Identification of Drought Resistance of 244 Spring Wheat Varieties at Seedling Stage
[Objective]Drought is a major environmental factor limiting global wheat production,and breeding drought-tolerant varieties is a key challenge faced by wheat breeders worldwide.Spring wheat,which has a short growth period,plays a vital role for national food security and planting structure,therefore,it is of great importance to identify and select drought tolerance of spring wheat varieties for breeding of high-yielding and drought-tolerant wheat.[Method]In this study,244 spring wheat varieties(lines)from 10 different regions were used to assess the drought tolerance of spring wheat varieties during the seedling stage,this study used the controlled water content method to impose drought stress during the seedling stage,5 seedlings with uniform and consistent growth were selected during the trefoil stage.Thirteen seedling stage indicators including maximum root length(MRL),first leaf length(FLL),first leaf width(FLW),coleoptile length(CL),shoot fresh weight(SFW)and root fresh weight(RFW)were measured.Comprehensive evaluation of drought resistance of various spring wheat varieties(lines)was conducted through methods such as using descriptive statistics,membership function,principal component analysis,cluster analysis,and correlation analysis.[Result]The drought tolerance of spring wheat varieties(lines)exhibits a large variation.The coefficient of variation of the measured traits under drought treatment conditions ranges from 2.1%to 32.9%,while the coefficient of variation of the control group ranges from 1.0%to 29.3%.Compared with the control,the coleoptile length,root dry weight,fresh weight root to shoot ratio,and dry weight root to shoot ratio under drought treatment were all greater than those under the control treatment.The original 13 indexes were summarized into 5 principal components,and the contribution rate reached 79.56%,and the D value of the comprehensive drought resistance coefficient was calculated according to the characteristic vector of each principal component and the drought resistance coefficient of each trait index,then the D value was clustered and analyzed,which could be divided into 5 subgroups.Therefore,the root biomass(underground fresh weight and dry weight)was screened as an effective comprehensive index for the identification of drought resistance at the seedling stage.We conducted correlation analysis between the seedling stage drought index and the agronomic traits of maturity stage showed that the coleoptile length,first leaf length was significantly positively correlated with flag length,plant height,spike length,the number of spike and grain length.Additionally,and the seedling biomass was significantly positively correlated with thousand-grain weight.[Conclusion]Twenty-two highly drought-tolerant varieties were screened,and root biomass(both fresh and dry weight of the underground part)was identified as an effective comprehensive indicator for evaluating seedling stage drought tolerance.
spring wheatseedling stagedrought resistancecomprehensive drought resistance coefficient
国家科技期刊平台
NSTL
万方数据
维普
