Diversidade genética de populações naturais de jauari (Astrocaryum jauari Mart.)

Abstract

The Amazon has valuable reservoir of genetic resources related to species of palms, which we highlight the jauari (Astrocaryum jauari Martius), a non-domesticated specie, verified as high dispersion and is the most common palm in flooded areas of the Rio Negro, in Brazilian Amazon. Specie very explored till 90s for the extraction of palm, which formed the basis of industrial production of palm in Central Amazonia, however, not very studied compared species like peach palm, acaí and tucumã. The high occurrence of natural populations of this palm can be associated with alternatives seeking improvements in quality of life of local populations and community development, but for this is necessary the expansion of basic and applied studies for a better understanding of its diversity, occupation of ecosystem, evolution, adaptation and development of suitable methods for the management and use of this potential. The objective of this study was to characterize the genetic variability of populations of jauari in Amazon, using microsatellite markers. Thirty samples were collected from leaves of jauari of three populations (Santa Luzia do Buiuçuzinho, Matrinxã and Nossa Senhora das Graças) and analyzed using nine microsatellite loci (Aac03, Aac04, Aac05, Aac06, Aac07, Aac10, Aac12, and Aac13 Aac14) developed for tucumã (Astrocaryum aculeatum) and transferred successfully to jauari. It was detected 47 alleles with an average of 5.2 alleles per locus being lower in Aac03, Aac05, Aac10 Aac13 and (3 alleles) and higher in Aac04 (9 alleles), confirming the high information content of this kind of genetic marker for genetic studies of palms. The alleles were classified according to their frequency and distribution among populations. A total of thirteen alleles was classified as rare (frequency <0.05), nineteen alleles as intermediaries (often between 0.05 and 0.2), and fifteen common (> 0.2). Eight private alleles were detected, four of these were found in population Nossa Senhora das Graças; nine sporadic alleles (present in two populations) and 30 broadcast (present in all three populations). The observed heterozygosity (Ho) were higher than the expected heterozygosity (He) in 89% of loci. The average of observed heterozygosity was higher in Santa Luzia do Buiuçuzinho (Ho = 0.77) and lowest in Matrinxã (Ho = 0.70). Moderate genetic divergence was observed among populations (Fst = 0.12). The analysis of molecular variance (AMOVA) revealed that the populations studied jauari have greater genetic variability within populations (87.75%), and a lower variability among populations (12.25%). The dendrogram based on SSR markers revealed the formation of two groups, showing that the populations of Santa Luzia do Buiuçuzinho and Matrinxã are more genetically similar. The results showed that genetic distances are not correlated with geographic distance. However, it was found high intrapopulation genetic diversity that can be used in breeding programs. Keywords: Genetic