Análise da diversidade genética em Tenebrio molitor por meio de marcadores moleculares ISSR

Abstract

The use of insects in animal and human food has aroused great interest from government agencies and researchers around the world, driven by the need for more sustainable agro-industrial practices. The species Tenebrio molitor has excellent bromatological qualities and ease of handling, configuring a great source of protein, mainly. No work has yet been carried out to estimate the genetic diversity of this insect, and this information is very relevant for efforts to improve and understand population dynamics. In this study, the objective was to analyze the genetic diversity of T. molitor through molecular markers amplified with ISSR (Inter Simple Sequences Repeats) oligonucleotides and biometric procedures. A DNA extraction protocol with adaptations was applied. PCR (Polymerase Chain Reaction) reactions were performed in the context of temperature gradient tests for 56 ISSR oligonucleotides, from a collection developed by the University of British Columbia (UBC primer set #9, Vancouver, Canada). Those that generated polymorphisms were used to amplify a collection of 48 accessions of T. molitor, collected from eight Brazilian municipalities. Molecular data were used to compare the genetic dissimilarities produced by the indices of "Nei and Li", "Jaccard" and "Simple Coincidence", the matrix of the first being also applied to the "Hierarchical" clustering (UPGMA) and optimization of "Tocher". Of the 56 oligonucleotides tested, 34 showed polymorphisms between accessions, under specific annealing temperatures. These, in turn, produced 131 fragments used to obtain the dissimilarity matrix, which showed high general variability among the 48 accessions (11.24% to 65.45%). Considering the dissimilarities between pairs of accesses, 79 presented values greater than 50%. The "Hierarchical" clustering and "Tocher" optimization methods discriminated five and four groups, respectively. When interpolating the two procedures, accessions 1, 15, 16 and 45 were detached; in relation to others. These results are of special interest for the choice of parents that potentiate heterotic effects and segregating populations in breeding programs.