Dissertation > Agricultural Sciences > Crop > Economic crops > Oil crops > Rapeseed ( Brassica )

Evaluation of Drought Tolerance in Varieties of Rapeseed (Brassica Napus L.) and Regulate by Exogenous GA3

Author LiZhen
Tutor ZouChongShun;ZhangXueKun
School Chinese Academy of Agricultural Sciences
Course Crop Genetics and Breeding
Keywords Brassica napus Tolerance exponential Polyethylene glycol Germplasm Resources Gibberellin Osmoregulation Antioxidant enzymes
CLC S565.4
Type Master's thesis
Year 2010
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Rape is one of the most important oil crops in China, the seasonal drought in Yangtze River Basin of China's rapeseed production caused a serious threat, Brassica drought-tolerant resources, breeding rapeseed drought-tolerant varieties is one of the effective ways to reduce drought losses . In this study, 81 Brassica napus germplasm resources germinated seeds under PEG stress drought tolerance were identified, measured germination rate, seedling height, fresh weight and relative vigor index and other indicators. Then select 17 Brassica napus varieties of potted drought, wilting rate of the main indicators related through the leaves, photosynthesis, roots, and other physiological traits compared filter out certain varieties DROUGHT TOLERANCE. Late to dual 10 material, carried out with different concentrations of gibberellin (GA3) soaking in promoting the role and mechanism of Brassica napus germination of Drought Tolerance. 10% (w / v) PEG6000 osmotic medium analog drought conditions, the different sources of Brassica napus (Brassica napus L.) cultivars (lines) under drought stress germination identification, analysis of genetic seed germination drought tolerance diversity. The results showed that: under drought stress, part of the material handling and control of germination traits have significant differences, the average height of 81 Brassica napus material processing is 36.5% lower than in the control, on average 31% lower than in the control fresh weight, seedling rate reduced by 11.1%. Greater genetic differences in drought tolerance of Brassica napus varieties (lines), seedling vigor index variation range of 19% -81%, the average vitality index was 55%. Correlation analysis showed that the germination vigor index and stress traits was highly significant positive correlation can be used as a comprehensive index of drought-resistant seed germination. Vigor index, 81 rape resources into strong, weak three drought level, and screened to 30295,30253, dual 6, 30703,30296,30290,30704, Zhongyouza 9, German oil 4 number and the number of drought-resistant genetic resources. Analysis of drought stress under 17 Brassica napus varieties Physiological and biochemical variation to explore the different varieties of drought tolerance differences and drought tolerance identification methods. 17 B. napus varieties under water stress conditions, leaf water retention capacity, the protection of the photosynthetic pigments, membrane lipid peroxidation and active oxygen scavenging ability showed a greater difference. The general trend is that the varieties under water stress the leaves wilting index and leaf photosynthetic rate, chlorophyll, carotenoid content, SOD, CAT activity of up to a positive correlation with the WSD, MDA content, electrical leakage amounted to a negative correlation. The leaves wilting index most intuitive, comprehensive reflects rape seedling drought tolerance. Leaves wilting index as the main indicators of the 17 species are classified into three drought-tolerant level screened B108, H3531, Q2, 9548,8056 seedling drought tolerance and germplasm resources. Induced drought tolerance improved plant growth regulator - gibberellin to improve the drought tolerance of rape, screening, and gibberellin soaking induced germination of Brassica napus drought tolerance mechanism research. Take advantage of a 15% (w / v) PEG6000 permeability media simulated drought conditions 0,100,200,300,400 and 500 mg · l-1 gibberellin solution soaking treatment 8h rapeseed (double the 10th ) germination and germination drought-resistant identification. The results show that: gibberellin can significantly improve seed germination traits under drought conditions. ,200-300 mg · l-1 gibberellin solution significantly improve drought tolerance index of 88%, 42% of the fresh weight and height 72.7% increase in the content of soluble substances (soluble sugar 47.2%, compared with the control 35.6% of the soluble protein proline 62.9%); to improve including CAT45.6% POD46.6% SOD13 the antioxidant enzymes Department activity, significantly reducing the the cotyledon cell membrane peroxidation level (MDA36.6%). Gibberellin as a way to promote seed germination, drought-tolerant oilseed rape germination period adjustment substances, and has a great potential for applications in production.

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