VARIABILIDADE GENÉTICA DE UMA COLEÇÃO DE GENÓTIPOS DE MACIEIRA DO PROGRAMA DE MELHORAMENTO DO IAPAR

Abstract

The apple (Malus × domestica Borkh) is one of the fruits most appreciated by the humans. This species, being originally from temperate regions, has problem in adaptation to Brazil. The Agronomic Institute of Paraná (IAPAR) developed some apple cultivars with low chilling requirements and apple scab resistance and has a collection of genotypes that has not been characterized as the variability. The use of molecular techniques can assist with this characterization. Therefore, this study aimed to genetic-molecular characterization of the apple genotypes from IAPAR. For molecular analyzes DNA from 60 apple accessions was extracted and amplified using ISSR primers. First, to selection of the best primers for apple, 42 primers were run on 10 access and calculated the PIC (Polymorphic information Content) and RP (Resolving Power) values and perform comparisons between cluster obtained with the data of all primers with the cluster obtained with data from the selected primers. After, the selected primers were run on the 60 genotypes from IAPAR. With the data obtained were made cluster analysis, Principal Coordinate Analysis (PCoA) and Bayesian analysis. Based on the PIC and RP values were selected nine ISSR primers (UBC-815, UBC-817, UBC-823, UBC-834, UBC-807, UBC-826, UBC-836, UBC-843 and UBC-873).The clustering obtained of the 10 apple accessions was the same with the data of the nine primer and the data for all the primers. The evaluation of these nine ISSR primers in 60 accessions allowed to observe that the genetic similarity among accessions ranges from 11% (between accesses Castel Gala and 53-80-149) and 80% (between the access Fuji Supreme and 2-80-59). The average similarity between all access was 46%. The obtained dendrogram resulted in the formation of two groups, showing high genetic variability. Principal Coordinate Analysis (PCoA) also showed high genetic variability in genotypes collection from IAPAR. The Bayesian analysis showed that this genetic variability is distributed in four genetic groups. The data obtained here may assist breeders in selecting accesses to performing crosses to obtain superior cultivars.