Mapping QTLs With G×E(Water) Interaction Analysis For Main Agricultural Traits And Leaf Developing In A RIL Population Of Rice (Oryza Sativa L.)

Drought is the most severe abiotic stress limiting rice yield in the world. Usually the grain yield and yield component under non-stress was the primary trait of interest in rice (Oryza Sativa. L) breeding programs, genetic mapping studies rarely concentrated on the quantitative trait loci (QTL) detection under water stress or on the QTL consistency across water stress and non-stress environment. Our research objective was to provide a solid basis for improving drought resistance by identifying the genetic factors underlying the complex responses of plants to drought stress through evaluating the consistency or the difference of QTLs for grain yield and other relative traits in rice across stress and non-stress conditions.247 recombinant inbred lines(RILs) derived from a cross between Zhenshan 97B and Miyang 46 were evaluated at the same time in well-watered field and water limited upland. The major results were as follows:l.The QTLs for drought resistance or tolerance were mapped to the regions between RZ717-RG252 on chromosome 2, RM232-RM218 on chromosome 3, RG978-RM210Aon chromosome 8, RZ649B-RG257 on chromosome 10 and R2816-RG103 on chromosome 11 respectively.2.The QTLs for drought sensitive were located in the regions between RG101 - RG472 and RG101-RG232 on chromosome 1, 470-RM274 on chromosome 5, nearly area of RZ989 on chromosome 7, RG103-RM187 on chromosome 11 and RM313-RM319 on chromosome 12.3.Tween-one QTLs with additive effects provided by donor female parent Miyang 46 were detected in RILs under continuous water stress condition and ten of them, which were contributed to grain yield and yield component, were located on chromosome 1,3,5 and 11, the another 11, which were contributed to leaf traits, were on chromosome 2,6,9 and 12.4.The interaction between gene and environment was strong and the variation of trait appearance under different condition was controlled by different sets of QTLs. Only a few traits related to yield, yield-related and leaf were presented consistency between stress and non-stress environment.5.It was found the loci that one QTL simultaneously controlled several different traits and one QTL interacted with other QTLs to affect different traits, i.e. gene linkage widely existed. 63 loci with pleiotropy or gene linkage, occupied 57% of total QTLs, were detected in this study. This means that there are very complicated relationships among traits.6.OnIy a few QTLs for yield, yield-related traits or leaf traits can be detected simultaneously across the water stress and non-stress conditions. The above results suggested that it was necessary to study drought resistance traits and detected target QTLs in target environment to enhance the efficiency of research work on rice drought resistance, and the success of marker assisted selection breeding was dependent on the direct combination of QTLs detection and breeding...