Variability and Association of Quantitative Traits in Plectranthus edulis (Vatke) Agnew

Abstract

Thirty six accessions of Plectranthus edulis were evaluated to estimate the nature and magnitude of variability and associations among tuber yield and related characteristics. Analysis of variance for each characters
indicated highly significant (p<0.01) variation among the accessions for all characters except tuber length. Relatively high phenotypic (43.17, 37.85, and 24.25 %) and genotypic coefficients of variation (42.42, 36.47 and
18.40%) were observed for tuber weight per hill, number of tuber per hill and stem number per hill in the order of magnitudes. High heritability (96.50 and 92.84%) coupled with high genetic advance as percent of mean (86.85 and 72.38%) were recorded for tuber weight per hill and number of tubers per hill respectively. Analysis of phenotypic correlation indicated that tuber yield per hill was significantly and positively associated with number
of branches (r =0.366), tuber diameter (r = 0.435), and number of tuber per hill (r =0.567). Path coefficient analysis at genotypic level also revealed that number of tubers per hill (p=0.982) exerted a high magnitude of positive direct effect on tuber weight per hill. Nevertheless, the need for confirmation of genotypic-environment interaction and widening of the genetic base for P. edulis improvements are suggested.

Keywords: Correlation Analysis; Genetic Variability; Path Analysis; Plectranthus edulis