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 - 5.34

SSR MARKERS TO ASSESS GENETIC STRUCTURE AND POPULATION DYNAMICS IN T.MAGNATUM

A. RUBINI, F. PAOLOCCI, F. TOPINI, C. RICCIONI, S. ARCIONI

CNR Istituto di Genetica Vegetale sez. di Perugia, Via Madonna Alta 130, 06128 Perugia, Italy

Truffle, SSR, Tuber magnatum

Among symbiotic Tuber spp., T. magnatum is the truffle species producing the most appreciate and valuable ascomata, which are only harvested in Italy and some Balkan areas. Despite its economic relevance only few studies have been so far carried out to shed light into its genetic structure and populations dynamics. Therefore SSR containing loci have been cloned and tested on 370 T. magnatum samples, grouped into 28 populations, collected over the species range of distribution in a search for patterns of genetic structure at two hierarchical levels: within and among populations. Although the average value of gene diversity and mean number of alleles resulted to be not significantly different among populations according to the Kruskall-Wallis ANOVA, some northernmost populations showed an average variance in repeat number higher than all the others and some population-specific or group-specific alleles were identified for southernmost populations too. Better still, we found a significant, although low, correlation between the genetic and geographic distance matrices (Fst: R = 0,278; P = 0,00423; Ds: R = 0,39889 p = 0,001; (delta micron)²: R = 0,4848, p = 0,0006) and between the pairwise values Fst/(1-Fst) versus the log of the geographical distance (R = 0.278; p = 0,00417). It is therefore more than likely the presence of an isolation by distance effect in T. magnatum and the possibility of differentiating among T. magnatum truffles of different geographical provenience as a tool for origin marks.