Filogeografia de Partamona helleri Friese, 1900 (Hymenoptera: Apidae: Meliponini)

Abstract

Meliponini is a tribe of bees popularly known as stingless bees that occurs in tropical and subtropical areas of the world, being more diversified in Neotropical and Indo-Malaya regions. Currently, 29 genus and 244 species are present in Brazil. Only a few phylogeographic studies were realized with species of this tribe. The genus Partamona Schwarz, 1939 clusters 33 species with exclusive occurrence in the Neotropical region. The species Partamona helleri presents wide distribution throughout Atlantic forest and part of the Cerrado from the State of Minas Gerais, reason of the choice of this species as our model organism. This study aimed to elucidate the phylogeographic pattern of P. helleri populations throughout its distribution area. For this purpose, samples of 347 nests from 67 localities situated from Northern Bahia to Santa Catarina were collected. Three mitochondrial genes fragments (COI, CytB and 12S) were analysed, which resulted in 339 concatenated sequences. The phylogenetic reconstruction by Bayesian Inference (IB) showed several lineages in a little resolved polytomy, what hampered the definition of the phylogenetic relationships among haplotypes. The haplotype network illustrated the relationship between 73 haplotypes identified, being 64 of them exclusive of localities. The AMOVA showed that 91.7% of the genetic variation is due to interpopulacional differences, indicating high structuring among populations. A low significant correlation between genetic and geographic distances was observed (r = 0,2487; P < 0,0010). The Bayesian population analysis implemented by BAPS showed that five groups were more suited to explain that genetic structuring. Such result was partly compliant with established lineages in the topology obtained by IB and with the results observed in the haplotype network. The results showed that the northern populations of P. helleri distribution are quite differentiated among themselves and also from the others populations observed along the central and southern regions. However, it was not possible to access how the genetic variation of the northern populations is organized, and there may be a division in two or more phylogroups. For other populations, the existence of three possible phylogroups was verified, two in the central region and a third occupying the central and southern regions. The results obtained for the demographic history of these phylogroups were not conclusive, however, it is likely that the phylogroup occupying the central and southern regions is in an expansion process. It was also verified that the level of variation observed by phylogroup decreases towards north/south, which allowed to raise a hypothesis about the origin and dispersion of this species.