Mohan Lal*, Dhirendra singh and Sain Dass**
A study was conducted of the heterosis in QPM maize, following line x tester analysis. The performance of fifty QPM maize hybrids along with their parents and checks were evaluated during rabi 2005-06. The analysis of variance revealed significant differences among the parents and F1 hybrids for all the characters. For days to 50% silking, thirteen hybrids exhibited negative significant heterobeltiosis. For days to 50% tasseling one hybrid (L4 xT5) exhibited negative significant economic heterosis in relation to best check, while none of the hybrids had given this indication for the days to silking. For grain yield per plant, hybrid L4 x T2 exhibited the highest heterosis (236.46 per cent) over better parent and checks. For protein content, thirteen hybrids depicted positive significant heterobeltiosis one hybrid exhibited positive significant economic heterosis over the best checks with magnitude was 9.18 percent (L2 X T5). For tryptophan content thirty two hybrids depicted positive significant heterobeltiosis, while four hybrids exhibited positive economic heterosis over the best checks. For lysine content only six hybrids depicted positive significant heterosis. The desirable crosses combination L 4 x T2, L7 x T3, L5 x T5, L4 x T3, and L7 xT1, L4 x T4, L7 x T4, L6 x T5 and L6 x T4 showed high magnitude of heterosis over better parents for yield along with quality characters.