Genetic variability of Sweet Potato on yield and yield related traits at werer Agricultural Research Center, Ethiopia

Abstract

Muluken Demelie 1 and Abiyot Aragaw 2 Ethiopian Institute of Agricultural Research (Werer Center), P.O. Box: 2003, Addis Ababa Ethiopia 1 International Potato Center – Ethiopia (CIP), .PO Box 10059 Addis Ababa, Ethiopia 2 ABSTRACT Sweet potato [ Ipomoea batatas (L.) Lam.] is important food security root crop in tropical and subtropical regions. It can tolerant of a wide range of edaphic and climatic conditions and grown with limited inputs. Genetic analysis reveals the genetic nature of the inheritance of tuber yield and yield components which is required to design efficient sweet potato improvement breeding strategy. Therefore, the objectives to determine genetic variability and to estimate the association of agro-morphological trait in sweet potato genotypes. Filed experiment was conducted at Were Agricultural Research Center using three varieties and eight accessions in Randomize Complete Block Design (RCBD) with three replications. Data were collected from twelve agro-morphological traits. This analysis of variance revealed significant (p<0.05) among sweet potato genotypes for all traits except stand count at sprout which showed non significant among sweet potato genotypes. Genotypes showed total tuber yield ranged from 123.67 to 370.04 with mean of 231.04 qt/ha while root weight 100 to 263 with mean of 168.04 gm. Newly released variety Ma’e gave highest yield. Genotypic coefficients of variation lower in magnitude than phenotypic coefficient of variation all agro-morphological traits. Genotypic coefficient of variation ranged from 0.77 (stand count at sprout) to 33.93 (unmarketable tuber yield) while phenotypic coefficient variation ranged between 3.47 (stand count at sprout) to 39.36 (unmarketable tuber yield). Heritability in broad sense was recorded for twelve traits ranged between 4.99% (stand count at sprout) to 86.45% (vine internode length). Genetic advance as percent mean ranged from 7.42% (stand count at harvest) to 60.27 (unmarketable tuber yield). Genotypic correlation higher in magnitude than corresponding phenotypic correlation for most of the traits. Genotypic correlation ranged from -0.56 (unmarketable and vine inter node length) to 0.98 (marketable and total tuber yield) while phenotypic correlation ranged from -0.56 (unmarketable and vine inter node length) to 0.97 (marketable and total tuber yield). This result suggested the importance of further collection to exploit the genetic variability between varieties and accessions for variety development of sweet potato in the country. Key words: phenotypic and genotypic coefficient of variation, heritability, genetic advance