Genetic Diversity Study of Brachiaria brizantha (A.Rich) Stapf Collected from Ethiopia Using Inter- Simple Sequence Repeat (ISSR) Markers

Abstract

Brachiaria brizantha is a grass that instigate the economical growth in livestock sectors. However, it is orphan forage species where genetic degradation due to poor rangeland management practices, particularly overgrazing  combine with climate changes highly affect its contribution in Ethiopia.  Research centers have been confused to re-introduce the germplasm.  It is because of lack of species profile documentation.  Genomic DNA was extracted from leaf by using a modified CTAB method. A total of 80 bands were amplified by the six ISSR primers. Percentage of polymorphic loci (PPL), gene diversity (h) and Shannon information’s index (I) were 96.25%, 0.366 and 0.539, respectively among population. Analysis of molecular variance indicated the presence of higher proportion of variation within population (64.66%) than among  populations (35.34 %). Cluster analysis using the un-weighted paired group method with arithmetic average (UPGMA) at Jaccard’s similarity coefficient of around 0.38 clustered the accessions into three major (I, II and III) clusters in their respective origin of collection.  Principal Component Analysis (PCO) showed accessions in populations formed their own distinct and clear cluster. Thus ISSR markers detected a range of genetic diversity in Brachiaria brizantha germplasm collections from Ethiopia.

Keywords: Brachiaria brizantha, Genetic diversity, ISSR markers