GENETIC VARIABILITY AND ASSOCIATION AMONG YIELD AND YIELD RELATED TRAITS IN SWEET POTATO [Ipomoea batatas (L.) Lam.] ACCESSIONS FROM EAST AND WEST HARARGE

Abstract

Assessing the causes and magnitude of variation is the key to success in crop improvement program. This study was therefore conducted to study the genetic variability and association among yield and yield related traits of [Ipomoea batatas (L.) Lam] accession from East and West Hararge. Accession were planted in 10/4/2020 at Haramaya University Hirna research center, Eastern Ethiopia using Randomized Complete Block Design with three replication and evaluated for 12 agro-morphological traits. Significant difference among accessions were observed for all traits except for average number of storage tubers per plot which show non-significant. Genotypes showed marketable tuber yield ranged from 10 to 158 with mean of 78.5 tha-1. EHMdh accession was gave the highest yield. Genotypic coefficient of variation lower in magnitude than phenotypic coefficient of variation on all agro-morphological traits. Heritability in broad sense and genetic advance as percent of mean ranged from 17.02 to 88.88% and 21.04 to 75.5% respectively. Genotypic correlation ranged from -0.76 (average number of storage tuber and marketable tuber yield) to 0.99 (marketable tuber weight per plant and marketable tuber yield) higher in magnitude than corresponding phenotypic correlation that ranged from -0.53 (average number of storage tuber and marketable tuber yield) to 0.97 (marketable tuber weight and marketable tuber yield).The genotypic path analysis of vine internode length, marketable tuber, green top weight and average storage tuber weight exerted direct positive effect on marketable tuber yield. Phenotypic path analysis of vine internode length, green top weight and average storage tuber weight had positive direct effect on marketable tuber yield. These results suggested that the importance of further collection to exploit the genetic variability between varieties and accession for variety development sweet potato in the country.