A Comparative Study On Index Of Wheat Varieties Drought Resistance

Drought is one of the main non-biological stress which is restricted production in the world. Drought is the main yield limiting factor in most parts of North Area., So the key road is improving water-saving agriculture , choosing and breeding drought resistance variety. To cultivate and demonstrate good drought resistance variety has important meaning of saving water resource , and evaluate wheat varieties drought resistance index exactly is the base of drought resistance wheat breeding and choosing .The wheat varieties drought resistance is a complex bio-characters, which reflects series of physiologys shapes . The scholars have done great number of works , but paid more attention to the choosing and evaluating of wheat drought resistance varieties , less to the drought resistance . As the different ways and materials ,these are different results . For get suitable wheat drought resistance evaluating index , using the winter wheat varieties of dry-land wheat in the regional test in north part of China as trial materials, we studied the drought resistance yield index ,characters index and photosyn the fical index ,it shows that:â‘ it was different the wheat varieties drought resistance measurement and the wheat germplasm resources screening with drought resistance, DRC expressed the stable yield ability of the wheat varieties, it was clearer to jig drought resistance wheat germplasm resources. Compared with the wheat varieties as contrast, DI included the opposite yield (drought resistance coefficient) and absolute yield of the wheat variety, it was more operational to combine the drought resistance measurement with the regional test and wheat varieties yield experiments. Therefore, the DI would be the comprehensive drought resistance measured index; it was the most perfect to be used in the wheat varieties regional test and wheat drought breeding;â‘¡Character index can increase early stage choosing efficienly of wheat drought resistance .For set character index , we study 9 of maximum plants , plant height, effective ear , grains per ear , thousand grain weight ,ear length, sterility small ear, small ear dewsity and relative circulation of grain drought resistance index.It indicates that , dffective ear, TAW, small ear, small grain density and grain drought resistance index shows aviliable, which can be the character index of variety drought resistance.â‘¢By measuring the chlorophyll fluorescence dynamic parameters the photosynthesis characteristic of the different ecological type wheat varieties under drought stress , Fm,Fv,Fv/Fm and Fv/Fo values decreased gradually, but Fo values increased under drought stress; The variable range depended on the ecological type. The variation of these chlorophyll fluorescence parameters was closely related to drought tolerance of wheat varieties. It was possible to determine the drought resistance in wheat using chlorophyll fluorescence characters.