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 - 4.07

MOLECULAR CHARACTERISATION (SSR) OF DURUM WHEAT (TRITICUM DURUM DESF.) GERMPLASM FROM SICILY

LACERENZA N.G.*, PILERI L.*, GALLO G.**, BENEDETTELLI S.*

*) Department of Agronomy and Land Management, University of Florence

**) Stazione Sperimentale di Granicoltura per la Sicilia, Caltagirone (CT)

Triticum durum, SSR, population genetics

Sample material utilised in this study derives from some durum wheat landraces (Farro Lungo, Russello, Bufala Corta, Urria, Real Forte, Sicilia R.N) cultivated in marginal areas of Sicily, characterised by high salt soil concentration, and from some old and new cultivars (Bivona, Capeiti, Platani, Karel, Simeto, Ciccio, Lina, Romano).

For each landrace and for each old variety, ten genotypes were sampled to extract the DNA, whereas for each new cultivar for the DNA extraction a bulk of three or four plants were utilised. The DNA extraction was carried out utilising The Nucleospin kit (Macherey-Nagel).

Molecular characterisation was performed with about twenty primers combination flanking microsatellite regions (SSR); these primers were synthesised according to the sequences published by Röder et al . (1998). The PCR reaction was carried out following the time schedule and the temperature conditions reported by Röder et al . (1998). In particular annealing temperatures of 50°, 55° and 60° C for each specified primer combination were used.

The amplified products were fractionated in 3% agarose gels with TBE buffer and then visualised by a fluorescent lamp in presence of ethidium bromide. The electrophoretic patterns were photographed by a Polaroid films and then utilised to construct the presence/absence matrix (1/0) for the alleles observed for each locus. The utilised SSR primer set had shown a high degree of genetic variability either within or between accessions (from two to six alleles per locus).

The genetic diversity index (expected average heterozygosity, H), the number of polymorphic loci (P) and the effective number of alleles (n_e ) will be calculated to quantify the genetic diversity within population. Beside to verify the similarity degree between the analysed genotypes, belonging to different landraces and cultivars it will be computed the Jaccard index. From the similarity matrix will be carried out the cluster analysis and a dendrogram will be obtained by the UPGMA algorithm. The NTSYS software release 1.7 (1992) will be utilised to carried out the statistical analysis. The location in the dendrogram occupied by the landraces genotypes referred to the cultivar genotypes it will allow to form the hypothesis that the eventual convergent selection improve the tolerance to abiotic stresses.