USE OF RAPD ANALYSIS TO CHARACTERIZE VACCINIUM ACCESSIONS

Blueberry is becoming a high value crop in Northern Italy (Trentino area) and several germplasm collections are now available. In the last few years, attention has been paid to varietal evaluation for high quality production. Previous studies, based on a total of 27 morphological, phenological and floral characteristics, revealed a possible misidentification of 4 clones out of 38 accessions, two of which are extensively cultivated. Up to now, the characterization of cultivars was mainly performed by the evaluation of a large set of phenotypic data, which can be difficult to assess and often requires the complete development of the plant. Phenotypic traits are also influenced by the genotype/environment interaction and their evaluation can become complex, subjective and sometimes inaccurate. Molecular markers can be used as tools to efficiently identify or reclassify misidentified germplasm. In order to characterize the accessions we performed a molecular marker analysis using RAPDs. Nine primers were tested on 38 accessions. The varieties Darrow, Brigitta and Duke were represented by two accessions each, coming from different geographical areas. A set of 3 primers (OPA05, OPA07 and OPA20), was enough to discriminate all the accessions except Northblue and Northland. The analysis pointed out a mismatching between the two accessions of Darrow and between those of Duke, confirming suspicions that had arisen after morphological evaluation in the field. Concerning the mismatching of the two Brigitta accessions the analysis showed a different pattern for several loci despite identical morphological and phenological descriptions. Similarity among the accessions ranged from 40.0% to 97.4% as expected in an outcrossing species subjected to inbreeding depression.