Variability and association among tuber yield and yield related traits of potato (Solanum tuberosum L.) genotypes in Debre markos district, north west Ethiopia

Abstract

Twenty five potato genotypes were tested 5*5 simple lattice design in Debremarkos, north western Ethiopia, during the main rainy season of 2019. The objectives of the study were to assess the nature and magnitude of variability, to estimate the genotypic and phenotypic association among characters and to cluster genotypes based on their genetic similarity and divergence. The analysis of variance showed the presence of significant (P < 0.05) differences among genotypes for all trait. The phenotypic coefficient of variation (PCV) ranged from 8.8 to 58.70% and genotypic coefficient of variation (GCV) from 5.62 to 35.17%. The values for heritability in broad sense and genetic advance as percent of mean ranged from 22.98 to 91.25% and 5.55–69.17% respectively. Tuber yield per hectare showed a positive and highly significant (P < 0.01) correlation with marketable tuber yield both at the genotypic and phenotypic levels. Tuber yield showed positive, negative and significant (P < 0.05) correlation with plant height, average number of tuber, average tuber weight and small tuber size at genotypic and phenotypic levels. Cluster analysis had revealed that the 25 genotypes were grouped in 5 distinct clusters. Maximum and minimum average intra cluster D2 was obtained in cluster III (D2 = 5.69) and cluster IV (D2 = 2.63) respectively. This shows that there is a maximum genetic recombination is expected from the hybridization of the parents selected from divergent cluster groups. Principal component analysis showed that the first seven principal components accounted for 84.65% for the observed variations among potato genotypes.