Investigation of genetic control for yield and related traits in maize ( Zea Mays L.) lines derived from temperate and sub-tropical germplasm

摘要

Combining ability estimation are important genetic attributes for maize breeders in anticipating improvement inproductivity via hybridization and selection. This research was carried out to investigation the genetic structureof the 28 F1 maize hybrids established from seven exotic lines derived from temperate germplasm of CIMMYTand four local testers (sub-tropical germplasm), to determine general combining ability (GCA) and determinecrosses showing specific combining ability (SCA). 28 F1 hybrids and two check commercial hybrids were studiedin randomized complete block (RCB) Design with three replications during 2011. The results of mean squaresshowed significant differences among 7 lines for day to tassel, day to silk and anthesis-silking interval. Fourtesters were significantly different for kernel yield, day to silking, ASI (anthesis-silking interval). Highlysignificant differences were observed for line x tester interaction for all traits except day to plant maturity, day ofsilking to plant maturity and anthesis-silking interval. Estimates of variance due to GCA and SCA and their ratiorevealed predominantly non-additive gene effects for all studied traits. Lines with the best GCA effects were: ‘L4’for grain yield, day to tassel and day to silk, L5 had highly positive significant for anthesis-silking interval. L6Line was undesired GCA effects for grain yield. The hybrids L7 × T2 showed significant positive SCA effects forkernel yield. The hybrids L1×T1 and L6 × T1 showed significant negative SCA effects for day to silk. Therefore,these hybrids may be preferred for hybrid crop development.