Niche modelling supports the origin of peanuts in the orchards of ancient inhabitants

SEIJO G.; CHALUP L.; SOLIS NEFFA V.; MORENO E.M.S.; ROBLEDO G.; PÉREZ L.; SAMOLUK S.

Córdoba

Congreso; Ninth International Conference of the Peanut Research Community: Advances in Arachis through Genomics & Biotechnology; 2017

Fundación Maní Argentino

Arachis duranensis (A genome) and A. ipaënsis (B genome) are, respectively, the maternal and paternal diploid genome donors of peanut and A. monticola (4x, AABB). Two hypotheses were proposed concerning the scenario of the origin of tetraploids, 1) spontaneous hybridization in natural environments, for which simpatric distribution of diploid parents is needed and, 2) ancient people used, moved and cultivated wild species, giving a chance to the progenitors of peanut to get in sympatry in their orchards. The only one known population of A. ipaënsis lives at the north limit of A. duranensis distribution, but the former species lives in an unexpected environment far from its phyllogenetically closest species (A. magna) and from any of the other species with the genome. In this work we modeled the present and past (22000 YBP, LMG) species distributions to test the natural ocurrence of A. duranensis in sympatrywith any of the B genome species. All the known localites for A. duranensis, and all the B genome species (excluding A. ipaënsis) were included in the analysis. Modelling evidence that it is largely improbable that any of the B genome species would be sympatrically distributed with A. duranensis at present. In the past, and considering only the points for A. magna, there is a low probability (0 ? 25%) that this species overlapped with A. duranensis in a restricted area in the south of Bolivia. This probability decreased to cero when all the B genome species were considered in the analysis. Although our results are not conclusive, the analysis here performed added dat to support an anthropic influence in the origin of peanut