Genetic diversity and similarity of pear (Pyrus communis L.) cultivars in Central Europe revealed by SSR markers

The Hungarian pear gene bank, located and founded in Keszthely in 1981, contains 210 pear cultivars including regional cultivars, cultivars of foreign origin and standard commercial cultivars. There are some cultivars with synonym names in the pear gene bank and in other pear growing areas within the Hungary. The aim of our work was to systematically analyse the genotypes of Hungarian cultivars in the pear gene bank and to set up a robust protocol for molecular identification and the interpretation of data. Eighty-eight cultivars were analysed employing eight SSR primers resulting in a total of 216 alleles. Seventy-seven cultivars were thoroughly analysed. Among the samples 29 were considered to be diploids and 59 triploids. A genetic diversity analysis was computed based on a Neighbour-Joining algorithm and combined with a PCA indicating close genetic relationship and an overall high amount of genetic diversity among the samples tested. Similarities and very close relations were verified in our studies between different pear cultivar variants: 'Korai szagos' A and B, which were planted with the same name in the gene bank. Six different 'Császár körte' and three 'Köcsög körte' cultivars were compared. It was important to establish how close their relationship was. Some cultivars originating from the same regions were compared. The 'Mezőkövesdi 2′ and '3′ are in the same main branch, however their distance is larger, the number of common alleles is less than those of the two 'Erdélyi körte' cultivars.