Genotypic Variability, Heritability and Path Analysis of Yield Components of Determinate Lablab (Lablab Purpureus (L.) Sweet) Inbred Lines in Kenya

Abstract

Lablab is a leguminous crop that offers great potential as food and cash crop in Kenya. However, high yielding early maturing determinate varieties suitable for short season environments and for intercropping systems are lacking. This study was conducted to estimate heritability, genetic advance and correlation between grain yields and yield attributing traits of advanced inbred determinate lines. Thirty nine lablab F5 inbred lines and a local determinate accession were evaluated at KALRO Katumani and Thika using randomized complete block design (RCBD) with two replications in 2017. Significant differences (P< 0.05) were observed among the genotypes for all the characters. Phenotypic coefficient of variability (PCV) and genotypic coefficient of variability (GCV) were highest for seed weight per plant and the lowest for maturity traits. Broad heritability for the 11 characters was moderate to high ranging from 0.40 - 0.86. The highest genetic gain (48.53%) was recorded on seed weight per plant and lowest on the maturity related traits. Pods number (r = +0.87) and raceme number (r = +0.81) had the highest positive and significant (P> 0.05) correlation with seed yield per plant. Path analysis revealed that pods per plant (0.68), racemes per plant (0.25) and pods per raceme (0.13) had the largest direct effect on seed yield. The study identified, moderate to high heritability and genetic advance estimates and significant positive correlations of pods per plant, raceme per plant, plant height, pod width, pods per raceme and number of flower nodes. The same traits also had high direct and indirect effects on seed yield and therefore suitable for phenotypic selection of improved determinate lablab genotypes. The results of the study are discussed in light of crop improvement of this leguminous crop.