关键词: 银杏, 叶籽银杏, 叶生种子, 中种皮, 内种皮, 超微结构

Abstract: The comparative ultrastructure of sclerotesta and endotesta of Ginkgo biloba var. epiphylla Mak. were studied, which involved both normal seeds and epiphyllous seeds from 6 individuals of Ginkgo biloba var. epiphylla. The research showed that normal seeds in 6 individuals consist of tracheid with bordered pit. However, difference was noticed between ep iphyllous seeds. There were two types of tracheid, i. e. tracheid with bordered pit and sp iral tracheid in the sclerotesta of Ginkgo biloba var. epiphylla in hipnüdong, Zhongpzhuang, Ji'nan, Tai'an, but there was only tracheid with bordered pit in sclerotesta in both normal seeds and epiphyllous seeds of Ginkgo biloba var. epiphylla in You'fang and Bai'yu. In respect to tracheid length and tracheid diameter, greater variation was observed in epiphyllous seeds than that of normal seed. In addition, difference was also observed in endotesta. Based on the research, tracheid evolution and systematic significance of Ginkgo biloba var. epiphylla were discussed

Key words: ginkgo biloba, Ginkgo biloba var. epiphylla Mak., epiphyllous seed, sclerotesta, endotesta, ultrastructure