Diversidade genética de genótipos promissores e acessos de café arábica

Abstract

Coffee is the second most consumed beverage in Brazil behind only water. Thus, a search for cultivars with high sensory quality of drink is constant by producers to serve the various categories of consumers, aiming at greater added value. A sensory analysis, in recent years, has undergone changes in its form of evaluation, since the market is more demanding with regard to the quality of coffee drink. In this context, the objective was to identify genotypes of Coffea arabica L. with superior drink quality and to verify the existence of genetic diversity through SNPs of markers. The genotypes are approximately ten years old and have morphological diversity, with emphasis on the size, color of the sprouts, large red fruits with a high percentage of grains with a sieve size 16 and above. To check the quality of the beans, genotypes were analyzed for sensory quality according to the methodology proposed by the Specialty Coffee Association (SCA). Genetic diversity was estimated with the help of molecular markers SNP (Single Nucleotide Polymorphisms). For the extraction of DNA, fully expanded leaves were collected from 15 genotypes and 62 accessions belonging to the germplasm bank of the Agricultural Research Corporation of Minas Gerias. Later as sent to the Laboratory of Sustainable Perennial Crops, United States Department of Agriculture, Agricultural Research Service (USDA - USA). A total of 288 candidate SNPs selected. The genetic structure of the population was provided using the Bayesian STRUCTURE v2.3.422 cluster analysis software. In addition, a cluster analysis using the UPGMA (Unweighted peer group method with arithmetic mean) was performed to better examine the genetic relationship between genotypes and accessions. The UPGMA dendrogram was generated from the resulting distance matrix using the computer program PHYLIP version 3.697. The SNPs markers used here are excellent for grouping similar accessions in phenotypic and / or genealogical characteristics. The 15 genotypes have intraspecific genetic variability, as well as high genetic similarity with the Mundo Novo access. The formulated coffee genotypes have high sensory quality, classified as special by the SCA methodology, obtaining scores above 80 categorized as very good and excellent. Genotype 7 stands out in terms of sensory quality, showing promise in obtaining programs for future breeding programs.