延边苹果梨分类地位的研究

Pingguoli is the main cultivar planted in the frigid zone. Because of existing demurral on its systematic status, we began to research on its systematic status in 2000. Representative cultivars of Pyrus bretschneideri Rehd., P. pyrifolia Burm., P. ussuriensis Maxim, P. communis L. and varieties ,hybrid cultivars of pingguoli were used for testing material .Using RAPD markers, isozyme analysis and pollen morphology identification , we considered that pingguoli should belong to P. bretschneideri Rehd. system after statistic treatment such as cluster analysis . At the same time, we systematic researched genetic relationship and systematic status of these main Pyrus cultivars, and resolved the existing demurral on systematic status of pingguoli ,meanwhile, the result provided scientific basis for cultivar identification , improvement and breeding.Main Research Contents and Important Results: ⑴ RAPD analysis of germ plasm resources on part of Pyrus. RAPD optimized reaction system of Pyrus and RAPD fingerprints patterns were built. At the same time, 40 Pyrus cultivars were also classified.⑵ Research on systematic status of pingguoli at the molecular level. Using RAPD markers, meanwhile, according to results of similar coefficient and cluster analysis, we concluded that pingguoli should belong to P. bretschneideri Rehd. system at the molecular level .⑶ Study on systematic status of pingguoli by the technique of isozyme analysis. By analyzing peroxidase isozymic in the leaves of 56 pyrus cultivars and 16 typical cultivar, we defined that genetic relationship between pingguoli and P. bretschneideri Rehd. was the closest , and it supported the result identified by RAPD. Meanwhile, all Pyrus cultivars used for testing material were classified.⑷ Study on systematic status of pingguoli by pollen morphology. Scanning pollen of 16 related cultivars by electronic microscope and applying cluster analysis of pollen morphology, we can distinctly distinguish P. communis L. from P. bretschneideri Rehd., P. pyrifolia Burm., P. ussuriensis Maxim . However, pollen morphology and stripe ornamentation on the surface of pollen grains of pingguoli are different from the other pears, it belongs to relatively special type.

苹果梨是延边的特产果树，并在东北中、南部、华北、西北地区广泛引种栽培。但关于其分类地位，多年来一直未有定论。有人认为其属于白梨系统，也有人认为属于砂梨系统。本研究拟在已有的对苹果梨分类地位研究的基础上，应用RAPD分析方法，对苹果梨与秋子梨、砂梨、白梨和西洋梨四个系统的代表品种进行RAPD指纹图谱鉴定，并结合同功酶等常规方法以及数值分类法，绘制梨品种亲缘关系树状图，彻底解决苹果梨的分类地位问题，为品种改良、开发利用苹果梨提供科学依据。.