Genetic Patterns of Domestication in Pigeonpea (Cajanus cajan (L.) Millsp.) and Wild Cajanus Relatives uri icon

abstract

  • Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providingsignificant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base,pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that wouldbenefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotidepolymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographicallyclustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzedCajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent geneflow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species.Evidence supports that primary domestication occurred in India, with a second and more recent nested populationbottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelicvariation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which wereport a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversitythan the progenitor clade of wild Indian species, indicating a severe ??domestication bottleneck?? during pigeonpeadomestication

publication date

  • 2012
  • 2012