关键词: 叶籽银杏, 染色体, 核型, 类型, 进化趋势

Abstract: The karyotype of 28 Ginkgo biloba var. epiphylla Mak. germplasms which came from Japan and Shandong were studied by method of squash with the young leaves. The results showed that all the chromosomes were diploid，the chromosome number could be described as 2n = 2x = 24，the karyotype was mainly composed of median centromere chromosome（m），nearly median centromere chromosome（sm）and subterminal region（st）；There were satellites in 6 germplasms. The variance’s analysis shows that there was significant difference between SY2 and other germplasms on length ratio of chromosome which was 3.97，the asymmetrical karyotype coefficient and mean arm ratio differed greatly among germplasms. GX3 and HB were more maximum than other germplasms，while the evolution extent of NS2 was originative.

Key words: Ginkgo biloba var. epiphylla Mak., chromosome, karyotype, type, evolutional trend