Heritability and correlation coefficient analysis for grain yield and yield-related traits in spring barley (Hordeum vulgare L.)

B. Dyulgerova1*, D. Valcheva1, D. Valchev1, M. Babulicova2, M. Havrlentova2

1Institute of Agriculture, 8400 Karnobat, Agricultural Academy, Bulgaria
2National Agricultural and Food Centre, Research Institute of Plant Production, Piešťany, Slovak Republic

(Manuscript received 24 February 2021; accepted for publication 14 June 2021)

Abstract. The objectives of this study were to estimate the heritability of yield and yield-related traits and to compute the correlation of grain yield with yield-related traits among the spring barley genotypes. The experiment was laid out in a complete block design with three replications in the Institute of Agriculture – Karnobat, Bulgaria during two consecutive years 2017 and 2018. Genotypes differed significantly for all the traits studied. Genotypic coefficients of variation were lower than the corresponding phenotypic coefficients in all the traits studied, indicating a considerable influence of the environment on the expression of the traits. Estimates for broad-sense heritability ranged from 0.65% for grain number per spike to 44.20% for 1000-grain weight. Moderate heritability coupled with relatively high genetic advance as a percent of the mean was found for 1000-grain weight suggesting a reliable possibility for improvement through selection. A significant and positive correlation between grain yield and number of spikes per m2 and grain weight per spike was found. Results of path analysis showed that grain weight per spike and number of spikes per m2 exhibited the highest direct effects on grain yield. The number of spikes per m2 was highly associated with grain yield but mostly influenced by environmental effects. The grain weight per spike should be prioritized for selection of superior spring barley genotypes under conditions of Southeast Bulgaria due to its highest direct effect on grain yield combined with higher heritability than that of grain yield. Moreover, it must be considered that the grain weight per spike had relatively low heritability in a broad-sense so the selection should be practised in later generations in replicated trials.