Genetic diversity analysis of Lima bean (Phaseolus lunatus L.) Landrace from Ethiopia as reveled by ISSR marker

Abstract

Lima bean (Phaseolus lunatus L.) is one of the five most important legume crops from the genus Phaseolus though it is one of the neglected crops in Ethiopia. There is no national breeding program for its improvement. As it is true for all crops, understanding the genetic diversity of Lima bean is useful for its improvement and sustainable use. Therefore, the objective of the current study was to investigate genetic diversity of Lima bean landrace collected in Ethiopia using eight issr markers. A total of 96 landrace were collected from five administrative zones of Ethiopia from which 106 clear bands were detected. About 95 (88.7%) of the bands were polymorphic. The genetic diversity analyses result revealed that landrace collected from West Wellega showed the highest (0.1864) genetic diversity. amova demonstrated highly significant (P=0.00) genetic diversity among and within populations. A considerable proportion (66%) of the total genetic diversity was distributed among populations and 34% within populations. In addition, the calculated Fst value was high (Fst = 0.66), associated with a low gene flow value (Nm=0.27) indicating lower differentiation of the populations, which, in turn, implied no significant exchange of planting materials among farmers in the studied populations and the nature of the crops that Lima bean is 52% self pollinated crop. upgma, structure and PCoA analysis showed very strong grouping among individuals collected from the same zones and geographically distinct zones. Overall, genetic diversity achieved from this study could be used as pioneer information about the existing genetic resource for future Lima bean conservation and improvement strategy in Ethiopia.