Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.27

THE ASCERTATION OF GENETIC CORRESPONDENCE OF ONE GENOTYPE IN ALMOND (AMYGDALUS COMMUNIS L.) FROM APULIA

R. CHAABANE*, F. LAMAJ*, N. LAMASCESE**, D. DE GIORGIO**, P. RESTA*

*) Dipartimento di Biologia e Chimica Agro-forestale e ambientale (DiBCA), Università degli Studi di Bari, Via Amendola 165/A, Bari, Italy

**) Istituto Sperimentale Agronomico, Ministero delle Politiche Agricole e Forestali, Via C. Ulpiani 5, Bari, Italy

cultivar identification, molecular descriptors, multivariate analysis, probability of coincidence, AFLP

Cultivar collections are fundamental for fruit tree breeding, and their maintenance drains significant resources. The study of homonimous and synonimous denominations has a role in the optimization of collections by eliminating duplications and clarifying uncertainties over cultivar classification. The employment of DNA comparisons together with the traditional morpho-physiological descriptors is a powerful approach for the optimization of collections. Fingerprint analyses are particularly well suited as a rapid and precise tool in the field of genetic correspondence in vegetatively propagated crops. However, their application is not immune to mistakes and subjectivity, thus it is necessary to use internal parameters to check the results. One significant test is first to identify an unknown sample within a collection based on the fingerprint alone, and to then establish a conservative estimate of the probability in association with the resulting identity. To this purpose, in a more general research in progress, DNA was isolated from the leaves of an almond cultivar, whose identity remained unknown throughout the steps of the analysis. The AFLP fingerprints obtained were compared with those corresponding to 43 almond cultivars. Based on the presence/absence matrix, both a descriptive analysis by the UPGMA-SM dendrogram and a statistical analysis by the estimation of the probability of coincidence of the DNA profiles were made. Both the unknown sample and the cultivars analysed originated from the collection gathered and maintained by the MiPAF Experimental Station of Bari. This collection includes numerous denominations with diverse diffusion in the Apulian region and, therefore, the group of 43 cultivars analysed is representative of the almond population in Apulia.

The unknown sample was correctly attributed as being the cultivar “Rossa”. This result demonstrates the possibility of identifying a corresponding cultivar on the basis of leaf DNA analysis, without prior information, and in a relatively short time with a few AFLP primer combinations. In addition, an estimate was determined of the probability that the unknown sample and the corresponding cultivar had the same genotype with respect to the alternative hypothesis that casuality led to the obtained result. In view of these results the possibile applications of DNA analyses in the field of cultivar identification and genetic correspondence are discussed.