Evaluation of potato (Solanum tuberosum L.) genotypes for yeild and tuber quality related traits at Lowland, Dire Dawa, Eastern Ethiopia

Abstract

Potato (Solanum tuberosum L.) produces more nutritious food on less land with short period of time, but the production in lowland areas is limited by high temperatures, because the crop is adapted to cool climates and perform best at about 20°C. The production of potato at lowland areas demands to develop heat tolerant cultivars adaptable specific to high temperatures. Therefore, this research was conducted with the objectives of evaluating the yield and tuber quality related traits of 26 potato genotypes and estimating the genetic diversity under heat stress. The experiment was conducted at Dire Dawa in 2012 during the hottest months with >26⁰C and >33⁰C daily average and highest temperatures, respectively. Genotypes were planted in Randomized Block Design with three replications. The presence of significant differences among potato genotypes were observed for 12 tuber yield and tuber quality related traits. The genotypes produced 7.41 to 24.3 and 4.44 to 22.52 t ha^-1 total and marketable tuber yields, respectively, with tuber dry matter content ranged from 14.89 to 20.96%. The highest yields and tuber dry matter content were obtained from heat tolerant genotype (Vivadial). Heritability and expected genetic advance ranged from 22.35 to 87.65 and 15.24 to 54.97%, respectively, while genotypic and phenotypic coefficient of variations ranged from 13.63 to 85.54 and 16.78 to 90.97%, respectively. All the variability components values were medium to high for all traits suggested that selection genotypes on the basis of their performance was effective method to improve the crop in lowland areas. The genotypes were clustered in three groups of which Cluster I and II consisting of 11and 14 genotypes, respectively, while Vivadial formed solitary Cluster III. The research results demonstrated the existence of wider genetic variations among the potato genotypes and the higher chance of developing cultivars adaptable to lowland areas.

Keywords: Cluster, Heat tolerant, Genetic variability, Genotypes, Variability components