Análise do ITS1 do DNA ribossômico em espécies do complexo Anastrepha fraterculus (Diptera: Tephritidae) / Analysis of ITS1 of ribosomal DNA in Species of the Anastrepha fraterculus complex (Diptera: Tephritidae).

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Fruit flies of Tephritidae family are important pest for the worldwide fruitculture because many species use commercial variety of fruits as host for the development of thier larval stage. Anastrepha is endemic of the American Continent and comprises about 200 described species, 90 of which occurs in Brazil. Among these species the most important is the nominal A. fraterculus, that, actually, comprises a complex of cryptic species, the so-called "fraterculus complex". Four species of the complex has been characterized, three of which occurs in Brazil (A.sp.1, A.sp.2, A. sp.3) and one in Ecuador (A. sp.4). In the present analyses the ITS1 spacer of the ribosomal genes was characterized by PCR and sequencing, in samples of A. fraterculus s.l. from several populations in Brazil and from different regions of South, Central America and Mexico. Amplyfication was carried out with primers designed in the present analyses, 18SF and 5.8SR, that generate fragments of 900 bp containing a partial sequence of the 18S gene, the complete ITS1 and the initial portion of the 5.8S gene. The length of the fragment did not varied significantly among the samples. The ITS1 size varied from 539 to 584 bp, and contained a very high content of AT, from 77.6 to 88.6 %, among samples. Similarity of the ITS1 sequences was high (from 88% to 99.8%) among the samples, and no signficant intraspecific differences were found in the sequences of samples from different brazilian populations. The POY software produced many parcimonious phylogenetic trees, and the strict consensus tree grouped the samples in distinct clades. First, there was a separation of the clade of Ceratitis species (outgroups) from the clade of Anastrepha. Within this clade A. obliqua was isolated from a large clade containg all the samples of A. fraterculus s.l.. Within A. fraterculus, one clade grouped the samples from Mexico and Guatemala, another clade the samples from Ecuador and Peru and a clade with the samples from Brazil and Argentina. The sample of Colombia was found as independent branch of the tree. In each of these clades there were subgroups of the different samples, and it was observed a relationship of these clades and subgroups to the biogeographic divisions of the entomofauna of Latin America with a few exceptions. The analysis of ITS1 clearly corroborate previous data indicating that there are three biological entities of the fraterculus complex in Brazil. It also indicates that different entities must exist in other regions of Latin America.

ASSUNTO(S)

fruit-fly moscas-das-frutas pest species filogenia espécies-praga phylogeny

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