Genetic relationships between peanut and wild species of Arachis sect Arachis (Fabaceae): Evidence from RAPDs

Twenty-six accessions of wild Arachis species and domesticated peanuts, A. hypogaea, introduced from South America were analyzed for random amplified polymorphic DNA (RAPD). The objective of the study was to investigate inter- and intraspecific variation and affinities among species of sect. Arachis which have been proposed as possible progenitors for the domesticated peanut. Ten primers resolved 132 DNA bands which were useful for separating species and accessions. The most variation was observed among accessions of A. cardenasii and A. glandulifera whereas the least amount of variation was observed in A. hypogaea and A. monticola. The two tetraploid species could not be separated by using RAPDs. Arachis duranensis was most closely related to the domesticated peanut and is believed to be the donor of the A genome. The data indicated that A. batizocoi, a species previously hypothesized to contribute the B genome to A. hypogaea, was not involved in its evolution. The investigation showed that RAPDs can be used to analyze both inter- and intraspecific variation in peanut species. Southern hybridization of RAPD probes to blots containing RAPD of the Arachis species provided information on genomic relationships and revealed the repetitive nature of the amplified DNA.