GENETIC DIVERSITY OF ETHIOPIAN MUSTARD (Brassica carinata A. Braun) USING INTER-SIMPLE SEQUENCE REPEAT MARKERS

Abstract

Brassica carinata (2n = 34, BBCC) is an amphidiploid plant arisen as a result of interspecific cross between Brassica nigra (2n = 16) and Brassica oleracea (2n = 18). It is economically important plant being cultivated for use as vegetable and oilseed. Though B. carinata is among important oil crops, study on its genetic variability is lacking and this study is meant to examine the genetic diversity and relationships of B. carinata accessions collected from selected B. carinata growing areas of Ethiopia. Six ISSR markers were used to analyze the genetic diversity and relationships of 60 accessions of B. carinata collected from four geographical areas; Wello, West Shewa, East Wellega and Illu Ababora and assigned to four populations according to the collection areas. A total of 73 bands were generated with an average of 12.17 bands per primer. The percentage polymorphism observed in the populations ranged from 65.75% to 84.93%. Nei’s gene diversity (0.34) was highest in accessions collected from Illu Ababora and least (0.26) in accessions collected from Wello. The proportion of the total genetic variation contributed by among population variation (GST) was 0.227 while 77.3% of the total genetic diversity was attributed to the within population variation. AMOVA analysis revealed higher (75%) genetic variation within the populations and less (25%) genetic variations among the populations. Clustering analysis and dendrogram constructed with UPGMA method resulted in similar clustering pattern. The patterns of clustering in 2D and 3D scatter plots were supportive of the clustering pattern obtained with UPGMA. The result in this study showed that ISSR Markers disclosed high level of genetic diversity. Although ISSR markers enabled detection of high genetic diversity in the 60 accessions used in this study, more analysis should be done with more number of accessions collected from vast geographical areas.