Heterotic response of three-way cross maize hybrids for grain yield and yield components

Abstract

The present study was performed to determine the extent of heterosis in three way cross maize hybrids for yield and yield contributing traits at Cereal Crops Research Institute (CCRI) Pirsabak, Nowshera, Pakistan, in 2012. In spring season, 18 three way cross hybrids were developed by crossing 18 elite inbred lines with three single cross hybrids in different combinations. In summer season, the crosses were evaluated along with commercial check hybrids. The experiment was conducted in a randomized complete block design with three replications. Data were recorded on plant height, ear height, cob length, kernel rows cob-1, 100-seed weight and grain yield. Hybrids showed highly significant differences for all traits studied except kernel rows cob-1. Maximum plant height was recorded for Ev3-157-5-4- 2×P-30k08, while minimum plant height was attained by Pop 9804×Bemisal. Maximum ear height was recorded for Swajk-4-9×P-3025. Pop 9804×Bemisal exhibited minimum ear height. Percent heterosis for plant and ear height over checks showed positive and negative differences. Among the hybrids, maximum ear length was observed for Ev3-157-5-1-7-3-9-5×Bemisal, while minimum was recorded for Ev3-157-5-1-1-9-1× P-3025. Maximum number of kernel rows ear-l was detected for Ev3-157-5-1-1-9-1×P-30k08 and Pop9804×Bemisal, while minimum number of kernel rows ear-l was exhibited for Ev3-157-5-4-2×P-30k08 and Ev3-45-4-3-7-2-3-2×P-30k08. Maximum 100- kernel weight was recorded for Ev3-120-2-3-2-1-2-1×P-30k08, while minimum 100-kernel weight was observed for Ev3-157-5-4-2×P- 30k08. Highest yielding cross was Swajk-6-6-3-5-1×P-30k08, while lowest grain yield was observed for Ev3-157-5-4-2×P-30k08. The magnitude of heterosis for yield and yield contributing traits varied and showed significant as well as non significant estimates for various traits studied during investigation.