Diversidade genética de tucumanzeiro (Astrocaryum aculeatum Mart.) com marcadores microssatélites

Abstract

The tucumanzeiro (Astrocaryum aculeatum) is a species of palm not domesticated an with great potential, very common and appreciated by the population of the Amazon region. The spontaneous populations present great variability for characteristics as height of plant, production and quality of the fruits (so great, pulp income, fiber flavor, content and oil). These populations consist in the genetic resources for current or potential use and are great source of genes of meaning for the genetic improvement of the species. The objective of this work was to characterize the genetic variability of populations of tucumanzeiro in the Amazônia, being used marking microssatélites. Thirty leaf samples had been collected of tucumanzeiro of twelve populations (Buiuçuzinho, Urucu, Manacapuru, UFAM, Tarumã, Porto Velho, Humaitá, Manicoré, Borba, Rio Preto da Eva, Itacoatiara and Maués) and analyzed using four loci microssatélites (Bg11, mBg41, mBg62 and mBg91) of the eleven developed for peach palm (Bactris gasipaes) and transferred for tucumã successfully. 48 alelos with average of 12 alelos for locus had been detected, being lesser in mBg41 (8 alelos) and greater in mBg62 (15 alelos), confirming the high content of genetic information of this type of marker for genetic studies in palms. The alelos had been classified in accordance with its frequencies and distribution between the populations. A total of thirty alelos was classified as rare (frequency < 0,05), twelve alelos as intermediate (frequency between 0,05 and 0,2), and six common (frequency > 0,2). 13 private alelos (present only in a population), 16 sporadical alelos (gifts of two the five populations) and 19 spread out had been detected (present in more than five populations). The estimate of total genic diversity (Ht) was 0,68 and estimative of genic diversity inside of the populations (Hs) he was 0,58 representing 85% of the total diversity. The observed heterozygosity (Ho) had been lower the heterozygosity waited (He) in 50% of loci. The observed heterozygosity was bigger in Buiuçuzinho (Ho=0,67) and minor in the Tarumã (Ho=0,54). Low genetic divergence was observed between the populations (Fst=0,161 and Gst=0,150). The analysis of the molecular variance (AMOVA) disclosed that the populations studied of tucumã present greater inside genetic variability of the populations (84%), and a lesser variability between the populations (16%). However, high genetic diversity was found intra-population that could be used in improvement programs.