Genetic variability, character association and path coefficient analysis in gladiolus for various quantitative traits

Abstract

Genetic variability, heritability and genetic advance, correlation co-efficient and path co-efficient analysis for different traits were studied in 20 gladiolus genotypes. The results showed significant differences for all the traits studied among the genotypes. The high genotypic co-efficient of variation was recorded for floret diameter (20.38%), flower stalk girth (25.01%), number of corms per plant (41.35%), corm weight (69.19%), number of cormels per plant (41.35%) and cormels weight (47.55%) coupled with narrow difference between the genotypic and phenotypic co-efficient of variation. Genetic advance as percent mean ranged from 0.13 to 141.47% among the traits. High heritability coupled with high genetic advance was observed for plant height (89.40%), leaf length (65.77%), spike length (88.01%), spike weight (97.46%), number of corms per plant (74.75%) and cormels per plant (95.60%) indicating additive gene action, which suggested that improvement of these traits would be effective for further selection of superior genotypes. The estimates that genetic correlations in general were higher than phenotypic correlations. The plant height exhibited positive significant correlation at genotypic and phenotypic levels with number of florets per spike, spike length and spike weight. The path coefficient analysis based on spike weight, as responsible variable showed that the traits, namely, plant height (1.347), number of leaves (0.006), number of florets per spike (0.072) and spike length (0.265) exhibited significantly positive direct effect. Spike weight imparted maximum positive direct effect on the plant height followed by spike length. Hence, traits like spike weight, plant height and spike length may be considered for further improvement.