Analysis on the chromosome karyotype of Arisaema heterophyllum Blume | 异叶天南星的染色体核型分析

Chinese. ［目的］对异叶天南星的染色体进行核型分析。［方法］以人工栽培的2年生异叶天南星种子为试材，观察种子中的中期分裂相细胞并对其进行统计和核型分析，其核型分类根据核型中染色体的长度比和臂比2项主要特征，按Stebbins的标准进行划分。［结果］异叶天南星的染色体数目为28条，组成2个染色体组。14对同源染色体中有9对是近中着丝粒染色体，5对是近端着丝粒染色体。异叶天南星的染色体核型公式为2n＝28＝18m+10sm，其染色体相对长度在24.464%～63.245%的范围内，最长染色体与最短染色体的比值为2.58，臂比值大于2∶1的染色体占总染色体的14.3%。异叶天南星的染色体核型为2B型，其核型不对称系数为62.83%。［结论］该研究为异叶天南星的栽培和良种选育提供了遗传学依据。

English. [Objective] The research aimed to analyze the chromosome karyotype of Arisaema heterophyllum Blume. [Method] With the seeds of artificially cultivated 2-year-old A. heterophyllum as tested materials，the cells in metaphase in the seeds were made for observation，statistic and karyotype analysis，and based on the 2 main features of length ratio and arm ratio of chromosome，the karyotypes were classified according to the criteria of Stebbins. [Result] A. heterophyllum had 28 strips of chromosomes and 2 genomes were composed of them. Nine of the 14 pairs of homologous chromosomes were submetacentric chromosomes and 5 of them were acrocentric chromosomes. The formula of chromosome karyotype of A. heterophyllum was 2n=28=18m+10sm，its chromosome relative length was in the range of 24.464%-63.245%，the ratio of the longest chromosome to the shortest chromosome was 2.58 and the chromosome with arm ratio above 2:1 accounted for 14.3% in total chromosomes. The chromosome karyotype of A. heterophyllum was Type 2B and its asymmetrical karyotype coefficient was 62.83%. [Conclusion] The study provided genetic basis for the cultivation and improved variety selection of A. heterophyllum.