Study On Physiological And Morphology Selecting Targets In Drought-resistant Breeding Of Soybean

This paper analyzed the practical situation of selecting targets and markers in drought-resistant breeding of soybean. It shows that, with the advance of research, various physiological biochemical targets and markers emerged on the basis of morphology ones. In addition with the development of molecular biology, the molecular markers related to drought-resistance of soybean are under investigation and some are applied in breeding activities. Study of drought resistance was made in ten soybean varieties of ecotype. Lots of physiological indexes related to drought resistance in seedling stage and flowering -podding stage were studied in both normal and drought conditions. Analysis of variance for field ' experiment was also made. And those kinds of index of drought-resistance were analyzed by using subordinate function which analogue drought-resistance breeding selecting. The result were as follows: physiological indexes-relative water content(RWC), relative conductivity, net photosynthesis velocity, transpirations velocity, water use efficiency, the perpxidase(POD), the superoxide dismutase(SOD), the catalase(CAT) and free prolin content; morphology indexes-dry weight of total biological, dry weight of plant above ground, dry weight of root, ratio of root to canopy, plant height, burl number of caulis, pod number of plant, No. of grain number of plant, grain yield of plant; all those can been target of drought resistance breeding. On seasonal drought of flower and pod age, physiological indexes and morphology index are significant relative to property of drought resistance of Soybean. Selecting good germs which can be used as parents and crossing each other by using colligation of coefficient of drought resistance filtering the varieties of soybean that has been exist, and synthetic selecting good varieties by using subordinate function of property index in there generational group are very useful drought resistance breeding. Only using morphology target, drought resistance breeding may lose small part of good germs. Only using physiological index, drought resistance breeding is no practical value. Synthesis the two is the better strategy of breeding.