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

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 1.35

Fingerprinting in FRUIT TREES: NEW PERSPECTIVES WITH ADVANCED TECHNOLOGIES

VENTURI S., FILIPPETTI I., INTRIERI C.

Dipartimento di Colture Arboree (DCA), CMVFV – CRIVE, University of Bologna, Italy

fingerprinting, SSR, AFLP

Recently a great number of patented fruit varieties have been released. Also the genetic panorama of the wine grapes is rich and characterized by many ancient varieties, most of them with several biotypes (clones), derived by bud sports, which generate the problem of correct denomination.

That means that in both fields the pomological and ampelographical descriptors must be integrated by new molecular analysis, belonging to the fingerprinting methodology.

This paper highlights the progress done with these advanced technology at the biotech lab of DCA-Bologna. Since several years the isoenzyme analysis and also the RAPD markers are almost abandoned for their limited efficiency and replaced from markers more reliable (for riproducibility) and much more polymorphic.

The new ways of the markers technology are rapresented by SSR (microsatellite) and AFLP; both have specific advantages. The highly reproductible SSR have already resolved cases of synonimy and omonimy in apple and other species (Venturi S. et al., 2001). They are also useful for genealogy studies.

Moreover, in viticulture the ampelographic characterization of more then 50 Italian grapevine varieties (Filippetti et al., 2002) have been implemented through the SSR technology, to identify cases of synonimy (Filippetti et al., 2001), within a polyclonal cultivar, to distinguish very similar biotypes (Silvestroni et al., 1993), i.e. seedlings from self pollinated mother plant, to ascertain the parent lines in ancestral analysis of segregating populations generated by controlled crosses.

The AFLP, in comparison with SSR, have a much higher degree of polymorphism, that permit to achieve better results in specific cases f.i. to distinguish very similar plums which have the same genealogy (Venturi et al., 2002). The AFLP, moreover, is a possible methodology for the distinction of sex in actinidia.

Unfortunately, although their big potential of use, both these innovative techniques remain still unable to solve the problem of the mutant identification. Most of the varieties of species like apple are polyclonal: the sports derived from “point” bud mutation, sometime in chimeric form, are impossible to discriminate by molecular analysis. It needs to assess new technology like SNP (Single Nucleotide Polymorphism) to achieve this new goal.