CONICET | Buscador de Institutos y Recursos Humanos

The cultivated peanut, a South American native cultigens, is one of the major oilseed crops of the tropics and subtropics. This natural and well-established allotetraploid (2n=4x=40, AABB) is included in section Arachis together with a wild allotetraploid and 29 wild diploid species. Researchers generally agree that the wild progenitors of peanut belong to section Arachis, however, there is still uncertainty on which A or B genome species has been the maternal parent. In order to address this particular topic of the genetic origin of peanut, we investigated the variability of cpDNA sequences in A. hypogaea and in eight closely related wild diploids. For this purpose, six no-coding cpDNA regions were PCR-amplified and sequenced. A total of 5200 bp were manually edited, and the substitutions as well as insertions/deletions were recorded. The comparative analysis of the sequences showed that species with A genome are more closely related to A. hypogaea and A. monticola than those with B genome. These results demonstrated that the maternal diploid parent of peanut, and its wild tetraploid ancestor, belongs to the A genome species group of section Arachis.