两种突颜蝗的染色体C带核型研究

采用染色体C分带技术初次对癞蝗科Pamphagidae中国特有的突颜蝗属Eotmethis B.-Bienko 2个种，即天祝突颜蝗E. tientsuensis (Chang)和景泰突颜蝗E.jintaiensis Xi et Zheng的精原细胞有丝分裂中期和初级精母细胞减数分裂中期（中期I）染色体C带核型进行了比较研究。结果表明: 2种突颜蝗的染色体基数、着丝粒位置及染色体分组形式相同，且与前人的研究结果基本吻合，反映了癞蝗科昆虫核型的稳定性。同时，2种突颜蝗染色体相对长度值较为接近；结构异染色质总含量没有明显差异；并且两者无论在精原细胞有丝分裂中期还是减数分裂中期I细胞，其3号、4号和X染色体上都显现深着色较大块的着丝粒C带， 9号染色体上都出现大块深着色的端部C带，2号染色体上都发生清晰的近中部居间C带，以上反映了2个种在系统发生上的亲缘关系。另外，2种突颜蝗在C带带型上的差异，在1号、7号、8号染色体上有不同程度的反映，尤其是对应的7号、8号染色体上着丝粒C带块的大小和强弱有明显变化。

Researches on C-banding Karyotypes of Two Species of Genus Eotmethis

The chromosome C-banding technique has been employed in studying C-karyotypes of two grasshoppers species of Genus Eotmethis from Pamphagidae, namely, E. tiantsuensis and E. jintaiensis which are only distributed in Northwest China. Spermatogenous mitotic metaphases and primary spermatocyte meiotic metaphases (metaphase 1) of two species are analyzed. The main points of results are as follows. Either basic numbers of chromosomes (2n male symbol) and karyotypes formulae or centromeres location of two species are coincident with the preceding studies. These provide a further backing for the karyotype stability in the Pamphagidae. The corresponding values of chromosome relative length are closer between E. tiantsuensis and E.jintaiensis, and there are no obvious differences in their total C-heterochromatin contents, No.3, 4, 9 and X chromosomes of both species have showed larger and darkly stained acrocentric C-bands, and No.2 chromosomes of both species have consistently showed a distinct mid-stained interstitial C-band proximal to the median of chromosome. The above-metioned facts reflect a close relation between the two species in their systematic development. In addition, the differences in the C-banding patterns between two species are reflected more or less in No.1, No.7 and No.8 chromosomes, especially obvious variations in the size and stained degree of acrocentric C-blocks of corresponding No.7 and No.8 chromosomes between the two species.