General and Specific combining ability studies for ear traits in maize (Zea mays L.)

Abstract

An investigation was carried out to assess the combining ability in maize genotypes using a diallel mating design (without reciprocal crosses) using 6 homozygous lines namely, DMIT 121, DMIT 123, DMIT 124, DMIT 125, DMIT 113 and DMIT 118. The experiment was set up in a randomized complete block design (RCBD) with 3 replications during kharif season of 2016-17 in maize research centre, Devihosur, Haveri district, which comes under UAS, Dharwad, Karnataka. The combining ability analysis revealed presence of higher magnitude of SCA variance than GCA variance indicating predominance of non-additive gene action for all the ear traits. General combining ability studies revealed that DMIT 123 was best general combiner for major ear traits cob length, kernel rows per cob and kernels per row and the line DMIT 118 was best combiner for cob length, cob girth and kernels per row. The line DMIT 125 is best general combiner for cob length hence, these lines are used in various hybrid breeding programmes to increase maize grain yield with superior ear traits. However, the estimates of specific combining ability showed the desirable SCA effects in crosses DH 1514(DMIT 125 × DMIT 118) and DH 1509(DMIT 123 x DMIT 118) for all the ear traits including cob length, cob girth, kernel rows per cob, and kernels per row,. As these crosses having one of their parents with good general combiner for all the traits having H x L or L x H GCA status showing dominance and epistatic interactions.