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.

Composition, digestibility, feeding value estimation of forage pea (Pisum sativum L.) varieties and hybrids in breeding process and genetic advance evaluation

Y. Naydenova*, V. Kosev

Institute of Forage Crops, 89 Gen. Vladimir Vazov, 5800 Pleven, Bulgaria

Abstract. Compositionanddigestibilityarestudiedandpotentialforagefeedingvalueisestimatedofeightbreedingspringandwinterforms–twoBulgarian and two Russian varieties and their four hybrids, presented as Component A – winter forms and Component B – spring forms. Forage quality is evaluated in three vegetative stages of plants, grown in Competitive variety trial (2011 –2013) on the Second Experimental Field of the Institute of Forage Crops, Pleven: budding stage, beginning of flowering stage and full pod formation stage. The parameters of principal composition (Weende analysis), plant cell walls fiber components content (Van Soest detergent analysis), enzyme in vitro digestibility of dry and organic matter (method Aufrere), potential energy and protein feeding value by different systems are analyzed, determined and estimated. The correlation relations between parameters are established. The highest values forthecrudeproteincontentbreedingformsappearinbuddingstage:CP23.55±7.75% andthehighestaveragedigestibilityinthefullpodformationstage, which is a stage of technological maturity of varieties and hybrids: Digestibility of dry matter (IVDMD) 70.00±3.32% and Digestibility of organic matter (IVOMD 71.28±3.06%). Potential energy feeding value of the forage biomass average for all breeding accessions is the highest at full pod formation stage and protein feeding value – at budding stage. Genetic advance is evaluated by Principal Component Analysis, Cluster analysis and heritability (broad sense) is established.


Genetic variability in two-rowed spring barley

B. Dyulgerova*, N. Dyulgerov, M. Dimitrova-Doneva

Institute of Agriculture, 8400 Karnobat, Bulgaria

Abstract. A total of 23 varieties of 2-rowed spring barley were grown in two successive seasons of 2011 and 2012 to study variability, heritability and genetic advance for 5 characters – spike length, spikelet number per spike, grain number per spike, grain weight per spike and 1000 grains weight. Significant differences were observed among the varieties regarding all the traits studied. Genotypic and phenotypic coefficients of variability were higher in 1000 grains weight than other traits. Estimates of heritability ranged from 66.62% for grain number per spike to 89.35% for 1000 grains weight. Heritability coupled with high genetic advance was observed for 1000 grains weight and spikelet number per spike indicating the importance of these traits in selection and crop improvement.