Combining ability studies for physiological and yield traits in maize (Zeamays L.) across three environments

The present study was conducted to assess the general combining ability effects of parents and specific combining ability effects of crosses for yield and yield contributing traits in maize hybrid development. Combining ability studies were conducted in10 X 10 half diallel fashion at Prayagraj to determine GCA and SCA effects of parents and single crosses respectively. The economic heterosis (hc) revealed that the hybrids CM- 124 x LM-13, HKI-193-2 x CM 129, DMR-QPM-28 x CM- 124, HKI-193-2 x POP 445 and CML 41 x POP 445 showed positive significant results across the three environments E1, E2 and E3. The combining ability study indicated that the parents, HKI-193-2 (P10)LM 13(P6) and line CM 129 (P5) can be considered as good general combiners and genetically worthy parents, as they contributed favourable genes for grain yield. The parent CML- 41 (P9) was a good general combiner for the trait chlorophyll content in all three environments, while the parent LM 13 (P6) was a good source for favourable alleles for leaf area index since they had significant positive gca effects.The parents HKI-193-2 (P10)LM 13(P6)can be considered as good general combiners for protein content.The pooled analysis of variance over three environments revealed the mean sum of squares due to genotypes was significant for the characters studied. The hybrid CM- 124 x LM-13 showed good specific combining ability effects for grain yield,days to 50 % tasseling, days to 50 % silking, days to 50% maturity, 100 seed weight, chlorophyll content, leaf relative water content, leaf area index, leaf area ratio and protein content.The hybrid HKI-193-2 x CM 129 showed good specific combining ability effects for grain yield, days to 50% maturity, one hundred seed weight, leaf area index, leaf area ratio and starch content.