Heterosis analysis for grain yield traits in maize (Zea mays L.)

Abstract

In the present study 6 inbreds were used as parents to make crosses in all possible cross combination in full diallel fashion to obtain total 30 possible F1 hybrids. These 30 F1’s were subjected to heterosis analysis for midparental, heterobeltiosis and standard heterosis, where 900M a prominent hybrid was used as standard check. For judging good F1 hybrids, negative heterosis was considered to be better for five traits (days to tasseling, days to silking, anthesis silking interval, days to maturity and plant height), while positive heterosis was considered to be desirable for the remaining traits (ear length, ear girth, number of kernel rows per ear, number of kernels per row, ear weight, shelling per cent, 100 grain weight and grain yield per plant). A perusal of standard heterosis revealed that out of 30 crosses studied, none of the hybrids were found to possess significant standard heterosis for all the traits studied. A total of eight hybrids exhibited significant and favourable standard heterosis for grain yield and its component traits. Among the eight hybrids, the hybrid UMI 133 x UMI 122 for seven traits and the remaining hybrids viz UMI 112 x UMI 66, UMI 112 x UMI 122, UMI 112 x UMI 133, UMI 122 x UMI 66, UMI 133 x UMI 112, UMI 133 x UMI 213 and UMI 213 x UMI 112 for five traits recorded significant and favourable standard heterosis and these could be adjudged as promising hybrids. Though the hybrids UMI 213 x UMI 176, UMI 133 x UMI 66 showed significant and favourable standard heterosis for maximum number traits, they were not considered as best ones due to the non significant standard heterosis of those hybrids for most important trait i.e. grain yield per plant. The extent of heterosis for grain yield per plant over check hybrid was found to be the maximum followed by ear weight. The heterosis over check hybrid recorded for anthesis silking interval was the maximum among the traits for which negative heterosis was favourable followed by plant height.