Drought Resistance Identification Of New Strain In Transgenetic Wheat By Gm/GhDREB Gene

Wheat is a kind of important food crops in arid and semi-arid regions of China. It has great significance in utilizing the drought-resistant gene resources to improve drought-resistant ability of wheat today. The development of transgenic technique provides an economical approach in cultivating new drought-resistant cultivars GhDREB,GmDREB1 gene transgenic lines, Glumai23 and Gjimai19 were used as materials. In order to comprehensively evaluate the drought-resistant performance of transgenic lines, Glumai23 and Gjimai19, after the test materials were used to detect, the coleoptile length , main radicle numbers and length of wheat seedlings, morphology of late growth stage, their physiological and biochemical characters (such as relative water content, soluble protein content, relative electric conductivity, proline content, photosynthesis rate, transpiration rate), yield and drought resistance index were further analyzed under 20% concentrations PEG-6000 osmotic solution simulated drought stress and field case at moisture critical period.1 The result indicated that in contrast to normal treatment, the coleoptile length,radicle length and radicle numbers of test materials reduced under 20% concentrations PEG-6000 osmotic solution simulated drought stress , and the control showed a significant decrease while the transgenic lines showed a modest one..2 Under field case at moisture critical period,with the increasing extent and duration of drought stress, the chlorophyll content, photosynthetic rate, relative water content of all materials showed a decreasing tendency, but transgenic lines showed a slight decrease and hovered at a high level in contrast to non-transgenic ones;the leaf soluble protein , proline and ABA content of transgenic lines, Glumai23 and Gjimai19, increased with the increasing extent and duration of drought stress. Glumai23 and Gjimai19 hold much more ABA content than the non-transgenic ones, and reach the highest point at flowering stage, while decline at grain filling stage. Leaf relative electric conductivity and malondialdehyde content of transgenic lines, Glumai23 and Gjimai19, slightly increase under the drought stress, which indicated that the transgenic lines could effectively perform the physiological autoregulation at the aspects of cell membrane permeability of leaf and regulation ability to adapt the drought.3 Under W0, W1 and W2, three different irrigation levels,transgenic lines always had higher plant height than control. The height in both groups of materials had different extent of decrease with the increase of drought stress, and the height of transgenic lines decreased slightly. The spike numbers of individual in control declined, while the spike numbers of transgenic lines stabilized relatively. Under W0 and W1 conditions, the 1000-grain weight of transgenic lines were much higher than the control one. Under the W0 condition, the yield of Glumai23 exceed the control one by 11.68%, and the drought index was 1.22, which belongs to a strong drought-resistant level; the yield of Gjimai19 exceed the control one by 6.36%, and the drought index was 1.23, which belongs to a strong drought-resistant level. The results demonstrated that the transgenic plants of Glumai23,Gjimai19 show stronger resistance to drought than the control ones.