The New Drought-resistant Agents On The Basic Physiology And Yield Of Field Crops

In the 3-leave stage, wheat(Triticum aestivum), maize(Zea mays) and cotton (Gossypiu,n hirsutum) seedlings were thinned out respectively , after that part of water soaking seeds continued to be watered as control one , the rest stopped watering as control two, the seedlings of newtype -drought-resister- soaking seeds stopped watering as the newtype drought resister's treatmeat. When crops began to wilt, the growth status and other Physiological indexes were measured, and the results were listed below: 1.the effects of newtype drought resister on the water content,shoot and root dry weight ,and the ratio of root to shoot of wheat,rnaize and cotton seedlings under drought stress. Drought stress significantly decreased water content and inhibited the accumulation of dry matter,and the inhibition to the shoot was greater than to the root. On the contrary, newtype drought resister can increase the water keeping capacity so as to alleviate the injury of drought to the seedlings.Furthermore, it can increase the ratio of assimulation products transportation from shoot to root,thus promoted the development of the root and control the growth of the shoot.the changing sequence of water content, dry weight of wheat, maize and cotton was: the control one > the newtype drought resister> the control two. The changing sequence of the ratio of root to shoot of wheat and cotton was: the control on the control two < the newtype drought resister, but that of maize was: the control two < the control one K the newtype drought resister. 2. The effects of newtype drought resister on photosynthesis of wheat,maize aix cotton seedlings under drought stress. Under drought stress, Pn and Cs of the three crops decreased with the elongation of treating time, and Ci of the control two was lower in the initial stage of drought and higher in the later stage of drought, while Ci of the newtype drought resister was always lower. The newtype drought resister releived inhibition of drought, decreased the susceptibility to drought. In the initial stage of drought, the changing sequence of Pn of the three crops was: the control one> the newtype drought resister> the control two; in the later stage of drought the sequence for wheat, maize was: the control on the newtype drought resister, while that of cotton was: the newtype drought resiste the control one > the control two. 3. The effects of newtype drought resister on evaporating and utilization of water of wheat, maize and cotton seedlings under drought stress. Ls increased, and Tr decreasing with the prolongation of treating time under drought stress. When the seedlings of the newtype drought resister were stressed with drought, Ls and Tr was lower than those of the control two, while WUE was higher. 4. The effects of newtype drought resister on chlorophyll content (Chl) and chlorophyll stability index(CSI) of wheat,maize and cotton Seedlings under drought stress. Under drought stress, the chlorophyll content in leaves of the three crops decreased, and the chlorophyll stability index increased. In contrast with the control plants the leaves of the newtype drought resister were light green or yellow-green, and Chl content was higher than that of the control two, whereas CS! was lower than the control plants.