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 F_2:3 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 thegenetic architecture of the two traits across two generations through combined analysis. In total, 27 quantitative trait loci (QTLs) (15 in F_2:3; 16 in RIL), two QTL × environment interactions (both in F_2:3), 11 pairs of epistatic interactions (seven in F_2:3; four in RIL) and four stable QTLs in both the F_2:3 and RILs were detected. The RIL population had higher detection power than the F_2:3 population. Nevertheless, QTL × environment interactions and epistatic interactions could be more easily detected in the F_2:3 population than in the RILs. Overall, the QTL mapping results in the F_2:3 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.