxylase (D4H), which catalyse the first and penultimate reactions of vindoline biosynthesis, was identified by immunocytochemistry in developing seedlings. The expression of TDC was restricted to the upper epidermis of cotyledons,

Felipe A Vázquez-Flota; Benoit St-Pierre; Vincenzo De Luca

2000-01-01

117

GROWTH OF OAK SEEDLINGS WITH SPECIFIC ECTOMYCORRHIZAE IN URBAN STRESS ENVIRONMENTS1  

Microsoft Academic Search

Eleven-month old container grown seedlings of pin oak {Quercus palustris) and sawtooth oak (Q. acutissima) were outplanted on an earth-filled, steeply graded highway interchange near Atlanta, Georgia. The pin oak seedlings had either Pisolithus tinctorius (Pt) ectomycorrhizae or natural ectomycorrhizae (controls). The sawtooth seedlings had either Pt, Thelephora terrestris (Tt), or natural (controls) ecto- mycorrhizae. At the end of two

L. M. Anderson; A. L. Clark; D. H. Marx

118

Differences in germination and seedling establishment of alien and native Impatiens species  

E-print Network

Differences in germination and seedling establishment of alien and native Impatiens species Rozdíly., Jarosík V. & Pysek P. (2009): Differences in germi- nation and seedling establishment of alien and native design. In this study seed and seedling traits of three congeneric alien species in Europe, differing

Kratochvíl, Lukas

119

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

120

ORIGINAL PAPER Unexpected seedling growth in the understory  

E-print Network

certain forest communities are disappearing, post-agricultural forests are emerging from old fields forest communities are disappearing, old fields are becoming increasingly colonized and dominated by fastORIGINAL PAPER Unexpected seedling growth in the understory of post-agricultural forests from

Paris-Sud XI, Université de

121

Original article Resistance to water stress in seedlings of eight  

E-print Network

Original article Resistance to water stress in seedlings of eight European provenances of Pinus. halepensis after one week of water stress (­0.033, ­0.4, ­0.8, ­1.2, ­1.6 MPa). P. halepensis showed osmotic ad- justments as a response to water stress, although the response varied between the provenances

Boyer, Edmond

122

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

123

First year field growth of chemically root pruned containerized seedlings  

Microsoft Academic Search

Containers deform seedling root systems and have a potential to inhibit tree growth after outplanting. Ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa), western white pine (Pinus monticola Dougl. ex D. Don), and Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) were grown in containers coated with latex paint containing different concentrations of cupric carbonate and outplanted in a forest.

D. L. Wenny; Y. Liu; R. K. Dumroese; H. L. Osborne

1988-01-01

124

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

125

Regulation of Flavonoid Biosynthetic Genes in Germinating Arabidopsis Seedlings.  

PubMed Central

Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632

Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM

1992-01-01

126

Sugar signalling during germination and early seedling establishment in Arabidopsis  

Microsoft Academic Search

Sugars have pronounced effects on many plant processes like gene expression, germination and early seedling development. Several screens for sugar insensitive mutants were performed to identify genes involved in sugar response pathways using the model plant Arabidopsis. These include sun, gin and sis screens explained earlier in this chapter. Both common mutants and dissimilar mutants were identified in the different

S. J. W. Dekkers

2006-01-01

127

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

128

The tolerance of newly emerged broadleaved tree seedlings to the  

E-print Network

, leading to death or suppression of tree seedlings. Hand weeding is usually expensive, and the safe use of broad-spectrum contact herbicides is seldom possible. Hence in the work reported here, the tolerance in the suppression or death of young, sown in the actual location which is to be affor- newly germinated tree

129

Micropropagation of flowering dogwood ( Cornus florida ) from seedlings  

Microsoft Academic Search

A method for regenerating whole plants from nodal (axillary bud) cultures of seedlings was developed for flowering dogwood (Cornus florida L.). The seed source significantly influenced the rate of proliferation, although cultures initiated from each of the seven mother trees produced some shoots. Woody plant medium (WPM) was superior to either Murashige and Skoog or Schenk and Hildebrandt basal medium.

K. M. Kaveriappa; L. M. Phillips; R. N. Trigiano

1997-01-01

130

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

131

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

132

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

133

Original article Sensitivity of seedlings from different oak  

E-print Network

palustris) to a 7-wk period of waterlogging was tested under greenhouse conditions. The seedlings had comple Résumé — Sensibilité à l'ennoyage de semis de plusieurs espèces de chêne : effets sur la croissance

Boyer, Edmond

134

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

135

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

136

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

137

Effect of GA3, kinetin and indole acetic acid on carbohydrate metabolism in chickpea seedlings germinating under water stress  

Microsoft Academic Search

Enhanced amylase activity was observed during a 7-day-growth period in the cotyledons of PEG imposed water stressed chickpea seedlings grown in the presence of GA3 and kinetin, when compared with stressed seedlings. During the first 5 days of seedling growth, the seedlings growing under water deficit conditions as well as those growing in the presence of PGRs had a higher

Satvir Kaur; Anil K. Gupta; Narinder Kaur

2000-01-01

138

The differential establishment of seedlings from chasmogamous and cleistogamous flowers in natural populations of the grass Danthonia spicata (L.) Beauv  

Microsoft Academic Search

The grass Danthonia spicata produces dimorphic seeds from chasmogamous and cleistogamous flowers. The seed remains attached to seedlings so one can identify the reproductive origin of seedlings. The proportion of chasmogamous and cleistogamous seedlings becoming established varies widely between populations. The types of seedlings becoming established was generally consistent from year to year and correlated with the proportion of flower

Keith Clay

1983-01-01

139

Lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis mutants lacking the glyoxylate cycle enzyme malate synthase.  

PubMed

The aim of this research was to test the role of the glyoxylate cycle enzyme malate synthase (MLS) in lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis. We hypothesized that in the absence of MLS, succinate produced by isocitrate lyase (ICL) could still feed into the tricarboxylic acid cycle, whereas glyoxylate could be converted to sugars using enzymes of the photorespiratory pathway. To test this hypothesis we isolated knock-out mls mutants and studied their growth and metabolism in comparison to wild type and icl mutant seedlings. In contrast to icl seedlings, which grow slowly and are unable to convert lipid into sugars (Eastmond, P. J., Germain, V., Lange, P. R., Bryce, J. H., Smith, S. M. & Graham, I. A. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 5669-5674), mls seedlings grow faster, use their lipid more rapidly, and are better able to establish as plantlets. Transcriptome and metabolome analyses show that icl seedlings exhibit many features characteristic of carbohydrate starvation, whereas mls seedlings differ relatively little from wild type. In the light mls seedlings generate more sugars than icl seedlings, and when fed with [14C]acetate, 14C-labeling of sugars is three times greater than in icl seedlings and more than half that in wild type seedlings. The mls seedlings also accumulate more glycine and serine than icl or wild type seedlings, consistent with a diversion of glyoxylate into these intermediates of the photorespiratory pathway. We conclude that, in contrast to bacteria and fungi in which MLS is essential for gluconeogenesis from acetate or fatty acids, MLS is partially dispensable for lipid utilization and gluconeogenesis in Arabidopsis seedlings. PMID:15272001

Cornah, Johanna E; Germain, Véronique; Ward, Jane L; Beale, Michael H; Smith, Steven M

2004-10-01

140

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

141

Tolerance of broadleaved tree and shrub seedlings to preemergence herbicides  

Microsoft Academic Search

Control of competing vegetation is essential for the successful establishment of tree seedlings in nurseries and direct-sown\\u000a woodland; this usually requires potentially expensive hand weeding or post-sowing preemergence herbicides. In order to identify\\u000a suitable herbicides, two container experiments tested the response of 12 broadleaved tree and shrub species to napropamide\\u000a and pendimethalin applied preemergence. Most species tolerated rates adequate for

I. Willoughby; F. L. Dixon; D. V. Clay; R. L. Jinks

2007-01-01

142

Proteomic identification of rhythmic proteins in rice seedlings  

Microsoft Academic Search

Many aspects of plant metabolism that are involved in plant growth and development are influenced by light-regulated diurnal rhythms as well as endogenous clock-regulated circadian rhythms. To identify the rhythmic proteins in rice, periodically grown (12h light\\/12h dark cycle) seedlings were harvested for three days at six-hour intervals. Continuous dark-adapted plants were also harvested for two days. Among approximately 3000

Heeyoun Hwang; Man-Ho Cho; Bum-Soo Hahn; Hyemin Lim; Yong-Kook Kwon; Tae-Ryong Hahn; Seong Hee Bhoo

2011-01-01

143

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

144

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

145

Gibberellins in seedlings and flowering trees of Prunus avium L  

Microsoft Academic Search

Extracts of acids from mature seeds, germinating seeds, first, second and third year seedlings as well as mature, flowering trees of sweet cherry (Prunus avium L. cv. Stella) were analysed by gas chromatography–mass spectrometry. The presence of the known gibberellins (GAs) GA1 (1), GA3 (4), GA5 (7), GA8 (11), GA19 (14), GA20 (12), GA29 (13), GA32 (5), GA85 (2), GA86

Patrick S. Blake; Gordon Browning; Lynda J. Benjamin; Lewis N. Mander

2000-01-01

146

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

147

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

148

Genetic variability in salt tolerance of selected boreal woody seedlings  

Microsoft Academic Search

In order to select woody plant candidates suitable for revegetation of saline–alkaline soils, we tested selected woody plant species and seed lots: Pinus contorta (lodgepole pine), Pinus banksiana (jack pine), Picea glauca (white spruce), Populus tremuloides (trembling aspen), and Alnus rubra, syn. Alnus oregona (red alder). Pre-germinated seedlings were grown for 4 weeks in a greenhouse in a semi-hydroponic system

P. D. Khasa; B. Hambling; G Kernaghan; M Fung; E Ngimbi

2002-01-01

149

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

150

Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings.  

PubMed

The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the beta oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings. PMID:16660087

Moreau, R A; Huang, A H

1977-08-01

151

Photosynthesis and transpiration of loblolly pine seedlings as influenced by moisture-stress conditioning  

SciTech Connect

One-yr-old seedlings were exposed to 8 wk of moisture stress conditioning (MSC); seedlings were watered only when pre-dawn needle water potential fell below -1.4 MPa. Water was then withheld and photosynthesis and transpiration rates recorded. Photosynthesis in well-watered controls and MSC seedlings was reduced to zero in 12 and 17 days respectively. Seedlings were harvested and water use efficiency calculated using photosynthesis and transpiration data; it was expressed as mg of CO/sub 2/ fixed per g of water lost. Seedlings exposed to MSC continued to photosynthesize to much lower needle water potentials. This response is at least partly attributed to the significant decrease (0.45 MPa) in needle osmotic potential found in MSC seedlings, which were able to maintain turgor to lower needle water potentials. Transpiration rate decreased 30% and water use efficiency increased 67% as a result of MSC. 26 references.

Seiler, J.R.; Johnson, J.D.

1985-01-01

152

Studies on germination, seedling vigour, lipid peroxidation and proline metabolism in Catharanthus roseus seedlings under salt stress  

Microsoft Academic Search

In the present investigation, ‘rosea’ and ‘alba’ varieties of Catharanthus roseus (L.) G. Don. seeds were grown with different concentrations (15, 30, 45 and 60 mM) of sodium chloride (NaCl), in order to study the effects of salinity on germination behaviour, seedling vigour (root and shoot length), lipid peroxidation (LPO) and proline metabolism. It was found that germination was delayed at

C. Abdul Jaleel; R. Gopi; B. Sankar; P. Manivannan; A. Kishorekumar; R. Sridharan; R. Panneerselvam

2007-01-01

153

Evaluation of pathogenicity and aggressiveness of F. langsethiae on oat and wheat seedlings relative to known seedling blight pathogens  

Microsoft Academic Search

Fusarium and Microdochium species are causal agents of seedling blight of small-grain cereal crops where they may contribute to a significant reduction\\u000a in crop establishment and final yield. Two experiments were carried out to investigate the potential pathogenicity and aggressiveness\\u000a of F. langsethiae, a recently identified fungus linked with the contamination of cereals with high levels of the trichothecene mycotoxins,

Samuel M. Imathiu; Martin C. Hare; Rumiana V. Ray; Matthew Back; Simon G. Edwards

2010-01-01

154

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

E-print Network

seedlings and soil and seed-borne ! organisms. In the 1930's, Pythium arrhenomanes, then the suspected causal agent of Periconia crown rot (11), was tested for pathogicity on sorghum seedlings. The organism was shown to cause reductions in percent... details of the procedure are given by Singleton and Ziv (38). I After incubation for 48 h in the blotter apparatus, the seedlings were inoculated with . 5 cm plugs of 7-day-old cultures of Fusarium moniliforme, Fusarium sp. , Pythium arrhenomanes...

Forbes, Gregory Allan

2012-06-07

155

Factors affecting the production of terpenes in seedlings of Pinus elliottii  

E-print Network

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... 16 18 TABLE OF CONTENTS jCONTINUED} Page Growth of seedlings Wounding effect and seedling age Total resin acid production Total monoterpene production Resin acid composition Monoterpene composition Terpene production in sterile conditions...

Ishihara, Hiroichi

2012-06-07

156

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

157

A comparative proteomic analysis of rice seedlings under various high-temperature stresses  

Microsoft Academic Search

To understand the responses of rice seedlings to different high-temperature stresses, seven-day-old rice seedlings were exposed to different high temperatures for 48 h, and the maximal quantum yield of PS II photochemistry measurements, ascorbate peroxidase activity assays and proteomic analyses in leaf tissue were performed. The results showed that when rice seedlings were exposed to high temperatures at 35 °C, 40 °C and

Feng Han; Hui Chen; Xiao-Juan Li; Ming-Feng Yang; Gong-She Liu; Shi-Hua Shen

2009-01-01

158

Sulphate uptake and xylem loading of young pea ( Pisum sativum L.) seedlings  

Microsoft Academic Search

Sulphate uptake and xylem loading was analysed in young pea (Pisum sativum) seedlings. The rate of sulphate uptake into intact 8-days-old pea seedlings (determined by a 1 h exposure to radiolabelled sulphate in the nutrient solution) was 585 nmol sulphate g-1 root fresh weight h-1. When the cotyledons were removed on day 6 the 8-days-old seedlings took up only 7%

C. Herschbach; B. Pilch; M. Tausz; H. Rennenberg; D. Grill

2002-01-01

159

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

160

Effects of soil compaction on root development of planted loblolly pine (Pinus taeda L.) seedlings  

E-print Network

then remeasured and the percent change was determined for each variable. Generally, seedling root growth decreased with an increase in compaction although site factors also had an effect on growth. Lab seedlings from both sites exhibited much higher growth... means than did those seedlings grown in the field due to the low soil moisture tension maintained at the lab. The differences among compaction treatments at the lab were usually not as great as differences be- tween sites, implying that the effects...

Simmons, Gerry Lynn

2012-06-07

161

Responses of ectomycorrhizal American elm ( Ulmus americana ) seedlings to salinity and soil compaction  

Microsoft Academic Search

American elm (Ulmus americana) seedlings were either non-inoculated or inoculated with Hebeloma crustuliniforme, Laccaria bicolor and a mixture of the two fungi to study the effects of ectomycorrhizal associations on seedling responses to soil compaction\\u000a and salinity. The seedlings were grown in the greenhouse in pots containing non-compacted (0.4 g cm?3 bulk density) and compacted (0.6 g cm?3 bulk density) soil and

Mónica Calvo Polanco; Janusz J. Zwiazek; Mihaela C. Voicu

2008-01-01

162

Nickel-induced oxidative stress and the role of antioxidant defence in rice seedlings  

Microsoft Academic Search

Seedlings of rice (Oryza sativa L.) cv. Pant-12 grown in sand cultures containing 200 and 400 ?M NiSO4, showed a decrease in length and fresh weight of roots and shoots. Nickel was readily taken up by rice seedlings and the\\u000a concentration was higher in roots than shoots. Nickel-treated seedlings showed increased rates of superoxide anion (O2\\u000a •?\\u000a ) production, elevated levels

Ruchi Maheshwari; R. S. Dubey

2009-01-01

163

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

164

13:00:09:11:10 Fungal endophytes protect grass seedlings against  

E-print Network

, the weeping alkaligrass (Puccinellia distans) seedlings are the hosts, and the grove snail (Cepaea nemoralis typhina endophyte stimulates the host, weeping alkaligrass (Puccinellia distans), to produce seeds

Kramarz, Paulina

165

Water stress can induce quiescence in newly-germinated onion (Allium cepa L.) seedlings.  

PubMed

The effect of water stress on the early seedling growth of onions was studied by placing newly-germinated seedlings in vermiculite equilibrated at different water potentials. Roots and shoots elongated more at -0.29 than at -0.64 MPa, but did not elongate at -1.66 MPa. However, roots and shoots of seedlings that had been incubated in vermiculite at -1.66 MPa for up to 35 d resumed elongation when subsequently placed on wet filter boards. This suggests that water stress can induce quiescence in newly-germinated seedlings. PMID:11432930

Whalley, W R; Lipiec, J; Finch-Savage, W E; Cope, R E; Clark, L J; Rowse, H R

2001-05-01

166

[Effects of sand burying on caryopsis germination and seedling growth of Bromus inermis Leyss].  

PubMed

This paper studied the effects of different depth sand burying on the caryopsis germination, seedling emergence and growth of Bromus inermis Leyss., a perennial gramineous grass dominated on Othidag sandy land. The results showed that the maximum burying depth for B. inermis caryopsis germination and seedling emergence was 12 cm and 8 cm, respectively. Below the thresholds, the percentages of caryopsis germination and seedling emergence decreased with increasing depth of sand burying. All the 1- and 2-week-old seedlings of B. inermis could survive when the sand burying depth was up to 33% of their height, and their biomass was no less than the unburied seedlings. When the burying depth increased to 66% of their height, 70% of 1-week-old seedlings and 25% of 2-week-old seedlings could survive, but their growth was impaired. No seedlings could survive when they were wholly buried in sand. When buried by sand, the seedlings allocated more biomass for the development of their aboveground part, which might be an important adaptation strategy of B. inermis to sand burying. PMID:18260444

Yang, Hui-ling; Cao, Zhi-ping; Dong, Ming; Ye, Yong-zhong; Huang, Zhen-ying

2007-11-01

167

Piriformospora indica rescues growth diminution of rice seedlings during high salt stress.  

PubMed

Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress. PMID:24494239

Jogawat, Abhimanyu; Saha, Shreya; Bakshi, Madhunita; Dayaman, Vikram; Kumar, Manoj; Dua, Meenakshi; Varma, Ajit; Oelmüller, Ralf; Tuteja, Narendra; Johri, Atul Kumar

2013-10-01

168

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

169

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

170

Analysis of peg formation in cucumber seedlings grown on clinostats and in a microgravity (space) environment  

NASA Technical Reports Server (NTRS)

In young cucumber seedlings, the peg is a polar out-growth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. Previous studies have indicated that peg formation is gravity dependent. In this study we analyzed peg formation in cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation). Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS 95) for 1-2 days, frozen and subsequently examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency of peg formation in space grown seedlings was found to be nearly identical to that of clinostat grown seedlings and to differ from that of seedlings germinated under normal gravity only in a minority of cases; approximately 6% of the seedlings formed two pegs and nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation was found to be less pronounced for space grown seedlings, compared to clinostat grown seedlings, indicating a greater degree of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook, the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even in microgravity environments. Peg morphologies were altered in space grown samples, with the pegs having a blunt appearance and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards. These phenotypes were not observed in clinostat or ground grown seedlings.

Link, B. M.; Cosgrove, D. J.

1999-01-01

171

Cysteine, ?-Glutamylcysteine, and Glutathione Levels in Maize Seedlings 1  

PubMed Central

The levels of cysteine (Cys), ?-glutamylcysteine (?EC), and glutathione (GSH) were measured in the endosperms, scutella, roots, and shoots of maize (Zea mays L.) seedlings. GSH was the major thiol in roots, shoots, and scutella, Cys predominated in endosperms. The endosperm, scutellum, and functional phloem translocation were required for maintenance of GSH pools in roots and shoots of 6-day-old seedlings. Exposure of roots to 3 micromolar Cd, besides causing a decline in GSH, caused an accumulation of ?EC, as if the activity of GSH synthetase was reduced in vivo. [35S]Cys injected into endosperms of seedlings was partly metabolized to [35S]sulfate. The scutella absorbed both [35S]sulfate and [35S]Cys and transformed 68 to 87% of the radioactivity into [35S]GSH. [35S]GSH was translocated to roots and shoots in proportion to the tissue fresh weight. Taken together, the data supported the hypothesis that Cys from the endosperm is absorbed by the scutellum and used to synthesize GSH for transfer through the phloem to the root and shoot. The estimated flux of GSH to the roots was 35 to 60 nanomoles per gram per hour, which totally accounted for the small gain in GSH in roots between days 6 and 7. For Cd-treated roots the GSH influx was similar, yet the GSH pool did not recover to control levels within 24 hours. The estimated flux of GSH to the entire shoot was like that to the roots; however, it was low (11-13 nanomoles per gram per hour) to the first leaf and high (76-135 nanomoles per gram per hour) to the second and younger leaves. PMID:16668359

Rauser, Wilfried E.; Schupp, Robert; Rennenberg, Heinz

1991-01-01

172

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

173

Fully automated compound screening in Arabidopsis thaliana seedlings.  

PubMed

High-throughput small molecule screenings in model plants are of great value to identify compounds that interfere with plant developmental processes. In academic research, the plant Arabidopsis thaliana is the most commonly used model organism for this purpose. However, compared to plant cellular systems, A. thaliana plants are less amenable to develop high-throughput screening assays. In this chapter, we describe a screening procedure that is compatible with liquid handling systems and increases the throughput of compound screenings in A. thaliana seedlings. PMID:24306857

Audenaert, Dominique; Nguyen, Long; De Rybel, Bert; Beeckman, Tom

2014-01-01

174

Mercuric Chloride Effects on Root Water Transport in Aspen Seedlings  

Microsoft Academic Search

HgCl2 (0.1 mM) reduced pressure-induced water flux and root hydraulic conductivity in the roots of 1-year-old aspen (Populus tremuloides Michx.) seedlings by about 50%. The inhibition was reversed with 50 mM mercaptoethanol. Mercurial treatment re- duced the activation energy of water transport in the roots from 10.82 6 0.700 kcal mol21 to 6.67 6 0.193 kcal mol21 when measured over

Xianchong Wan; Janusz J. Zwiazek

1999-01-01

175

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

176

Signalling molecules and the synthesis of alkaloids in Catharanthus roseus seedlings  

Microsoft Academic Search

The Madagascar periwinkle, Catharanthus roseus, produces numerous alkaloids, several of which have important pharmaceutical uses. Catharanthus seedlings rapidly accumulate the monomeric alkaloids, vindoline, catharanthine and tabersonine, during germination. Various plant signalling molecules were tested for their ability to enhance alkaloid synthesis in Catharanthus seedlings. The compounds tested included plant hormones, fatty acid-derived messengers and agents that can induce systemic-acquired resistance

Rob J. Aerts; Andrea Schäfer; Manfred Hesse; Thomas W. Baumann; Alan Slusarenko

1996-01-01

177

EFFECTS OF HAYSCENTED FERN DENSITY AND LIGHT ON WHITE ASH SEEDLING GROWTH  

Microsoft Academic Search

Communities of hayscented ferns ( Dennstaedtia punctilobula (Michx.) Moore 1 are present in many forested areas of Pennsylvania. These ferns can reduce the number and height growth of desirable tree seedlings. A study was conducted to determine the effects of fern frond density on the stem growth and leaf development of bare- root planted white ash (Fraxinus americana L.) seedlings.

Tracy E. Hippensteel

178

Variation in baobab seedling morphology and its implications for selecting superior planting material  

Microsoft Academic Search

With the aim of helping to select superior planting material for drought characteristics, baobab seedlings from two countries, one in western and one in south-eastern Africa, were grown in a greenhouse and their growth and morphology were studied. Seedlings were grown for 18 weeks and several morphological characteristics (length, diameter and dry weights of different plant parts, number of leaves,

A. Cuni Sanchez; S. De Smedt; N. Haq; R. Samson

2011-01-01

179

FOLIAR N RESPONSE OF PONDEROSA PINE SEEDLINGS TO ELEVATED CO2 AND O3  

EPA Science Inventory

Interactions between needle N status and exposure to combined CO2 and O3 stresses were studied in Pinus ponderosa seedlings. The seedlings were grown for three years (April 1998 through March 2001) in outdoor chambers in native soils from eastern Oregon, and exposed to ambient ...

180

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

181

Extending the Planting Period of Dormant and Growing Norway Spruce Container Seedlings to Early Summer  

Microsoft Academic Search

Luoranen, J., Rikala, R., Konttinen, K. & Smolander, H. 2005. Extending the planting period of dormant and growing Norway spruce container seedlings to early summer. Silva Fennica 39(4): 481-496. In order to make mechanized planting economically viable, the present spring planting period for Norway spruce (Picea abies (L.) Karst.) seedlings in Scandinavia needs to be extended. To evaluate the possibilities

Jaana Luoranen; Risto Rikala; Kyösti Konttinen; Heikki Smolander

182

The effect of mollusc grazing on seedling recruitment in artificially created grassland gaps  

Microsoft Academic Search

Two experiments conducted in spring and autumn 1992 examined the effect of mollusc grazing on seedling regeneration from natural grassland seedbanks by creating artificial gaps in plots in a grassland sward. Molluscs were excluded from half the gaps by application of molluscicide. Mollusc grazing in both the spring and autumn experiment significantly reduced seedling recruitment, though the intensity of grazing

M. E. Hanley; M. Fenner; P. J. Edwards

1996-01-01

183

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

184

Shared ectomycorrhizal fungi between a herbaceous perennial (Helianthemum bicknellii) and oak (Quercus) seedlings  

Microsoft Academic Search

Summary • Ectomycorrhizal infection of Quercus seedlings can be low at a distance from established ectomycorrhizal vegetation. Here we investigate whether Helianthemum bicknellii , a herbaceous ectomycorrhizal perennial of prairies and oak savannas, creates patches of elevated ectomycorrhizal infection of Quercus seedlings. •W e performed two studies. First, ectomycorrhizas of H. bicknellii were compared with ectomycorrhizas of Quercus spp. Second,

Ian A. Dickie; Rebecca C. Guza; Sarah E. Krazewski; Peter B. Reich

2004-01-01

185

Sensitivity of tree seedlings to aluminum: I. Honeylocust. [Gleditsia triacanthos L  

Microsoft Academic Search

Literature about the effects of Al on trees is reviewed in this article, emphasizing factors to consider when interpreting how seedling growth responds to Al. This article integrates two soil and two hydroponic studies that examine how honeylocust (Gleditsia triacanthos L.) seedlings respond to Al. The studies determined that honeylocust is the most Al-sensitive forest tree to have been studied

E. Sucoff; F. C. Thornton; J. D. Joslin

2009-01-01

186

Effects of 24-Epibrassinolide on Antioxidant System in Cucumber Seedling Roots Under Hypoxia Stress  

Microsoft Academic Search

This article aims to study the effects of exogenous 24-epibrassinolide (EBR) on the changes in ROS, activities of antioxidative enzymes and antioxidants in cucumber (Cucumis sativus L.) seedling roots under hypoxia stress. Seedlings of a hypoxiaresistant cultivar, Lübachun 4, and a hypoxia-sensitive cultivar, Zhongnong 8, were hydroponically grown for 8 d in normoxic or hypoxic nutrient solutions that were added

Yun-yan KANG; Shi-rong GUO; Juan LI; Jiu-ju DUAN

2007-01-01

187

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

188

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

189

Seedling growth of allopolyploids from Lolium multiflorum L. x Festuca arundinacea L  

Microsoft Academic Search

Seedlings of allopolyploid families from Lolium multiflorum x Festuca arundinacea were compared with varieties of the two parental species. They were investigated at different stages in a heated and an unheated greenhouse and in the field. Early seedling growth in the hybrid families in most cases, proved to be significantly better than in the two Festuca arundinacea standard varieties. One

J. Dijkstra; A. L. F. DE VOS

1975-01-01

190

Phytotoxicity of American beech leaf leachate to sugar maple seedlings in a greenhouse experiment  

Microsoft Academic Search

In an effort to reexamine the factors that affect codominance of American beech (Fagus grandifolia Ehrh.) and sugar maple (Acer saccharum Marsh.), a greenhouse experiment was conducted to test the potential phytotoxic ef- fects of American beech leaf leachate on sugar maple seedlings. We utilized an experimental protocol that addressed phytotoxic, nutrient, and pH effects by watering seedlings with seven

Elizabeth N. Hane; Steven P. Hamburg; Adelia L. Barber; Jennifer A. Plaut

2003-01-01

191

BIOCHEMICAL CHANGES IN MAIZE SEEDLINGS EXPOSED TO DROUGHT STRESS CONDITIONS AT DIFFERENT NITROGEN LEVELS  

Microsoft Academic Search

Normally, under field conditions, maize seedlings are often exposed to early water stress. The objective of the present study was to evaluate the biochemical changes in maize seedlings exposed to drought stress at different nitrogen levels. Maize (Zea mays L.) hybrid SC 704 plants were grown in 18 kg pots containing the same soil from the field that maize is

Ali Ahmadi; Yahya Emam; Mohammad Pessarakli

2010-01-01

192

Seed Dispersal and Seedling Establishment of Pinon and Juniper Species within the Pinon-Juniper Woodland  

Microsoft Academic Search

Understanding the prehistoric and historic dynamics of pinon-juniper woodland requires knowledge of the seed dispersal mechanisms and seedling establishment requirements of the tree species. Here, the types and effectiven-ess of the different seed dispersers and the environmental requirements for seedling estab­ lishment are compared and contrasted for the various pinon and juniper species within the woodlands. The importance of long­

Eugene W. Schupp; Stephen B. Vander Wall

193

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

194

Comparative Seedling Ecology of Eight North American Spruce (Picea) Species in Relation to their Geographic Ranges  

PubMed Central

• Background and Aims Allowing for dispersal limitation, a species' geographic distribution should reflect its environmental requirements. Comparisons among closely related species should reveal adaptive differentiation in species characteristics that are consistent with their differences in geographic distribution. This expectation was tested by comparing characteristics of seedlings of spruce species in relation to environmental factors representative of their current natural ranges. • Methods Seedlings were grown from a total of 34 populations representing eight North American spruce (Picea) species in a controlled environment chamber for 140 d. Traits related to the potential of seedling establishment, including tolerance to stress events (high temperature, desiccation) were evaluated. Correlations were sought between these characteristics and modal values of latitude, aridity and continentality in the geographic range of each species. • Key Results Many seedling traits changed significantly in response to stress events, but only the response of chlorophyll concentration differed significantly among species. Components of seedling growth were good correlates of species distribution. Seedling relative growth rate (RGR) and specific leaf area (SLA) were positively correlated with latitude, and leaf weight ratio (LWR) negatively correlated with aridity. Seed mass was negatively correlated with latitude. • Conclusions Relationships found between seedling traits and geographical variation in environmental conditions suggest that factors such as temperature regime, water availability and perhaps litter depth affect species range in North American spruces. Seedling characteristics appear to be elements in a reasonably distinct environmental niche for each spruce species at the continental scale. PMID:15329335

MIYAZAWA, KAE; LECHOWICZ, MARTIN J.

2004-01-01

195

Effect of Continuous Cropping Generations on Each Component Biomass of Poplar Seedlings during Different Growth Periods  

PubMed Central

In order to investigate the change rules and response characteristics of growth status on each component of poplar seedling followed by continuous cropping generations and growth period, we clear the biomass distribution pattern of poplar seedling, adapt continuous cropping, and provide theoretical foundation and technical reference on cultivation management of poplar seedling, the first generation, second generation, and third generation continuous cropping poplar seedlings were taken as study objects, and the whole poplar seedling was harvested to measure and analyze the change of each component biomass on different growth period poplar leaves, newly emerging branches, trunks and root system, and so forth. The results showed that the whole biomass of poplar seedling decreased significantly with the leaf area and its ratio increased, and the growth was inhibited obviously. The biomass aboveground was more than that underground. The ratios of leaf biomass and newly emerging branches biomass of first continuous cropping poplar seedling were relatively high. With the continuous cropping generations and growth cycle increasing, poplar seedling had a growth strategy to improve the ratio of root-shoot and root-leaf to adapt the limited soil nutrient of continuous cropping.

Xia, Jiangbao; Zhang, Shuyong; Li, Tian; Liu, Xia; Zhang, Ronghua; Zhang, Guangcan

2014-01-01

196

Transcriptional and posttranscriptional regulation of the glycolate oxidase gene in tobacco seedlings  

Microsoft Academic Search

The roles of light and of the putative plastid signal in glycolate oxidase (GLO) gene expression were investigated in tobacco (Nicotiana tabacum cv. Samsun NN) seedlings during their shift from skotomorphogenic to photomorphogenic development. GLO transcript and enzyme activities were detected in etiolated seedlings. Their respective levels increased three- and six-fold during 96 h of exposure to light. The GLO transcript

Simon Barak; Ali Nejidat; Yair Heimer; Micha Volokita

2001-01-01

197

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

198

Drought susceptibility and xylem dysfunction in seedlings of 4 European oak species  

E-print Network

occurred in oak from the 1920s. A survey in 1987 in the UK has shown that 18% of oak trees had less than 10Note Drought susceptibility and xylem dysfunction in seedlings of 4 European oak species KH Higgs V June 1994; accepted 8 March 1995) Summary — Seedlings of oak (Quercus robur, Q petraea, Q cerris

Paris-Sud XI, Université de

199

Urban polluted forest soils induce elevated root peroxidase activity in Scots pine ( Pinus sylvestris L.) seedlings  

Microsoft Academic Search

Plant biomass, mycorrhizal status and root peroxidase activity were measured in ectomycorrhizal Scots pine (Pinus sylvestris L.) seedlings grown in urban polluted and native, non-polluted forest soils with added ammonium or potassium sulphates simulating N and S deposition of urban areas. Peroxidase activity in the fine roots of seedlings planted in polluted forest soils was higher than in those planted

A. M Markkola; O Tarvainen; U Ahonen-Jonnarth; R Strömmer

2002-01-01

200

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

201

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

202

Dynamics and determinants of Quercus alba seedling success following savanna encroachment and restoration  

E-print Network

Dynamics and determinants of Quercus alba seedling success following savanna encroachment and regeneration dynamics. We characterized seedling success of the savanna- forming species Quercus alba within transplanted along transects radiating from tree boles of overstory Q. alba trees to inter-canopy gaps

203

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

204

Nursery conditions affect seedling chemistry, morphology and herbivore preferences for Eucalyptus nitens  

Microsoft Academic Search

We examined intraspecific variation in leaf chemistry and seedling morphology of Eucalyptus nitens grown under three different nursery conditions, and compared these with preferences of two species of marsupial herbivore: red-bellied pademelons, Thylogale billardierii, and common brushtail possums, Trichosurus vulpecula. Chemical and morphological variation with nursery treatment reflected variation in light and nitrogen limitation to seedlings. This variation is discussed

Clare McArthur; Nadia R Marsh; Dugald C Close; Andrew Walsh; Stephen Paterson; Hugh Fitzgerald; Noel W Davies

2003-01-01

205

OIKOS 101: 345353, 2003 Seedling resistance to herbivory as a predictor of relative  

E-print Network

OIKOS 101: 345­353, 2003 Seedling resistance to herbivory as a predictor of relative abundance in a synthesised prairie community G. S. Burt-Smith, J. P. Grime and D. Tilman Burt-Smith, G. S., Grime, J. P. and Tilman, D. 2003. Seedling resistance to herbivory as a predictor of relative abundance in a synthesised

Minnesota, University of

206

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

207

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

PubMed

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

208

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

209

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

210

Effects of Burning and Canopy Density on Seedling Growth in an Iowa Oak\\/Hickory Forest  

Microsoft Academic Search

In areas like central Iowa that are dominated by prairie, forests have not received the study they deserve. We examined the effects of late fall burning and canopy density on a variety of representative tree species' seedlings in the upland White Oak forest of the Conard Environmental Research Area (CERA). The num- ber, diameter, and height of seedlings was estimated

Anna Isis-Brown; Corey Langseth; Samantha Worzalla

2004-01-01

211

SAVANNA RESTORATION THROUGH PRESCRIBED FIRE: DEMOGRAPHIC AND PHYSIOLOGICAL RESPONSES OF OAK AND HICKORY SEEDLINGS  

E-print Network

AND HICKORY SEEDLINGS AND SAPLINGS TO A CHANGING LIGHT ENVIRONMENT A Thesis Presented to The Graduate College: DEMOGRAPHIC AND PHYSIOLOGICAL RESPONSES OF OAK AND HICKORY SEEDLINGS AND SAPLINGS TO A CHANGING LIGHT;SAVANNA RESTORATION THROUGH PRESCRIBED FIRE: DEMOGRAPHIC AND PHYSIOLOGICAL RESPONSES OF OAK AND HICKORY

Wait, D. Alexander

212

Young restored forests increase seedling recruitment in abandoned pastures in the Southern Atlantic rainforest.  

PubMed

Planting seedlings is a common technique for abandoned pastures restoration in the tropics, supposedly by increasing the seedling recruitment and accelerating succession. In this study we evaluated the role of a young restored forest (one year old) in enhancing seedling establishment from two sources (seed rain and seed bank), in the Atlantic Rainforest region in Southern Brazil. We compared abandoned pasture, young restored forest and old-growth forest with respect to the seedlings recruited from different sources, by monitoring 40 permanent plots (0.5 m x 0.5 m) over 20 months. From the three studied areas a total of 392 seedlings of 53 species were recruited. Species were mainly herbaceous (85%), pioneers (88%), zoochorous (51%) and small-seeded species (60%). Seedling recruitment from the seed bank (density and species richness) was higher and dominated by herbaceous species in the abandoned pasture and in the young restored forest; on the other hand, the recruitment of woody species from seed rain was more pronounced in the old-growth forest. The young restored forest increased the species richness of woody seedlings recruitment from the seed bank (two-fold) and from seed rain (three-fold) compared to the abandoned pasture. Also, the seedling density in young restored forest was still higher than abandoned pastures (seed bank: four times; seed rain: ten times). Our results show that even young restored areas enhance the establishment of woody species and should be considered an important step for pasture restoration. PMID:21246991

Leitão, Flora H M; Marques, Marcia C M; Ceccon, Eliane

2010-12-01

213

Carbon and phosphorus relations in mycorrhizal and non-mycorrhizal pine seedlings  

E-print Network

Carbon and phosphorus relations in mycorrhizal and non-mycorrhizal pine seedlings J.V.D. Rousseau C physiological and developmental responses to mycorrhizal fungus inocula- tion and applied phosphorus were exam unique to the mycorrhizal association. Materials and Methods Pinus taeda L. seedlings, initially grown

Paris-Sud XI, Université de

214

Effect of Zinc on Cadmium Toxicity-Induced Oxidative Stress in Winter Wheat Seedlings  

Microsoft Academic Search

Two hydroponic experiments were conducted to investigate the antioxidant response of winter wheat (Triticum aestivum L.) to cadmium (Cd)-zinc (Zn) interactions, Seedlings of winter wheat (cv. Yuandong 977), were grown in modified Hoagland nutrient solution with the addition of increasing concentrations of Cd (0, 10, 25, 50 ?M). In experiment 2, the seedlings of the same cultivar were treated with

Z.-Q. Zhao; Y.-G. Zhu; R. Kneer; S. E. Smith

2005-01-01

215

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

216

The gravitropic setpoint angle of dark-grown rye seedlings and the role of ethylene  

Microsoft Academic Search

The orientation growth of coleoptiles of dark-grown seedlings of rye (Secale cereale L. cv. Marder II), when grown under various conditions, was analysed with respect to the gravivector ('gravitropic setpoint angle', GSA). Coleoptiles growing through moist ver- miculite attain and maintain a GSA with an average of about 180?, i.e. a vertical orientation. Seedlings growing uncovered either on the surface

Hans G. Edelmann; Gennadi Gudi; Frank Kuhnemann

2002-01-01

217

Soil seed bank and seedling populations of Hordeum murinum and Cardaria draba in saffron fields  

Microsoft Academic Search

Geostatistical techniques were used to characterize the spatial relationship between Hordeum murinum and Cardaria draba seedling and soil seed bank over the entire growing season of 2004–2005 in three saffron (Crocus sativus) fields, located in Southern Khorasan (33°N latitude, 57°E longitude), Iran. The maps of H. murinum seed bank density corresponded moderately to those seedling density in a and strongly

H. Makarian; M. H. Rashed Mohassel; M. Bannayan; M. Nassiri

2007-01-01

218

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

219

Proline in relation to free radical production in seedlings of Brassica juncea raised under sodium chloride stress  

Microsoft Academic Search

The production of malondialdehyde (MDA) was higher in cotyledons from NaCl-raised Brassica juncea seedlings than in control seedlings. Light accelerated the MDA-producing capacity of thylakoids isolated from both control and treated seedlings. When exposed to strong white light (920 µmol photons m-2 s-1) the thylakoids from NaCl seedlings produced nearly 5 times more MDA than control thylakoids. In the cotyledons

Alia; P. Pardha Saradhi; Prasanna Mohanty

1993-01-01

220

[Utilization of insoluble phosphate by Larix gmelini seedlings under phosphorus starvation].  

PubMed

The utilization of insoluble phosphate by 2 years old larch(Larix gmelini) seedlings was studied in greenhouse. The seedlings were grown in sand and AlPO4 was supplied as a source of P. The results showed that larch seedlings could utilize some amount of AlPO4. Supplied with AlPO4 but not incubated with mycorrhizal-fungi, the seedlings could absorb 35.1% and 64.9% of the phosphorus uptake when supplied with soluble phosphate. The effects of various mycorrhizal-fungi on utilization of phosphate were different, i.e., the utilization rate of AlPO4 was higher when incubated with Suillus granulatus, but was similar to control when incubated with Suillus grevillei. The proportion of root/crown became higher under P-starvation, and larch seedlings could gain more P by enlarging their root growth. PMID:11767518

Zhang, Y; Bai, S; Liu, X; Wang, Z

2000-10-01

221

Mixed heavy metals tolerance and radial oxygen loss in mangrove seedlings.  

PubMed

The effects of a mixture of heavy metals (Pb, Zn and Cu) on growth, radial oxygen loss (ROL) and the spatial pattern of ROL were investigated in mangrove seedlings of three species: Aegiceras corniculatum, Avicennia marina and Bruguiera gymnorrhiza. Heavy metals inhibited the growth of seedlings and led to decreased ROL and changes in the "tight" barrier spatial pattern of ROL. There was a significant positive correlation between the amount of ROL from the roots of seedlings and metal tolerance. The species with the highest ROL amount, B. gymnorrhiza, were also the most tolerant to heavy metals. The "tight" barrier spatial ROL pattern was also related to metal tolerance in the seedlings. Therefore, we conclude that both ROL amount and "tight" barrier spatial ROL pattern in the roots of the mangrove seedlings play an important role in resistance to heavy metal toxicity. PMID:19692098

Liu, Y; Tam, N F Y; Yang, J X; Pi, N; Wong, M H; Ye, Z H

2009-12-01

222

[Effects of litter coverage and watering frequency on seed germination and seedling survival of Castanopsis fissa].  

PubMed

Castanopsis fissa is an important pioneer species commonly used in the restoration of degraded subtropical grassland in southern China. The study on the effects of litter coverage and watering frequency on the seed germination and seedling survival of C. fissa showed that the effects of litter coverage depended on soil moisture condition. When the watering frequency was 1 time per day, litter covering could restrain seed germination and increase seedling mortality; while watering 2 or 3 times per day, the covering would ameliorate soil moisture condition, and benefit seed germination and seedling establishment. The biomass of C. fissa seedlings was enhanced significantly by litter covering. It was suggested that keeping a litter layer on soil surface could benefit the seed germination and seedling survival of C. fissa to restore subtropical shrub land. PMID:19123340

Wang, Jun; Wang, Zhuo-Han; Yang, Long; Ren, Hai

2008-10-01

223

Transformation of natural and synthetic estrogens by maize seedlings.  

PubMed

In agricultural fields, crop plants may transform or degrade hormonally active compounds in manure used as fertilizer and thereby affect the overall endocrine-disrupting activity of agricultural runoff. This study examined the transformation of two natural steroid estrogens [17?-estradiol (17?-E2) and estrone (E1)] and two synthetic estrogen mimics [zeranol (?-ZAL) and zearalanone (ZAN)] by maize seedlings. Growing whole maize seedlings in hydroponic solutions of target estrogens resulted in both oxidative (i.e., 17?-E2 to E1 and ?-ZAL to ZAN) and reductive (i.e., E1 to 17?-E2 and ZAN to ?-ZAL) transformations. Although all four estrogens accumulated in maize roots as both parents and products, the shoots contained only 17?-E2 and ?-ZAL, regardless of whether they were the parent or the product. Crude plant enzyme extracts led to substantial reductive transformations but created only trace amounts of oxidation products. In contrast, only oxidative transformations occurred in solutions exposed to plant-associated microbes. Thus, the combined effects of plant enzymes and plant-associated microbes account for the reversible transformations observed with whole plants. These effects are expected to generally decrease the overall estrogenicity of runoff from manure-fertilized fields. PMID:23488817

Card, Marcella L; Schnoor, Jerald L; Chin, Yu-Ping

2013-05-21

224

[Heat shock modification of nitrosomethylurea action on sunflower seedlings].  

PubMed

Separate and combined action of nitrosomethylurea (NMU) and heat shock (HS) on germination of seeds of the inbred line 3629 and derived nuclear and plastome mutant lines, n-chlorina-1 and en-chlorina-5, respectively, were studied. NMU at a concentration of 0.015%, as well as HS (40 degrees C), had no effect on the spontaneous level of chromosome aberrations in root meristem of sunflower seedlings. However, at a concentration of 0.03%, the mutagen considerably increased the frequency of chromosome rearrangements. Pretreatment with heat for 30 min enhanced the cytogenetic effect of NMU (0.03%) on line 3629 seedlings. In the nuclear mutant, the reaction of root meristematic cells did not depend on the additional heat treatment. The combined action of HS and NMU at early germination stages had no effect on the survival of line 3629 plants and plastome mutant en-chlorina-5; the survival of n-chlorina-1 plants decreased. The highest frequency of M1 plants with chlorophyllic abnormalities (green revertants, lethals, and variegated forms) was observed in n-chlorina-1 line. PMID:11357366

Gus'kov, E P; Markin, N V; Usatov, A V; Mashkina, E V

2001-03-01

225

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

226

Ureide metabolism during seedling development in French bean (Phaseolus vulgaris).  

PubMed

French bean (Phaseolus vulgaris) is a legume that transports most of the atmospheric nitrogen fixed in its nodules to the aerial parts of the plant as ureides. Changes in ureide content and in enzymatic activities involved in their metabolism were identified in the cotyledons and embryonic axes during germination and early seedling development. Accumulation of ureides (ca. 1300 nmol per pair of cotyledons) was observed in the cotyledons of dry seeds. Throughout germination, the total amount of ureides slightly decreased to about 1200 nmol, but increased both in cotyledons and in embryonic axes after radicle emergence. In the axes, the ureides were almost equally distributed in roots, hypocotyls and epicotyls. The pattern of ureide distribution was not affected by the presence of nitrate or sucrose in the media up to 6 days after imbibition. Ureides are synthesized from purines because allopurinol (a xanthine dehydrogenase inhibitor) blocks the increase of ureides. Allantoin and allantoate-degrading activities were detected in French bean dried seeds, whereas no ureidoglycolate-degrading activity was detected. During germination, the levels of the three activities remain unchanged in cotyledons. After radicle emergence, the levels of activities in cotyledons changed. Allantoin-degrading activity increased, allantoate-degrading activity decreased and ureidoglycolate-degrading activity remained undetectable in cotyledons. In developing embryonic axes, the three activities were detected throughout germination and early seedling development. The embryonic axes are able to synthesize ureides, because those compounds accumulated in axes without cotyledons. PMID:19121096

Quiles, Francisco Antonio; Raso, María José; Pineda, Manuel; Piedras, Pedro

2009-01-01

227

Effects of topsoil removal on seedling emergence and species diversity  

SciTech Connect

Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with Plutonium. As part of a cleanup effort, both the vegetation and the top 5--10 cm of soil may be removed. A study was developed to determine the effects of topsoil removal on seedling emergence and plant species diversity. Trial plots were prepared by removing 5, 10, or 20 cm of topsoil, seeding a mix of nine native species, mulching with straw, and then anchoring the straw with erosion netting. Additional plots (0 topsoil removal treatment) were lightly bladed to remove existing vegetation and then treated as above. Approximately 85 mm of supplemental irrigation was applied to help initiate germination during early spring. Seedling density data of seeded and nonseeded species was collected following emergence, and species diversity was calculated with the Shannon diversity index for the nonseeded species. Densities of seeded species either were unaffected by or increased with increased depth of topsoil removal. In general, densities of nonseeded species decreased with increased depth of topsoil removal. The number of species, species diversity and evenness also decreased with increased depth of topsoil removal. Initial emergence of seeded species is apparently unaffected by topsoil removal at this site.

Winkel, V.K.; Ostler, W.K.

1994-02-01

228

Seedling herbivory by slugs in a willow hybrid system: developmental changes in damage, chemical defense, and plant performance  

Microsoft Academic Search

We evaluated feeding preference and damage by the slug, Arion subfuscus, on seedlings of two willow species, Salix sericea and S. eriocephala, and their F1 interspecific hybrids. Trays of seedlings were placed in the field and excised leaves were presented to slugs in choice tests. Slugs preferred feeding on and caused the most damage to S. eriocephala seedlings. S. sericea

Robert S. Fritz; Cris G. Hochwender; Debra A. Lewkiewicz; Sara Bothwell; Colin M. Orians

2001-01-01

229

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

230

Phenotypic variation in seedlings of a “keystone” tree species ( Quercus douglasii ): the interactive effects of acorn source and competitive environment  

Microsoft Academic Search

Blue oak (Quercus douglasii) is a deciduous tree species endemic to California that currently exhibits poor seedling survival to sapling age classes. We used common garden techniques to examine how genetic variation at regional and local scales affected phenotypic expression in traits affecting oak seedling growth and survival. Between-population variation was examined for seedlings grown from acorns collected from a

K. J. Rice; D. R. Gordon; J. L. Hardison; J. M. Welker

1993-01-01

231

Species-specific effects of woody litter on seedling emergence and growth of herbaceous plants.  

PubMed

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest--evergreen spruce (Picea abies), deciduous hazel (Corylus avellana), and a mixture of the two species--and litter amount--shallow (4 mm), deep (12 mm) and leachate--on seedling emergence and biomass of three understorey species. The effect of litter amount on seedling emergence was highly dependent on litter type; while spruce needle litter had a significant negative effect that increased with depth, seedling emergence in the presence of hazel broadleaf litter did not differ from control pots containing no litter. Mixed litter of both species also had a negative effect on seedling emergence that was intermediate compared to the single-species treatments. Spruce litter had a marginally positive (shallow) or neutral effect (deep) on seedling biomass, while hazel and mixed litter treatments had significant positive effects on biomass that increased with depth. We found non-additive effects of litter mixtures on seedling biomass indicating that high quality hazel litter can reduce the negative effects of spruce. Hazel litter does not inhibit seedling emergence; it increases seedling growth, and creates better conditions for seedling growth in mixtures by reducing the suppressive effect of spruce litter, having a positive effect on understorey species richness. PMID:22028890

Koorem, Kadri; Price, Jodi N; Moora, Mari

2011-01-01

232

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

233

Species-Specific Effects of Woody Litter on Seedling Emergence and Growth of Herbaceous Plants  

PubMed Central

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest—evergreen spruce (Picea abies), deciduous hazel (Corylus avellana), and a mixture of the two species—and litter amount—shallow (4 mm), deep (12 mm) and leachate—on seedling emergence and biomass of three understorey species. The effect of litter amount on seedling emergence was highly dependent on litter type; while spruce needle litter had a significant negative effect that increased with depth, seedling emergence in the presence of hazel broadleaf litter did not differ from control pots containing no litter. Mixed litter of both species also had a negative effect on seedling emergence that was intermediate compared to the single-species treatments. Spruce litter had a marginally positive (shallow) or neutral effect (deep) on seedling biomass, while hazel and mixed litter treatments had significant positive effects on biomass that increased with depth. We found non-additive effects of litter mixtures on seedling biomass indicating that high quality hazel litter can reduce the negative effects of spruce. Hazel litter does not inhibit seedling emergence; it increases seedling growth, and creates better conditions for seedling growth in mixtures by reducing the suppressive effect of spruce litter, having a positive effect on understorey species richness. PMID:22028890

Koorem, Kadri; Price, Jodi N.; Moora, Mari

2011-01-01

234

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

235

Effect of exogenous lead on growth and carbon metabolism of pea (Pisum sativum L) seedlings.  

PubMed

The present study investigated the effect of exogenous lead (Pb) on seedling growth, carbohydrate composition and vital enzymes of sucrose metabolism, starch degradation, pentose phosphate pathway and glycolysis in pea seedlings. With 0.5 mM Pb, reduction of about 50 % in shoot and 80 % in root lengths was observed. At 5 and 7 days of seedling growth, cotyledons of Pb-stressed seedlings had about 25-50 % lower ?- and ?-amylase activities resulting in their higher starch content. Low starch content in the cotyledons of control seedlings at days 1, 3, 5 and 7 may be due to higher investment of carbon for seedling growth. Seedlings exposed to Pb showed significant inhibition of about 30-50 % in acid invertase activity in the growing tissues i.e. roots and shoots. Sucrose content increased by 10-20 % in shoots with much larger increase in cotyledons at 5-7 days of growth in Pb-stressed seedlings. In stressed seedlings, sucrose synthase (SS) and sucrose-6-phosphate synthase (SPS) enzymes were down regulated in the roots but SS activity was up regulated in the cotyledons leading to increased sucrose content. Exogenous Pb increased the activities of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) in the cotyledons. Down regulation of G6PDH and up regulation of hexokinase (HXK) in the roots and shoots of stressed seedlings indicated that hexoses could be utilised preferably for glycolysis rather than pentose phosphate pathway in these tissues. Due to limited supply of sugars to growing tissues in the stressed seedlings, increased HXK may play a role in sugar sensing. Phosphoglucomutase (PGM) activity was maximum in the cotyledons and minimum in roots showing its importance in the conversion of glucose-1-phosphate into glucose-6-phosphate. Reduced seedling growth observed in the presence of exogenous Pb was mainly due to the decrease in the activities of amylases and invertases in the cotyledons and growing tissues respectively. Further biosynthetic capacity of the roots and shoots was down regulated in the pea seedlings due to reduced efficiency of pentose phosphate pathway under Pb toxicity. PMID:24381440

Devi, Rachana; Munjral, Nidhi; Gupta, Anil K; Kaur, Narinder

2013-01-01

236

Retention of cotyledons is crucial for resprouting of clipped oak seedlings.  

PubMed

Although resprouting plays an important role in facilitating persistence of damaged seedlings, the functional attributes of cotyledons and taproots during resprouting of 1-year oak seedlings are not well explored. In this study, cotyledons were removed from Quercus mongolica seedlings to explore resprouting in response to simulated disturbance as a function of shoot clipping, and to examine the resprouting ability in relation to timing of clipping and cotyledon removal. Isotope labeling experiments were also performed to evaluate contribution of the cotyledons and taproots to resprouting. Regardless of timing of shoot clipping, seedlings successfully resprouted provided their cotyledons were not detached. Clipped seedlings were less likely to resprout when cotyledons were removed. Seedlings clipped at earlier development stage exhibited higher resprouting capacity than those clipped at later stage. Cotyledon removal, more than timing of clipping, decreased the dry masses of newly-resprouted shoots. However, no significant influences of cotyledon removal and timing of clipping were found on the dry masses of roots, suggesting the importance of cotyledons for resprouting. Roots became functional and accumulated more soil nitrogen after shoot clipping and cotyledon removal, representing a double security-based strategy for the clipped seedlings to resprout despite the importance of cotyledons. PMID:24888417

Yi, Xianfeng; Liu, Changqu

2014-01-01

237

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

238

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

239

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

240

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

241

Establishment of Ulmus pumila seedlings on steppe slopes of the northern Mongolian mountain taiga  

NASA Astrophysics Data System (ADS)

The potential of Siberian elm ( Ulmus pumila) to regenerate from seeds was experimentally studied on south-facing slopes in the northern Mongolian mountain taiga. These slopes are covered with a vegetation mosaic of different steppe communities and small, savanna-like, U. pumila open woodlands. The hypothesis is tested that the xeric microclimate and high herbivore densities limit the success of seedling establishment in U. pumila and thereby prevent elm from complete encroachment of the grassland-dominated slopes. Seeds were sown and 2-yr-old seedlings were planted prior to the growing season. The water supply was manipulated by irrigation, as was the feeding pressure by caterpillars with an insecticide. Large herbivores were excluded by fencing. Seeds germinated throughout the summer, but the emerged seedlings did not survive for more than 2 or 3 weeks. Germination rates increased with increasing soil water content and decreasing soil temperatures. Many seeds were consumed by granivores. Most planted 2-yr-old seedlings survived the two growing seasons covered by the study. However, the seedlings suffered from feeding damage by insects (gypsy moth, grasshoppers) and small mammals, from nitrogen deficiency and, to a lesser degree, from drought. The results suggest that high susceptibility of newly emerged seedlings to environmental stresses is a serious bottle neck for U. pumila that prevents them from the formation of closed forests on northern Mongolia's steppe slopes, whereas the probability for seedling survival after this early stage is high.

Dulamsuren, Choimaa; Hauck, Markus; Nyambayar, Suran; Osokhjargal, Dalaikhuu; Leuschner, Christoph

2009-09-01

242

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

243

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

244

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

245

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

246

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

247

Effects of light on the feedback control of GA-20 oxidase gene homolog in DongJinByeo seedlings.  

PubMed

The effects of gibberellin (GA) on the expression of GA-20 oxidase gene homolog were examined in light-grown seedlings and dark-grown seedlings of DongJinByeo. The growth rates of the stems of etiolated seedlings were faster than those of green seedlings. However, upon addition of GA to these seedlings, the stem growth rates of green seedlings were faster than those of etiolated seedlings. To understand the molecular mechanism of GA gene regulation in DongJinByeo, total RNA from DongJinByeo was hybridized with cDNA of GA-20 oxidase gene homolog. Greater accumulation of transcript of GA-20 oxidase gene homolog was observed in green seedlings than in etiolated seedlings. However, upon addition of GA, higher accumulation of the gene transcript was found in etiolated seedlings than in green seedlings, indicating that expression of the transcript of GA-20 oxidase gene homolog might be inhibited by light. These results suggest that light might regulate feedback control of the transcript of GA-20 oxidase gene homolog in DongJinByeo. PMID:17436525

Kim, JaeHong; Yoon, InSun; Lee, MiYoung

2006-05-01

248

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

249

Root cold tolerance of black spruce seedlings: viability tests in relation to survival and regrowth.  

PubMed

Root systems of 6-month-old, cold-hardened, container-grown black spruce seedlings (Picea mariana (Mill.) B.S.P.) were exposed to 0, -5, -10, -15, -20, or -22.5 degrees C. Freezing-induced damage to fine roots, coarse roots and the whole root system was assessed by various viability tests including leakage of electrolytes, leakage of phenolic compounds, water loss, root and shoot water potentials, and live root dry mass. To assess the long-term effects of freezing-induced root damage, seedling survival and regrowth were measured. Leakage of both electrolytes and phenolic compounds differed among fine roots, coarse roots, and whole root systems. In coarse roots and the whole root system, but not in fine roots, leakage of electrolytes, leakage of phenolic compounds, water loss, and root and shoot water potentials were correlated with percentage of live root dry mass which, in turn, was highly correlated with seedling survival and regrowth. Compared with live root dry mass, electrolyte and phenolic leakage, water loss, and root and shoot water potentials were less well correlated with seedling survival and regrowth. Among the viability tests, electrolyte leakage of the whole root system correlated most closely with seedling survival and regrowth. Under freezing conditions that destroyed less than 50% of each seedling's root system, about 70% of the seedlings survived and subsequent growth was little affected, whereas under freezing conditions that destroyed 70% of each seedling's root system, only about 30% of the seedlings survived and subsequent growth was reduced compared with that of undamaged plants. PMID:14759854

Bigras, F J

1997-05-01

250

Seedling-herbivore interactions: insights into plant defence and regeneration patterns  

PubMed Central

Background Herbivores have the power to shape plant evolutionary trajectories, influence the structure and function of vegetation, devastate entire crops, or halt the spread of invasive weeds, and as a consequence, research into plant–herbivore interactions is pivotal to our understanding of plant ecology and evolution. However, the causes and consequences of seedling herbivory have received remarkably little attention, despite the fact that plants tend to be most susceptible to herbivory during establishment, and this damage can alter community composition and structure. Scope In this Viewpoint article we review why herbivory during early plant ontogeny is important and in so doing introduce an Annals of Botany Special Issue that draws together the latest work on the topic. In a synthesis of the existing literature and a collection of new studies, we examine several linked issues. These include the development and expression of seedling defences and patterns of selection by herbivores, and how seedling selection affects plant establishment and community structure. We then examine how disruption of the seedling–herbivore interaction might affect normal patterns of plant community establishment and discuss how an understanding of patterns of seedling herbivory can aid our attempts to restore semi-natural vegetation. We finish by outlining a number of areas where more research is required. These include a need for a deeper consideration of how endogenous and exogenous factors determine investment in seedling defence, particularly for the very youngest plants, and a better understanding of the phylogenetic and biogeographical patterns of seedling defence. There is also much still be to be done on the mechanisms of seedling selection by herbivores, particularly with respect to the possible involvement of volatile cues. These inter-related issues together inform our understanding of how seedling herbivory affects plant regeneration at a time when anthropogenic change is likely to disrupt this long-established, but all-too-often ignored interaction. PMID:23925939

Barton, Kasey E.; Hanley, Mick E.

2013-01-01

251

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.

252

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

253

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

254

Responses of Wheat Seedlings to Exogenous Selenium Supply Under Cold Stress  

Microsoft Academic Search

Dose-dependent effects of selenium on growth and physiological trait of wheat seedlings (Triticum aestivum L. cv Han NO.7086) exposed to cold stress are reported. Responses of seedlings were different depending on the Se concentration.\\u000a The treatments with 0.5 and 1.0 mg Se kg?1 significantly increased biomass and chlorophyll content of seedlings. However, the treatments at 2.0 and 3.0 mg Se kg?1 only induced an evident increase

Jianzhou Chu; Xiaoqin Yao; Zhuona Zhang

2010-01-01

255

Suppression and promotion of growth by ethylene in rice seedlings depends on ambient humidity.  

PubMed

We examined the effect of ethylene on the growth of rice seedlings (Oryza sativa L.) at various degrees of humidity. Ethylene significantly suppressed the growth of shoots when applied to seedlings grown under 30% relative humidity (RH), but promoted the growth of shoots when applied to seedlings grown under 100% RH. The application of gibberellic acid (GA(3)) promoted the elongation of shoots in seedlings grown under 30% and 100% RH. Ethylene inhibited the shoot elongation induced by GA(3) at 30% RH, but enhanced the elongation induced by GA(3) at 100% RH. These results indicate that ethylene can either promote or suppress the growth of rice shoots depending on ambient humidity, and that these actions of ethylene may be mediated through modulating the responsiveness of shoots to gibberellin. PMID:17728010

Azuma, Tetsushi; Honda, Takenori; Sadai, Ayako; Sasayama, Daisuke; Itoh, Kazuyuki

2007-12-01

256

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

257

Interaction between a dark septate endophytic isolate from Dendrobium sp. and roots of D. nobile seedlings.  

PubMed

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 the DSE hyphae invaded the velamen layer, passed through passage cells in exodermis, entered the cortex cells, and then formed fungal pelotons of orchid mycorrhiza. D. nobile seedlings' plant height, stem diameter, new roots number and biomass were greatly enhanced by inoculating the fungus to seedlings. The fungus was identified as Leptodontidium by sequencing the polymerase chain reaction-amplified rDNA ITS1-5.8S-ITS2 (internal transcribed spacer (ITS)) regions and comparison with similar taxa. PMID:21452589

Hou, Xiao-Qiang; Guo, Shun-Xing

2009-04-01

258

Slugs, willow seedlings and nutrient fertilization: intrinsic vigor inversely affects palatability  

E-print Network

evaluates how preference by a generalist slug herbivore Arion subfuscus changes inversely with seedling size palatable to three slug species (including the slug Arion subfuscus) than leaves of woody plants

Orians, Colin

259

Oak Woodland Artificial Regeneration Correlating Soil Moisture to Seedling Survival1  

E-print Network

Oak Woodland Artificial Regeneration Correlating Soil Moisture to Seedling Survival1 Tim R. Plumb to factors ranging from poor acorn crops and unsatisfactory fall and winter weather conditions to predation

Standiford, Richard B.

260

Amino acids liberated into the culture medium by pea seedling roots  

Microsoft Academic Search

Summary The amino acid composition of the medium in which seedlings of peas had been grown aseptically with and without quartz sand were determined by ion-exchange chromatography. Besides considerable amounts of amino acids, peptide material was also present.

D. Boulter; J. J. Jeremy; M. Wilding

1966-01-01

261

[Effect of Pinus sylvestriformis seedlings density on net photosynthetic rate under elevated CO2].  

PubMed

The effect of Pinus sylvestriformis seedlings density on net photosynthetic rate was studied under elevated CO2. Atmospheric CO2 concentration was controlled in OTC (Open Top Chamber). The results showed that elevated CO2 not only made net photosynthetic rates (NPRs) of two Pinus sylvestriformis seedlings densities increased, but also mitigated their intra-specific competition. Meanwhile, the difference of seedling NPRs between 100 and 400 plant.m-2 under 500 mumol.mol-1 air CO2 concentration was less tha that under 350 mumol.mol-1 with the same PAR levels. When air CO2 concentration reached 700 mumol.mol-1, the NPRs of seedlings under both planting densities were close to each other with the same PAR levels. The intra-specific competition was minimized under air CO2 concentration of 700 mumol.mol-1. PMID:12561191

Wang, Chenrui; Huang, Guohong; Zhou, Yumei; Han, Shijie; Zhang, Junhui; Zou, Chunjing

2002-09-01

262

Root-Shoot lnteraction in the Greening of Wheat Seedlings Grown under Red Light  

Microsoft Academic Search

Wheat seedlings grown with roots exposed to constant red light (300-500 pmol m-* s-') did not accumulate chlorophyll in the leaves. In contrast, seedlings grown with their roots shielded from light accumulated chlorophylls. Chlorophyll biosynthesis could be induced in red-light-grown chlorophyll-deficient yellow plants by either reducing the red-light intensity at the root surface to 100 pmol m-'s-' or supplementing with

Baishnab C. Tripathy; Christopher S. Brown

263

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

264

Reproductive strategy of an invasive thistle: effects of adults on seedling survival  

Microsoft Academic Search

Invasive species are known for their ability to form monocultures that exclude native species, yet intraspecific interactions\\u000a among invasives have not been well studied. Cynara cardunculus (L.) is an invasive perennial thistle that establishes high-density populations in coastal California grasslands. We examined\\u000a the natural distribution of C. cardunculus seedlings in an established population and found that nearly 100% of seedlings grew

Robin G. Marushia; Jodie S. Holt

2008-01-01

265

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

266

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

E-print Network

species (2, 16, 18, 21) have used primary trisomics to locate genes on specific chzomosomcs, b triso- mics in sorghum have only recently become available (19) and no trisome linkage inforrmtion has been published. The association of seedling characters... species (2, 16, 18, 21) have used primary trisomics to locate genes on specific chzomosomcs, b triso- mics in sorghum have only recently become available (19) and no trisome linkage inforrmtion has been published. The association of seedling characters...

Hanna, Wayne William

2012-06-07

267

Development of a screening method for drought tolerance in cotton seedlings  

E-print Network

of his protocol. Wright and Jordan (1970) used Wright?s 1964 method to select among boer lovegrass (Eragrostis curvula Nees) seedlings for drought tolerance. The most tolerant selection of 16 clones evaluated was assessed for range performance... of Lehmann lovegrass. Crop Sci. 11:324- 326. Wright, L.N., and G.L. Jordan. 1970. Artificial selection for seedling drouth tolerance in Boer lovegrass (Eragrostis curvula Nees). Crop Sci. 10:99-102. 29 VITA Name: Polly Suzanne Longenberger...

Longenberger, Polly Suzanne

2007-04-25

268

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

2012-06-07

269

Selection for increased seed weight Panicum coloratum L. and its relationship to early seedling performance  

E-print Network

SELECTION FOR INCREASED SEED HEIGHT Panicum col oratum L. AND ITS RELATIONSHIP TO EARLY SEEDLING PERFORMANCE A Thesis by MARK ALLEN HUSSEY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTEP, OF SCIENCE December 1979 Major Subject: Plant Breeding SELECTION FOR INCREASED SEED WEIGHT IN Panicum coloratum L. AND ITS RELATIONSHIP TO EARLY SEEDLING PERFORMANCE A Thesis by MARK ALLEN HUSSEY Approved as to style...

Hussey, Mark Allen

2012-06-07

270

Auxin-impregnated hygroscopic gel: effects on ponderosa pine and common hackberry seedlings  

Microsoft Academic Search

Greenhouse and field studies were conducted to determine the effects of indole3-butyric acid (IBA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on root development and survival of 3+0 bareroot Pinus ponderosa (Dougl. ex Laws.) and 2+0 bareroot Celtis occidentalis (L) seedlings. In the greenhouse, 100 and 200 ppm. IBA and 10 and 50 ppm 2,4-D were applied to seedlings through a root dip

Gerald A. Tuskani; Patricia L. Ellis

1991-01-01

271

Growth of Pinus Taeda L. Seedlings varies with Family and ozone exposure level  

Microsoft Academic Search

Loblolly pine seedlings of five half-sib families were grown under ambient, subambient (approximately 0.6 × ambient), and elevated [ambient + 60 ppb O3 (120 µg m-3)] O3 levels for one growing season in open-topped chambers. Diameter and height of the seedlings were measured periodically over the growing season, and above ground and below ground biomass were determined at harvest. Significant

Mary Beth Adams; J. Michael Kelly; Nelson T. Edwards

1988-01-01

272

Water relations of rough lemon ( Citrus jambhiri Lush.) citrus seedlings infected with Fusarium solani  

Microsoft Academic Search

Summary  Rough lemon citrus seedlings were inoculated withFusarium solani and evaluated for changes in water relations of leaves, stems, and roots. Inoculated seedlings had decreased leaf stomatal\\u000a conductance, lower leaf water potential, lower water content, and higher leaf osmotic values compared to healthy plants. Visible\\u000a wilt symptoms occurred as early as 24 h after inoculation. Transpiration and root conductivity were lower

S. Nemec; J. Syversten; Y. Levy

1986-01-01

273

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

274

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

E-print Network

stress. Shoot He' t and Seedlin Mass Shoot height can atfect both survival and subsequent growth of seedlings at outplanting. In a study on Doughts-fir Pseudotsu menziesii (Mirb. ) Franco), Richter (1971) found a strong correlation between height... stress. Shoot He' t and Seedlin Mass Shoot height can atfect both survival and subsequent growth of seedlings at outplanting. In a study on Doughts-fir Pseudotsu menziesii (Mirb. ) Franco), Richter (1971) found a strong correlation between height...

Wall, Margot Marie

2012-06-07

275

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

276

The ecology of Carex oxyandra II. The behavior of seedlings and tillers  

Microsoft Academic Search

A study on the seedlings and tillers ofCarex oxyandra, a pioneer perennial, was carried out at Mt. Bandai, Fukushima Prefecture, Japan. A field experiment showed that seedlings\\u000a had a rather low rate of growth, a small biomass and a high mortality rate. On the other hand, tillers in clones befan growth\\u000a much earlier, had a rapid growth rate and grew

Azuma Tsujimura

1987-01-01

277

Survival of selected pine seed sources with different seedling treatments on droughty sites in East Texas  

E-print Network

CONTENTS Pacae INTRODUCTION. LITERATURE REVIEW Containerized Seedlings. Mycorrhizae. Root Dip. Drought Resistant Sources. STUDY AREA. METHODS. . 12 23 . . 25 . 32 . 40 Seedling Preparation and Planting. Climatic Data. Soil Analysis. Vigor... and Survival Tests Data Analysis. RESULTS AND DISCUSSION. SUMMARY AND CONCLUSIONS. 40 . 45 46 47 ~ 51 97 LITERATURE CITED. APPENDIX I GREENHOUSE PROCEDURES APPENDIX II CLIMATIC DATA. APPENDIX III SOILS DATA. APPENDIX IV EMS TABLE. 105 114 119...

Echols, Ralph James

2012-06-07

278

Assessment of hedgerow species for seed size, stand establishment and seedling height  

Microsoft Academic Search

The relationships between seed size, emergence, stand establishment and seedling height were examined in a trial comparing\\u000a tree and shrub species as hedgerows for alley cropping in four environments in Haiti. Logarithmic functions relating % emergence,\\u000a % stand establishment and seedling height to seed weight were positive and significant. These relationships were stronger\\u000a when species weighing > 10 g 100?1

D. A. Shannon; L. Isaac; F. E. Brockman

1996-01-01

279

Development of Douglas-fir seedling root architecture in response to localized nutrient supply  

Microsoft Academic Search

Three months following sowing, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were trans- planted into pots with controlled-release fertilizer (CRF) applied at rates of 0, 8, 16, and 24 g\\/2200 cm3 soil as a sin- gle uniform layer beneath the root system. Seedlings were destructively harvested periodically, and roots were divided into vertical segments above (S1), within (S2), and below (S3)

Douglass F. Jacobs; Robin Rose; Diane L. Haase

2003-01-01

280

Seed-litter-position drives seedling establishment in grassland species under recurrent drought.  

PubMed

Changes in land use and climate interfere with grassland ecosystem processes. Here I experimentally investigated the combined effects of land-use change related litter cover and contrasting water supply on seedling emergence. In this context, the role of the initial relative position of seeds, i.e. seeds on top of the litter versus seeds beneath the litter in interaction with water supply has not been investigated so far. I hypothesised that facilitative effects of litter on seedling emergence occur when seeds are covered by litter and deteriorate when litter covers the ground and seeds fall on it (seeds on top of the litter). Further, I hypothesised that the importance of seed position for seedling emergence will increase under conditions of recurrent drought. I performed a controlled pot experiment on seedling emergence of three common European grassland species (Pimpinella saxifraga, Leontodon autumnalis, Sanguisorba officinalis) by experimental manipulations of litter and water availability. Seedling emergence under moist conditions showed no significant differences between each litter position compared to the control across species. In contrast, under recurrent drought, seedling emergence was significantly higher below the litter compared to seeds on top of the litter and the control (i.e. no litter). In abandoned land, seedling emergence may be limited when seeds fall on ground-covering litter. In contrast, in grasslands with regular low-intensity land use, seedling emergence may be enhanced when a moderate level of litter covers seeds at the end of the growing season. Protective mechanisms that occur with seeds positioned beneath litter are particularly important under recurrent drought. PMID:22822918

Wellstein, C

2012-11-01

281

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

282

Field performance of containerized black spruce seedlings with root systems damaged by freezing or pruning  

Microsoft Academic Search

Roots of 2-year-old black spruce seedlings (Picea mariana [Mill.] B.S.P.) were exposed to freezing temperatures to destroy 20, 40, 60, and 80% of the root systems. For comparison, other root systems were pruned to eliminate the same proportions of roots. Treated and control seedlings were planted in spring 1992 at Forêt Montmorency (the Université Laval forest research station, 50 km

Francine J. Bigras

1998-01-01

283

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

284

Impacts of seedling herbivory on plant competition and implications for species coexistence  

PubMed Central

Background and Aims Although the causes and consequences of seedling herbivory for plant community composition are well understood, the mechanisms by which herbivores influence plant species recruitment to the established phase remain less clear. The aim was to examine how variation in the intensity of seedling herbivory interacts with growth-defence trade-offs and herbivore feeding preferences to affect plant community development. Methods Using 14-d-old seedlings of Trifolium pratense and T. repens, relative growth and susceptibility to herbivory by the snail Helix aspersa was quantified to elucidate putative growth-defence trade-offs for these species. Then mixed assemblages of 14-d-old Trifolium seedlings were exposed to herbivory by zero, two, five or ten snails and determined how variation in the intensity of herbivory affected competitive interactions into the mature phase (as measured by total plant biomass at 120 d old). Key Results In the absence of herbivory, communities were dominated by T. pratense; a result expected on the basis that it yielded larger and presumably more competitive seedlings. However, when seedlings were exposed to herbivory, the balance of competition shifted. At low levels of herbivory (two snails), both Trifolium species contributed equally to total plant biomass. More intense herbivory (five snails) resulted in almost total mortality of T. pratense and dominance of the mature community by T. repens. The most intense herbivory (ten snails) effectively removed all seedlings from the experimental community. Conclusions The study illustrates a mechanism whereby spatio-temporal fluctuations in seedling herbivory, when coupled with species-specific variation in competitive ability and sensitivity to herbivore attack, can differentially influence plant recruitment into the mature phase. This mechanism may be a key element in our attempts to understand plant species coexistence, since fluctuations in plant recruitment are fundamental to the many theories that view coexistence as a consequence of a spatio-temporal lottery for dominance over regeneration micro-sites. PMID:19351683

Hanley, M. E.; Sykes, R. J.

2009-01-01

285

Photosynthetic response to precipitation\\/rainfall in predominant tree ( Ulmus pumila ) seedlings in Hunshandak Sandland, China  

Microsoft Academic Search

The responses of gas exchange and chlorophyll fluorescence of field-growing Ulmus pumila seedlings to changes in simulated precipitation were studied in Hunshandak Sandland, China. Leaf water potential (?wp), net photosynthetic rate (P\\u000a N), stomatal conductance (g\\u000a s), and transpiration rate (E) were significantly increased with enhancement of precipitation from 0 to 20 mm (pU. pumila seedlings that could be avoided

Y.-G. Li; G.-M. Jiang; M.-Z. Liu; S.-L. Niu; L.-M. Gao; X.-C. Cao

2007-01-01

286

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

287

Drought Induces Oxidative Stress and Enhances the Activities of Antioxidant Enzymes in Growing Rice Seedlings  

Microsoft Academic Search

When rice seedlings grown for 10 and 20 days were subjected to in vitro drought stress of ?0.5 and ?2.0 MPa for 24 h, an increase in the concentration of superoxide anion (O2.?), increased level of lipid peroxidation and a decrease in the concentration of total soluble protein and thiols was observed in stressed seedlings compared to controls. The concentration of H2O2 as

Pallavi Sharma; Rama Shanker Dubey

2005-01-01

288

Abscisic acid-responsive proteins induce salinity tolerance in wheat seedlings  

Microsoft Academic Search

The response of wheat seedlings germinated under salinity stress to exogenous abscisic acid was discussed. Exogenous ABA acid\\u000a induces two characteristic proteins of high molecular weights (109.4 and 84.0 kDa) in addition to the new protein set formed\\u000a under high salinity levels. ABA, also induces synthesized forms of guaiacol peroxidase in seedlings treated with 200 mM NaCl.\\u000a The induction and\\/or

A. E. El-Enany

2000-01-01

289

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

290

Long-distance dispersal helps germinating mahogany seedlings escape defoliation by a specialist caterpillar.  

PubMed

Herbivores and pathogens with acute host specificity may promote high tree diversity in tropical forests by causing distance- and density-dependent mortality of seedlings, but evidence is scarce. Although Lepidoptera larvae are the most abundant and host-specific guild of herbivores in these forests, their impact upon seedling distributions remains largely unknown. A firm test of the mechanism underpinning the Janzen-Connell hypothesis is difficult, even for a single tree species, because it requires more than just manipulating seeds and seedlings and recording their fates. Experimental tests require: (1) an insect herbivore that is identified and highly specialised, (2) linkage to an in situ measure (or prevention) of herbivory, and (3) evaluation and confirmation among many conspecific adult trees across years. Here we present experimental evidence for a spatially explicit interaction between newly germinating seedlings of a Neotropical emergent tree, big-leaf mahogany (Swietenia macrophylla, Meliaceae), and caterpillars of a noctuid moth (Steniscadia poliophaea). In the understory of a southeastern Amazon forest, the proportion of attacks, leaf area lost, and seedling mortality due to this specialised herbivore peaked near Swietenia trees, but declined significantly with increasing distance from mature fruiting trees, as predicted by the Janzen-Connell hypothesis. We conclude that long-distance dispersal events (>50 m) provided an early survival advantage for Swietenia seedlings, and propose that the role of larval Lepidoptera as Janzen-Connell vectors may be underappreciated in tropical forests. PMID:19885680

Norghauer, Julian M; Grogan, James; Malcolm, Jay R; Felfili, Jeanine M

2010-02-01

291

Survival and growth of loblolly pine as influenced by seedling grade: 13-year results  

SciTech Connect

One-yr-old seedlings were classified into grades 1-3, with root collar diameter more than 4.7 mm, 3.2-4.7 mm and less than 3.2 mm respectively, and planted out in Louisiana on a site with index 94 (ft at base age 25 yr). Survival and height were recorded at age 3 yr, and survival, height and diameter recorded in June 1980 (13 yr old). Seedling grade affected survival, height and volume production. Survival in grades 1 and 2 was significantly higher than in grade 3. Volume production of grade 1 seedlings was 17.5% greater than that of grade 2. The value, discounted to the planting date, of the additional wood produced by grade 1 at age 13 compared with grade 2 was estimated at $50-139 per thousand seedlings. Average volume production for grade 1 seedlings was more than 440 cubic ft/acre p.a. It is suggested that a portion of nurseries should be sown at low densities (approximately 200/squared m) to provide for the choice of planting a high proportion of grade 1 seedlings. 26 references.

South, D.B.; Boyer, J.N.; Bosch, L.

1985-01-01

292

Growth and lignification in seedlings exposed to eight days of microgravity  

NASA Technical Reports Server (NTRS)

Four-day-old pine seedlings and mung bean and oat seeds were prepared for flight on the third Space Transport System Mission (STS-3). The seedlings and seeds were planted in six mini-growth chambers (two chambers per species) which were placed in a plant growth unit (PGU). Another set of seedlings and seeds was prepared and placed in another PGU as the 1 g control. The flight PGU was positioned in the orbiter mid-deck locker area about 11 h prior to launch. The pine seedlings and germinating mung bean and oat seeds were exposed to 194 h of microgravity. The PGU was received at a temporary laboratory about 75 min post-landing. Plants were observed, photographed and the atmospheric gases analyzed at the landing site. The plants were then brought to our Houston laboratory where they were measured and analyzed for lignin and protein content and for phenylalanine ammonia-lyase (PAL) and peroxidase activities. Flight seedlings were shorter than the controls in all three species. Twenty-five to 40 per cent of the mung bean and oat roots were growing upward, and the mung beans showed signs of disorientation. Flight mung beans showed a significant reduction in lignin content in comparison to the controls, and PAL and peroxidase activities were reduced in flight pine seedlings. The results generally support the postulate that lignin synthesis is reduced in near-weightlessness and show other interesting findings.

Cowles, J. R.; Scheld, H. W.; Lemay, R.; Peterson, C.

1984-01-01

293

Studies on the methods of identification of irradiated food I. Seedling growth test  

NASA Astrophysics Data System (ADS)

A seedling growth test for the identification of gamma irradiated edible vegetable seeds was described. The identification of gamma irradiated grape and the other seeds has been investigated. The purpose of this study was to develop an easy, rapid and practical technique for the identification of irradiated edible vegetable seeds. Seven different irradiated edible vegetable seeds as: rice ( Oryza sativa), peanut ( Arachis hypogaea), maize ( Zeamays), soybean ( Glycine max), red bean ( Phaseolus angularis), mung bean ( Phaseolus aureus) and catjang cowpea ( Vigna cylindrica) were tested by using the method of seedling growth. All of the edible vegetable seeds were exposed to gamma radiation on different doses, O(CK), 0.5, 1.0, 1.5, 2.0, 3.0, 5.0 kGy. After treatment with above 1.0 kGy dose to the seeds, the seedling rate was less than 50% compared with the control. Although the seedling rate of rice seeds can reached 58%, the seedling growth was not normal and the seedling leaves appeared deformed. The results by this method were helpful to identify gamma treatment of the edible vegetable seeds with above 1.0 kGy dose.

Qiongying, Liu; Yanhua, Kuang; Yuemei, Zheng

1993-07-01

294

Genetic Analysis of Gravity Signal Transduction in Arabidopsis thaliana Seedlings  

NASA Astrophysics Data System (ADS)

The primary roots of Arabidopsis thaliana seedlings respond to gravity stimulation by developing a tip curvature that results from differential cellular elongation on opposite flanks of the elongation zone. This curvature appears modulated by a lateral gradient of auxin that originates in the gravity-perceiving cells (statocytes) of the root cap through an apparent lateral repositioning of a component the auxin efflux carrier complex within these cells (Friml et al, 2002, Nature 415: 806-809). Unfortunately, little is known about the molecular mechanisms that govern early phases of gravity perception and signal transduction within the root-cap statocytes. We have used a molecular genetic approach to uncover some of these mechanisms. Mutations in the Arabidopsis ARG1 and ARL2 genes, which encode J-domain proteins, resulted in specific alterations in root and hypocotyl gravitropism, without pleiotropic phenotypes. Interestingly, ARG1 and ARL2 appear to function in the same genetic pathway. A combination of molecular genetic, biochemical and cell-biological approaches were used to demonstrate that ARG1 functions in early phases of gravity signal transduction within the root and hypocotyl statocytes, and is needed for efficient lateral auxin transport within the cap. The ARG1 protein is associated with components of the secretory and/or endosomal pathways, suggesting its role in the recycling of components of the auxin efflux carrier complex between plasma membrane and endosome (Boonsirichai et al, 2003, Plant Cell 15:2612-2625). Genetic modifiers of arg1-2 were isolated and shown to enhance the gravitropic defect of arg1-2, while resulting in little or no gravitropic defects in a wild type ARG1 background. A slight tendency for arg1-2;mar1-1 and arg1-2;mar2-1 double-mutant organs to display an opposite gravitropic response compared to wild type suggests that all three genes contribute to the interpretation of the gravity-vector information by seedling organs. The molecular structure of these new loci is being investigated. Furthermore, a proteomic approach is being developed to characterize root-tip proteins that are differentially expressed, modified or targeted in response to gravity stimulation. We acknowledge funding by NASA and NSF.

Boonsirichai, K.; Harrison, B.; Stanga, J.; Young, L.-S.; Neal, C.; Sabat, G.; Murthy, N.; Harms, A.; Sedbrook, J.; Masson, P.

295

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

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... IN PLANT TISSUES BY NON-DESTRUCTIVE THERMAL NEUTRON ACTIVATION ANALYSIS Introduction and Review of Literature Experimental Results 13 Discussion 21 Summary 24 THE EFFECT OF SODIUM AND OUABAIN ON THE INFLUX OF POTASSIUM INTO THE SEEDLINGS...

Singh, Jagat

2012-06-07

296

Proteomic identification of rhythmic proteins in rice seedlings.  

PubMed

Many aspects of plant metabolism that are involved in plant growth and development are influenced by light-regulated diurnal rhythms as well as endogenous clock-regulated circadian rhythms. To identify the rhythmic proteins in rice, periodically grown (12h light/12h dark cycle) seedlings were harvested for three days at six-hour intervals. Continuous dark-adapted plants were also harvested for two days. Among approximately 3000 reproducible protein spots on each gel, proteomic analysis ascertained 354 spots (~12%) as light-regulated rhythmic proteins, in which 53 spots showed prolonged rhythm under continuous dark conditions. Of these 354 ascertained rhythmic protein spots, 74 diurnal spots and 10 prolonged rhythmic spots under continuous dark were identified by MALDI-TOF MS analysis. The rhythmic proteins were functionally classified into photosynthesis, central metabolism, protein synthesis, nitrogen metabolism, stress resistance, signal transduction and unknown. Comparative analysis of our proteomic data with the public microarray database (the Plant DIURNAL Project) and RT-PCR analysis of rhythmic proteins showed differences in rhythmic expression phases between mRNA and protein, suggesting that the clock-regulated proteins in rice are modulated by not only transcriptional but also post-transcriptional, translational, and/or post-translational processes. PMID:21300183

Hwang, Heeyoun; Cho, Man-Ho; Hahn, Bum-Soo; Lim, Hyemin; Kwon, Yong-Kook; Hahn, Tae-Ryong; Bhoo, Seong Hee

2011-04-01

297

Multidimensional fluorescence microscopy of multiple organelles in Arabidopsis seedlings  

PubMed Central

Background The isolation of green fluorescent protein (GFP) and the development of spectral variants over the past decade have begun to reveal the dynamic nature of protein trafficking and organelle motility. In planta analyses of this dynamic process have typically been limited to only two organelles or proteins at a time in only a few cell types. Results We generated a transgenic Arabidopsis plant that contains four spectrally different fluorescent proteins. Nuclei, plastids, mitochondria and plasma membranes were genetically tagged with cyan, red, yellow and green fluorescent proteins, respectively. In addition, methods to track nuclei, mitochondria and chloroplasts and quantify the interaction between these organelles at a submicron resolution were developed. These analyzes revealed that N-ethylmaleimide disrupts nuclear-mitochondrial but not nuclear-plastids interactions in root epidermal cells of live Arabidopsis seedlings. Conclusion We developed a tool and associated methods for analyzing the complex dynamic of organelle-organelle interactions in real time in planta. Homozygous transgenic Arabidopsis (Kaleidocell) is available through Arabidopsis Biological Resource Center. PMID:18489765

Kato, Naohiro; Reynolds, Dexter; Brown, Matthew L; Boisdore, Marietta; Fujikawa, Yukichi; Morales, Andrea; Meisel, Lee A

2008-01-01

298

Landfill leachate affects metabolic responses of Zea mays L. seedlings.  

PubMed

With an increasing focus on phyto-remediation options for landfill leachate, it is important to understand the responses of plant systems to landfill leachate stress. It is especially important to study the tolerant mechanisms of plant systems. We investigated several physiological changes of Zea mays L. (maize) in response to landfill leachate. Specifically, we investigated growth, chlorophyll content, lipid peroxidation, protein oxidation and activities of antioxidant enzymes. The results indicate that landfill leachate affected the growth and chlorophyll level of maize seedlings. Furthermore, landfill leachate elevated the levels of lipid peroxidation and protein oxidation in leaf tissues in a time-dependent manner, accompanied by the changes in antioxidant status. The physiological responses varied as a function of leachate concentration, and the growth inhibition, chlorophyll content inhibition and oxidative stress occurred after the exposure of higher concentrations of leachate. Higher concentrations of landfill leachate contained higher levels of pollutants. Our results indicate that landfill leachate affected the metabolic responses of plant systems. The risk of pollution occurred mainly in samples of higher concentration. Therefore, the critical aspect of phyto-remediation for landfill leachate is controlling its concentration. In doing so, plant systems may be able to tolerate the environmental stress of landfill leachate. PMID:20149964

Sang, Nan; Han, Ming; Li, Guangke; Huang, Mingzhu

2010-05-01

299

Effect of Cadmium on ?-Glutamylcysteine Synthesis in Maize Seedlings 1  

PubMed Central

Cysteine, ?-glutamylcysteine, and glutathione and the extractable activity of the enzymes of glutathione biosynthesis, ?-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots and leaves of maize seedlings (Zea mays L. cv LG 9) exposed to CdCl2 concentrations up to 200 micromolar. At 50 micromolar Cd2+, ?-glutamylcysteine contents increased continuously during 4 days up to 21-fold and eightfold of the control in roots and leaves, respectively. Even at 0.5 micromolar Cd2+, the concentration of ?-glutamylcysteine in the roots was significantly higher than in the control. At 5 micromolar and higher Cd2+ concentrations, a significant increase in ?-glutamylcysteine synthetase activity was measured in the roots, whereas in the leaves this enzyme activity was enhanced only at 200 micromolar Cd2+. Labeling of isolated roots with [35S]sulfate showed that both sulfate assimilation and glutathione synthesis were increased by Cd. The accumulation of ?-glutamylcysteine in the roots did not affect the root exudation rate of this compound. Our results indicate that maize roots are at least in part autonomous in providing the additional thiols required for phytochelatin synthesis induced by Cd. PMID:16668902

Ruegsegger, Adrian; Brunold, Christian

1992-01-01

300

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

301

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

302

Cadmium exposure affects iron acquisition in barley (Hordeum vulgare) seedlings.  

PubMed

This study addresses the question of the interference between iron (Fe) nutrition and cadmium (Cd) toxicity at the level of growth performance, phytosiderophores (PS) release, micronutrient accumulation and expression of genes involved in Fe homeostasis in barley seedlings, a plant with strategy II-based response to Fe shortage. Cd exposure induced responses similar to those of genuine Fe deficiency also in Fe-sufficient plants. Most genes involved in PS biosynthesis and secretion (HvNAS3, HvNAS4, HvNAS6, HvNAS7, HvNAAT-A, HvDMAS1 and HvTOM1) induced by Fe deprivation were also significantly upregulated in the presence of Cd under Fe sufficient conditions. Accordingly, the enhanced expression of these genes in roots under Cd exposure was accompanied by an increase of PS release. However, induced expression of HvIRO2 and the downregulation of HvIDEF1 and HvIRT1, after Cd exposure, suggested the presence of a pathway that induces HvIRO2-mediated PS biosynthesis under Cd stress, which probably is not simply caused by Fe deficiency. The downregulation of HvIRT1 and HvNramp5 may represent a protective mechanism at transcriptional level against further Cd uptake by these transporters. These results likely indicate that Cd itself may be able to activate Fe acquisition mechanism in an Fe-independent manner. PMID:24724721

Astolfi, Stefania; Ortolani, Maria R; Catarcione, Giulio; Paolacci, Anna R; Cesco, Stefano; Pinton, Roberto; Ciaffi, Mario

2014-12-01

303

Seedling Discrimination with Shape Features Derived from a Distance Transform  

PubMed Central

The aim of this research is an improvement of plant seedling recognition by two new approaches of shape feature generation based on plant silhouettes. Experiments show that the proposed feature sets possess value in plant recognition when compared with other feature sets. Both methods approximate a distance distribution of an object, either by resampling or by approximation of the distribution with a high degree Legendre polynomial. In the latter case, the polynomial coefficients constitute a feature set. The methods have been tested through a discrimination process where two similar plant species are to be distinguished into their respective classes. The used performance assessment is based on the classification accuracy of 4 different classifiers (a k-Nearest Neighbor, Naive-Bayes, Linear Support Vector Machine, Nonlinear Support Vector Machine). Another set of 21 well-known shape features described in the literature is used for comparison. The used data consisted of 139 samples of cornflower (Centaura cyanus L.) and 63 samples of nightshade (Solanum nigrum L.). The highest discrimination accuracy was achieved with the Legendre Polynomial feature set and amounted to 97.5%. This feature set consisted of 10 numerical values. Another feature set consisting of 21 common features achieved an accuracy of 92.5%. The results suggest that the Legendre Polynomial feature set can compete with or outperform the commonly used feature sets. PMID:23624690

Giselsson, Thomas Mosgaard; Midtiby, Henrik Skov; J?rgensen, Rasmus Nyholm

2013-01-01

304

Germination and seedling development of Trapa bispinosa Roxb.  

PubMed

Trapa bispinosa is a freshwater macrophyte occurring in stagnant or slow moving water streams. Information on assessment of seeds storage and germination of Trapa bispinosa is less available in literature. Dependence on fresh seeds abundance only from natural environment for plant propagation or cultivation may lead to insufficient supply of seeds due to various biotic and abiotic factors. This study evaluated the viability and germination of Trapa bispinosa seeds stored in zip-lock plastic bag at low temperature of 7 degrees C for six months and fresh seeds. In addition germinating seeds progressive development to juvenile plants was recorded and described. Experiments were conducted where stored and fresh seeds were soaked in 62 x 45 x 54 cm glass tanks filled with aged tap water to the level of 15 cm depth. Stored seeds showed low percentage germination of 2.82% compared to fresh seeds which was 71.19%. Eight distinct developmental stages were identified from germinating seeds to juvenile plants. Both stored and fresh seeds produced plants of similar morphology but stored seeds progressive development from germination, seedling to juvenile plants needed longer duration to achieve. The storage of seed at low temperature at 7 degrees C for six months showed reduced viability and also vigorousity. Improved methods should be developed for Trapa seeds storage taking into account of the seeds' endurance to dryness and moisture levels in order to maintained seeds viability for future uses either for production, research purposes or even conservation and restoration programs. PMID:24218936

Mirani, O Ima; Harah, Z Muta; Sidik, B Japar

2012-07-01

305

Investigations into peach seedling stunting caused by a replant soil.  

PubMed

Replant diseases often occur when pome and stone fruits are grown in soil that had previously been planted with the same or similar plant species. They typically lead to reductions in plant growth, crop yield and production duration. In this project, greenhouse assays were used to identify a peach orchard soil that caused replant disease symptoms. Biocidal treatments of this soil led to growth increases of Nemaguard peach seedlings. In addition, plants grown in as little as 1% of the replant soil exhibited reduced plant growth. These results suggest that the disease etiology has a biological component. Analysis of roots from plants exhibiting various levels of replant disease symptoms showed little difference in the amounts of PCR-amplified bacterial or fungal rRNA genes. However, analysis using a stramenopile-selective PCR assay showed that rRNA genes from this taxon were generally more abundant in plants with the smallest top weights. Nucleotide sequence analysis of these genes identified several phylotypes belonging to Bacillariophyta, Chrysophyceae, Eustigmatophyceae, Labyrinthulida, Oomycetes, Phaeophyceae and Synurophyceae. Sequence-selective quantitative PCR assays targeting four of the most abundant phylotypes showed that both diatoms (Sellaphora spp.) and an oomycete (Pythium ultimum) were negatively associated with plant top weights. PMID:19573200

Bent, Elizabeth; Loffredo, Angelo; Yang, Jiue-In; McKenry, Michael V; Becker, Jörn Ole; Borneman, James

2009-05-01

306

Prosopis pubescens (screw bean mesquite) seedlings are hyperaccumulators of copper.  

PubMed

Due to health reasons, toxic metals must be removed from soils contaminated by mine tailings and smelter activities. The phytoremediation potential of Prosopis pubescens (screw bean mesquite) was examined by use of inductively-coupled plasma optical emission spectroscopy. Transmission electron microscopy was used to observe ultrastructural changes of parenchymal cells of leaves in the presence of copper. Elemental analysis was used to localize copper within leaves. A 600-ppm copper sulfate exposure to seedlings for 24 days resulted in 31,000 ppm copper in roots, 17,000 ppm in stems, 11,000 in cotyledons and 20 ppm in the true leaves. For a plant to be considered a hyperaccumulator, the plant must accumulate a leaf-to-root ratio <1. Screw bean mesquite exposed to copper had a leaf-to-root ratio of 0.355 when cotyledons were included. We showed that P. pubescens grown in soil is a hyperaccumulator of copper. We recommend that this plant should be field tested. PMID:23612918

Zappala, Marian N; Ellzey, Joanne T; Bader, Julia; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge

2013-08-01

307

Seedling discrimination with shape features derived from a distance transform.  

PubMed

The aim of this research is an improvement of plant seedling recognition by two new approaches of shape feature generation based on plant silhouettes. Experiments show that the proposed feature sets possess value in plant recognition when compared with other feature sets. Both methods approximate a distance distribution of an object, either by resampling or by approximation of the distribution with a high degree Legendre polynomial. In the latter case, the polynomial coefficients constitute a feature set. The methods have been tested through a discrimination process where two similar plant species are to be distinguished into their respective classes. The used performance assessment is based on the classification accuracy of 4 different classifiers (a k-Nearest Neighbor, Naive-Bayes, Linear Support Vector Machine, Nonlinear Support Vector Machine). Another set of 21 well-known shape features described in the literature is used for comparison. The used data consisted of 139 samples of cornflower (Centaura cyanus L.) and 63 samples of nightshade (Solanum nigrum L.). The highest discrimination accuracy was achieved with the Legendre Polynomial feature set and amounted to 97.5%. This feature set consisted of 10 numerical values. Another feature set consisting of 21 common features achieved an accuracy of 92.5%. The results suggest that the Legendre Polynomial feature set can compete with or outperform the commonly used feature sets. PMID:23624690

Giselsson, Thomas Mosgaard; Midtiby, Henrik Skov; Jørgensen, Rasmus Nyholm

2013-01-01

308

Growth, water relations and solute accumulation in osmotically stressed seedlings of the tropical tree Colophospermum mopane.  

PubMed

Root and hypocotyl elongation, water status and solute accumulation were studied in osmotically stressed seedlings of the tropical tree, Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard, which grows in hot arid areas of southern and central Africa. Seeds were imbibed for 24 h and then subjected to a polyethylene-glycol-generated osmotic stress of -0.03 (control), -0.2, -0.8, -1.6 or -2.0 MPa for 60 h. Seedlings subjected to moderate water stress (-0.2 MPa) had higher root growth rates (2.41 +/- 0.24 mm h(-1)), greater final root lengths (111 +/- 3.8 mm) and longer cells immediately behind the root elongation zone than control seedlings (1.70 +/- 0.15 mm h(-1) and 93 +/- 3.9 mm, respectively). Root lengths of seedlings in the -0.8 and -1.6 MPa treatments were similar to those of control seedlings, whereas the -2.0 MPa seedlings had significantly shorter roots. Both root and hypocotyl tissues exhibited considerable osmotic adjustment to the external water potential treatments. Seedlings in the -0.03, -0.2, and -0.8 MPa treatments had similar cell turgor pressures (0.69 +/- 0.10, 0.68 +/- 0.07 and 0.57 +/- 0.04 MPa, respectively), whereas the -2.0 MPa treatment lowered cell turgor pressure to 0.17 +/- 0.04 MPa. Root vacuolar osmotic pressures were generally similar to sap osmotic pressures, indicating that the increased root elongation observed in moderately water-stressed seedlings was not caused by increased turgor pressure difference. Neutral-fraction solute concentrations, including the osmoticum pinitol, increased approximately two-fold in root sap in response to a low external water potential. In hypocotyl sap of seedlings in the -2.0 MPa treatment, pinitol more than doubled, sucrose increased from about 2 to 75 mol m(-3) but glucose and fructose remained unchanged and, as a result, total sugars increased only slightly. The benefits of rapid early root elongation and osmoticum accumulation under conditions of water stress are discussed in relation to seedling establishment. PMID:14871694

Johnson, J M; Pritchard, J; Gorham, J; Tomos, A D

1996-08-01

309

[Seedling regeneration and affecting factors of Quercus variabilis in different distribution regions].  

PubMed

Twenty four fixed plots in three distribution regions of Quercus variabilis (Loess Plateau, marginal distribution zone; north slope of Qinling Mountains, semi-arid core area; and south slope of Qinling Mountains, moist core area) were installed, respectively, to investigate the age structure, growth status, and dry mass accumulation and allocation of 1-8 years old Q. variabilis seedlings, and path analysis was adopted to determine the key factors affecting the regeneration of the seedlings. In the distribution regions, the density of the seedlings decreased with their increasing age, and the density of the 1-8 years old seedlings all decreased in the order of south slope of Qin-ling Mountains > north slope of Qinling Mountains > Loess Plateau. The transformation rate of the seedlings with adjacent ages differed significantly among the three distribution regions. On Loess Plateau, the transformation rate of 7 years old to 8 years old seedlings was the lowest (30.2 +/- 2.9) %; on the north and south slopes of Qinling Mountains, the transformation rate of 4 years old to 5 years old seedlings was the lowest, being (53.9 +/- 3.7) % and (50.0 +/- 2.1) %, respectively. With the increasing age of the seedlings, their height and dry mass presented an increasing trend, with the order of south slope of Qinling Mountains > north slope of Qinling Mountains > Loess Plateau, the rate of root length to plant height tended to decline, and the rates of root breadth to canopy breadth and of root dry mass to shoot dry mass decreased after an initial increase. The rates of root length to plant height, root breadth to canopy breadth, and root dry mass to shoot dry mass were all the highest on Loess Plateau, and the lowest on south slope of Qinling Mountains. Air temperature, irradiance, canopy density and shrub coverage were the direct key factors affecting Q. variabilis seedling regeneration, among which, air temperature and irradiance were the positive factors, while canopy density and shrub coverage were the negative ones. Soil available nitrogen content and herb coverage were the indirect key factors affecting the Q. variabilis seedling regeneration positively and negatively, respectively. PMID:24380326

Wu, Min; Zhang, Wen-hui; Zhou, Jian-yun; Ma, Chuang; Ma, Li-wei

2013-08-01

310

Light Affects the Chloroplast Ultrastructure and Post-Storage Photosynthetic Performance of Watermelon (Citrullus lanatus) Plug Seedlings  

PubMed Central

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

311

Mapping quantitative trait loci (QTLs) for seedling-vigor using recombinant inbred lines of rice ( Oryza sativa L.)  

Microsoft Academic Search

Seedling-vigor is important for optimum stand establishment and increasing weed competitive ability in rice cropping systems. In the current study, three seedling-vigor-related traits, seed germination rate, seedling shoot length and dry matter weight, were investigated by the paper-roll tests with rice recombinant inbred lines derived from a cross between Lemont (japonica) and Teqing (indica). The phenotype data, together with a

Zhi-Hong Zhang; Si-Bin Yu; Ting Yu; Zheng Huang; Ying-Guo Zhu

2005-01-01

312

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

313

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

314

A Critical Overview of Forestry Seedling Production Policies and Practices in Relation to Smallholder Forestry in Developing Countries  

Microsoft Academic Search

This paper reviews forestry seedling production systems in South-east and East Asia and identifies problems with respect to\\u000a seedling quality, seedling distribution and financial sustainability, and measures which have been adopted or advocated to\\u000a improve performance in this sector. The paper draws in particular on experience in a series of research projects on smallholder\\u000a forestry in the Philippines. Some observations

Steve Harrison; Nestor Gregorio; John Herbohn

2008-01-01

315

Growth, anatomy and morphology of the mesocotyl and the growth of appendages of the wild oat ( Avena fatua L.) seedling  

Microsoft Academic Search

Morphological and histological studies were made on the mesocotyl and the emergence of seedlings of a nondormant strain (CS40)\\u000a of wild oats (Avena fatua L.). The elongation of the mesocotyl was primarily responsible for the emergence of seedlings from deeper levels of soil.\\u000a The mesocotyl of the seedling is here interpreted as the hypocotyl. The functionally suctorial scutellum together with

M. V. S. Raju; T. A. Steeves

1998-01-01

316

Recruitment dynamics in a rainforest seedling community: context-independent impact of a keystone consumer.  

PubMed

The influence of keystone consumers on community structure is frequently context-dependent; the same species plays a central organising role in some situations, but not others. On Christmas Island, in the Indian Ocean, a single species of omnivorous land crab, Gecarcoidea natalis, dominates the forest floor across intact rainforest. We hypothesised that this consumer plays a key role in regulating seedling recruitment and in controlling litter dynamics on the island, independent of the type of vegetation in which it occurred. To test this hypothesis, we conducted crab exclusion experiments in two forest types on the island and followed the dynamics of seedling recruitment and litter processing for six years. To determine if these effects were likely to be general across the island, we compared land crab densities and seedling abundance and diversity at ten sites across island rainforest. Surveys across island rainforest showed that seedlings of species susceptible to predation by land crabs are consistently rare. Abundance and diversity of these species were negatively correlated to red crab abundance. Although red land crabs may be important determinants of seedling recruitment to the overstorey, differences in overstorey and seedling composition at the sites suggests that recruitment of vulnerable trees still occurs at a temporal scale exceeding that of this study. These "windows" of recruitment may be related to infrequent events that reduce the effects of land crabs. Our results suggest that unlike the context dependence of most keystone consumers in continental systems, a single consumer, the red land crab, consistently controls the dynamics of seedling recruitment across this island rainforest. PMID:18320231

Green, Peter T; O'Dowd, Dennis J; Lake, P S

2008-05-01

317

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

318

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

319

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

320

Canopy structure and light interception in Quercus petraea seedlings in relation to light regime and plant density.  

PubMed

Foliage structure was measured on 1- and 2-year-old Quercus petraea (Matt.) Liebl. seedlings grown in 100 or 18% sunlight at a planting density of 2.8 or 25 plants per m(2). A three-dimensional digitizing device was used to acquire the spatial position and orientation of all leaves within the seedlings and of all seedlings within the plot. The data were used to obtain (1) quantitative information on canopy structure, including leaf area index (LAI), seedling leaf area, number of leaves, leaf area density and leaf orientation; and (2) structural information on foliage arrangement from virtual images to estimate light interception by individual seedlings (STAR) and light partitioning among seedlings. During the second year, shading significantly reduced total leaf area and number of leaves but increased individual leaf area. The STAR was greater for seedlings in shade than in full sunlight because of the more horizontal orientation of leaves. Leaf area density was unaffected by the full sun treatments, and changes in leaf area dispersion had no effect on light-interception efficiency. No plant density effect was observed during the first year. During the second year, only the high plant density treatment induced mutual shading between seedlings, resulting in greater competition for light among seedlings in the full sun treatment than in the shade treatment. The small treatment-induced changes in light interception indicate that Q. petraea has low morphological plasticity of foliage structure compared with other species. PMID:11696413

Farque, L; Sinoquet, H; Colin, F

2001-11-01

321

Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings  

NASA Technical Reports Server (NTRS)

Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

1996-01-01

322

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

323

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

324

Plant growth-promoting rhizobacteria affect the growth and nutrient uptake of Fraxinus americana container seedlings.  

PubMed

Plant growth-promoting rhizobacteria (PGPR) are important catalysts that regulate the functional properties of agricultural systems. However, there is little information on the effect of PGPR inoculation on the growth and nutrient accumulation of forest container seedlings. This study determined the effects of a growth medium inoculated with PGPR on the nutrient uptake, nutrient accumulation, and growth of Fraxinus americana container seedlings. PGPR inoculation with fertilizer increased the dry matter accumulation of the F. americana aerial parts with delayed seedling emergence time. Under fertilized conditions, the accumulation time of phosphorous (P) and potassium (K) in the F. americana aerial parts was 13 days longer due to PGPR inoculation. PGPR increased the maximum daily P and K accumulations in fertilized seedlings by 9.31 and 10.44 %, respectively, but had little impact on unfertilized ones. Regardless of fertilizer application, the root exudates, namely sugars, amino acids, and organic acids significantly increased because of PGPR inoculation. PGPR inoculation with fertilizer increased the root, shoot, and leaf yields by 19.65, 22.94, and 19.44 %, respectively, as well as the P and K contents by 8.33 and 10.60 %, respectively. Consequently, the N, P, and K uptakes increased by 19.85, 31.97, and 33.95 %, respectively. Hence, PGPR inoculation with fertilizer can be used as a bioenhancer for plant growth and nutrient uptake in forest container seedling nurseries. PMID:22777281

Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

2013-05-01

325

Dynamics and partitioning of the ionome in seeds and germinating seedlings of winter oilseed rape.  

PubMed

Germination and seedling establishment are among the most critical phases in the development of plants, and seed vigour has become an important trait for the selection of robust crop cultivars. Little is known about the potentially limiting role of mineral nutrients in early metabolic and developmental processes during germination. Therefore, we assessed the ionome and relative distribution of mineral elements in different seed and seedling tissues of oilseed rape (Brassica napus L.) and monitored the internal allocation of nutrients during germination. In seeds, cotyledons harboured the main pool of K, P, S, Mg, Fe, Mn and Zn, whereas the seed coat contained most of the Ca, Na, B, Cu and Mo. Although the early root and hypocotyl tissue expanded first, concentrations of most elements were initially low. Re-allocation of elements to the root/hypocotyl tissue from other pools set in two days after seed imbibition and was most rapid for K. Relative to the critical deficiency levels of vegetative tissues, seed tissues were particularly low in B, K and Fe. Further analyses of the ionome of seeds and seedlings, grouped according to their germination efficiency, indicated that in particular low S, Mg and Ca coincided with germination failure. This study documents highly dynamic changes in the ionome of seed and seedling tissues and provides evidence for potentially limiting elements during early germination and seedling establishment in rapeseed. PMID:23939714

Eggert, Kai; von Wirén, Nicolaus

2013-09-01

326

G protein signaling in UV protection: methods for understanding the signals in young etiolated seedlings.  

PubMed

A seed is competent to respond to light soon after imbibition. A new developmental program begins in or on the ground where the young seedling may be exposed to heat, cold, drought, flooding (anoxia), salts, varying levels of visible light, and the topic of this paper, ultraviolet radiation. Herein what is described is a method for growing and maintaining seedlings, then methods of UV irradiation in order to measure discrete effects of UV wavelengths in signal transduction, very early in seedling development. The physiological response to an abiotic signal is partly dependent on the developmental state of the plant. Dark-grown seedlings of plant species possess young leaves or leaf primordia in a "suspended" state of development whereby exposure to sunlight, visible and UV, is required to initiate the leaf developmental program, including development of etioplasts or proplastids into fully functioning chloroplasts. In order for us to understand the initial and persisting effects of UV in seedlings, we "delay" light-induced development by carrying out all experiments in complete darkness between days 0 (seed) and day 7 (Arabidopsis). In this case, the UV regulation of a simple signaling pathway in Arabidopsis, G protein signaling in UV protection and acclimation early in development, is investigated with the use of several mutants and easily score-able phenotypes. PMID:23913039

Orozco-Nunnelly, Danielle A; Kaufman, Lon S; Warpeha, Katherine M

2013-01-01

327

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

328

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

Gimenez-Benavides, Luis; Escudero, Adrian; Iriondo, Jose M.

2007-01-01

329

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

330

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

331

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.; Salomao, Antonieta N.; Costa, Tania da S.A.; Azevedo, Vania C.R.

2014-01-01

332

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

333

Tolerance to cadmium of Agave lechuguilla (Agavaceae) seeds and seedlings from sites contaminated with heavy metals.  

PubMed

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; Yáñez-Espinosa, Laura; Flores, Joel

2013-01-01

334

Seedling development and evaluation of genetic stability of cryopreserved Dendrobium hybrid mature seeds.  

PubMed

Vitrification, a simple, fast, and recommended cryopreservation method for orchid germplasm conservation, was evaluated for Dendrobium hybrid "Dong Yai" mature seeds. The genetic stability of regenerated seedlings was also evaluated using flow cytometry. Mature seeds from this hybrid were submitted to plant vitrification solution (PVS2) for 0, 0.5, 1, 2, 3, 4, 5, or 6 h at 0 °C. Subsequently, they were plunged into liquid nitrogen (LN) at -196 °C for 1 h and recovered in half-strength Murashige and Skoog culture medium (1/2 MS), and seed germination was evaluated after 30 days. Seeds directly submitted to LN did not germinate after cryopreservation. Seeds treated with PVS2 between 1 and 3 h presented the best germination (between 51 and 58%), although longer exposure to PVS2 returned moderated germination (39%). Germinated seeds were further subcultured in P-723 culture medium and developed whole seedlings in vitro after 180 days, with no abnormal characteristics, diseases, or nutritional deficiencies. Seedlings were successfully acclimatized under greenhouse conditions with over 80% survival. Flow cytometry analysis revealed no chromosomal changes on vitrified seedlings, as well as seedlings germinated from the control treatment (direct exposure to LN). These findings indicate that vitrification is a feasible and safe germplasm cryopreservation method for commercial Dendrobium orchid hybrid conservation. PMID:24402568

Galdiano, Renato Fernandes; de Macedo Lemos, Eliana Gertrudes; de Faria, Ricardo Tadeu; Vendrame, Wagner Aparecido

2014-03-01

335

The gravitropic setpoint angle of dark-grown rye seedlings and the role of ethylene.  

PubMed

The orientation growth of coleoptiles of dark-grown seedlings of rye (Secale cereale L. cv. Marder II), when grown under various conditions, was analysed with respect to the gravivector ('gravitropic setpoint angle', GSA). Coleoptiles growing through moist vermiculite attain and maintain a GSA with an average of about 180 degrees, i.e. a vertical orientation. Seedlings growing uncovered either on the surface of vermiculite or positionally fixed on filter paper attain and maintain a GSA of 140-150 degrees (i.e. deviating from the vertical by an average of 30-40 degrees ). Changing the position of the embryo relative to the horizontally fixed seed kernel or of the angle of the seed with respect to gravity during germination (+/-40 degrees relative to the horizontal) had no significant effect on the subsequent GSA of both covered and uncovered seedlings. The GSA of uncovered coleoptiles could be restored close to 180 degrees by treatment of the seedlings with ethylene, either applied via ethephon or 1-aminocyclopropane-1-carboxylic acid (ACC) as well as by fruit-released ethylene. The results are discussed with respect to the mechanism of the regulation of gravitropic growth of grass seedlings. PMID:12096101

Edelmann, Hans G; Gudi, Gennadi; Kühnemann, Frank

2002-07-01

336

Proline partially overcomes excess molybdenum toxicity in cabbage seedlings grown in vitro.  

PubMed

In vitro grown cabbage (Brassica oleracea var. capitata) seedlings exposed to excess molybdenum (Mo) ions exhibited severely reduced plant growth at the cotyledonary stage. Adding 80 mM proline (Pro) to the Mo-treated medium could help 50% seedlings to overcome the toxicity and grow true leaves. Under excess Mo stress, seedlings accumulated blue/purple anthocyanin in their cotyledons and hypocotyls. The anthocyanin content under Mo with 40 mM Pro was 4-fold higher than the control medium, MS with 40 mM Pro. The presence of Pro in the excess-Mo condition reduced chlorophyll a, whereas the chlorophyll b content was much higher than the control media of MS with and without Pro. Moreover, supplementing various concentrations of Pro into the Mo-stressed condition promoted the seedlings with higher antioxidant enzyme activities of superoxide dismutase, ascorbate peroxidate, and catalase. In addition, genes in the anthocyanin biosynthesis and accumulation pathways, phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), flavonone 3-hydroxylase (F3H), leucoanthocyanidin dioxygenase (LDOX), and glutathione-S-transferase (GST), were all upregulated. Our study indicated that, under excess Mo stress, the antioxidant activity of cabbage seedlings was induced in an attempt to protect plants from the Mo-induced toxicity and exacerbated growth. Pro, on the other hand, functioned in producing higher antioxidant enzyme activity to partially help recover plant growth. PMID:24301928

Kumchai, J; Huang, J-Z; Lee, C-Y; Chen, F-C; Chin, S-W

2013-01-01

337

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

338

The detection of chlorophyll content for salt stress of the wheat seedling by hyperspectral imaging  

NASA Astrophysics Data System (ADS)

An auto-development pushbroom imaging spectrometer (PIS) with wavelength range of 400-1000 nm was applied to measure the chlorophyll content of wheat seedling. It showed that according to images of spectral imaging for leaves of Chinese Spring (Salt-sensitive), Zhouyuan 9369(common and high-yield) and Changwu 134(salt-tolerant) wheat seedling under salt stress, growth of salt-sensitive Chinese Spring wheat seedling was inhibited and it was feasible to carry out qualitative analysis. Images could intuitively reflect morphological information of growth status of wheat seedling and could show spectral differences of different leaves and different locations of one leave. Also, it was feasible to identify green and yellow locations of leaf and to carry out qualitative analysis. The tested sites of spectrum and the chlorophyll content measured sites were on the same area of single leaf. After measuring the hyperspectral image of leaf, the mean reflectance spectra of each leaf was calculated Totally, 126 samples were collected, which were then divided into a calibration set and a prediction set. Partial least square regression (PLSR) method was used to build the calibration model. Results showed that the extracted hyperspectral spectra had high correlation with chlorophyll content. The correlation coefficient of the calibration model is R=0.8138, the standard error of prediction is SEP=4.75. The results indicated that hyperspectral imaging were suitable for the non-invasive detection of chlorophyll content of wheat seedling.

Wu, Qiong; Zhu, Dazhou; Wang, Cheng; Ma, Zhihong; Zhang, Dongyan; Chen, Kun; Wang, Jihua

2011-08-01

339

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

340

Females make tough neighbors: sex-specific competitive effects in seedlings of a dioecious grass.  

PubMed

If males and females of a species differ in their effect on intraspecific competition then this can have significant ecological and evolutionary consequences because it can lead to size and mortality disparities between the sexes, and thus cause biased population sex ratios. If the degree of sexual dimorphism of competitive effect varies across environments then this variation can generate sex ratio variation within and between populations. In a California population of Distichlis spicata, a dioecious grass species exhibiting extreme within-population sex ratio variation (spatial segregation of the sexes), I evaluated the intraspecific competitive effects of male and female D. spicata seedlings in three soil types. The sex of seedlings was determined using a RAPD-PCR marker co-segregating with female phenotype. Distichlis spicata seedlings, regardless of sex, were six times larger when grown with male versus female conspecific seedlings in soil from microsites where the majority of D. spicata plants are female, and this sexual dimorphism of competitive effect was weaker or did not occur in other soil types. This study suggests that it is not just the higher costs of female versus male reproduction itself that cause spatial segregation of the sexes in D. spicata, but that differences in competitive abilities between the sexes--which occur as early as the seedling stage--can generate sex ratio variation. PMID:16341552

Eppley, Sarah M

2006-01-01

341

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

342

Spatial patterns of grass seedling recruitment imply predation and facilitation by harvester ants.  

PubMed

Extended drought on the Edwards Plateau, TX, causes high mortality in grass species' populations and their replacement by recruitment from the seeds of survivors. Harvester ant nests may act as refugia for perennial plants during drought, as evidenced by a high survivorship of plants directly adjacent to nests. Because grasses tend to disperse seeds short distances and drought eliminated seed banks, we hypothesized that the spatial pattern of grass seedlings and adults would be clumped at small scales around these refugia. In contrast, nests would be regular at small to moderate scales. We studied the spatial patterns of seedlings, adults, and ant nest locations using a modified Ripley's K-function technique for transect data. Point data were collected along a 1-km transect. Spatially regular patterns were found for nests from 1.0- to 22.0-m scales. We found that two species' seedlings and adults were significantly clumped with ant nests, and two species had significantly regular spatial patterns with nests. Surprisingly, patterns of clumped seedlings occurred up to 30-m scales with nests. Nests appear to affect seedling establishment at multiple scales. These results suggest that nests may facilitate colonization for some grass populations, but regular spatial patterns in other species imply that forager seed harvest may inhibit establishment. PMID:20146848

Nicolai, N; Feagin, R A; Smeins, F E

2010-02-01

343

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

344

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

345

Short term signaling responses in roots of young soybean seedlings exposed to cadmium stress.  

PubMed

In the present study, the expression of fourteen genes involved in various signal transduction pathways was examined in young soybean (Glycine max) seedlings exposed to cadmium at two concentrations (10 mg L(-1) and 25 mg L(-1)) for short time periods (3, 6 and 24 h). The results show that cadmium causes induction of genes encoding proteins involved in ethylene and polyamines metabolism, nitric oxide generation, MAPK cascades and regulation of other genes' expression. The bioinformatic analysis of promoter sequences of Cd-inducible genes revealed that their promoters possess several regulative motifs associated with the plant response to stress factors and abscisic acid and ethylene signaling. The involvement of ethylene in the response of soybean seedlings to cadmium stress was further confirmed by the real-time analysis of ethylene production during 24 h of CdCl2 treatment. The role of the described signaling elements in transduction of the cadmium signal in young soybean seedlings is discussed. PMID:23942356

Chmielowska-B?k, Jagna; Lefèvre, Isabelle; Lutts, Stanley; Deckert, Joanna

2013-12-15

346

[Effects of shading on squash seedlings' morphological and photosynthetic physiological characteristics].  

PubMed

The study of squash seedlings' morphological and photosynthetic physiological characteristics under different shading showed that under 60% light transmittance, their relative growth rate, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (EVAP), water use efficiency (WUE), saturation steam pressure (MBR), apparent quantum yield of photosynthesis (AQY), and chlorophyll contents were higher, while the intercellular CO2 concentration (Ci) was lower, compared with those under 20% light transmittance and CK. The seedlings under 60% light transmittance had a higher light saturation point (1 125 micromol x m(-2) x s(-1)) but a lower light compensation point (15.2 micromol x m(-2) s(-1)). Squash seedlings under lower light intensity could endure lower concentration of CO2, while those under higher light intensity could endure higher concentration of CO2. Under 60% light transmittance, the malondialdehyde (MDA) and praline (Pro) contents were the lowest, while the peroxidase (POD) and catalase (CAT) activities were the highest. PMID:16836096

Qin, Shuhao; Li, Lingling

2006-04-01

347

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

348

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

349

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

350

Does relatedness matter? Phylogenetic density-dependent survival of seedlings in a tropical forest.  

PubMed

A complex set of interactions among neighbors influences plant performance and community structure. Understanding their joint operation requires extensive information on species characteristics and individual performance. We evaluated first-year survival of 35719 tropical forest seedlings of 222 species and 15 annual cohorts relative to the density of conspecific and heterospecific neighbors and the phylogenetic similarity of heterospecific neighbors. Neighbors were from two size classes, and size asymmetric interactions provided insight into likely mechanisms. Large heterospecific and conspecific neighbors reduced seedling survival equally, suggesting resource competition rather than host-specific enemies as a mechanism. In contrast, much stronger negative conspecific effects were associated with seedling neighbors capable of limited resource uptake, suggesting shared pests rather than competition as the mechanism. Survival improved, however, near phylogenetically similar heterospecific neighbors, suggesting habitat associations shared among closely related species affect spatial patterns of performance. Improved performance near phylogenetically similar neighbors is an emerging pattern in the handful of similar studies. PMID:24933813

Lebrija-Trejos, Edwin; Wright, S Joseph; Hernández, Andrés; Reich, Peter B

2014-04-01

351

The impact of shifting precipitation patterns on the establishment and biomass allocation patterns of shrub and grass seedlings in southwest Texas  

E-print Network

might interact with precipitation patterns to influence grass and shrub seedling establishment and biomass allocation. Seedlings of 3 shrub species (Prosopis glandulosa var. glandulosa, Acacia berlandieri, and A. wrightii var. greggii) and 3 grass...

Perkins, Steven Richard

2012-06-07

352

Patterns of dynamic irradiance affect the photosynthetic capacity and growth of dipterocarp tree seedlings.  

PubMed

In the deeply shaded understorey of S.E. Asian rain forests the growth and survival of dipterocarp seedlings is limited by their ability to maintain a positive carbon balance. Photosynthesis during sunflecks is an important component of carbon gain in understorey plants. To test the sensitivity of photosynthesis and growth to variation in the pattern of dynamic irradiance, dipterocarp tree seedlings (Shorea leprosula and Hopea nervosa) were grown for 370 days under shaded forest light treatments of equal total daily photosynthetic photon flux density (approximately 3.3 mol m(-2) day(-1)), but characterised by either long flecks (LF) or short flecks (SF). Seedling growth was more than 4-fold greater under LF, compared with SF, in both species. Variation in the relative growth rates (RGR) and light saturated rates of photosynthesis (A(max)) were strongly positively correlated with the mean duration of sunflecks. Variation in RGR was strongly correlated with greater unit leaf rate growth, indicating that photosynthetic carbon gain per unit leaf area was greater under LF. The accumulation of starch in leaves over the diurnal period was 117% greater in both species under LF, compared with SF. Greater carbon gain in seedlings under LF is likely to have resulted from the combination of (1) greater A(max) (S. leprosula 35%, H. nervosa 40%), (2) more efficient dynamic photosynthesis, and (3) greater incident photosynthetic quantum yield, compared with seedlings receiving the SF irradiance treatment. The pattern of dynamic irradiance received by seedlings may significantly impact their growth and survival to a previously unrecognised extent, with important consequences for regeneration processes and hence forest structure and composition. PMID:12698339

Leakey, A D B; Press, M C; Scholes, J D

2003-04-01

353

The Effects of Cadmium-Zinc Interactions on Biochemical Responses in Tobacco Seedlings and Adult Plants  

PubMed Central

The objective of the present study was to investigate the effects of cadmium-zinc (Cd-Zn) interactions on their uptake, oxidative damage of cell macromolecules (lipids, proteins, DNA) and activities of antioxidative enzymes in tobacco seedlings as well as roots and leaves of adult plants. Seedlings and plants were exposed to Cd (10 µM and 15 µM) and Zn (25 µM and 50 µM) as well as their combinations (10 µM or 15 µM Cd with either 25 µM or 50 µM Zn). Measurement of metal accumulation exhibited that Zn had mostly positive effect on Cd uptake in roots and seedlings, while Cd had antagonistic effect on Zn uptake in leaves and roots. According to examined oxidative stress parameters, in seedlings and roots individual Cd treatments induced oxidative damage, which was less prominent in combined treatments, indicating that the presence of Zn alleviates oxidative stress. However, DNA damage found in seedlings, and lower glutathione reductase (GR) and superoxide dismutase (SOD) activity recorded in both seedlings and roots, after individual Zn treatments, indicate that Zn accumulation could impose toxic effects. In leaves, oxidative stress was found after exposure to Cd either alone or in combination with Zn, thus implying that in this tissue Zn did not have alleviating effects. In conclusion, results obtained in different tobacco tissues suggest tissue-dependent Cd-Zn interactions, which resulted in activation of different mechanisms involved in the protection against metal stress. PMID:24475312

Tkalec, Mirta; Stefanic, Petra Peharec; Cvjetko, Petra; Sikic, Sandra; Pavlica, Mirjana; Balen, Biljana

2014-01-01

354

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

355

Altered allocation to roots and shoots in the endophyte-infected seedlings of Puccinellia distans (Poaceae).  

PubMed

Endophytes play an important role in ecological and evolutionary processes in plants and have marked economic value. Seed-transmitted fungal endophytes are conventionally regarded as mutualistic symbionts, but their fitness consequences for the offspring of the host are not clear. Puccinellia distans infected with the fungus Epichloë typhina (E+) produces seeds that are several times smaller than normal (E-). This observation suggests that the E+ seedlings face a developmental disadvantage. Our growth chamber experiments compared the germination rates of the small E+ and large E- seeds of P. distans and examined the biomass allocation of seedlings to roots and shoots. The E+ seedlings germinated more slowly and maintained shorter shoots and a smaller root biomass for 30-50?days after sowing. Despite this disadvantage, the E+ plants more quickly increased their total size, attaining a larger shoot and whole-plant biomass. The shoot:root biomass ratio increased more rapidly through time in the E+ seedlings, attaining a value nine times higher in the E+ than the E- group 50?days after sowing. Such differences between the E+ and E- seedlings were not explained by the growth allometry between shoots and roots. The seedlings of P. distans infected with the Epichloë endophyte were initially handicapped by their postponed emergence, but this disadvantage was quickly overcome by their superior growth capacity. The decrease in the relative allocation to roots may indicate that endophytes increase the performance of roots as resource-acquiring organs and/or reduce the role of roots in protection against herbivores. PMID:22726626

Czarnoleski, M; Olejniczak, P; Górzy?ska, K; Koz?owski, J; Lembicz, M

2013-03-01

356

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

357

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

358

Global gene expression responses to waterlogging in leaves of rape seedlings.  

PubMed

Soil waterlogging is a serious constraint to crop production. We investigated the physiological responses of rape (Brassica napus L.) seedlings to waterlogging stress and analyzed global gene transcription responses in the aerial leaves of waterlogged rape seedlings. Seedlings of 'Tammi' and 'Youngsan' cultivars were subjected to waterlogging for 3 and 6 days and recovery for 5 days. Waterlogging stress caused a significant decrease in leaf chlorophyll content and premature senescence of the leaves. Maximal quantum efficiency of PSII (F(v)/F(m)) decreased in the waterlogged seedlings compared with the control plants. To evaluate whether the observed physiological changes in the leaves are associated with the differential regulation of gene expression in response to waterlogging stress, we analyzed the global transcriptional profile of leaves of 'Tammi' seedlings that were exposed to waterlogging for a short period (36 and 72 h). SolexaQA RNA-seq analysis revealed that a total of 4,484 contigs (8.5 %) of all contigs assayed (52,747) showed a twofold change in expression after 36 h of the start of waterlogging and 9,659 contigs (18.3 %) showed a twofold change after 72 h. Major genes involved in leaf photosynthesis, including light reactions and carbon-fixing reactions, were downregulated, while a number of genes involved in the scavenging of reactive oxygen species, degradation (proteins, starch, and lipids), premature senescence, and abiotic stress tolerance were upregulated. Transcriptome analysis data suggested that the aerial leaves of waterlogged rape seedlings respond to hypoxia by regulating the expression of diverse genes in the leaves. PMID:24384821

Lee, Yong-Hwa; Kim, Kwang-Soo; Jang, Young-Seok; Hwang, Ji-Hye; Lee, Dong-Hee; Choi, In-Hu

2014-02-01

359

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

360

Growth and gibberellin-A 1 metabolism in normal and gibberellin-insensitive ( Rht3 ) wheat ( Triticum aestivum L.) seedlings  

Microsoft Academic Search

Growth parameters were determined for tall (rht3) and dwarf (Rht3) seedlings of wheat (Triticum aestivum L.). Plant statures and leaf length were reduced by 50% in dwarfs but root and shoot dry weights were less affected. Leaves of dwarf seedlings had shorter epidermal cells and the numbers of cells per rank in talls and dwarfs matched the observed relationships in

John L. Stoddart

1984-01-01

361

Survival, growth, and photosynthesis of tree seedlings competing with herbaceous vegetation along a water-light- nitrogen gradient  

Microsoft Academic Search

In herbaceous dominated patches and ecosystems, tree establishment is influenced partly by the ability of woody seedlings to survive and grow in direct competition with herbaceous vegetation. We studied the importance of season long wet and dry spells on the competitive interactions between herbaceous vegetation and oak seedlings along a light and nitrogen gradient in an infertile secondary successional grassland

Mark A. Davis; Keith J. Wrage; Peter B. Reich

1999-01-01

362

Survival, growth, and photosynthesis of tree seedlings competing with herbaceous vegetation along a water-light-nitrogen gradient  

Microsoft Academic Search

In herbaceous dominated patches and ecosystems, tree establishment is influenced partly by the ability of woody seedlings to survive and grow in direct competition with herbaceous vegetation. We studied the importance of season long wet and dry spells on the competitive interactions between herbaceous vegetation and oak seedlings along a light and nitrogen gradient in an infertile secondary successional grassland

Mark A. Davis; Keith J. Wrage; Peter B. Reich; Mark G. Tjoelker; Toni Schaeffer; Carolyn Muermann

1999-01-01

363

Herbivory has a greater impact in shade than in sun: response of Quercus pyrenaica seedlings to multifactorial environmental variation  

Microsoft Academic Search

Many biotic and abiotic factors affect seedling establishment in woody plants. In Mediterranean environ- ments, the major factors affecting tree regeneration are light, water, and herbivory. We investigated the response of some morphological and chemical traits of Quercus pyrenaica Willd. seedlings to simulated herbivory (hand removal of 50% of the aerial mass) and two levels of light (sun vs. shade)

Elena Baraza; José M. Gómez; José A. Hódar; Regino Zamora

2004-01-01

364

Spatial structure and richness of ectomycorrhizal fungi colonizing bioassay seedlings from resistant propagules in a Sierra Nevada forest: comparisons using  

E-print Network

resistant propagules in a Sierra Nevada forest: comparisons using two hosts that exhibit different seedling propagules (e.g. spores or sclerotia) in a mixed-conifer forest in the Sierra Nevada, Califor- nia. Soils with seedlings of hosts that establish best in stronger light (Pinus jeffreyi) or that are shade-tolerant (Abies

California at Berkeley, University of

365

Influence of warming on soil water potential controls seedling mortality in perennial but not annual species in a temperate grassland.  

PubMed

In a water-limited system, the following hypotheses are proposed: warming will increase seedling mortality; elevated atmospheric CO2 will reduce seedling mortality by reducing transpiration, thereby increasing soil water availability; and longevity (i.e. whether a species is annual or perennial) will affect the response of a species to global changes. Here, these three hypotheses are tested by assessing the impact of elevated CO2 (550 micromol mol(-1) and warming (+2 degrees C) on seedling emergence, survivorship and establishment in an Australian temperate grassland from autumn 2004 to autumn 2007. Warming impacts on seedling survivorship were dependent upon species longevity. Warming reduced seedling survivorship of perennials through its effects on soil water potential but the seedling survivorship of annuals was reduced to a greater extent than could be accounted for by treatment effects on soil water potential. Elevated CO2 did not significantly affect seedling survivorship in annuals or perennials. These results show that warming will alter recruitment of perennial species by changing soil water potential but will reduce recruitment of annual species independent of any effects on soil moisture. The results also show that exposure to elevated CO2 does not make seedlings more resistant to dry soils. PMID:18631296

Hovenden, Mark J; Newton, Paul C D; Wills, Karen E; Janes, Jasmine K; Williams, Amity L; Vander Schoor, Jacqueline K; Nolan, Michaela J

2008-01-01

366

Effects of soil organic matter, moisture, shading and ash on white pine (Pinus strobus L.) seedling emergence  

Microsoft Academic Search

The effects of soil organic matter, soil moisture, shading and ash on white pine (Pinus strobus L.) emergence were investigated using soil monoliths in greenhouse experiments. White pine seedling emergence increased with soil organic matter removal, and levelled with the elimination of the litter and fermentation layers, where seedling emergence did not significantly increase further. Increased shade and soil moisture

D. G. Herr; L. C. Duchesne; R. J. Reader

1999-01-01

367

Effects of Roads on Castanopsis carlesii Seedlings and Their Leaf Herbivory in a Subtropical Forest in China  

PubMed Central

The effects of a forest road on Castanopsis carlesii (Hemsley) Hayata (Fagales: Fagaceae) seedlings and their leaf herbivory were investigated in a subtropical forest at Jiulianshan National Nature Reserve, Jiangxi, China. A total of 1124 seedlings, 33949 leaves, 468 leaf mines, and 205 leaf galls were found. Generally, individual numbers, tree heights, and leaf numbers of C. carlesii seedlings became lower with increasing distances from the road. These results might indicate that old seedlings were fewer and survival rate of seedlings was lower in forest interiors. Leaf miners preferred the seedlings close to the forest road, while leaf gallers preferred the seedlings about 2 m from the road. Species diversity of leaf miners was higher in the forest interior area, while species diversity of leaf gallers was higher near the road. However, both leaf miners and leaf gallers decreased in general from the road to the interior forest. There were interspecific differences in the effects of roads on leaf miner species and leaf galler species. The effects of the road on seedlings and insects could be explained by varying microhabitat conditions and different ecological strategies. PMID:25373164

Dai, Xiao-Hua; Xu, Jia-Sheng; Cai, Lu-Rong

2014-01-01

368

A LOW COST, HIGH ACCURACYOPTICAL FLOW METHOD FOR MEASURING 2D AND 3D CORN SEEDLING GROWTH  

E-print Network

­ cal flow method for the use in (accurately) measuring young corn seedling growth. The 2D plant motion of measuring 2D and 3D corn seedling growth. 2. Literature Survey Measurement of minute increments in plant, the transducer technique for growth measurement re­ quires mechanical coupling of the transducer to the plant

Barron, John

369

The window of desiccation tolerance shown by early-stage germinating seedlings remains open in the resurrection plant, Xerophyta viscosa.  

PubMed

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

370

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

371

Abscisic acid-dependent and -independent expression of the carrot LEA class gene Dc3 in transgenic tobacco seedlings  

E-print Network

We studied the expression of three promoter deletion mutants (A218, A599, and A1312) of the Late Embryo Abundant (LEA) class gene Dc3 fused to the reporter gene, B-glucuronidase (GUS) in 14 d old transgenic tobacco seedlings. Seedlings were...

Siddiqui, Najeeb Ullah

2012-06-07

372

The effects of size of opening in vegetation and litter cover on seedling establishment of goldenrods ( Solidago spp.)  

Microsoft Academic Search

We investigated the effects of size of opening in the vegetation and litter cover on seedling establishment of two species of goldenrods (Solidago spp.) in an abandoned field in southwestern Michigan, U.S.A. Seeds of S. canadensis and S. juncea were sown into clipped plots, ranging from 0 cm (control, unclipped) to 100 cm in diameter, with and without litter. Seedling

Deborah E. Goldberg; Patricia A. Werner

1983-01-01

373

Allelopathic effects of Juglone and decomposed walnut leaf juice on muskmelon and cucumber seed germination and seedling growth  

Microsoft Academic Search

In this study, effects of juglone and decomposed walnut leaf juice on muskmelon (Cucumis melo cv. Galia) and cucumber (Cucumis sativus cv. Beith Alpha) seed germination percentage and post- germination seedling growth were investigated. Decomposition was carried out by keeping the leaves in distilled water. Muskmelon and cucumber seeds were germinated in Petri dishes at 25°C. Seed germination, seedling elongation

I. Terzi

2008-01-01

374

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

375

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

376

Taxonomic scale-dependence of habitat niche partitioning and biotic neighbourhood on survival of tropical tree seedlings  

PubMed Central

In order to differentiate between mechanisms of species coexistence, we examined the relative importance of local biotic neighbourhood, abiotic habitat factors and species differences as factors influencing the survival of 2330 spatially mapped tropical tree seedlings of 15 species of Myristicaceae in two separate analyses in which individuals were identified first to species and then to genus. Using likelihood methods, we selected the most parsimonious candidate models as predictors of 3 year seedling survival in both sets of analyses. We found evidence for differential effects of abiotic niche and neighbourhood processes on individual survival between analyses at the genus and species levels. Niche partitioning (defined as an interaction of taxonomic identity and abiotic neighbourhood) was significant in analyses at the genus level, but did not differentiate among species in models of individual seedling survival. By contrast, conspecific and congeneric seedling and adult density were retained in the minimum adequate models of seedling survival at species and genus levels, respectively. We conclude that abiotic niche effects express differences in seedling survival among genera but not among species, and that, within genera, community and/or local variation in adult and seedling abundance drives variation in seedling survival. These data suggest that different mechanisms of coexistence among tropical tree taxa may function at different taxonomic or phylogenetic scales. This perspective helps to reconcile perceived differences of importance in the various non-mutually exclusive mechanisms of species coexistence in hyper-diverse tropical forests. PMID:19740886

Queenborough, Simon A.; Burslem, David F. R. P.; Garwood, Nancy C.; Valencia, Renato

2009-01-01

377

Effects of roads on Castanopsis carlesii seedlings and their leaf herbivory in a subtropical forest in China.  

PubMed

The effects of a forest road on Castanopsis carlesii (Hemsley) Hayata (Fagales: Fagaceae) seedlings and their leaf herbivory were investigated in a subtropical forest at Jiulianshan National Nature Reserve, Jiangxi, China. A total of 1124 seedlings, 33949 leaves, 468 leaf mines, and 205 leaf galls were found. Generally, individual numbers, tree heights, and leaf numbers of C. carlesii seedlings became lower with increasing distances from the road. These results might indicate that old seedlings were fewer and survival rate of seedlings was lower in forest interiors. Leaf miners preferred the seedlings close to the forest road, while leaf gallers preferred the seedlings about 2 m from the road. Species diversity of leaf miners was higher in the forest interior area, while species diversity of leaf gallers was higher near the road. However, both leaf miners and leaf gallers decreased in general from the road to the interior forest. There were interspecific differences in the effects of roads on leaf miner species and leaf galler species. The effects of the road on seedlings and insects could be explained by varying microhabitat conditions and different ecological strategies. PMID:25373164

Dai, Xiao-Hua; Xu, Jia-Sheng; Cai, Lu-Rong

2014-01-01

378

Tree shelters and weed control: Effects on protection, survival and growth of cherrybark oak seedlings planted on a cutover site  

Microsoft Academic Search

In the southern USA oaks (Quercusspp.) are often favored by forest owners havingmultiple objectives for forest ownership as oaksprovide mast for wildlife, are consideredaesthetically pleasing, and are valuable for timberproducts. Regeneration and early seedling growth isa concern to those forest owners interested insustaining oaks as a component of their forests. Theeffects of tree shelters and herbaceous weed controlon second-year seedling

Mark R. Dubois; Arthur H. Chappelka; Efrem Robbins; Greg Somers; Karl Baker

2000-01-01

379

The combined impacts of deep shade and drought on the growth and biomass allocation of shade-tolerant woody seedlings  

Microsoft Academic Search

To test whether the impact of drought on the growth and biomass allocation of first-season shade-tolerant woody seedlings in low irradiance differs from that in high irradiance, seedlings of Viburnum lantana, V. opulus, V. tinus and Hedera helix were grown in pots at two watering frequencies 2 three irradiances. Hypotheses in the recent literature variously predict that drought will have

Lawren Sack; Peter J. Grubb

2002-01-01

380

Impacts of mechanical site preparation on foliar nutrients of planted white spruce seedlings on mixed-wood  

E-print Network

nutrition of planted white spruce (Picea glauca (Moench) Voss) seedlings were examined at two mixed-woodImpacts of mechanical site preparation on foliar nutrients of planted white spruce seedlings on mixed-wood boreal forest sites in Alberta S. Ellen Macdonalda,* , Margaret G. Schmidtb , Richard L

Macdonald, Ellen

381

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

382

Evaluation of Trenching & Fertilization at Planting for Enhancing Douglas-fir Seedling Growth on a Dry Salal-Dominated Sites.  

E-print Network

Evaluation of Trenching & Fertilization at Planting for Enhancing Douglas- fir Seedling Growth Forest Region Two trials established near Nanaimo, B.C. (CWHxm1) evaluated fertilization at planting (FAP and combined on the drier and more nutrient poor (2 / B) of the two sites. Fertilized seedlings mortality

383

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

384

Responses of plant seedlings to hypergravity: cellular and molecular aspects  

NASA Astrophysics Data System (ADS)

Hypergravity produced by centrifugation has been used to analyze the responses of plant seedlings to gravity stimulus. Elongation growth of stem organs is suppressed by hypergravity, which can be recognized as a way for plants to resist gravitational force. The mechanisms inducing growth suppression under hypergravity conditions were analyzed at cellular and molecular levels. When growth was suppressed by hypergravity, a decrease in the cell wall extensibility was brought about in various plants. Hypergravity also induced a cell wall thickening and an increase in the molecular mass of the certain hemicellulosic polysaccharides. Both a decrease in the activities hydrolyzing such polysaccharides and an increase in the apoplast pH were involved in such changes in the cell wall constituents. Thus, the cell wall metabolism is greatly modified under hypergravity conditions, which causes a decrease in the cell wall extensibility, thereby inhibiting elongation growth in stem organs. On the other hand, to identify genes involved in hypergravity-induced growth suppression, changes in gene expression by hypergravity treatment were analyzed in Arabidopsis hypocotyls by differential display method. Sixty-two genes were expressed differentially: expression levels of 39 genes increased, whereas those of 23 genes decreased under hypergravity conditions. The expression of these genes was further analyzed using RT-PCR. One of genes upregulated by hypergravity encoded hydroxymethylglutaryl-CoA reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of hormones such as gibberellic acid and abscisic acid. The expression of HMGR gene increased within several hours after hypergravity treatment. Also, compactin, an inhibitor of HMGR activity, prevented hypergravity-induced growth suppression, suggesting that HMGR is involved in suppression of Arabidopsis hypocotyl growth by hypergravity. In addition, hypergravity increased the expression levels of CCR1 and ERD15, which were shown to take part in the signaling pathway of environmental stimuli such as temperature and water. These cellular and molecular changes appear to be involved in a series of events leading to growth suppression of stem organs under hypergravity conditions.

Hoson, T.; Yoshioka, R.; Soga, K.; Wakabayashi, K.; Takeba, G.

385

Inheritance and interrelationships of some seedling disease escape characteristics in cotton, Gossypium hirsutum L  

E-print Network

of the requirements for the degree of MASTER OF SCIENCE May 1968 Major Subject Genetics INHERITANCE AND INTERRELATIONSHIPS OP SOME SEEDLING DISEASE E ~ CAPE CHARACINRISIICS IN CORI'ON, COSSHPIUN HIIISUIUN I. A Thesis By Salem A. Abd-Alla Approved as to style... of the requirements for the degree of MASTER OF SCIENCE May 1968 Major Subject Genetics INHERITANCE AND INTERRELATIONSHIPS OP SOME SEEDLING DISEASE E ~ CAPE CHARACINRISIICS IN CORI'ON, COSSHPIUN HIIISUIUN I. A Thesis By Salem A. Abd-Alla Approved as to style...

Abd-Alla, Salem Abdel-Kirim

2012-06-07

386

[Research progress in seegrass seed dormancy, germination, and seedling growth and related affecting factors].  

PubMed

Seagrass bed is the main primary producer in coastal areas, having highly ecological and economical values, and being one of the most important shallow-marine ecosystems. This paper reviewed the research progress in the seed dormancy, germination, and seedling growth of seagrass and related affecting factors, summarized the seed dormancy modes and durations and their affecting factors, and discussed the effects of water salinity, temperature, transparency, hormone, dissolved oxygen, and population structure on the seed germination and the seedling survival and growth. Some issues in related researches and several research directions in the future were prospected. PMID:22303688

Zhang, Pei-Dong; Sun, Yan; Niu, Shu-Na; Zhang, Xiu-Mei

2011-11-01

387

Increased acidification in the rhizosphere of cactus seedlings induced by Azospirillum brasilense  

NASA Astrophysics Data System (ADS)

Acidification of the rhizosphere of cactus seedlings (giant cardon, Pachycereus pringlei) after inoculation with the plant growth-promoting bacterium Azospirillum brasilense Cd, in the presence or absence of ammonium and nitrate, was studied to understand how to increase growth of cardon seedlings in poor desert soils. While ammonium enhanced rhizosphere and liquid culture acidification, inoculation with the bacteria enhanced it further. On the other hand, nitrate increased pH of the rhizosphere, but combined with the bacterial inoculation, increase in pH was significantly smaller. Bacterial inoculation with ammonium enhanced plant growth.

Carrillo, Angel; Li, Ching; Bashan, Yoav

2002-08-01

388

Alteration in growth and peroxidase activity by heavy metals in Phaseolus seedlings  

Microsoft Academic Search

The aim of the present work was to see the effect of mercury and chromium on elongation growth of phaseolus seedlings and\\u000a changes in chlorophyll content. Phaseolus seedlings were treated with two different concentrations of two heavy metals viz. mercury (0.05 mM and 0.4 mM HgCl2, and chromium (0.5 mM and 1.0 mM K2Cr2O7). Both mercury and chromium inhibited root

N. G. Parmar; S. D. Vithalani; S. V. Chanda

2002-01-01

389

Freezing tolerance and soluble sugar contents affected by water stress during cold-acclimation and de-acclimation in cabbage seedlings  

Microsoft Academic Search

The effect of water stress on freezing tolerance during cold-acclimation and de-acclimation in cabbage seedlings were studied. The seedlings were subjected to water stress by withholding water. The treatment wilted the seedlings and decreased the water content of their shoots. Exposure of seedlings to low temperatures (5°C) for 7 days induced freezing tolerance. Water stress promoted the increase in freezing

Hidekazu Sasaki; Kazuo Ichimura; Kunihiko Okada; Masayuki Oda

1998-01-01

390

Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).  

PubMed

Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress. PMID:25154813

Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

2014-11-01

391

EFFECT OF VARIOUS ABIOTIC STRESSES ON THE GROWTH, SOLUBLE SUGARS AND WATER RELATIONS OF SORGHUM SEEDLINGS GROWN IN LIGHT AND DARKNESS  

Microsoft Academic Search

Summary. The effect of NaCl, PEG, heat and cold treatments on growth, water content, FW, DW and soluble sugar levels in 3 day old seedlings of Sorghum bicolor CSH-6 were studied. Under these stress conditions, RWC and water potential of seedlings decreased dramatically. Subsequently this reduction resulted in the markable decrease in FW of different parts of stress imposed seedlings.

Prabhjot Kaur Gill; Arun Dev Sharma; Prabhjeet Singh; Sukdev Singh Bhullar

2001-01-01

392

Effect of litter, leaf cover and cover of basal internodes of the dominant species Molinia caerulea on seedling recruitment and established vegetation  

Microsoft Academic Search

The effects of litter removal, leaf cover of established plants and cover of basal internodes of a dominant species Molinia caerulea on seedling germination and the dynamics of established plants were studied in a field experiment in an oligotrophic wet meadow. Although the negative influence of litter on total seedling number and seedling species composition was non-significant, litter significantly affected

Jan Lepš

2005-01-01

393

Irrigation and fertilization effects on seed number, size, germination and seedling growth: implications for desert shrub establishment.  

PubMed

Plants with limited resources adjust partitioning among growth, survival, and reproduction. We tested the effects of water and nutrient amendments on seed production, size, and quality in Sarcobatus vermiculatus (greasewood) to assess the magnitude and importance of changes in reproductive partitioning. In addition, we assessed interactions among the environment of seed-producing plants (adult plant scale), seed size, and seedling microenvironment (seedling scale) on successful seedling establishment. Interactions of these factors determine the scale of resource heterogeneity that affects seedling establishment in deserts. Both total number of seeds produced per plant and seed quality (weight and germination) increased significantly in the enriched treatment in a 3-year field experiment. Seedling length 3 days after germination and seed N concentration, other measures of seed quality, were higher for seed from both irrigated and enriched plants than for seed from control plants. Field S. vermiculatus seed production and quality can be substantially increased with irrigation and nutrient enrichment at the adult plant scale and this allows management of seed availability for restoration. However, based on a greenhouse study, seedling environment, not the environment of the seed-producing plant or seed size, was the most important factor affecting seedling germination, survival, and growth. Thus it appears that production of more seed may be more important than improved seed quality, because higher quality seed did not compensate for a low-resource seedling environment. For both natural establishment and restoration this suggests that heterogeneity at the scale of seedling microsites, perhaps combined with fertilization of adult shrubs (or multi-plant patches), would produce the greatest benefit for establishing seedlings in the field. PMID:18481096

Breen, A N; Richards, J H

2008-08-01

394

Effects of Increased Nitrogen Deposition and Precipitation on Seed and Seedling Production of Potentilla tanacetifolia in a Temperate Steppe Ecosystem  

PubMed Central

Background The responses of plant seeds and seedlings to changing atmospheric nitrogen (N) deposition and precipitation regimes determine plant population dynamics and community composition under global change. Methodology/Principal Findings In a temperate steppe in northern China, seeds of P. tanacetifolia were collected from a field-based experiment with N addition and increased precipitation to measure changes in their traits (production, mass, germination). Seedlings germinated from those seeds were grown in a greenhouse to examine the effects of improved N and water availability in maternal and offspring environments on seedling growth. Maternal N-addition stimulated seed production, but it suppressed seed mass, germination rate and seedling biomass of P. tanacetifolia. Maternal N-addition also enhanced responses of seedlings to N and water addition in the offspring environment. Maternal increased-precipitation stimulated seed production, but it had no effect on seed mass and germination rate. Maternal increased-precipitation enhanced seedling growth when grown under similar conditions, whereas seedling responses to offspring N- and water-addition were suppressed by maternal increased-precipitation. Both offspring N-addition and increased-precipitation stimulated growth of seedlings germinated from seeds collected from the maternal control environment without either N or water addition. Our observations indicate that both maternal and offspring environments can influence seedling growth of P. tanacetifolia with consequent impacts on the future population dynamics of this species in the study area. Conclusion/Significance The findings highlight the importance of the maternal effects on seed and seedling production as well as responses of offspring to changing environmental drivers in mechanistic understanding and projecting of plant population dynamics under global change. PMID:22194863

Li, Yang; Yang, Haijun; Xia, Jianyang; Zhang, Wenhao; Wan, Shiqiang; Li, Linghao

2011-01-01

395

The Role of Reproductive Phenology, Seedling Emergence and Establishment of Perennial Salix gordejevii in Active Sand Dune Fields  

PubMed Central

Background and Aims The function of sexual reproduction of perennials in restoration of vegetation of active dune fields frequently has been underestimated. The objective of this study was to evaluate the role of sexual reproduction of the perennial Salix gordejevii in the revegetation of active dunes. Methods Seedling emergence and establishment of S. gordejevii were examined both in controlled experiments (germination at different burial depths with different watering regimes) and in field observations in three dune slacks. The reproductive phenology and soil seed bank of S. gordejevii, the dynamics of soil moisture, the groundwater table and the landform level of three dune slacks were monitored. Key Results Seeds of S. gordejevii began maturation on 1 May, and seed dispersal lasted from 8 May to 20 May. Seeds on the soil surface germinated significantly faster than those buried in soil (P<0·05). Seedling emergence was negatively correlated with landform level. When most seedlings emerged, there was a significantly positive correlation between soil moisture and seedling emergence (P<0·01). Rainfall was negatively correlated with seedling emergence. Seedling establishment was significantly and positively correlated with seedling emergence (P<0·05), and 72·3 % of the emergent seedlings were established at the end of the growing season. These results indicated that (a) seeds matured and dispersed before the rainy season; (b) seeds germinated as soon as they contacted a moist surface and relied more on soil moisture than on rainfall; and (c) more seedlings emerged at lower sampling points in dune slacks. Conclusions In natural conditions, restoration of active sand dune fields generally commences with revegetation of dune slacks where sexual reproduction of perennials contributes greatly to species encroachment and colonization and hence plays an important role in restoration of active dune fields. Furthermore, aeolian erosion in dune slacks, leading to good soil moisture, facilitates seed germination, seedling emergence and establishment of S. gordejevii. PMID:17085475

Yan, Qiaoling; Liu, Zhimin; Ma, Junling; Jiang, Deming

2007-01-01

396

Leaf life span spectrum of tropical woody seedlings: effects of light and ontogeny and consequences for survival  

PubMed Central

Background and Aims Leaf life span is widely recognized as a key life history trait associated with herbivory resistance, but rigorous comparative data are rare for seedlings. The goal of this study was to examine how light environment affects leaf life span, and how ontogenetic development during the first year may influence leaf fracture toughness, lamina density and stem density that are relevant for herbivory resistance, leaf life span and seedling survival. Methods Data from three experiments encompassing 104 neotropical woody species were combined. Leaf life span, lamina and vein fracture toughness, leaf and stem tissue density and seedling survival were quantified for the first-year seedlings at standardized ontogenetic stages in shade houses and common gardens established in gaps and shaded understorey in a moist tropical forest in Panama. Mortality of naturally recruited seedlings till 1 year later was quantified in 800 1-m2 plots from 1994 to 2011. Key Results Median leaf life span ranged widely among species, always greater in shade (ranging from 151 to >1790 d in the understorey and shade houses) than in gaps (115–867 d), but with strong correlation between gaps and shade. Leaf and stem tissue density increased with seedling age, whereas leaf fracture toughness showed only a weak increase. All these traits were positively correlated with leaf life span. Leaf life span and stem density were negatively correlated with seedling mortality in shade, while gap mortality showed no correlation with these traits. Conclusions The wide spectrum of leaf life span and associated functional traits reflects variation in shade tolerance of first-year seedlings among coexisting trees, shrubs and lianas in this neotropical forest. High leaf tissue density is important in enhancing leaf toughness, a known physical defence, and leaf life span. Both seedling leaf life span and stem density should be considered as key functional traits that contribute to seedling survival in tropical forest understoreys. PMID:23532047

Kitajima, Kaoru; Cordero, Roberto A.; Wright, S. Joseph

2013-01-01

397

Differential Gene Expression in Chilling-Acclimated Maize Seedlings and Evidence for the Involvement of Abscisic Acid in Chilling Tolerance.  

PubMed Central

An acclimation phenomenon was characterized in seedlings of chilling-sensitive maize (Zea mays L.) inbred G50 (Pioneer). Seedlings were germinated at 27[deg]C for 3 d and then exposed to chilling treatments of 4, 5, or 6[deg]C for 2, 4, 7, or 10 d in darkness. Damage symptoms in the more severe treatments included a waterlogged appearance and a discoloration of the tissue. The symptoms were most obvious in the mesocotyl. After a 10-d grow-out period in the greenhouse, moderately damaged seedlings exhibited chlorotic areas, an occasional disruption in leaf expansion, and a constriction of the mesocotyl. Growth and survival were improved by first exposing seedlings to a 14[deg]C acclimation treatment for 3 d before applying the chilling treatment. After chilling at 5[deg]C for 7 d, 79% of the acclimated seedlings survived, whereas only 22% of the nonacclimated seedlings survived. Differences in gene expression between acclimated and control seedlings were investigated using subtraction and differential screening techniques. Transcripts corresponding to three genes, car333, car30, and car757 (chilling acclimation responsive), were present in higher levels in seedlings after acclimation. Sequence analysis identified car333 as cat3, which encodes maize mitochondrial catalase isozyme 3. Characterization of these three clones revealed that all corresponding transcripts were elevated in acclimated seedlings in a manner that depended on the organ, i.e. coleoptile, mesocotyl, or root. Although transcripts were elevated in all three organs in response to acclimation, car30 was most abundant in the coleoptile and root, whereas cat3 and car757 were most abundant in the coleoptile and mesocotyl. Catalase activity followed the same general trend as cat3 transcript levels. Exogenous treatment with abscisic acid (ABA) resulted in an improvement in growth and survival of nonacclimated, chilled seedlings. Inhibition of ABA biosynthesis with fluridone abolished acclimation-induced chilling tolerance, and exogenous application of ABA to fluridone-treated seedlings restored chilling tolerance. Exogenous ABA treatment also resulted in increases in cat3, car30, and car757 transcript levels and catalase activity in the same organ-specific manner as in acclimated seedlings. These results indicate that ABA synthesis is essential for chilling tolerance. However, measurement of ABA levels in mesocotyls during acclimation and chilling revealed only a marginal increase during acclimation and a dramatic increase during chilling, regardless of whether or not seedlings were acclimated. Thus, although ABA may be required for chilling tolerance, we have no conclusive evidence that the acclimation process is mediated by ABA. PMID:12232205

Anderson, M. D.; Prasad, T. K.; Martin, B. A.; Stewart, C. R.

1994-01-01

398

Effects of ethylene diurea and ozone on the growth of tree seedlings  

Microsoft Academic Search

The efficacy of ethylene diurea (EDU) was tested as a protectant against Oâ-induced leaf injury and growth reduction in Fraxinus americana and Prunus serotina. Seedlings were subjected to weekly 4-hr fumigations at 0, .10, .20, .30, or .40 ppm Oâ for 9 successive weeks. Three days before each fumigation, foliage of plants in each Oâ treatment was misted with distilled

McClenahen

1979-01-01

399

Water relation characteristics and photosynthesis of saline-stressed seedlings of non-halophyte species  

E-print Network

Water relation characteristics and photosynthesis of saline-stressed seedlings of non of the present study was to ex- amine the distribution of salts and its effect on photosynthesis for non as relative values against 0% treatment. Photosynthesis by O. asiaticus var. aurantiacus decreased

Paris-Sud XI, Université de

400

HISTONE DEACETYLASE 9 represses seedling traits in Arabidopsis thaliana dry seeds.  

PubMed

Plant life is characterized by major phase changes. We studied the role of histone deacetylase (HDAC) activity in the transition from seed to seedling in Arabidopsis. Pharmacological inhibition of HDAC stimulated germination of freshly harvested seeds. Subsequent analysis revealed that histone deacetylase 9 (hda9) mutant alleles displayed reduced seed dormancy and faster germination than wild-type plants. Transcriptome meta-analysis comparisons between the hda9 dry seed transcriptome and published datasets demonstrated that transcripts of genes that are induced during imbibition in wild-type prematurely accumulated in hda9-1 dry seeds. This included several genes associated with photosynthesis and photoautotrophic growth such as RuBisCO and RuBisCO activase (RCA). Chromatin immunoprecipitation experiments demonstrated enhanced histone acetylation levels at their loci in young hda9-1 seedlings. Our observations suggest that HDA9 negatively influences germination and is involved in the suppression of seedling traits in dry seeds, probably by transcriptional repression via histone deacetylation. Accordingly, HDA9 transcript is abundant in dry seeds and becomes reduced during imbibition in wild-type seeds. The proposed function of HDA9 is opposite to that of its homologous genes HDA6 and HDA19, which have been reported to repress embryonic properties in germinated seedlings. PMID:25146719

van Zanten, Martijn; Zöll, Christian; Wang, Zhi; Philipp, Christina; Carles, Annaick; Li, Yong; Kornet, Noortje G; Liu, Yongxiu; Soppe, Wim J J

2014-11-01

401

Effects of exogenous ABA on photosynthesis and stomatal conductance of cut twigs from oak seedlings  

E-print Network

Effects of exogenous ABA on photosynthesis and stomatal conductance of cut twigs from oak seedlings of the observed decline in net photosynthesis (Downton etal., 1988) or is there some direct ef- fect of ABA on mesophyll photosynthesis (Raschke and Hedrich, 1985)? Do forest trees display the same responses to ABA

Paris-Sud XI, Université de

402

Carbohydrate sources used in new root growth following transplant of Quercus rubra L. seedlings  

E-print Network

Carbohydrate sources used in new root growth following transplant of Quercus rubra L. seedlings primarily on stored carbohydrates during the shoot linear stage of growth, while current photosynthate). This suggests that initial new root growth following transplant relies on stored carbohydrates, while current

403

Mapping of quantitative trait loci for gibberellic acid response at rice ( Oryza sativa L.) seedling stage  

Microsoft Academic Search

The development of molecular genetic maps has accelerated the identification and mapping of genomic regions controlling quantitative trait loci (QTLs) in rice. The degree of gibberellin response affects various physiological processes in plant growth and development. This study was conducted to map QTLs for gibberellic acid (GA3) response in the rice seedling stage in a recombinant inbred (RI) population derived

Yanjun Dong; H. Kamiuten; Zhongnan Yang; Dongzhi Lin; T. Ogawa; Lijun Luo; H. Matsuo

2006-01-01

404

Enantiomeric resolution and growth-retardant activity in rice seedlings of uniconazole.  

PubMed

The increasing application of chiral pesticides has enhanced interest in their enantioselectivity. However, little relevant information is currently available for enantioselective activity of chiral plant growth regulators. In an attempt to screen active enantiomers of uniconazole, this work investigated enantiomeric separation and the enantioselective effect of uniconazole on the growth of rice seedlings and cyanobacteria. Baseline resolution of uniconazole enantiomers was achieved on a Chiralpak AD column by chiral high-performance liquid chromatography (HPLC). The relationship among circular dichroism (CD), optical rotation (OR), and absolute configuration was successfully established by coupling of CD and OR detection. The t test at the 95% level of confidence indicated significant differences between the enantiomers in their retardant activity toward growth of rice seedlings and stimulation effect on growth of cyanobacteria, the natural biofertilizers in rice paddy fields. The S-(+)-enantiomer was more active than the R-(-)-enantiomer in retarding growth of rice seedlings and stimulating growth of Microcystis aeruginosa . This special enantiomeric selectivity was further elucidated by probing the binding mode of enantiomers to gibberellin (GA) 20-oxidase by molecular docking. The S-(+)-enantiomer was found to bind tightly with GA 20-oxidase. The results suggested that the S-(+)-enantiomer instead of a racemate of uniconazole should be used to improve rice seedling quality. PMID:22148239

Sun, Jianqiang; Zhang, Anping; Zhang, Jing; Xie, Xuemei; Liu, Weiping

2012-01-11

405

SEEDLING EXPRESSION OF CROSS-GENERATIONAL PLASTICITY DEPENDS ON REPRODUCTIVE ARCHITECTURE1  

Microsoft Academic Search

Through adaptive cross-generational plasticity, stressed plants can alter their offspring in specific ways that promote seedling success. As yet, very little is known about the expression of such plasticity, and whether it varies within a plant due to offspring position. The effects of parental light deprivation on distinct reproductive structures were tested in the annual Polygonum hydropiper, which produces both

MARJORIE R. LUNDGREN; SONIA E. SULTAN

406

SEEDLING EXPRESSION OF CROSS-GENERATIONAL PLASTICITY DEPENDS ON REPRODUCTIVE ARCHITECTURE 1  

Microsoft Academic Search

Through adaptive cross-generational plasticity, stressed plants can alter their offspring in specific ways that promote seedling success. As yet, very little is known about the expression of such plasticity, and whether it varies within a plant due to offspring position. The effects of parental light deprivation on distinct reproductive structures were tested in the annual Polygonum hydropiper, which produces both

MARJORIE R. LUNDGREN; SONIA E. SULTAN

2005-01-01

407

Effects of forest fragmentation on seed dispersal and seedling establishment in ornithochorous trees.  

PubMed

Habitat fragmentation increases seed dispersal limitation across the landscape and may also affect subsequent demographic stages such as seedling establishment. Thus, the development of adequate plans for forest restoration requires an understanding of mechanisms by which fragmentation hampers seed delivery to deforested areas and knowledge of how fragmentation affects the relationship between seed-deposition patterns and seedling establishment. We evaluated the dispersal and recruitment of two bird-dispersed, fleshy-fruited tree species (Crataegus monogyna and Ilex aquifolium) in fragmented secondary forests of northern Spain. Forest fragmentation reduced the probability of seed deposition for both trees because of decreased availability of woody perches and fruit-rich neighborhoods for seed dispersers, rather than because of reductions in tree cover by itself. The effects of fragmentation went beyond effects on the dispersal stage in Crataegus because seedling establishment was proportional to the quantities of bird-dispersed seeds arriving at microsites. In contrast, postdispersal mortality in Ilex was so high that it obscured the seed-to-seedling transition. These results suggest that the effects of fragmentation are not necessarily consistent across stages of recruitment across species. Habitat management seeking to overcome barriers to forest recovery must include the preservation, and even the planting, of fleshy-fruited trees in the unforested matrix as a measure to encourage frugivorous birds to enter into open and degraded areas. An integrative management strategy should also explicitly consider seed-survival expectancies at microhabitats to preserve plant-population dynamics and community structure in fragmented landscapes. PMID:20184646

Herrera, José Manuel; García, Daniel

2010-08-01

408

Development-specific responses to drought stress in Aleppo pine (Pinus halepensis Mill.) seedlings.  

PubMed

Aleppo pine (Pinus halepensis Mill.) is a pioneer species, highly competitive due to exceptional resistance to drought. To investigate the stress resistance in the first and second year of development, a steady-state drought experiment was implemented. Photosynthesis (A(net)), stomatal conductance and transpiration (E) were measured on three different sampling dates together with phloem soluble sugars, amino acids and non-structural proteins. Needle ascorbic acid (AsA) and reactive oxygen species were measured to evaluate the seedlings' drought stress condition in the final sampling. Drought impaired A(net) and E by 35 and 31%, respectively, and increased AsA levels up to 10-fold, without significant impact on the phloem metabolites. Phloem sugars related to temperature fluctuations rather than soil moisture and did not relate closely to A(net) levels. Sugars and proteins decreased between the second and third sampling date by 56 and 61%, respectively, and the ratio of sugars to amino acids decreased between the first and third sampling by 81%, while A(net) and water-use efficiency (A(net)/E) decreased only in the older seedlings. Although gas exchange was higher in the older seedlings, ascorbic acid and phloem metabolites were higher in the younger seedlings. It was concluded that the drought stress responses depended significantly on developmental stage, and research on the physiology of Aleppo pine regeneration should focus more on temperature conditions and the duration of drought than its severity. PMID:24200584

Alexou, Maria

2013-10-01

409

Carbon dioxide assimilation of hardwood seedlings in relation to community dynamics in central illinois  

Microsoft Academic Search

Field measurements of net assimilation and respiration for seedlings of four hardwood species were made periodically over a growing season with soil moisture tension maintained between 0 and 0.75 bar. Total net assimilation per day was significantly greater for Acer saccharum than either Quercus rubra or Quercus alba and for Quercus macrocarpa as compared with Q. rubra, when measurements were

James W. Geis; Robert L. Tortorelli; William R. Boggess

1971-01-01

410

Lipid utilization in radish seedlings as affected by weak horizontal extremely low frequency magnetic field.  

PubMed

Composition and content of lipids were studied in 5-day-old radish seedlings (Raphanus sativus L. var. radicula DC.) grown in lowlight and darkness in an extremely low frequency (ELF) magnetic field characterized by 50?Hz frequency and ?500?µT flux density. The control seedlings were grown under the same conditions, but without exposure to the magnetic field. The products of lipid metabolism were compared with lipid composition in seeds. In control seedlings, reserve neutral lipids, mostly triacylglycerides, were utilized for the formation of polar lipids (PL). As a result, the amount of the latter doubled, particularly due to glycolipids (GL) and phospholipids (PhL) compared to their content in seeds. At 20-22?°C in light, magnetic field exposure increased the production of PL by threefold specifically, GL content increased fourfold and PhL content rose 2.5 times, compared to seeds. In darkness, the effect of magnetic field on lipids was weaker. At the lower temperature of 13-16?°C in light, the effect of the magnetic field was weak, but in the darkness, no magnetic field action was recorded. It is concluded that ELF magnetic field stimulated lipid synthesis in chloroplast, mitochondrial, and other cell membranes in radish seedlings grown in light at 20-22?°C and 13-16?°C. PMID:24123065

Novitskii, Yurii I; Novitskaya, Galina V; Serdyukov, Yurii A

2014-02-01

411

Characterization of Cadmium Binding, Uptake, and Translocation in Intact Seedlings of Bread and Durum Wheat Cultivars  

Microsoft Academic Search

High Cd content in durum wheat (Triticum turgidum L. var durum) grain grown in the United States and Canada presents potential health and economic problems for consumers and grow- ers. In an effort to understand the biological processes that result in excess Cd accumulation, root Cd uptake and xylem translocation to shoots in seedlings of bread wheat (Triticum aestivum L.)

Jonathan J. Hart; Ross M. Welch; Wendell A. Norvell; Lori A. Sullivan; Leon V. Kochian

1998-01-01

412

Effects of root temperature on growth and photosynthesis in conifer seedlings during shoot elongation  

Microsoft Academic Search

Summary Growth and gas exchange characteristics were studied in pine (Pinus sylvestris L.) and spruce (Picea shies Karst.) seedlings grown in hydroponic culture in the presence of N (50 mg 1-l) and transferred at the start of their second growing season to tap water at 5, 8, 12, 16 or 20 \\

E. M. VAPAAVUORI; R. RIKALA; A. RYYPPQ

413

The development of winter hardiness of pine and spruce seedlings in a simulated acid rain experiment  

E-print Network

The development of winter hardiness of pine and spruce seedlings in a simulated acid rain-April, when the starch grains again appeared (Fig. 4). The exposure to acid rain did not significantly affect.g., Davison and Barnes, 1986; Freer- Smith and Mansfield, 1987). However, the effects of acid rain on conifer

Paris-Sud XI, Université de

414

Studies on the paradox of seedling rarity in Vaccinium myrtillus L. in NE Scotland  

Microsoft Academic Search

On the moors studied Vaccinium myrtillus produced many berries containing highly viable seed, yet seedlings were rare. Offtake of berries by birds or mammalian herbivores was apparently minor, most berries simply falling from the bushes when ripe. Fallen berries quickly disappeared, probably being removed by small rodents. Berries were fed experimentally to captive field voles and capercaillies, and it was

David Welch; David Scott; Sean Doyle

2000-01-01

415

Seedling Nursery Culture of Whitebark Pine at Dorena Genetic Resource Center: Headaches, Successes, and Growing Pains  

Microsoft Academic Search

The production of whitebark pine (Pinus albicaulis) seedlings for white pine blister rust (Cronartium ribicola) resistance screening and reforestation has required the development of nursery culturing regimes to optimize both germination and subsequent growth. Germination and culturing studies have been conducted to modify and adapt growing regimes to the environment of USDA Forest Service Dorena Genetic Resource Center. As a

Lee Riley; Judith Danielson; John C. Berdeen

416

Growth and survivorship of ramets and seedlings of agave deserti: influences of parent-ramet connections  

Microsoft Academic Search

Parent-ramet connections for Agave deserti, a common perennial of the Sonoran Desert, greatly enhanced ramet growth and survivorship compared with its seedlings. One year after ramets had been severed from their parents, 27% of the ramets had died, while all unsevered ramets remained alive; survivorship of severed ramets increased from 38% at 2 g dry weight (DW) to 100% at

Deborah O. Raphael; Park S. Nobel

1986-01-01

417

Plant Availability of Boron Adsorbed or Occulted on Goethite to Rape (Brassica napus L.) Seedling  

Microsoft Academic Search

The purpose of the study was to determine plant availability of boron (B) and relaxation of soil acid to rape seedling exhibited by B-doped goethite in acidic soil. For this purpose, two kinds of B-doped goethite were synthesized: one was goethite with adsorbed B prepared by reacting goethite with borax solution, and the other was goethite with occluded B by

Liying Ren; Jingzhen Cui; Yuliang Dong; Duanwei Zhu; Shuijiao Liao; Mingjian Geng; David Hamilton

2010-01-01

418

Induction of Heat Stress Tolerance in Barley Seedlings by Pre-Sowing Seed Treatment with Glycinebetaine  

Microsoft Academic Search

Heat stress adversely affects plant growth and development, while glycinebetaine (GB) plays a protective role under stressful conditions. The objective of this study was to assess the optimum level of GB for use as a presowing seed treatment and the subsequent effect on the heat tolerance of barley (Hordeum vulgare L. cv. Haider-93) seedlings. Among a range of GB levels,

Abdul Wahid; Asma Shabbir

2005-01-01

419

Effects of thiosulfate and tetrathionate on urease activity and seedling growth  

Microsoft Academic Search

Interest in use of ammonium thiosulfate (ATS) in conjunction with urea as a fertilizer has been stimulated by reports that ATS retards hydrolysis of urea by soil urease. We recently found, however, that ATS significantly retarded urea hydrolysis in soil only when applied at very high rates (>2,500 (?g\\/g soil) that adversely affected seedling development. Because ATS is rapidly oxidized

G. W. McCarty; J. M. Bremner; M. J. Krogmeier

1991-01-01

420

Mobilization of seed storage lipid by Arabidopsis seedlings is retarded in the presence of exogenous sugars  

Microsoft Academic Search

BACKGROUND: Soluble sugar levels must be closely regulated in germinating seeds to ensure an adequate supply of energy and building materials for the developing seedling. Studies on germinating cereal seeds indicate that production of sugars from starch is inhibited by increasing sugar levels. Although numerous studies have focused on the regulation of starch metabolism, very few studies have addressed the

Jennifer PC To; Wolf-Dieter Reiter; Susan I Gibson

2002-01-01

421

Salt Sensitivity and the Activities of the H+ -ATPases in Cotton Seedlings  

E-print Network

Salt Sensitivity and the Activities of the H+ -ATPases in Cotton Seedlings Howard Lin, Sandra S environ- ments. Sensitivityto high levels of salt in plants is associated with an inability to effectively+ -pumping ATPases may provide the driving force for Na+ transport via Na+ -H+ exchangers. In a salt

Schumaker, Karen

422

Combined effects of lanthanumion and acid rain on growth, photosynthesis and chloroplast ultrastructure in soybean seedlings  

Microsoft Academic Search

Rare earth elements (REEs) have been accumulated in the agricultural environment. Acid rain is a serious environmental issue. In the present work, the effects of lanthanum ion (La3+) and acid rain on the growth, photosynthesis and chloroplast ultrastructure in soybean seedlings were investigated using the gas exchange measurements system, chlorophyll fluorometer, transmission electron microscopy and some biochemical techniques. It was

Kejia Wen; Chanjuan Liang; Lihong Wang; Gang Hu; Qing Zhou

2011-01-01

423

Control of Pest Species: Tree shelters help protect seedlings from nutria (Louisiana)  

USGS Publications Warehouse

Various methods of nutria preventative techniques were tested in attempts to curb the loss of seedlings due to nutria capturing. The results of testing possibly indicate that tree shelters have real potential for use in forest restoration projects on sites with moderate nutria populations. Tree shelters may even prove effective on sites with high nutria populations, as long as alternative food supplies are available.

Allen, J.A.; Boykin, R.

1991-01-01

424

Effects of GA3 pregerminative treatment on Gentiana lutea L. var. aurantiaca germination and seedlings morphology.  

PubMed

Gentiana lutea L. is widely used in bitter beverages and in medicine; Gentianae Radix is the pharmaceutical name of the root of G. lutea. These uses have generated a high demand. The wild populations of Gentiana lutea var. aurantiaca (M. Laínz) M. Laínz have been decimated; it is necessary to establish guidelines for its cultivation. Gentian as most alpine species has dormant seeds. Dormancy can be removed by cold and by means of a gibberellic acid (GA3) treatment. However, cold treatments produce low germination percentages and GA3 treatments may produce off-type seedlings. So, the objective was to determine, for the first time, the presowing treatments that allow high germination rate and good seedling morphology. The best pregerminative doses of GA3 to break seed dormancy were 100, 500, and 1000 ppm, while the best doses to optimize the seedling habit were 50 and 100 ppm. This study provides, for the first time, a 100 ppm GA3 dose that led to a high germination rate and good seedling morphology, as the starting point for gentian regular cultivation. PMID:25105167

González-López, Óscar; Casquero, Pedro A

2014-01-01

425

In vitro germination and seedling development of cryopreserved Dendrobium hybrid mature seeds  

Microsoft Academic Search

In vitro germination and seedling development from Dendrobium Swartz. hybrid ‘Sena Red’, ‘Mini WRL’, ‘Jaquelyn Thomas’, and ‘BFC Pink’ seeds cryopreserved through vitrification (PVS2) were evaluated. Germination percentages after cryopreservation (LN) were variable among different controls and treatments, despite the initial high seed viability for all hybrids. Seeds exposed to PVS2 at ice temperature from 1 to 3h prior to

Wagner A. Vendrame; V. S. Carvalho; J. M. M. Dias

2007-01-01

426

Effects of space environment on biological characters of cultured rose seedlings  

NASA Astrophysics Data System (ADS)

Cultured rose seedlings were carried into space by SHENZHOU-4 spacecraft and then used as the experimental material to investigate effects of the space environmental conditions on morphology cytology physiology and molecular biology of the seedlings After loaded on the space flight the plant s height number of leaves and fresh weight per seedling were all increased significantly compared to the ground controls The content of chlorophyll was basically unchanged In some cells the ultrastructural changes involved twist contraction and deformation of cell wall curvature and loose arrangement of lamellae of some chloroplasts and a significant increase in number of starch grains per chloroplast In addition the number of mitochondria increased but some mitochondrial outer membrane broke and some mitochondrial cristae disappeared The activities of the defense enzymes such as superoxide dismutase peroxidase and catalyse in rose leaves increased and the content of malondialdehyde decreased In the RAPD analysis with 40 10-mer primers 36 primers generated 148 DNA bands from both of the space flight treated seedlings and the ground controls and five primers amplified polymorphic products The rate of DNA variation was 6 34

Min, L.; Huai, X.; Jinying, L.; Yi, P.; Chunhua, Z.

427

Survival and growth of native and alien woody seedlings in open and understory environments  

Microsoft Academic Search

Although plant invasion is often facilitated by disturbance, several non-native trees and shrubs have successfully invaded intact forest habitats in northeastern North America. To better understand invasive plant performance in intact versus disturbed forest habitats, we compared survival, relative height growth rate, aboveground biomass allocation, and leaf area of alien and native woody seedlings. In replicated understory versus open treatment

Nicole L. Sanford; Robin A. Harrington; James H. Fownes

2003-01-01

428

Plant regeneration from seedling explants of green bean (Phaseolus vulgaris L) via organogenesis  

Microsoft Academic Search

Green bean (Phaseolus vulgaris L.) plants were regenerated from 3-day old seedling explants via organogenesis. The explants contained a cotyledon and a small portion (2–3 mm) of embryonic axis split in half. Explants were cultured on a defined medium containing glutamine as the sole nitrogen source. A ring of meristematic tissue was produced at the base of the axillary bud

Chandra I. Franklin; Tony N. Trieu; Robert A. Gonzales; Richard A. Dixon

1991-01-01

429

GENERAL TECHNICAL REPORT PSW-GTR-240 Plant Compensatory Growth in Aspen Seedlings  

E-print Network

GENERAL TECHNICAL REPORT PSW-GTR-240 124 Plant Compensatory Growth in Aspen Seedlings: The Role compensatory growth, to the front of research in plant ecology and plant-herbivore interactions. We conducted a greenhouse experiment to evaluate how carbon sink-source relationships and compensatory plant growth operate

Standiford, Richard B.

430

Survival and growth of balsam fir seedlings and saplings under multiple controlled ungulate densities  

Microsoft Academic Search

Tree species composition in forests can be strongly modulated by high densities of cervid herbivores ultimately leading to local extirpation of species. To establish which cervid densities are compatible with the recruitment of a browse sensitive tree species, seedlings and saplings should be surveyed under variable cervid densities rather than in their presence or absence alone. We studied the growth

B. Hidding; J. P. Tremblay; S. D. Cote

2012-01-01

431

Author's personal copy Survival and growth of balsam fir seedlings and saplings under multiple  

E-print Network

Author's personal copy Survival and growth of balsam fir seedlings and saplings under multiple Received in revised form 19 March 2012 Accepted 24 March 2012 Keywords: Balsam fir White tailed deer stages of balsam fir (Abies balsamea) on Anticosti island (Québec, Canada) under controlled densities

Laval, Université

432

Do isolated gallery-forest trees facilitate recruitment of forest seedlings and saplings in savannna?  

NASA Astrophysics Data System (ADS)

Facilitation is an ecological process that allows some species to establish in environments they can hardly afford in the absence of the process. This study investigated if the subcanopy of gallery-forest trees isolated in savanna is suitable for the early recruitment of forest woody species. We measured tree crown area as well as the density of seedlings and saplings of gallery-forest tree species beneath isolated trees and in the savanna matrix along 50 transects of 5-km long and 600 m wide located along four gallery forests. We then tested the nurse-plant effect and Janzen-Connell hypothesis beneath isolated trees. We also examined the relationships between the crown area and the density of seedlings and saplings. Among the eight identified tree species isolated in savanna, only Daniellia oliveri and Khaya senegalensis showed nurse-plant effect and promoted a significant, yet low early recruitment with a seedling-to-sapling survival of 0.044 and 0.578, respectively. The suitability of the subcanopy of isolated trees decreased with the recruitment progression and Janzen-Connell effects were absent. Seedlings had neutral association with the crown area of isolated trees which shifted to positive at the sapling stage. The species of the isolated tree and the crown area explained less than 20% of total variance, indicating that other predictive factors are important in explaining the nurse-plant effect observed in this study.

Azihou, Akomian Fortuné; Glèlè Kakaï, Romain; Sinsin, Brice

2013-11-01

433

Seedling establishment in different microsites on Mount St. Helens, Washington, USA  

Microsoft Academic Search

On the volcanically devastated Pumice Plain of Mount St. Helens, plant species colonized microsites differentially. Peak colonization did not occur in the same microsites as peak establishment and growth. In addition, observed microsite colonization patterns differed between years. Two studies were conducted. The first assessed seedling establishment and growth from seeds sown at different microsites. The second assessed colonization into

Jonathan H. Titus; Roger del Moral

1998-01-01

434

The effect of elevation, light and water availability on the growth of Sierran conifer seedlings  

SciTech Connect

The composition of many plant communities will be altered with global change, and this will depend on individual species' abilities to reproduce and to survive under new climate conditions. Two experiments are underday to test the hypothesis that seedling demography is affected by the relative drought and shade tolerances of seven co-occurring species of Sierran conifers. The first experiment is being conducted at three sites in Sequoia National Park, California, elevations 1600 m, 1900 m and 2200 m. At each site, closed canopy [open quotes]shade[close quotes] plots and open canopy [open quotes]gap[close quotes] plots are being used. Seedling growth of each species is compared between light levels and elevations. The second experiment also measures seedling growth in low and high levels, but with four levels of water availability at one elevation (1900 m). Microenvironmental monitoring (soil and air temperature, relative humidity, radiation, and soil moisture) by surrounding mature trees are also being measured in order to develop a mechanistic model of seedling growth and survival.

Kern, R.A.; Dale, V.H.; Beauchamp, J.J. (Duke Univ., Durham, NC (United States) Oak Ridge National Lab., TN (United States))

1994-06-01

435

Proteomic alterations in root tips of Arabidopsis thaliana seedlings under altered gravity conditions  

Microsoft Academic Search

Gravity has a profound influence on plant growth and development Removed the influence of gravitational acceleration by spaceflight caused a wide range of cellular changes in plant Whole seedling that germinated and grown on clinostats showed the absent of gravitropism At the cellular level clinostat treatment has specific effects on plant cells such as induce alterations in cell wall composition

H. Q. Zheng; H. Wang

2006-01-01

436

Higher-order interaction between molluscs and sheep affecting seedling numbers in grassland  

Microsoft Academic Search

Vertebrate and invertebrate herbivores are both important in mesotrophic grasslands and these two different classes of herbivore potentially interact in their effect upon plant populations. We used two field experiments to test for higher order interactions (HOIs) among sheep, slugs and seedlings, using the mechanistic definition that an HOI occurs when the presence of one species modifies the interaction between

B. H. Clear Hill; J. Silvertown

1997-01-01

437

Effect of soil HHCB on cadmium accumulation and phytotoxicity in wheat seedlings.  

PubMed

The accumulation of cadmium (Cd) in wheat seedlings under single and joint stress of galaxolide (HHCB) and Cd was investigated, and their phytotoxicity and oxidation stress including chlorophyll (CHL), malondialdehyde (MDA), superoxide dismutase, and perosidase were assessed. The results showed that the accumulation of Cd in wheat seedlings increased with an increase in the concentration of Cd in soil. The low concentration of HHCB inhibited the accumulation of Cd, while the high concentration of HHCB induced the accumulation of Cd. The content of CHL increased significantly in treatments with 1-50 mg kg(-1) Cd. However, the content of CHL under joint stress of Cd and HHCB was significantly lower than that in the control. Besides, the content of MDA in wheat leaves and roots was also significantly affected by HHCB and Cd, particularly by their joint stress. Co-contamination of HHCB significantly affected the activity of antioxidant enzymes in wheat seedlings stressed by Cd. In a word, HHCB could aggravate the phytotoxicity of Cd to wheat seedlings. PMID:25142349

Chen, Cuihong; Zhou, Qixing; Cai, Zhang

2014-12-01

438

Variations in seed and seedling responses to water stress in three provenances of Eucalyptus camaldulen-  

E-print Network

relations, water use efficiency, partitioning of dry matter into roots, stems and leaves, leaf growthVariations in seed and seedling responses to water stress in three provenances of Eucalyptus within a species may differ in their germination and growth responses to water stress. Seeds from 3

Boyer, Edmond

439

Differential Effects of Typha Litter and Plants on Invasive Lythrum Salicaria Seedling Survival and Growth  

Microsoft Academic Search

Invasive species are a problem because of their detrimental ecological and economic effects. Increased disturbance caused by human impacts is hypothesized as a primary factor promoting the spread of invaders. Plants and plant litter can have important effects on plant colonization and community composition by affecting seedling survival and growth. I examined the hypothesis that invasion of non-native Lythrum salicaria

Heather A. Hager

2004-01-01

440

Effects of sand burial depth on seed germination and seedling emergence of Cirsium pitcheri  

Microsoft Academic Search

A greenhouse study was conducted to determine the effects of sand burial on seed germination and seedling emergence of Cirsium pitcheri, a threatened species along Lake Huron sand dunes. In October 1996, seeds of C. pitcheri were sorted into three groups (small, medium and large) and artificially buried at 2, 4, 6, 8, 10 and 12 cm depths in plastic

Hua Chen; M. A. Maun

1999-01-01

441

[Effects of Chinese onion' s root exudates on cucumber seedlings growth and rhizosphere soil microorganisms].  

PubMed

Taking the Chinese onion cultivars with different allelopathy potentials as the donor and cucumber as the accepter, this paper studied the effects of Chinese onion' s root exudates on the seedlings growth of cucumber and the culturable microbial number and bacterial community structure in the seedlings rhizosphere soil. The root exudates of the Chinese onion cultivars could promote the growth of cucumber seedlings, and the stimulatory effect increased with the increasing concentration of the root exudates. However, at the same concentrations of root exudates, the stimulatory effect had no significant differences between the Chinese onion cultivars with strong and weak allelopathy potential. The root exudates of the Chinese onion cultivars increased the individual numbers of bacteria and actinomyces but decreased those of fungi and Fusarium in rhizosphere soil, being more significant for the Chinese onion cultivar with high allelopathy potential (L-06). The root exudates of the Chinese onion cultivars also increased the bacterial community diversity in rhizosphere soil. The cloning and sequencing results indicated that the differential bacteria bands were affiliated with Actinobacteria, Proteobacteria, and Anaerolineaceae, and Anaerolineaceae only occurred in the rhizosphere soil in the treatment of high allelopathy potential Chinese onion (L-06). It was suggested that high concentration (10 mL per plant) of root exudates from high allelopathy potential Chinese onion (L-06) could benefit the increase of bacterial community diversity in cucumber seedlings rhizosphere soil. PMID:23898672

Yang, Yang; Liu, Shou-wei; Pan, Kai; Wu, Feng-zhi

2013-04-01

442

Effect of Water Deficit and Membrane Destruction on Water Diffusion in the Tissues of Maize Seedlings  

Microsoft Academic Search

We investigated diffusion of water in maize seedlings (Zea mays L. cv. Dnepropetrovskaya) following addition of polyethylene glycol (PEG) 6000 (osmotic potential -0.1 and -0.3 MPa) to the root medium by NMR method with pulsed gradient of magnetic field. Diffusion coefficients of different water phases in plant tissues (water of apoplast and vacuoles, water transported through the membranes) have been

I. F. Ionenko; A. V. Anisimov

2001-01-01

443

Dim-Red-Light-Induced Increase in Polar Auxin Transport in Cucumber Seedlings1  

E-print Network

Dim-Red-Light-Induced Increase in Polar Auxin Transport in Cucumber Seedlings1 I. Development and characterized a system to analyze light effects on auxin transport independent of photosynthetic effects. Polar transport. This light- induced change probably manifests itself by alteration of function of the auxin

Jones, Alan M.

444

Salt influence on germination and seedling survival of six cool season turfgrass species  

Microsoft Academic Search

‘Merion’ Kentucky bluegrass (Poa pratensis L.), ‘Pennfine’ perennial ryegrass (Lolium perenne L.), ‘Seaside’ creeping bent?grass (Agrostis palustris Huds.), ‘Dawson’ slender creeping red fescue (Festuca rubra trichophylla (L.) Gaud.), ‘Fults’ weeping alkaligrass (Puccinellia distans (L.) Parl.), and ‘common’ Lemmon alkaligrass (Puccinellia lemmoni (Vasey) Scribn.) were evaluated for germination and seedling survival in the greenhouse and laboratory under saline conditions. Overall results

M. A. Harivandi; J. D. Butler; P. M. Soltanpour

1982-01-01

445

Effects of saline stress on Eucalyptus seedlings R.A. Fathi D. Prat  

E-print Network

. Difficulties arise not only from drought but also from the salinity of soils (Chapman, 1975). Plants must that of sodium. The potassium content was significantly lower in roots of plants exposed to a 300 mM salineEffects of saline stress on Eucalyptus seedlings R.A. Fathi D. Prat Laboratoire de G6n6tique des

Paris-Sud XI, Université de

446

Evaluation of some markers of vigor in seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco)  

E-print Network

Evaluation of some markers of vigor in seedlings of Douglas fir (Pseudotsuga menziesii (Mirb is an impor- tant aspect of forest regeneration in the Pacific Northwestern United States. When a plantation content of roots (Puttonen, 1986), the osmotic concentration of xylem sap and biochemical markers

Boyer, Edmond

447

The use of seedling leaf death score for evaluation of drought resistance of rice  

Microsoft Academic Search

Leaf death (drought score) of seedlings has been extensively used in rice breeding programs as a selection index for drought resistance. This paper investigates the factors that affect the drought score of rice cultivars exposed to water stress during the vegetative stage and the relationship between drought score and yield. Two upland experiments consisting of 21 and 8 cultivars, respectively,

J. H. Mitchell; D. Siamhan; M. H. Wamala; J. B. Risimeri; E. Chinyamakobvu; S. A. Henderson; S. Fukai

1998-01-01

448

Differential seed and seedling predation by crabs: impacts on tropical coastal forest composition  

Microsoft Academic Search

Recently, the importance of seed predation by crabs on mangrove species distributions and densities has been established by several studies. In a tropical coastal terrestrial forest in Costa Rica, we investigated the relative importance of predation by land crabs, Gecarcinus quadratus, and hermit crabs, Coenobita compressus, on measured forest composition through a series of seed removal and seedling establishment experiments.

Erin Stewart Lindquist; C. Ronald Carroll

2004-01-01

449

A Spatially Explicit Analysis of Seedling Recruitment in the Terrestrial Orchid Orchis purpurea  

Microsoft Academic Search

• Seed dispersal and the subsequent recruitment of new individuals into a population are important processes affecting the population dynamics, genetic diversity and spatial genetic structure of plant populations. • Spatial patterns of seedling recruitment were investigated in two populations of the terrestrial orchid Orchis purpurea using both univariate and bivariate point pattern analysis, parentage analysis and seed germination experiments.

Hans Jacquemyn; Rein Brys; Katrien Vandepitte; Olivier Honnay; Isabel Roldán-Ruiz; Thorsten Wiegand

2007-01-01

450

THE EFFECT OF CHRONIC OZONE EXPOSURE ON THE METABOLITE CONTENT OF PONDEROSA PINE SEEDLINGS  

EPA Science Inventory

Ponderosa Pine (Pinus ponderosa Laws.) seedlings grown in field exposure chambers and fumigated with ozone at a concentration of 200 g/cu m 6 h/day; 7 days/wk for variable periods of up to 20 weeks. Pines were harvested at 4 wk intervals to determine the levels of the metabolites...

451

ACCUMULATION OF CESIUM-137 AND STRONTIUM-90 IN PONDEROSA PINE AND MONTEREY PINE SEEDLINGS  

EPA Science Inventory

Because Pinus ponderosa (Dougl.ex Laws) and P. radiate (ID.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. . ponderosa and P. radiata seedling...

452

EFFECTS OF ALUMINIUM (Al 3+ ) ON SEED GERMINATION AND SEEDLING GROWTH OF WHEAT (TRITICUM AESTIVUM L.)  

Microsoft Academic Search

Effects of different concentrations of aluminium (Al 3+ ) on seed germination of high yielding varieties of wheat (Triticum aestivum L.) were investigated. Al 3+ at 500 ppm had inhibitory effect on seed germination, seedling growth and its dry matter. Relatively higher root and shoot dry matter in Sonlika, Fang-60 and lower in Baw-923 and Protiva were found. Root growth

A. N. M. ALAMGIR; SUFIA AKHTER

2009-01-01

453

Lunisolar tidal synchronism with biophoton emission during intercontinental wheat-seedling germination tests.  

PubMed

Synchronic measurements of spontaneous ultra-weak light emission from germinating wheat seedlings both in Brazil and after transportation to Japan, and with a simultaneous series of germinations with local seedlings in the Czech Republic, are presented. A series of tests was also performed with samples returned from Japan to Brazil and results compared with those from undisturbed Brazilian seedlings. Native seedlings presented semi-circadian rhythms of emission which correlated with the gravimetric tidal acceleration at their locality, as did seeds which had been transported from Brazil to Japan, and then returned to Brazil. Here, however, there were very small disturbances within the periodicity of emissions, perhaps as a result of similar tidal profiles at locations whose longitudes are 180° apart, as in this case, different from previous results obtained in Brazil-Germany tests with other longitude shift. This feature of the Brazil and Japan locations may have minimized the requirement for the acclimatization of the transported seed to their new location. PMID:24714075

Gallep, Cristiano M; Moraes, Thiago A; Cervinková, Kate?ina; Cifra, Michal; Katsumata, Masakazu; Barlow, Peter W

2014-01-01

454

Ecotoxicological effects of paracetamol on seed germination and seedling development of wheat ( Triticum aestivum L.)  

Microsoft Academic Search

In order to assess ecological risk of pharmaceutical compounds entering into agricultural ecosystems, toxic effects of paracetamol with therapeutic action on wheat (Triticum aestivum L.) were investigated as an example, using early growing and developmental indexes of wheat, including seed germination, shoot height and root length, peroxidase, superoxide dismutase, chlorophyll, and soluble protein in the seedlings. The results showed that

Jing An; Qixing Zhou; Fuhong Sun; Lei Zhang

2009-01-01

455

Nitric oxide alleviates arsenic-induced toxic effects in ridged Luffa seedlings.  

PubMed

Hydroponic experiments were conducted to investigate whether exogenous addition of nitric oxide (NO) as sodium nitroprusside (SNP) alleviates arsenic (As) toxicity in Luffa acutangula (L.) Roxb. seedlings. Arsenic (5 and 50 ?M) declined growth of Luffa seedlings which was accompanied by significant accumulation of As. SNP (100 ?M) protected Luffa seedlings against As toxicity as it declined As accumulation significantly. The photosynthetic pigments and chlorophyll fluorescence parameters such as Fv/Fm, Fv/F0, Fm/F0 and qP were decreased while NPQ was raised by As. However, the toxic effects of As on photosynthesis were significantly ameliorated by SNP. The oxidative stress markers such as superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) contents were enhanced by As, however, these oxidative indices were diminished significantly in the presence of SNP. As treatment stimulated the activities of SOD and CAT while the activities of APX and GST, and AsA content and AsA/DHA ratio were decreased. Upon SNP addition, along with further rise in SOD and CAT activity, APX and GST activity, and levels of AsA and AsA/DHA ratio were restored considerably. Overall results revealed that significant accumulation of As suppressed growth, photosynthesis, APX and GST activities and decreased AsA content, hence led to the oxidative stress. However, the addition of SNP protected seedlings against As stress by regulating As accumulation, oxidative stress and antioxidant defense system. PMID:23917073

Singh, Vijay Pratap; Srivastava, Prabhat Kumar; Prasad, Sheo Mohan

2013-10-01

456

Quantitative trait loci associated with seed and seedling traits in Lactuca.  

PubMed

Seed and seedling traits related to germination and stand establishment are important in the production of cultivated lettuce (Lactuca sativa L.). Six seed and seedling traits segregating in a L. sativa cv. Salinas x L. serriola recombinant inbred line population consisting of 103 F8 families revealed a total of 17 significant quantitative trait loci (QTL) resulting from three seed production environments. Significant QTL were identified for germination in darkness, germination at 25 and 35 degrees C, median maximum temperature of germination, hypocotyl length at 72 h post-imbibition, and plant (seedling) quality. Some QTL for germination and early seedling growth characteristics were co-located, suggestive of pleiotropic loci regulating these traits. A single QTL (Htg6.1) described 25 and 23% of the total phenotypic variation for high temperature germination in California- and Netherlands-grown populations, respectively, and was significant between 33 and 37 degrees C. Additionally, Htg6.1 showed significant epistatic interactions with other Htg QTL and a consistent effect across all the three seed production environments. L. serriola alleles increased germination at these QTL. The estimate of narrow-sense heritability (h2) of Htg6.1 was 0.84, indicating potential for L. serriola as a source of germination thermotolerance for lettuce introgression programs. PMID:16177902