关键词: 木瓜属, 花粉形态, 品种分类, 聚类分析

Abstract:

The pollen grains of 19 cultivars 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 cultivar classification based on pollen morphology variation. The result of cluster analysis suggested that there was close relationship among C. speciosa，C. japonica and C. × superba，and there was alienation between C. sinensis and the other 4 species，which was consistent with traditional classification result.

Key words: Chaenomeles, pollen morphology, cultivar classification, clustering analysis