内蒙古中东部草原贝加尔针茅、大针茅和克氏针茅的染色体核型分析

以内蒙古草原3种针茅属植物为材料,常规压片法制片后观察记录染色体数,并进行核型分析。实验结果表明: 贝加尔针茅、大针茅和克氏针茅细胞染色体数均为2n=44,属于2A核型，为二倍体。在3种针茅的染色体中，中部着丝粒染色体占大多数平均为62.1%，其次近中部着丝粒染色体平均为28.9%，近端部着丝粒染色体较少约为9.0%。在3种针茅的第五号染色体上均有随体，表明起源于同一祖先。虽然染色体核型均属于较对称型，但是染色体不对称系数随着3种针茅分布生境的干旱程度的增加而逐渐增加，可能是长期适应与进化的结果。

Chromosome Numbers and Karyotypes of Stipa baicalensis,Stipa grandis and Stipa krylovii in Inner-mongolia Steppe

Using the common(slice-making) method,the chromosome numbers and karyotypes of three Stipa species from Inner-Mongolia steppe were studied.The chromosome numbers of the three species were found to be 2n=2x=44(2A type).In all species,metacentric chromosomes were the most common(mean value 62.1%),followed by sub-metacentrics(mean value 28.9%),and sub-telocentrics were rare(mean value 9.0%).The fifth chromosome had a satellite in the three species.These results indicated that their genome structure and origin ...