| This experiment was carried out at the laboratory and the Science and Technology Education Garden of Henan Agricultural University during 2009-2010, We investigated the growth and development, water physiology, output and analyzed water use efficiency. Water use efficiency and its partial physiological mechanism of different drought resistance wheat were researched systematically.The main conclusions are as follows:1. The influence of the drought on the spike number of the three winter wheat species is not obvious, but the economic yield and the thousand seed weight reduced significantly. Varieties with different drought resistance and yield decline in grain weight showed that:Yunong 202> Luohan 7>durum 2008, same as the dry matter decline in wheat cultured indoor. That the levels of drought resistance of three varieties were as follows:Durum 2008, Luohan 7 and Yunong 202. Moderate drought during the filling period can increase the yield and the level of water use efficiency of single leaf, especially the single leaf water use efficiency increased significantly. The growth size of the different species were Durum 2008,Luohan 7 and Yunong 202 successively.2. The net photosynthetic rate(Pn),transpiration rate(Tr),intercellular CO2 concentration(Ci),stomatal conductance(Gs),chlorophyll,chlorophyll a and b of the flag leaves of the three winter wheat species were reduced with the increasing drought of filling stage, while the chlorophyll a/b has a tendency to increase. Under drought stress, the fall in Pn of the Yunong 202 was larger than Luohan 7 and Durum 2008, however, the rate of Gs and Tr decline is smaller than Luohan 7 and Durum 2008. It is showed that drought resistant varieties which were Luohan 7 and durum 2008 could reduce the transpiration rate and stomatal conductance effectively under drought stress. Thus, the water use efficiency of drought resistant varieties could be improved.3. Under drought stress, the production rate of O2-, H2O2 and MDA content in the leaves of the three winter wheat species were all increased. The increase of Yunong 202 was higher than Luohan 7 and Durum 2008, indicating that drought stress can make leaves membrane of winter wheat peroxidation to strengthen and accelerate the aging of winter wheat, and peroxidation of drought resistance weak Yunong 202 is higher than the drought resistance strong Luohan 7 and durum 2008. SOD and POD activity of the three species of winter wheat leave increase significantly under drought stress, while no significant increase of CAT activity, the increasing in Luohan 7 and durum 2008 is higher than Yunong 202. Results showed that the winter wheat can improve the antioxidant protection enzyme activity to adapt to drought and other stress factors, while the SOD, POD enzyme activity of Luohan 7 and Durum 2008 are higher than Yunong 202. Thus, they could reduce the damage of membrance lipid peroxidation.4. Under drought stress, total soluble sugar and free Pro content of winter wheat leaves increased significantly, especially in severe stress; Drought resistance of different varieties showed an increase of soluble sugar content of durum 2008> Luohan 7> Yunong 202, while the Pro increases the opposite. Soluble protein content has a evident decline, The order among the varieties with different drought resistance showed that: Yunong 202> Luohan 7> durum 2008. It is concluded that decrease of soluble protein in the varieties of strong drought resistance is lower, while the accumulation of osmotic adjustment material is higher, indicating that the accumulation of osmotic adjustment material is one of the ways to improve the drought resistance of winter wheat. |
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