Effects Of Water Stress On Germination Of Seeds And Physiological And Biochemical Characters Of Seedlings Of Wheat Of Different Genotype

In order to know the difference of the drought-resistance of different winter wheat varieties during germination and seedling stage and give reliant evidence for ampliate breeding experts and the production of winter wheat, we studied the ability of germination and the physiological and biochemical characters of four winter wheat varieties in seedling with different drought-resistance under 20% PEG 6000(w/v) stress. The main results in this study are listed as follows:1. Under 20% PEG 6000(w/v) osmotic stress, the length of coleoptiles and major radicles of the four winter wheat varieties were all restrained obviously. But the degree of Yumai34 and Zhengzhou9023 restrained was bigger and different from the drought-resistant cultivars No.Luohan2 and Luohan6 obviously. The anti-stress indexes of coleoptiles of Yumai34, Zhengzhou9023, No. Luohan2 and Luohan6 were 0.60, 0.58, 0.64, 0.83. The anti-stress indexes of major radicles of Yumai34, Zhengzhou9023, No. Luohan2 and Luohan6 were 0.63, 0.68, 0.72, 0.84.2. 20% PEG 6000(w/v) osmotic stress restrained the length of side roots of the four wheat varieties obviously. The anti-stress indexes of side radicles of Yumai34, Zhengzhou9023, No. Luohan2 and Luohan6 were 0.73, 0.74, 0.71, 0.82. 20% PEG 6000(w/v) osmotic stress influenced the number of side roots slightly. The number of side roots of No. Luohan2 increased. The anti-stress index of it was 1.01.3. Under 20% PEG 6000(w/v) osmotic stress, the percents of gemmation of the four varieties all descended. But the degrees of falling of Yumai34 and Zhengzhou9023 were bigger, and different from the controls and drought-resistant cultivars No. Luohan2 and Luohan6 obviously. The relative gemmation percents of Yumai34 and Zhengzhou9023 were 78.4%, 79.7%. No. Luohan2 and Luohan6 were restrained more slightly, the relative gemmation percents were 92%, 94%.4. The relative water content of winter wheat descended under 20% PEG 6000(w/v) osmotic stress. After 72 hours the relative water contents of the four wheat varieties Yumai34, Zhengzhou9023, No. Luohan2 and Luohan6 were 65.9%, 66.4%, 73.7%, 72.4%. The relative water contents of Yumai34 and Zhengzhou9023 were different from the controls and the water contents of Yumai34 and Zhengzhou9023 obviously.5. Under the condition of 20% PEG 6000(w/v) water stress, the relative electric conductivity in winter wheat leaves of seedling of the four cultivars increased. The relative electric conductivities of Yumai34 and Zhengzhou9023 were 30.5%, 31.6%, and different from the controls obviously. The relative electric conductivities of No. Luohan2 and Luohan6 were 18.4%, 19.44%, and different from the relative electric conductivities of Yumai34 and Zhengzhou9023 obviously.6. After 72 hours, imposition of water stress with 20% PEG 6000(w/v), the contents of chlorophyll a,chlorophyll b and carotinoid of the four cultivars all decreased. But only the chlorophyll a,chlorophyll b of Yumai34 and Zhengzhou9023 were all different from the controls. The contents of chlorophyll a, chlorophyll b of Yumai34 were 1.04 mg/g·fw, 0.18 mg/g·fw. The contents of chlorophyll a, chlorophyll b of Zhengzhou9023 were 0.98 mg/g·fw, 0.30 mg/g·fw.7. After 72 hours, imposition of water stress with 20% PEG 6000(w/v), the soluble sugar contents of the four cultivars all went up, and were all different from the controls. The soluble sugar contents of cultivars sensitive to water Yumai34 and Zhengzhou9023 were 24.79mg/g·fw, 24.98mg/g·fw. The contents of No.Luohan2 and Luohan6 were 30.49mg/g·fw, 33.9mg/g·fw. The cultivars sensitive to water were different from the drought-resistant cultivars obviously in the extreme.8. Under the condition of water stress with 20% PEG 6000(w/v), the soluble protein content of different cultivars all decreased. After 72 hours, the soluble protein content of drought-resistant variety No. Luohan6 decreased most and was different from the control obviously. No. Luohan2 decreased most slightly.