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

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

USE OF AFLP TO CLARIFY HOMONYMS AND SYNONYMS IN THE VARIETAL GROUP OF "MORAIOLO"

LABOMBARDA P., FONTANAZZA G.

Istituto di Ricerche sull’Olivicoltura CNR, Via della Madonna Alta, 128 Perugia

Olea europaea, Moraiolo, AFLP, cluster analysis, genetic variability

Olive (Olea europaea L.) is one of the most ancient arboreous species of the Mediterranean region. It consists of around 2000 varieties of which approximately 500 grown in Italy. One hundred and thirty-nine varieties has been morphologically and physiologically characterised in “Catalogo Mondiale delle Varietà di Olivo” C.O.I.. Complications in the olive identification and classification are the numerous homonyms and synonyms and the existence of cultivars with similar bio-morphological characteristics, which form the so called "varietal populations".

In this study we analysed the "Moraiolo" group which collectively refers to cultivars widespread particularly in the Centre Italy where it is known with synonyms such as "carboncella", "corniolo", "fosco" and "morella". The aim of the present work was to verify if the "Moraiolo" group is made up of cultivars genetically related. In this survey we considered both plants commonly called "Moraiolo" and olives morphologically similar to this group but differently named.

Thirty-seven accessions coming from Lazio, Liguria, Umbria, Marche and Toscana were analysed with 10 primer combinations which showed 121 polymorphic fragments. All the plant material comes from secular olives which are collected in the germplasm collection of I.R.O-C.N.R.. Genetic similarity was calculating using the Dice index; the similarity tree was produced by clustering the similarity data with the UPGMA method. Analysis were performed with the NTSYS-PC software ver.2.0.

As a result of the AFLP analysis a dendrogram was constructed which shows both cases of genetic identity and different degrees of genomic dissimilarity. Particularly there are three groups in which we can find accessions genetically identical that cluster in the same taxonomic group. Moreover the dendrogram allows to clarify cases of synonyms. Particularly Fosco and Corniolo are identical to some Moraiolo coming from Umbria, Toscana and Marche; Prugnolo from Emilia Romagna is identical to Moraiolo from Toscana.; a Carboncella results to be identical to two Moraiolo coming from Toscana and Liguria.

This research pointed out that the analysed cultivars cannot be considered as members of a common taxonomic group: they are genetically distinguished and cluster in different groups. As a consequence the knowledge of the varietal patrimony is of fundamental importance for the protection of genetic identity that must characterise the genetic material of thenursery. Particularly the valorisation of the olive oil depends not only on the environment, on the plants growing techniques and on oil extraction systems, but strongly also on the variety cultivated and on the relation between cultivars and environment.