Genetic diversity in pigeonpea (Cajanus cajan (L.)Millsp.) Landraces as revealed by simple sequencerepeat markers uri icon

abstract

  • Genetic relationships among 88 pigeonpea accessions from a presumed centre of origin and diversity,India and a presumed secondary centre of diversity in East Africa were evaluated using sixmicrosatellite markers. Forty-seven (47) alleles were detected in the populations studied, with a mean ofeight alleles per locus. Populations were defined by region (India and East Africa) and sub-populationsby country in the case of East Africa and State in the case of India. Substantial differentiation amongregions was evident from Roger?s modified distance and Wright?s F statistic. Greatest genetic diversityin terms of number of alleles, number of rare alleles and Nei?s unbiased estimate of gene diversity (H)was found in India as opposed to East Africa. This supports the hypothesis that India is the centre ofdiversity and East Africa is a secondary centre of diversity. Within East Africa, germplasm fromTanzania had the highest diversity according to Nei?s unbiased estimate of gene diversity, followed byKenya and Uganda. Germplasm from Kenya and Tanzania were more closely related than that ofUganda according to Roger?s modified distance. Within India, results did not indicate a clear centre ofdiversity. Values of genetic distance indicated that genetic relationships followed geographicalproximity

publication date

  • 2010