中文摘要：

报道了水龙骨科丝带蕨属丝带蕨Drymotaenium miyoshianum Makino 的染色体数目、核型及生殖方式。结果表明：丝带蕨体细胞的染色体数目为2n=72，核型公式为2n=2x=72=18m＋26sm＋24st＋4T，核型为3B，核型不对称系数As．K=71．24％，丝带蕨的核型为首次报道。丝带蕨是有性生殖二倍体。结合前人的研究结果，讨论了染色体数目、核型在水龙骨科系统学研究中的意义。

英文摘要：

A cytological study of Drymotaenium miyoshianum Makino was carried out. The somatic chromosome number in root-tip cells of D. miyoshianum is found to be 2n =72. The karyotype formula is 2n =2x =72 = 18m ＋ 26sm ＋24st ＋4T. The karyotype belongs to 3B type. The chromosomes range in length from 1.74 to 4.61μm, with the ratio of the longest to the shortest 2.65. The index of karyotype asymmetry （As.K%） is 71.24. The karytype of D. miyoshianum Makino was reported for the first time. The reproductive type in D. miyoshianum Makino is sexual diploid. Based on our study and previous data, the significance of chromosome number in phylogeny was discussed.