SEIJO Jose Guillermo
congresos y reuniones científicas
The haplotypes of Arachis correntina and A. villosa reflects an associated history with the alluvial fan of the Parana River during the Upper Quaternary.
GRABIELE MARINA; CHALUP, L.; ROBLEDO, G.; J. G. SEIJO
Congreso; 5th International Conference of the Peanut Research Community on Advances in Arachis through Genomics and Biotechnology (AAGB).; 2011
Arachis correntina and A.villosa are perennial diploid species (2n=2x=20). The former is found in the Northeast Argentina and East of Paraguay River near Asunción (Paraguay), while the latter growths in a disjunct area along Uruguay River, from 29ºS to the North bank of La Plata River. Both taxa are morphologically similar and they have been considered as only one species. They show the most southern distribution of the section and most of their populations are associated to watercourses. In order to understand the colonizing pathways and to shed light on the evolutionary relationships between A.correntina and A.villosa we analyzed the haplotypic variability in the whole range of distribution of these species. For this purpose, a Neighbour-Joining tree was constructed from two cpDNA regions (trnT-S and trnT-Y) isolated from 28 populations. Six haplotypes were identified. One of them was shared by all A.villosa and some A.correntina accessions and it was widely distributed at the edges of the Paraná megafan and along the Uruguay River. The other five were exclusive of A.correntina, and in general, they were restricted to smaller areas associated to present rivers that are thought as ancient paleochannels. The network analysis of haplotypes revealed a close relationship between both species. The mutational pathways of haplotypes evidenced a more ancient dispersion of the haplotype shared by A.correntina and A.villosa and a more recent dispersion of those exclusive for A. correntina through the main river channels of the alluvial megafan generated by the Paraná River during the Upper Quaternary.