钝叶决明核型分析

Karyotype Analysis of Cassia obtusifolia L.

决明核型报道存在不一致性,本研究采用常规切片和显微分析技术对钝叶决明(Cassia obtusifoliaL.)染色体数目、核型、体积等进行了系统研究.结果表明:钝叶决明根尖细胞为2n=24的丝状染色体;核型公式为K(2n)=24=24 m;染色体相对长度组成为2n=24=4L+8 M2+6 M1+6S,属于"1B"型.全染色体总长为54.17μm,长臂总长31.49μm,核型不对称系数为58.13%.染色体总体积53.17μm3.钝叶决明染色体为2n=24形态清晰的丝状染色体,与前人2n=22的点状小染色体和2n=26的报道不同.

There have been contradictory reports as regards to the karyotype of Cassia obtusifolia L.,this research aimed to systematically study the chromosome number,karyotype and chromosome volume of Cassia obtusifolia L.by conventional sections combined with micrographics in order to make a clarification and thus to lay a basis for further studies.Results show that Cassia obtusifolia L.has normal diploid 2n=24;karyotype formula is K（2n） = 24 = 24 m.The relative length of chromosomes was 2n=24=4L＋8M2＋6M1＋6S,which belongs to＂1B＂ type.The total length of the chromosome groups was 54.17 μm;the total length of long arms of the chromosome group was 31.49 μm;the AS.K% was 58.13%;the total volume of chromosomes was 53.17 μm3.Thus the chromosomes of Cassia obtusifolia L..were morphologically well-defined 2n=24 filamentous chromosomes,different from 2n=22 small dot chromosomes and 2n=26 reported by others.