Germplasm Resources Of Pear And Apple-pear Classification Status

Classification of varieties and types, including p.ussriensis Max.. p.pyrifolia Nak. P.bretscheideri Rehd. P.communis L. was studied based on peroxidase isozymes analysis and palynology and the position of classification of apple pear was discussed.The results of peroxidase isozymes analysis showed apple pear clustered with most of varieties. It's showed that the relationship between apple pear and p.bretschneideri Rehd. was relatively close. It is believed that apple pear belonged to p.bretschneideri Rehd. The characters of apple pear were unusual in the size and shape of pollen grains, but the characteristic of stripe ornamentation showed more similar to Yali of p.bretschneideri Rehd. It was reasonable that apple pear belonged to p.bretschneideri Rehd.The characteristics of peroxidase isozymic patterns analysis for 56 varieties of pyrus believed that the peroxidase isozymes of pyrus could be divided into three isozymic sections. There were four isozymic bands in the first isozymic section and the Rf value was from 0.1348 to 0.3146; There were two isozymic bands in the second isozymic section and the Rf value was from 0.5056 to 0.5392; There were five isozymic bands in the third isozymic section and the Rf value was from 0.5843 to 0.8427; The three isozymic sections added up to eleven isozymic bands.There were the same characteristic pattern bands among 56 pear varieties and types of pyrus. The isozyme pattern type of among cultivars has significant differences. Among them the difference of between p.communis L. and oriental pears was greater. There was different among varieties as well. Based on the clustering analysis with the coefficient of similarity p.communis L. derived from Europe and three species derived from China didn't respectively cluster, but there was different genetic distance among each of materials. The 56 varieties could be divided into eight kinds, which had the same results with the traditional classification. It's showed that peroxidase isozyme analysis provided the basis for the classification and identification of germplasm resources of pyrus.There were the same characters in the pollen morphology of pyrus. The significant differences existed in the size and shape of pollen grains and stripe ornamentation of different species and between varieties. The differences of characteristic of pollen morphology among oriental pears were relatively small and between p.communis L. and oriental pears were relatively great. Based on the systemic clustering analysis with pollen quantitative character derived from Europe and 3 species derived from China could be classified evidently. It's believed that palynology provided the reference for the identification of species and varieties.The analysis of palynology confirmed further that Chaoxianyangli has the relationship of p.communis L. and p.pyrifolia Nak. Shenbuzhi inherited the relationship of p.communis L. Nanguoli has the relationship of p.ussriensis Max..The optimum condition of the distilled isozymic solution of peroxidase isozyme in pyrus was that: (1) the ratio of fresh weight to water equaled to the ratio of one to two; (2) the separated speed was 5000 rpm; (3) the separated time was 15 minutes; The concentration of interlayer pastern was percent of 3.75:; The concentration of separated pastern was percent of 10; The fitting sampling part of peroxidase isozyme analysis in pyrus was the footstalk and center nerve of mature leaves.