Genetic variability, evaluation and multivariate analysis for yield and yield components in sunflower (Helianthus annuus L.)

Abstract

The current experiments were carried out to evaluate some sunflower (Helianthus annuus L.) genotypes through study genetic variability, heritability, genetic advance, and genetic advance as percent of mean, correlation coefficient and cluster analysis. In this context, a total of 11 sunflower genotypes were grown in a randomized complete block design with four replications at experimental filed of Oilseeds Section during the growing two season, 2018 and 2019at Sakha Agric. Res. Station, Kafr El-Sheikh, Governorate, the mean squares were significantly differed (P≤0.01) for all the studied traits among the tested genotypes, these genotypes might be useful in sunflower breeding programme. The genotype G4 gave higher seed yield plant -1 and seed yield fed -1 . The correlation values depicted that traits, such as, days to50% flowering, stem diameter, head diameter, plant height, established positive and significant correlations with seed yield plant -1 , head diameter also established positive and significant correlations with plant height and yield fed -1 The values of Phenotypic coefficient of variation (PCV) were marginally higher than Genotypic coefficient of variation (GCV). This indicates that the large amount of variation was contributed by genetic component and least by environment. Demonstrating that genotypes having higher extent of these traits may be preferred in selection for evolving high yielding sunflower genotypes. High heritability broad sense estimates were obtained for all the characters studied. High heritability (>60%) and high genetic advance (>10) were shown by Seed yield fed -1 and seed yield plant -1 , High heritability and moderate genetic advance were exhibited by oil %, Head diameter showed high heritability but low genetic advance. The highly heritable character with high or moderate genetic advance could be further improved with individual plant selection. Characters with high heritability and low genetic advance indicated little scope for further improvement through individual plant selection. Cluster analysis proved to be better tools for assessing genetic diversity and precise associations among genotypes. The selection of genotypes from different clusters and components having more than one positive trait may lead to improvement in seed yield and oil contents in sunflower. Cluster analysis classified the sunflower varieties into three groups based on agronomic traits and seed yield. The largest number of genotypes were included in cluster I (6 genotypes) and II (4 genotypes) followed by cluster III, the genotype 4, which has the highest value for seed yield, was separate.