INHERITANCE OF ADAPTIVE CHARACTERISTICS WITH HIGH-PLANT DENSITY AND LOW-N IN MAIZE (ZEA MAYS L.).

Information on the inheritance of adaptive traits to high plant density (HD) and low N (LN) in maize is a prerequisite for breeders to develop tolerant varieties to these stresses. The objective of the presented study was to estimate additive and dominance variances, heritability, and genetic advancement of the adaptive traits of tolerance to HD and LN stresses. Eight diverse maize inbred lines tolerant to HD and LN were options for diallel crosses. Parents and F1 crosses sustained evaluation in two seasons under nine environments, viz., three plant densities (high = HD, medium = MD, and low = LD) × three N levels (high = HN, medium = MN, and low = LN). A randomized complete block design with three replications functioned in each environment. Both additive and dominance variances were significant; dominance was appreciably higher than the additive variance in most cases. The degree of dominance was more in the over-dominance range. The highest heritability, along with the highest genetic advance, succeeded from the environment stressed for both HD and LN for leaf angle, penetrated light at the bottom of the plant, and leaf area produced 1g grain, and from the environment stressed for HD for plant height and 100-kernel weight. Moreover, the results suggested that heterosis breeding is the method of choice for the genetic improvement of most studied traits. [ABSTRACT FROM AUTHOR]