古银杏半同胞家系染色体核型分析及进化趋势研究

以采自山东、浙江、贵州等15个省份的古银杏半同胞家系种质资源圃中28个家系为研究对象，随机取其幼叶，采用压片法对其核型进行研究。结果表明：28个家系染色体数均为2n=2x=24；染色体以中短和中长染色体为主；核型主要由中部着丝粒染色体(m)、近中部着丝粒染色体(sm)和近端部着丝粒染色体(st)组成，有2A、2B、3A和3B 4种类型。71^#家系最为原始，而40^#家系最为进化，来自中国西南部的家系进化程度较低，东部和南部的家系进化程度较高。

Chromosome Karyotype Analysis and Evolutional Trend of Ancient Ginkgo biloba Half-sib Families

This study was based on the karyotype and evolution trend of 28 families from Shandong, Zhejiang, Guizhou and other 12 provinces which existed in ancient Ginkgo biloba half-sib families germplasm repository by squashing method with random young leaves as test materials. The result showed that the karyotype of all 28 families could be described as 2n=2x=24; The chromosome composition based on relative length of main medium-short and medium-long; The karyotype was mainly composed of median centromere chromosome (m), nearly median centromere chromosome (sm) and acrocentric chromosome(st), and the karyotype could be divided into 4 types, which were 2A, 2B, 3A and 3B; 40# might be the most advanced while 71# family might be the most primitive family. The families from southwest of China were more primitive, while the families from east and south were more advanced.