Phap, Vu Anh: Induction of salt tolerance in rice (Oryza sativa L.) by brassinosteroids. - Bonn, 2006. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5N-08679
@phdthesis{handle:20.500.11811/2384,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5N-08679,
author = {{Vu Anh Phap}},
title = {Induction of salt tolerance in rice (Oryza sativa L.) by brassinosteroids},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2006,
note = {Salinity is one of the most serious constraints of rice production in the Mekong Delta of Vietnam. Currently, recommended strategies to overcome the adverse effects of salt stress include the use of tolerant cultivars, ameliorative water management and diverse cultural practices. However, none of these strategies is fully effective under the diverse environmental conditions or adoptable by farmers in the Mekong Delta. For improvement of quality parameters in rice grown under salt stress conditions, biological processes have been established on the basis of plant protectants, the brassinosteroids. They have been demonstrated to show effects in yield increase and its parameters in the induction of salt tolerance and in adaptation mechanisms against salt-stress. Recent findings on the effects of brassinosteroids on the stress tolerance of crops open new avenues to address the salinity problems in rice (Oryza sativa L.). The effects of an application of brassinosteroid “24-epibrassinolide” (EBl) on growth, yield and physiological traits of salinity-tolerant (MTL119) and salinity-sensitive (IR28) rice cultivars were studied under controlled growing conditions in hydroponics and potted soil. The effect of brassinosteroid treatment on the salinity tolerance of rice during the germination involved seed soaking in 0, 0.5, 1.0 and 1.5 mg l-1 of EBl solution with 0 and 100 mmol NaCl addition. The effect of brassinosteroid treatment on the salinity tolerance of rice during the seedling stage involved seed soaking in 0 and 1 mg l-1 of EBl solution and subsequent germination in nutrient solution with 0 and 100 mmol NaCl addition. The effect of brassinosteroid treatment on the salinity tolerance of rice during vegetative and reproductive growth stages involved seed soaking and the foliar application of EBl solution at a concentration of 1 mg l-1 of EBl at the early vegetative (25 days after sowing) and the panicle initiation stages of rice grown in potted soil. Salinity levels of 0, 50 and 100 mmol NaCl (approx., 0, 5 and 10 dSm-1) were applied between 30 and 51 days after seeding. Seed soaking with EBl improved both the earliness and the total germination (up to 50%) of cultivar MTL119 but had no effect on the salinity-sensitive cultivar IR28. While EBl application affected neither shoot or root growth nor the chlorophyll content of 14 day-old seedlings, it tended to improve the salinity tolerance of the seedlings. This trend was associated with a significant increase in the leaf proline content from 1.23 in control to 2.02 µmol (64%) in EBl-treated plants. EBl application during the vegetative and reproductive growth stages had little or no significant effect on the salinity tolerance of both varieties as measured by yield and yield parameters or a range of physiological parameters (leaf area, chlorophyll content, photosynthesis). However, most parameters, including the grain yield, tended to increase by up to 30% in the salt tolerant cultivar MTL119 and by up to 14% in the salt-sensitive cultivar IR28. However, EBl application significantly enhanced the number of filled grains by 20% in cultivar MTL119 under mild salinity stress of 5 dS m-1. This tendency was accompanied by a significant increase in leaf proline concentration (48-70%). It may be concluded that brassinosteroids appear to improve the salinity tolerance of some rice cultivars under mild salt stress. The physiological mechanism for this enhanced stress tolerance has been shown to involve the accumulation of proline in the cell of leaves. Further studies are needed to confirm the positive effect of EBl application on salt stress tolerance and the positive mechanism of proline accumulation and must involved field studies using a wider range of rice germplasm and more diverse environmental conditions.},
url = {http://hdl.handle.net/20.500.11811/2384}
}

Die folgenden Nutzungsbestimmungen sind mit dieser Ressource verbunden:

InCopyright