5个木薯品种染色体核型与聚类分析

本研究对5个木薯品种进行核型分析以揭示其核型特征,通过聚类分析来自4个产地的5个品种间的相似性,以探讨其亲缘关系。实验采用压片法,以木薯嫩叶为材料,运用DPS软件对核型资料按照最长距离法进行聚类分析。结果表明,木薯5个品种的染色体数目均为2n=36,其中,SC12的核型公式为2n=36=34m+2sm,SM2300-1的核型公式为2n=36=36m(4SAT)、桂热5号的核型公式为2n=36=36m,云南8号与ZM8752的核型公式均为2n=36=34m(4SAT)+2sm。核型不对称系数范围在56.58～58.85之间,核型类型依次为1A、1B、1B、2A、1A,对称程度较高。聚类结果显示,在遗传距离为0.4时,5个品种分为3类。第Ⅰ类为云南8号,第Ⅱ类包括ZM8752与SM2300-1,第Ⅲ类包括SC12和桂热5号,5个品种存在一定的核型差异,说明具有丰富的遗传多样性。

Karyotype and Cluster Analysis of Five Cassava (Manihot esculenta Crantz) Varieties

Karyotype analysis was performed on five cassava cultivars to reveal the karyotype characteristics. The similarity and genetic relationship among the five cultivars were analyzed by cluster analysis, using young leaves as the materials and the squashing method to analyze the features of chromosomes. The results showed that the chromosome number of the five varieties was 2n=36, and the karyotype formula of SC12, SM2300-1, Guire No. 5 was 2n=36=34m+2sm, 2n=36=36m(4SAT), 2n=36=36m, respectively, and that of both Yunnan No. 8 and ZM8752 was 2n=36=34m(4SAT)+2sm. The asymmetrical karyotype coefficient was ranged from 56.58 to 58.85, and the karyotype types was 1A, 1B, 1B, 2A and 1A, respectively. The degree of symmetry was high. The clustering results showed that when the genetic distance was 0.4, the five varieties were divided into 3 categories. The first category was Yunnan No. 8, the second category included ZM8752 and SM2300-1, and the third category included SC12 and Guire No. 5. The five cultivars had certain karyotype differences, indicating that they had abundant genetic diversity.