Line x tester analysis for yield and related traits in maize

Abstract

Abstract : Early generation evaluation of inbred lines through line * tester method was conducted at Bangladesh Agricultural Research Institute, Gazipur during Rabi 2014-15 involving 26 S4 lines of maize (Zea mays L.) variety Pinacle and three testers for grain yield, yield components and other characters to estimate the general combining ability of the lines and specific combining ability effects of the crosses and to evaluate the test cross performance of the hybrids for grain yield and yield related traits. Performance of the test crosses was evaluated with their parents in alpha lattice design with three replications. Highly significant genotypic differences were observed indicating wide range of variability present among them. Eight lines viz., Pinacle S4-l, Pinacle S4-2, Pinacle S4-5, Pinacle S4-6, Pinacle S4-15, Pinacle S4-19, Pinacle S4-28, and Pinacle S4-30 were good general combiners for grain yield and possessed high means also. The crosses with significant specific combining ability effect for grain yield were Pinacle S4-2 x BIL79, Pinacle S4-5 x BIL79, Pinacle S4-8 x BIL79, Pinacle S4-10x BIL79, Pinacle S4-15x BIL79, Pinacle S4-19X BIL79, Pinacle S4-28x BIL79, Pinacle S4-2x BIL106, Pinacle S4-6x BIL106, Pinacle S4-15x BIL106, Pinacle S4-19x BIL106, Pinacle S4-22x BIL106, Pinacle S4-2x BIL28, Pinacle S4-5x BIL28, Pinacle S4-6x BIL28, Pinacle S4-13x BIL28, Pinacle S4- 15x BIL28, and Pinacle S4-24x BIL28 evolved mostly from low x low general combiner parents that revealed dominance x dominance type of gene action. These 17 combinations might be used for obtaining high yielding hybrids. The information on the nature of gene action with respective variety and character might be used depending on the breeding objectives. Heterosis estimation was carried out using two commercial varieties BHM 9 and NK40. When standard commercial check NK40 was used, the percent heterosis for grain yield varied from 33.20 to 12.30 %. Among the 78 crosses, 11 crosses exhibited significant positive and heterosis for grain yield. Higher heterosis was exhibited by the crosses Pinacle S4-15 x BIL 79 (12.30%), Pinacle S4-5 x BIL 79 (11.07%), and Pinacle S4-2 x BIL 106 (7.46%). The crosses showing significant positive specific combining ability (SCA) values could be used for variety development after verifying them across the agro-ecological zones of Bangladesh.