Sunflowers
Mostrando 25-31 de 31 artigos, teses e dissertações.
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25. Transpiration, a prerequisite for long-distance transport of minerals in plants?
The major “benefit” alleged to accrue from transpiration (the evaporative loss of water from plant surfaces) is that it is essential for the long-distance transport of mineral ions, but the possible interrelation between these two processes has rarely been tested. Transpiration was experimentally dissociated from mineral supply by growing sunflowers (Hel
The National Academy of Sciences.
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26. Strain-Dependent Temperature-Sensitive Phase in Crown Gall Tumorigenesis 1
The effect of high temperature treatments on the early stages of crown gall tumorigenesis in sunflowers was investigated. Treatments of 32 C initiated at various times during the first ten days after infection had a similar effect on tumors induced by Agrobacterium tumefaciens strains B6 and C58. Tumor growth was sensitive to 32 C until 60 to 72 hours after
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27. Production and Characterization of Two Monoclonal Antibodies Specific for Plasmopara halstedii
Sunflower downy mildew, caused by the fungus Plasmopara halstedii, is a potentially devastating disease. We produced two monoclonal antibodies (MAbs) (12C9 and 18E2) by immunizing mice with a partially purified extract of P. halstedii race 1. Both MAbs detected in enzyme-linked immunosorbent assay (ELISA) all races of P. halstedii present in France. No cross
American Society for Microbiology.
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28. Rapid hybrid speciation in wild sunflowers
Hybrid or “recombinational” speciation refers to the origin of a new homoploid species via hybridization between chromosomally or genetically divergent parental species. Theory predicts that this mode of speciation is punctuated, but there has been little empirical evidence to support this claim. Here, we test the hypothesis of rapid hybrid speciation by
The National Academy of Sciences.
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29. Presence and Identification of Polyamines in Xylem and Phloem Exudates of Plants 1
Polyamines were identified by high performance liquid chromatography (benzoylation) and by thin layer chromatography (dansylation) in xylem exudates from stems of sunflowers (Helianthus annuus [L.]), mung bean (Vigna radiata [L.] Wilczek), grapevine (Vitis vinifera [L.] cv Grenache), and orange (Citrus sinensis [L.] Osbeck, cv Valencia), as well as in phloem
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30. Molecular and Physiological Responses to Water Deficit in Drought-Tolerant and Drought-Sensitive Lines of Sunflower1 : Accumulation of Dehydrin Transcripts Correlates with Tolerance
To investigate correlations between phenotypic adaptation to water limitation and drought-induced gene expression, we have studied a model system consisting of a drought-tolerant line (R1) and a drought-sensitive line (S1) of sunflowers (Helianthus annuus L.) subjected to progressive drought. R1 tolerance is characterized by the maintenance of shoot cellular
American Society of Plant Physiologists.
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31. Influence of Drought Acclimation and CO2 Enrichment on Osmotic Adjustment and Chlorophyll a Fluorescence of Sunflower during Drought
Osmotic adjustment occurred during drought in expanded leaves of sunflowers (Helianthus annuus var Hysun 30) which had been continuously exposed to 660 microliters CO2 per liter or had been previously acclimated to drought. The effect was greatest when the treatments were combined and was negligible in nonacclimated plants grown at 340 microliters CO2 per li