七种紫胶虫染色体核型分析与亲缘关系探讨
Karyotype and Genetic Relationships Among Seven Commercial Species of Lac Insects
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摘要: 对7种具有重大经济价值的紫胶虫染色体数量、形态及核型进行了分析和比较。7种紫胶虫的染色体形状有棒状、卵圆形、肾形、椭圆形、长圆形以及哑铃形，染色体数目均为2n=18。从核型分析上看，7种紫胶虫的染色体均由中部（或近中部）着丝点染色体与端部着丝点染色体组成，有K=10m+8T, K=8m+10T, K=6m+12T, K=4m+14T四种不同的组成方式。采用Leven et al(1964)、Stebbins(1971)以及Guo et al (1972) 核型分类标准对7种紫胶虫进行核型分析, 结果显示：信德紫胶虫与紫胶蚧在着丝粒类型、核型对称性和相对长度组成上相一致，因此两者亲缘关系最近；尼泊尔紫胶虫与普萨紫胶虫在核型不对称系数与染色体类型上相近似，两者的关系较为紧密；田紫胶虫与云南紫胶虫的染色体均是由8条中部（或近中部）着丝粒染色体与10条端部着丝粒染色体组成，亲缘关系也较紧密；而中华紫胶虫的核型较为特殊，与其他6种差异较大，亲缘关系较远。研究结果澄清了紫胶生产虫种在分类上的混淆，证实了中国紫胶生产虫种为云南紫胶虫。Abstract: Chromosome quantities, forms and karyotype of seven lac insect species, which are of significant economic value, were analyzed and compared. Several type of chromosomes shape such as stick-alike, ellipse, kidney-alike and dumbbell-alike were found in the seven species. Their chromosome number was all 2n=18. All the chromosomes were composed of metacentric (or sub-metacentric) and telocentric chromosomes. And there were four kinds of chromosomes structure shape: K=10m+8T, K=8m+10T,K=6m+12T, K=4m+14T. The result of karyotype analysis showed that Kerria sindica and K. lacca had a close relationship, of which the chromosome type, karyotypic style and constitution of relative length were in consistent. Kerria pusana and K. nepalensis were similar in the chromosome type and karyotype asymmetry index, which revealed their near homology from chromosomes level. The chromosomes of K. ruralis and K. yunnanensis were both formed with eight metacentric (or sub-metacentric) chromosomes and 10 telocentric chromosomes, indicating the close nexus between them. The karyotype of K. chinensis was different from other six species and it has the far relationship with others. We concluded that the main commercial species of lac insect belonged to K. yunnanensis.
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