QTL Mapping And Effect Verification Of Rice Quality Related Traits

Rice quality is an important trait that affects the yield and market value of rice.With the increase of population and rapid economic development,it is of great significance to increase rice yield and improve rice quality.In this study,the grain shape,chalkiness,thousand-grain weight,amylose content,and fatty acid content of rice were investigated.And a series of QTL were detected and validated using different populations.The main results are as follows.1. The BC₃F₂ indica-japonica introduced population with 276 families was constructed with japonica rice Kongyu 131 as the female parent and indica rice BG94-1 as the male parent.The genetic map construction and QTL mapping of quality-related traits were carried out.The genetic linkage map contained 148 pairs of SSR markers and In Del markers spreading over 12 chromosomes with a total length of about 1047.9 c M.We investigated the population phenotypes of grain shape,chalkiness,thousand-grain weight,amylose content,fatty acid content and detected QTL.A total of 43 QTL were identified,including 8 grain-length QTL,6 grain-wide QTL,and 3 thousand-grain weights QTL,10 chalky QTL,1 amylose content QTL,and 15 fatty acid content related QTL.Using the BC₃F₄ strain to verify the effects of these QTL,we confirmed the effects of qGL3,qGL12.1,qGW1.2 and qGW5,which indicated that these sites may have genes that affected grain shape.2. We used the F₄ population constructed with R287 and Zhongzao 35 as the parents and initially locate 7 QTL related to grain shape and chalkiness,and the F₅ generation strain was used to verify the effect of QTL.qGL11-1 and qGW5-1 had significant effects.Their additive effects were 0.21mm?P=8.30E?13?and 0.07mm?P=3.25E?12?respectively.And qGW5-1 and GW5 were not in the same position.3. We used the F₂ and F_2:3 populations constructed by Hua 5178S and Hua 611 as parents to initially locate 7 QTL related to chalkiness.Then we verified the effects using F₄ generation strain.q WBR6.1-2 and q WCR6-2 and q CR6-2 had significant effects.Their additive effects were 0.06%?P=4.48E?06?,0.02%?P=0.0001?and 0.06%?P=0.0003?respectively.In addition,q WCR6-2 and q CR6-2 were located in the same interval.In summary,we used three different populations for initial positioning and effect verification of rice quality-related QTL.A total of 8 QTL sites related to grain quality and chalkiness had significant genetic effects.This work is conducive to the analysis of the genetic basis of rice quality traits,and laid the foundation for the cloning of rice quality-related genes.