Studies On The Genetic Relationship Between Rice Cooking Quality And Yield Traits

High yield and good quality are two important goals of rice breeding. The prerequisite for commencing high yield and good quality breeding is to understand genetic basis of rice yield and quality, as well as their relationship. 60 varieties, including 30 indica varieties and 30 japonica ones, were employed, and some agricultural traits and yield traits of sixty rice cultivars, as well as rice cooking quality characteristics were investigated. The relationship between rice quality and yield traits were analyzed. And three DH(Doubled haploid) populations were also used to study the relationship between the yield and cooking quality. In order to explore the mechanism of yield and quality relationship on molecular level, SSR markers were further used, and a linkage map were constructed based on a DH population derived from NongKen57/Wuyunjing 8, which contains 130 lines, composite interval mapping and single marker ANOVA were carried out to analyze the genetic basis of both yield and quality traits. The main results were summarized as following:1 In indica cultivars, no significant correlations between yield traits and AAC, GC, RVA profile characteristics. As fox japonica cultivars, TGW appears to negatively correlate with AAC, positively with GC. RVA profile characteristics had no significant correlation with most yield traits, only PaT had significant correlation with EP and PL, PKV and HPV had significant correlation with TG and TGW. In both indica and japonica varieties, the correlation between GWP and cooking traits was not found, suggesting varieties with high yield and good quality can be achieved though the recombination between two traits.2 Most yield traits had no significant correlation with cooking qualities, protein content in three DH populations. SD, TG, GWP negatively correlated with PKV, HPV and BDV, positively with SBV, suggesting that increasing SD, TG, GWP, may lead to inferior cooking quality.3 SSR markers were used to analyze the genotypes of DH population, whichcontains 130 stable genetic lines. The polymorphism between two parents was about 12.0%, and 60 polymorphic markers were found. Then the polymorphic markers were further used to detect the genotype of every DH lines. The results indicate that the parent Wuyunjing 8 contribute about 49.6% to the progeny, and the genetic composition distribution of each lines approximates to normal distribution, indicating that this population can be used to analyze the genetic basis of complex traits due to no distorted segregation occurred.4 Partial SSR linkage maps were built through Jionmap3.0. Composite interval mapping and single marker analysis methods were used to identify the QTLs controlling all the traits involved in this experiments. Totally, 27 QTLs of agronomic traits, yield traits and quality traits were identified. Except one QTLs on chr6 controlled both yield related trait - SD and BDV, SBV of quality related traits, no markers were detected, which had remarkable correlation with both yield and quality traits. This results further indicated that recombination between yield and quality traits can occurred, and to achieve a varieties with high yield and good quality is possible.