[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.