Genetic Variability and Correlation of Cassava (Manihot esculenta Crantz) Accessions for Yield and Related Traits

Abstract

The study was carried out in Tapioca and Castor Research Station, Yethapur, India to study the Genetic Variability and Correlation of Cassava (Manihot esculenta Crantz) accessions for yield and related traits. Observations on quantitative and qualitative traits of cassava were recorded and the analysis of variability and association analysis were carried out. High Genotypic coefficients of variation (GCV) were found for LAI, height at first branching, number of leaves per plant, number of tiers, yield of tuber per plant and severity scores of CMD whereas low GCV were found for Chlorophyll content. Phenotypic Coefficients of Variation were higher than Genotypic coefficients of Variation for all the observed characters.  Plant height, number of tiers, internodal length, number of leaves per plant, LAI, height at first branching, length of tubers, dry matter content, severity scores of CMD, tuber yield recorded high heritability with high GAM suggesting that these characters are under the additive gene control and selection for genetic improvement would be successful. Chlorophyll content, girth of tuber and starch content recorded high heritability coupled with moderate GAM whereas stem girth recorded moderate heritability and GAM which offers only less scope for selection that is due to non-additive gene actions. The correlation analysis results showed that yield of tuber per plant had high positive and high significant correlation with plant height, number of tubers per plant, starch content, length of tuber, girth of tuber and weight of tuber. Genetic variability and correlation analysis provides a knowledge which would be helpful in selecting the cassava accessions with greater yield potential.