Abstract:

Many high-yield varieties usually exhibit inferior grain quality in rice. The understanding of the relationship between rice yield and its components, cooking and eating qualities is beneficial for successfully breeding the high-yield variety with good quality. A DH population, consisting of 130 lines, derived from the cross between japonica cultivar Nongken 57 and Wuyunjing 8, was employed to explore the genetic correlation between yield traits and cooking quality. In the DH population, the productive panicles per plant, grains per panicle, grain density, and yield per panicle significantly correlated with PKV, HPV, BDV, CPV, SBV, and CSV positively or negatively, while no significant correlations between other yield traits and cooking quality indices were detected, preliminarily indicating the certain correlation between yield and grain quality. Furthermore, to fully understand these correlation relationships, 60 SSR markers distributed on the entire rice genome, being polymorphic between two parents, were used to detect the genotypes of each line; composite interval mapping and marker-based analysis of variance were employed to analyze the genetic basis for yield traits and cooking quality indices. The results showed that there were a QTL in the interval of RM234–RM505 on chromosome 7 conferring yield per plant, PKV, HPV, and CPV simultaneously，and another QTL at RM454–RM162 on chromosome 6, with effects on grain density, BDV, and SBV. But it also should be pointed out that no QTLs were found contributing to yield per plant, BDV, and SBV, simultaneously, the latter two indices were related to cooking quality. Taken together, it is possible that high yield variety with good quality can be achieved through optimizing the structure of yield components, together with selection of favorable alleles on the gene loci conferring rice grain quality.

Key words: Rice, Yield, Cooking quality, Correlation analysis