Vol. 11, Special Issue 9 (2022)

Author(s):
DS Kar, CM Panda, GS Sahu, P Tripathy, AK Das, S Sahu, A Mohanty, Gargi Gautami Padhiary and Subha Laxmi Mishra

Abstract:
The experiment was taken up to elicit the information on magnitude of genetic variability, heritability and to predict the gains realized through selection, character association, cause and effect relationship and divergence for the quantitative characters in sweet potato (Ipomoea batatas (L.) Lam.) genotypes. Fifteen genotypes of sweet potato were evaluated in RBD with three replications during kharif season of 2019 & 2020 at in the K.V.K Dhenkanal District. The study revealed significant differences among genotypes for different characters studied. Among all the genotypes studied, genotype Accession-22 recorded the highest root yield per hectare and found suitable to the local agro-climatic conditions. The genotypes ST-14 were also found to be elite for different characters. Among the characters studied, high PCV and GCV were observed for characters like vine length, vine internodal length, number of branches per plant, number of leaves per plant, total leaf area, number of roots per plant, root yield per plant, β-carotene content, starch content, total sugars, reducing sugars, non reducing sugars and total root yield per hectare content indicating high variability available in the germplasm for these characters for further improvement. High heritability coupled with high genetic advance as per cent of mean was observed for characters vine length, vine internodal length, number of branches per plant, length of leaf lobe, number of leaves per plant, total leaf area, root girth, root yield per plant, β-carotene content, starch content, total sugars, reducing sugars, non reducing sugars and total root yield per hectare indicated that these characters were least influenced by the environmental effects, and these characters were governed by additive genes and selection will be rewarding for improvement of such traits. The total root yield per hectare (t/ha) had significant positive correlation with traits like number of branches per plant, number of roots per plant, root girth, root yield per plant and β-carotene content suggesting the importance of these traits in selection for yield and can be identified as yield attributing characters for the genetic improvement of yield in sweetpotato. The total root yield per hectare (t/ha) was result of direct effect of number of branches per plant, number of roots per plant, root length, root yield per plant, starch content and reducing sugars. The high direct effect of these traits appeared to be the main factor for their strong association with total root yield per hectare. Analysis for divergence using D² statistic revealed highly significant differences for different traits, grouping the 15 genotypes into 6 clusters. Cluster II had the maximum number of genotypes (8) followed by cluster I (7). Maximum inter cluster distance was observed between clusters III and VI while the intra cluster distance was maximum in cluster II and VI. Highest percent contribution to divergence came from β-carotene content, starch content, total sugar, total leaf area, root dry matter content, number of leaves per plant, root yield per plant, petiolelength, root girth, vine length and reducing sugar suggested that selection of one or two elite genotypes from divergent (II & VI) and (III & VI) clusters based on the above characters and crossing would result in more heterosis and novel hybrid.