木瓜属植物的花粉形态及品种分类

Pollen Morphology and Cultivar Classification of the Genus Chaenomeles

对木瓜属19个品种的花粉亚显微形态进行扫描电镜观察。结果表明:其花粉属于N3P4C3型,为辐射对称的长球形至超长球形,大小为极轴长48.64～39.95μm、赤道轴长25.28～20.97μm,外壁纹饰为条纹状或皱波状纹饰,具覆盖层穿孔。花粉亚显微形态对于木瓜属品种分类具有很大价值,根据花粉形态编制品种分类检索表。聚类分析结果表明,贴梗海棠、日本木瓜和傲大贴梗海棠的亲缘关系最近,而木瓜与其他种类的亲缘关系疏远,这与本属的经典分类结果一致。

The pollen grains of 19 cuhivars in Chaenomeles were observed under SEM （Scan Electronic Microscope）. The results showed that they all belonged to N3 P4 C3 type, and were of prolate or perprolate and of radial symmetric. The length between poles varied from 48.64 to 39.95 μm and diameter of the equator ranged 25.28 - 20.97 μm. The cover was embellished with streak or striate, with pores in the tectum. Pollen submicroscopic morphology is valuable traits in cultivar classification in this genus. A retrieval key was established for cuhivar classification based on pollen morphology variation. The result of cluster analysis suggested that there was close relationship among C. speciosa, C. japonica and C. x superba, and there was alienation between C. sinensis and the other 4 species, which was consistent with traditional classification result.