QTL Analysis Of Flag Leaf Shape And Rice Yield In Different Environments

The flag leaf is the most essential organ for photosynthesis in rice. Ideal flag leaf shape plays animportant role in rice breeding for ideal plant type. We had resequenced the core recombinant inbredlines of Liang–You–Pei–Jiu, the widely cultivated super hybrid rice, and constructed a high-resolutionlinkage map. The pair-wise correlation analysis was conducted on three flag leaf shape traits and yieldper plant in Hangzhou and Hainan. The following are the main results of our study:1) The values of flag leaf length, flag leaf width and yield per plant of93-11were bigger than those ofPeiai64s in the environments of Hangzhou and Hainan. In Hangzhou, the two parents hadextremely significant difference involving in the traits of flag leaf width and yield per plant andhad significant difference involving in the traits of flag leaf length and length-width ratio; inHainan, the two parents had extremely significant difference involving in the traits of flag leaflength, length-width ratio and yield per plant and had significant difference involving in the trait offlag leaf width. Therefore, they were the genetic factors rather than the environments factors thatmade contribution to the difference between two parents.2) There were significant correlations among flag leaf shape traits. Moreover, flag leaf width had apositive effect on the yield per plant.3) Because high-density SNP markers increased quantity and precision of QTL,42QTLs weredetected for three flag shape traits and yield per plant, among which30QTLs were unreported sofar. The least genetic interval was0.19cM among the QTLs detected.4) Eight QTLs were identified common in two environments, which indicated that these QTLs hadlittle influence by environments and can make contribution in different environments.5) Ten QTL clusters were found. Two QTL clusters can control the traits of flag leaf length and yieldper plant at the same time, while one QTL cluster contributed to both length-width ratio and yieldper plant.6) Both qFLW8for flag leaf width and qPY8for yield per plant were mapped in the same region onchromosome12, which can explain24%and10%of the phenotypic variation, respectively.Therefore, flag leaf width were the important factor that associated with the trait of yield per plant,and can enhance the function of source leaves by multiplying the area of photosynthesis, resultingin increase of yield per plant.