COMBINING ABILITY ANALYSIS IN MAIZE DIALLEL HYBRID POPULATIONS UNDER OPTIMUM AND DROUGHT STRESS CONDITIONS.

The latest study strategized to evaluate the maize populations by combining ability analysis under optimum and drought-stress environments to assemble the promising parental inbred lines and their hybrid populations with high productivity and resistance to drought stress. From the collection of the Trunojoyo Madura University, Indonesia, came five maize pure lines (UTM 2, UTM 7, UTM 10, UTM 19, and UTM 31) that received crossing in a complete diallel fashion to obtain 20 hybrid populations. The performance of five parental inbred lines and their 20 F1 hybrids' evaluation in crop season 2021 had a randomized complete block design with three replications under four each for optimum and droughtstress environmental conditions. Data recording ensued on grain yield and drought susceptibility index (DSI). The GCA and SCA variances revealed that grain yield had more influences from the dominant genes with maternal effects at the eight locations; hence, the parental lines have less stimulus on the hybrids' performance. The genotype UTM2 (G1) appeared resistant to drought-stress conditions based on the DSI value (0.70) and has positive GCA effects for grain yield. Therefore, it can better serve to improve drought resistance and grain yield. The results further exhibited that six maize hybrids, i.e., G3 (UTM 2 x UTM 10), G6 (UTM 7 x UTM 2), G10 (UTM 7 x UTM 31), G11 (UTM 10 x UTM 2), G22 (UTM 31 x UTM 10), and G24 (UTM 31 x UTM 19) were remarkable as commercial hybrids with high grain yield and resistance to drought stress. [ABSTRACT FROM AUTHOR]