Estimation of Combining Ability of Growth and Yield and Its Components of Maize under Salicylic Acid Concentrations

Abstract

An experiment was carried out in the fields of Al-Hamidhyia research station - College of Agriculture / Anbar University to study the concentrations of salicylic acid (0, 200 and 400 mg L-1 ) and fifteen genotypes (5 lines + 10 hybrids) of maize using a randomized complete block design according to split plots arrangement at three replications, the main plots included spraying of salicylic acid concentrations, while the subplots include maize genotypes (inbreds and hybrids) in order to produce hybrids (superior) by introducing a group of inbreds and reciprocal hybrids of maize within half diallel reciprocal crosses program. The results showed that Zm 6inbred was significantly superior and gave the highest general combining ability of grain yield (5.77 and 9.65) for both seasons due to its superiority in the number of rows per ear and weight of 300 grains (0.27 and 1.48), respectively in the spring season, and early flowering in the autumn season. Also, the spraying of salicylic acid at 400 mgL-1 was significantly superior in all studied traits for both seasons, with non-significant differences with the spraying of salicylic acid at 200 mgL-1 .The effect of hybrids' specific combining ability (SCA) significantly affected the studied traits. The BK116×ABS6 hybrid had the highest specific effect on the early female flowering (-2.76). In contrast, the Zm6×BK104 hybrid with control treatment had the highest specific effect on the weight of 300 grains and grain yield (13.84 and 50.12), respectively, in the spring season, while the BK104×Inb27 hybrid with the spraying of salicylic acid at a 400 mgL-1 had the highest effect of the specific combining ability (72.11) in the autumn season. We recommend spraying salicylic acid at 200 mg L-1 and using superior inbreds and hybrids in general and specific combining ability in both seasons. Keywords: Inbred line, hybrid, SA, SCA, GCA.