Chinese Pear Plant Chloroplast Dna Diversity

The Pyrus is originated across the land of Europe and Asia to the north of Africa. Up to now, the classification of pyrus still has many problems which are not resolved reasonably. Exactly discriminating the genus and variety of the pear is the foundation that the pear resource to get conservancy and a new variety to be registered and be protected. For a long time , the identification of the pear variety mainly depends on morphological, pollen, cytological and iso-enzyme methods. The molecular marker , RAPD, AFLP and SSR, have many researches and have highly accuracy, which are being applied to the pears gradually .this article analyse the polymorphism of the cpDNA of pears by PCR-RFLP and DNA sequencing analysis, and make a simple discussion to the category and phylogeny.the main results were as follows:(1)fifty-two genotypes of cultivated pears were analyzed by PCR-RFLP. Generating total of 28 polymorphous bands, then 52 pear germplasm resource were divided into 8 genotype.(2) sequencing the PCR products of primer 1). We clustered the sequences of 52 pears with the same region of apple(malus x domestica), found 8 mutation , Basing on those mutation , 52 pear germplasm resource were divided into 5 genotype.(3)The research of pear's cpDNA shows: P. sinkiangensis Yu is hybrid pear which have the kinship of P. Cummis Linn and china pear; P. Ussrienss Maxim is closed with P.betulaefolia Bge; P. bretschneiderRehd is hybrid pear containing the kinship of P. betulaefolia Bge , P. phaecarpa Rehd and P.pyrifolia Nakai; apple pear should be belonged to P. bretschneiderRehd:dangshanshu is special and become an independence branch...