Genetic variability and heritability of growth, yield and quality traits in Gymnema sylvestre: an anti-diabetic medicinal herb

Abstract

Gymnema sylvestre (Retz.) R. Br. ex Schult is a highly demanded antidiabetic medicinal herb native to India. There are no improved varieties available and the plant is still collected from the wild and therefore it is important to estimate the genetic variability and heritability parameters for devising appropriate crop improvement strategy. The present study was undertaken to assess the genetic variability, heritability, character association and path analysis for growth, yield and bioactive traits in 35 accessions of G. sylvestre collected from Indian South Peninsular region. Genetic variability parameters: genotypic variance, phenotypic variance, genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), broad-sense heritability, genetic advance and genetic advance as per cent over mean of yield and quality related characters were computed to understand the extent of variability present. High levels of GCV and PCV (>20%) were observed for most of the traits. Leaf length, leaf area, leaf yield and gymnemagenin content reported with high heritability (>60%) and genetic advance over mean (>30%) suggest that variation in these traits is influenced predominantly by the genetic factors making selection more effective in improving them. The correlation and path analysis studies highlighted the importance of selecting leaf length, leaf breadth, leaf area index, fresh leaf yield and gymnemagenin content for improving dry leaf yield of G. sylvestre. The study also identified promising morphotypes (IIHR-GS-27 and IIHR-GS-9) and chemotypes (IIHR-GS-44) which can be utilized for the commercial exploitation or can serve as pre-breeding materials in the crop improvement programmes.