叶籽银杏种质资源染色体核型分析及进化趋势

 以来自日本、中国山东等地的28株叶籽银杏种质幼叶为试材，采用常规压片法，对其核型进行了研究。结果表明：各种质染色体均为二倍体，2n = 2x = 24，核型有中部着丝粒染色体（m）、近中部着丝粒染色体（sm）和近端部着丝粒染色体（st）等3种类型；有6个种质具随体。方差分析表明：种质SY2染色体长度比与其它种质差异显著，为3.97；各种质的平均臂比和核型不对称系数之间差异较大。种质GX3和种质HB较进化，种质NS2较原始。

Analysis on Karyotype and Its Evolutional Trend of Ginkgo biloba var. epiphylla Germplasms Resources

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.