Diversidade e estrutura genética da coleção regional de germoplasma de mandioca da EMBRAPA Amazônia Ocidental.

Abstract

Manioc (Manihot esculenta Crantz) performs an important social role as a food source in the tropical world. The germplasm maintained manioc forms the basis for technological exploitation of the species in the development of new cultivars. To be efficiently used require different methods of genetic characterization. Markers based on transposable elements are suitable for genetic analyzes because of their qualities of reproducibility and abundant polymorphism. We used 430 manioc accessions that compose the Embrapa germplasm collected in the Amazon basin. The retrotransposons sequences were located in the Phytozome database, IRAP primers designed with Primer3 program, structuring within the germplasm has been detected by STRUCTURE software v. 2.2 and the genetic diversity was assessed using the Popgen software v1.32. IRAP data to the software STRUCTURE suggested the existence of two gene clusters (k = 2) with 93 and other with 127 varieties of total 430 plants, considering only the fidelity above 80%. The AMOVA for K = 2 showed greater variation within the group (89%) than among groups (11%). The six IRAP primer pairs were informative for assessing genetic diversity, with averages of 96% polymorphism, 0.4 heterozygosity and Shannon index 0.57, however, did not detect structuring within cassava germplasm compared to other assisted structuring markers.