Genetic Dissection of the General Combining Ability of Yield-Related Traits in Maize.

Maize yield components including row number, kernel number per row, kernel thickness, kernel width, kernel length, 100-kernel weight, and volume weight affect grain yield directly. Previous studies mainly focused on dissecting the genetic basis of performances for yield-related traits, but the genetic basis of general combining ability (GCA) for these traits is still unclear. In the present study, 328 RILs were crossed as males to two testers according to the NCII mating design, resulting in a hybrid panel composed of 656 hybrids. Both the hybrids and parental lines were evaluated in four environments in 2015 and 2016. Correlation analysis showed the performances of GCA effects were significantly correlated to the performances of RILs for all yield-related traits (0.17 ≤ ≤ 0.64, > 0.01). Only 17 of 95 QTL could be detected for both performances of RILs and GCA effects for eight yield-related traits. The QTL and , which could explain more than 10% of the variation in the GCA effects of KN and HKW, were also detected for performances for the traits. The pleiotropic loci and , which together explained 14.92% of the observed variation in GCA effects for RN, were associated with the GCA effects of KW and HKW, but not with performances for these traits. In contrast, , which was related to seed weight in maize, was mapped to the region surrounding MK2567 at the locus, but no GCA effect was detected. The QTL identified in present study for performances and corresponding GCA effects for yield-related traits might be useful for maize hybrid breeding.