GENETIC ANALYSIS OF VARIABILITY AND INHERITANCE OF NITROGEN HARVEST INDEX IN WHEAT (TRITICUM AESTIVUM L.)

Z. Jestrovic, M. Pavlovic, O. Nikolic

Abstract: Hybrid progeny of F1 and F2 generations were produced in diallel crosses (without reciprocals) of five genetically divergent wheat cultivars (Zitnica, Jugoslavija, Zelengora, NS Rana 2 and Nizija). The variability, mode of inheritance, gene effect, combining ability of parent cultivars and F1 and F2 hybrids for NHI were studied. The different mode of inheritance: partial dominance, dominance and overdominance for analyzed traits were established, with prevalence of overdominance, taking into account all crossing combinations. On the base of genetic components of variance analysis was estimated that non-additive gene action has higher impact than additive in the inheritance of NHI, with higher frequency of dominant alleles and positive interaction additive x dominant genetic effects. The average degree of dominance was positive and indicates overdominance as prevailing inheritance mode, considering all crossing combinations. Dominance i.e. overdominance as inheritance mode was recorded by regression analysis. The parents were divergent in terms of order of dominant and recessive alleles. The inter-alleles interaction was registered, too. Analysis of combining ability showed high significance of specific combining abilities in both of generations, while general combining abilities were significant only in F2 generation, what confirm higher proportion of non – additivegenetic variance. The relation genetic combining abilities/specific combining abilities was less than 1. The best general combiner for NHI in both F1 and F2 generation was Zitnica cultivar. The highest values of specific combining abilities were obtained in combinations Zelengora x Nizija and Zitnica x NS Rana 2. The emphasized cultivars could be recommended for wheat breeding programes as source of desirable properties.

Keywords: inheritance; nitrogen harvest index; variability; wheat

Date published: 2017-08-18