Determination of genetic diversity in pear genotypes using ISSR markers

Iran is known as one of the most important pear genetic resources because of being near to the pear diversity centers and having more than 10 species of genus Pyrus. On the other hand, Iran with acreage of 17,000 hectares, is one of the pear production centers. Despite its unique geographical location, there is no sufficient genetic information among pear germplasm in Iran and it is not clear what genetic relationship is between Iranian local genotypes and imported genotypes. In this study, Inter Simple Sequence Repeat (ISSR) markers was used for clustering of 10 Iranian Pear genotypes and positioning of their genetic variation among 13 imported genotypes. Fifteen ISSR primers were screened that yielded a total of 257 amplified products, of which 213 bands (81.6%) were polymorphic. Dendrogram of pear cultivars with ISSR banding patterns was drawn with NTSYS V. Pc-2.02e software using Dice coefficient and UPGMA (Unweighted Pair-Group Method Arithmetic Average), method. The 23 genotypes of pear were clustered in to three groups. The first group includes Conference, Mohammad Ali, Sardroudi, Bartlett, Red Bartlett, Harrow Sweet, Pass Crassane, Doyenneducomice, Anjou, Palestine,Lies Bonne, Duchesse and Daregazi. Kolikhaj, Sebri, Khuj labtorsh, Dom kaj, Khuj Katesar, Khuj Mordab Anzali and Shah Miveh belong to the second group. The third group includes SK10 and SK13. Cultivars were classified according to the geographical origin and the figures belonging to P. communis and P. pyrifolia, were completely separated. Iranian commercial cultivars including: Dom kaj, Shah miveh, Sebri with different Khuj accessions were placed in a group, that seems that thay have originated from different Khuj. While the three cultivars: Mohammad Ali, Sard roudi and Daregazi revealed closer to the European figures and possibility they have different origin than different Khuj And have a common ancestor with European figures. The results of this study indicate that ISSR markers have higher level of discrimination in evaluating genetic diversity and fingerprinting of pear genotypes.