Multivariate Analysis of Genetic Diversity in the Ethiopian Garden Cress (Lepidium sativum L.) Genotypes
Legesse Tadesse
Department of Biology, College of Natural and Computational Sciences, Dire Dawa University, P.O.Box 1362, Dire Dawa, Ethiopia and School of Plant Sciences, College of Agriculture and Environmental Sciences, Haramaya University, P.O.Box 138, Dire Dawa, Ethiopia
Firew Mekbib
School of Plant Sciences, College of Agriculture and Environmental Sciences, Haramaya University, P.O.Box 138, Dire Dawa, Ethiopia
Adugna Wakjira
Ethiopian Institute of Agricultural Research, P.O.Box 2003, Addis Ababa, Ethiopia
Zerihun Tadele *
Institute of Plant Sciences, University of Bern, Altenbergrain 2, 3013 Bern, Switzerland
*Author to whom correspondence should be addressed.
Abstract
Aims: The use of multivariate techniques is an important strategy for germplasm classification and study of genetic relationships among genotypes. This study was designed to evaluate using multivariate analysis the genetic divergence among 112 garden cress (Lepidium sativum L.) genotypes collected from different Administrative Zones of Ethiopia.
Methodology: The experiment was conducted at Haramaya University Research Site and Kulumsa farmer field. Twelve agro-morphological traits were evaluated in Randomized Complete Block Design (RCBD) with two replications. Region-wise analyses of variance, principal component and cluster analyses were applied.
Results: The analysis of diversity pattern based on the region of genotype origin revealed highly significant variability within and between regions of origin for almost all studied traits. The geographical pattern of distributions of genotypes in groups were not dependent on the regions of origin. The first three principal components explained 80.3% of the total variations suggesting that traits such as number of secondary branches, days to maturity, plant height, biomass/plant and biomass/plot, harvest index, grain yield/plant, thousand seed weight and grain yield/ha are the principal discriminatory traits in the germplasm studied. The cluster analysis categorised the 112 genotypes into six groups. The most diverse genotypes were found between cluster I and II which could be used for producing new genetic variability and exploitation of heterotic effects with the traits of interest in crossing programs.
Conclusion: The genetic diversity existing in the current study could be utilised in the genetic improvement of the Ethiopian garden cress germplasm.
Keywords: Cluster analysis, garden cress, genetic divergence, Lepidium sativum, multivariate analysis, principal component analysis