Identification of pear cultivars by molecular markers

Pear (Pyrus communis L.) germplasm was collected in Piemonte (North Italy) propagated and planted in 2 collection fields located in Cussanio (CN) and Bibiana (TO); the 2 fields account altogether about 100 varieties. The germplasm was mainly found and rescued from single trees or small family orchards and the origin of most cultivars was unknown or uncertain. For this reason, besides the evaluation of the agronomic traits, the check and the identification of the genotypes has become a priority for the rationalisation and the correct management of the collections. The characterisation of the pear germplasm using molecular markers has been carried out in order to confirm homonymy and synonymy cases supposed on the basis of morphological and phenological observations, and to establish the phylogenetic relationship between the cultivars. The results obtained by RAPD markers concerned 17 cultivars, in particular: - a varietal group which includes 3 types, present in collection under the name "Gudun", with very similar agronomic traits; - the cultivar Martin sec "autunnale", which was found to be closer to the "Madernassa" type of pear than to the "Martin sec" one; - a variety called S.5T, at first considered a seedling, bearing fruit with same characteristics as in "Abate Fétel" but with minor differences as concerns the ripening time (5-6 days earlier in “S.5T”) and the growth habit of the plant. The results of the DNA analysis indicated that the 3 "Gudun" could be sports of a same genotype of local origin and that "S.5T" is more likely a mutation of "Abate Fétel" than a seedling. "Martin sec autunnale" resulted to have different RAPD profiles from "Martin sec" and, on the contrary, could be a synonym of "Madernassa".