云南蝗不同地理种群染色体研究

Chromosome Study on Different Geographical Populations of Yunnanites coriacea

云南蝗为我国特有种,为了解云南蝗不同地理种群的染色体特征,采用常规的液氮冰冻压片法和BSG显带法对云南蝗2个地理种群的染色体核型和C带带型进行了研究。结果表明:云南蝗2个地理种群的染色体数目都为2n(♂)=19,染色体臂指数NF=19;染色体类型为端着丝粒染色体;性别决定机制均为XO型;染色体组式为3L+6M+X,缺小型染色体,性染色体X属大型染色体,相对长度位居第1。昆明西山猫儿箐种群C带带型单一,每条染色体仅具有着丝粒带,染色体组异染色质总含量为10.67%;昆明东川拖布卡种群具有着丝粒带和端带,带纹条数较多,除10条着丝粒带外还具有8条端带,异染色质总含量明显高于前者,为29.53%。结合两者在外部形态上的差异,建议可将其视为2个不同的地理亚种。

Yunnanites coriacea was an endemic species of China.1n order to understand the cytogenetic characteristics of different populations of Y.coriacea,the chromosome karyotype and C-band patterns of 2 geographic populations of Y.coriacea were studied by squashing and BSG chromosomal banding technique.The results showed that the 2 geographic populations had a diploid chromosome number of 2n(?)=19 with a fundamental number(NF)=19,all chromosomes were telocentric and an XO sex-determining mechanism.The karyotype formula of Y.coriacea was 2n(?)=3L+6M+X,large and medium,and the X chromosome was the first element in size.The C-band karyotype analysis indicated that there were only 10 centromeric C-bands with a total of heterochromatic content(THC)was 10.67%in Kunming Western mountain population while the population in Dongchuan tuobuka had 10 centromeric C-bands and 8 terminal C-bands,and the total of heterochromatic content was 29.53%.Combining the external morphological differences of the 2 population,1t could be considered as 2 different geographic subspecies.