Genetic variability in the ITS of nuclear ribosomal genes of Calophyllum brasiliense Cambess natural populations

IRRAZABAL TORRES, SANNY PIERINA; TALAVERA STÉFANI, LILIANA NOELIA; ARGÜELLES, CARINA FRANCISCA; PERCUOCO, CECILIA BEATRIZ

Foz de Iguazu

Congreso; 11th International Congress of Plant Molecular Biology; 2015

MINCYT Argentina - Sociedad Brasilera de Genetica

Calophyllum brasiliense Cambess. (Calophyllaceae) "arary" is a native tree that grows in higrophyle forest on the banks of the Paraná River and Esteros del Iberá wetlands in Argentina, standing in small and fragmented populations. Its distribution range extends from southern Mexico to northeastern Argentina. The probable origin of the southernmost populations is still uncertain and in order to contribute to this issue, this work aimed to evaluate the genetic variability within the ITS regions of 34 individuals collected in five natural populations of C. brasiliense from Argentina, one from Paraguay and one from Mexico. The ITS-1 and ITS-2 transcribed spacers of nuclear ribosomal DNA region were amplified and sequenced in all 34 samples. Fragments of 621 bp in length were aligned, obtaining a haplotype diversity of Hd=0.116 and a nucleotide diversity of Pi=0.00411 with three haplotypes identified: H1 was shared between Argentine and Paraguayan populations while H2 and H3 were exclusive for Mexican population. H1 and H3 differed by 28 mutational steps whereas H3 and H2 showed five mutation events between them, including ten InDels of 1 to 23 nucleotides in length, ten transitions and twelve transversions. These novel results for C. brasiliense supported the hypothesis of a common origin for the southernmost species populations. Even though previous chloroplast sequences analysis suggested a different origin of Paraguayan and Argentine populations. The analysis of other nuclear regions as well as a great number of populations from the species distribution will be carried out to elucidate the dispersion routes of C. brasiliense.