THE GENETIC BASIS OF INHERITANCE OF PLANT HEIGHT IN MAIZE

The aim of this study, on the grounds of direct and reciprocal diallel crossing of five inbred lines of maize, was to determine: variability, heterosis, combining ability and genetic basis of plant height inheritance. The experiment was based on the principle of randomized block design in four repetitions during two years. Analysis of variance of combining abilities for plant height indicates the significance of general and specific combining abilities. The GCA/SCA ratio shows that for the inheritance of these traits non-additive genes are the most important. Variations between direct and reciprocal crossing of this trait were highly significant in all combinations except in combination of ZPL-11/6 x NS-1445, with the largest effect of reciprocity established in combination of ZPL-11/6 x BL-47 in both years. This indicates that regarding the inheritance of plant height, apart from nuclear genes, plasma genes are involved as well. Eight out of ten hybrid combinations had highly significant positive values of SCA. The high value of SCA for this trait was noticed in the case of a hybrid combination of F-7R and lines that were generally bad combiners (ZPL-11/6 and BL-47; hybrid combinations where one parent was with high GCA and the other with low GCA), which was probably due to interactions between parents’ genes.