evaluation of genetic diversity of some pear (pyrus spp.) genotypes and species based on morphological characteristics

pears (pyrus spp.) belongs to the rosaceae family, which have been cultivated formore than 3000 years. pears are among the most important fruits in all the temperateregions in about 50 countries of the world. the objectives of this study were to classifypear genotypes based on qualitative and quantitative characteristic and determination oftheir genetic distance. evaluation of genetic diversity of 47 pear accessions includingeuropean, asian and wild species, was started since 2008 in university of tehran andseed & plant certification & registration institute. result showed that some traits such asfruit size, maximum fruit diameter, fruit shape, shape of base and apex in leaf had highvariability. in this study genotypes were classified according to their characteristics andward's method. results derived from cluster analysis divided the genotypes into threemain groups including european, asian and wild species. results of simple correlationanalysis showed that leaf blade length and width have positive correlation with fruitweight and size. results of factor analysis indicated that nine main factors indicated80% of total variance. first and second factors that were related to leaf and fruitcharacteristics, described nearly up to 32% of variance.