Comparative mapping of quantitative trait loci for tassel-related traits of maize in F2:3 and RIL populations.

Tassel architecture is an important trait in maize breeding and hybrid seed production. In this study, we investigated total tassel length (TTL) and tassel branch number (TBN) in 266 F2:3 families across six environments and in 301 recombinant inbred lines (RILs) across three environments, where all the plants were derived from a cross between 08-641 and Ye478. We compared the genetic architecture of the two traits across two generations through combined analysis. In total, 27 quantitative trait loci (QTLs) (15 in F2:3; 16 in RIL), two QTL × environment interactions (both in F2:3), 11 pairs of epistatic interactions (seven in F2:3; four in RIL) and four stable QTLs in both the F2:3 and RILs were detected. The RIL population had higher detection power than the F2:3 population. Nevertheless, QTL × environment interactions and epistatic interactions could be more easily detected in the F2:3 population than in the RILs. Overall, the QTL mapping results in the F2:3 and RILs were greatly influenced by genetic generations and environments. Finally, fine mapping for a novel and major QTL, qTTL-2-3 (bin 2.07), which accounted for over 8.49% of the phenotypic variation across different environments and generations, could be useful in marker-assisted breeding.