Abstract:

China is rich in indigenous pigeonpea genetic resources in Yunnan, Guangxi and their nearby provinces. Morphologically and ecologically, Chinese local pigeonpea genetic resources differe greatly from those of Indian originated accessions. The research was designed mainly to answer the questions on how different between pigeonpea genetic resources of Chinese origin and foreign origin, by genetic diversity analysis from DNA level. The results will help to guide the genetic resource collecting, research and breeding programs of pigeonpea in China and abroad. In the research, a representative set of 139 pigeonpea genetic resources from India, China, Africa and Latin America, together with a wild pigeonpea (Cajanus scarabaeiodes) accession as check, were analyzed by AFLP methodology using 17 informative primer pairs. In total, 502 unambiguous bands were detected, of which 494 were polymorphic. According to the dendrogram by UPGMA cluster analysis, almost all the accessions were distinct and revealed enough genetic diversity for identification and classification of accessions within Cajanus cajan. Using genetic distance matrix, by ME cluster analysis from MEGA three statistical package, eight distinct evolutionary groups were detected. According to the study on the eight evolutionary groups, Indian local pigeonpea resources held broad genetic diversity, followed by those from Africa and America with close consanguineous relationships to Indian local accessions. The preliminary results indicated Chinese indigenous pigeonpea resources held unique characteristic on their genetic diversity, with less consanguineous relationships to Indian, African and American local accessions. The preliminary results partly support the traditional theory on “India is the center for pigeonpea origin and genetic diversity, Africa is the sub-center on genetic diversity of pigeonpea”. But, China may be another sub-center for origin and genetic diversity of pigeonpea, according to the study. Distinct AFLP bands between sterile line (A line) and maintainer line (B line) of pigeonpea CMS system were detected, which may potentially use for marker assisted hybrid breeding program in pigeonpea.

Key words: Pigeonpea, AFLP, Cluster analysis, Genetic diversity, Center of origin