2种鉴定泥鳅多倍体方法的比较

Comparison of Two Identification Methods on Ploidy of Weather Loach,Misgurnus anguillicaudatus

以湖北省武汉市、沙市、恩施、枝江4个地理种群的天然泥鳅各30尾为材料,采用计数染色体和测量红细胞大小2种方法,鉴定了4个地理种群泥鳅的倍性。染色体计数采用体内注射PHA短期培养法,经鉴定,武汉和沙市地理种群的泥鳅为四倍体,恩施和枝江地理种群的泥鳅为二倍体。红细胞测量采用常规血涂片法,用显微测微尺测量每尾鱼100个红细胞的大小,分析和比较了二倍体和四倍体泥鳅红细胞及其核的长径、短径、面积和体积。经统计分析表明,四倍体泥鳅的红细胞和红细胞核极显著地大于二倍体泥鳅,其中红细胞核体积鉴定二倍体和四倍体泥鳅的准确率达到90.6%以上。通过对这2种鉴定泥鳅多倍体方法的比较,发现均能得到较高的准确率,其中红细胞核大小测量法较为简便,可操作性强,表明红细胞核的大小可作为大规模鉴定天然泥鳅倍性的一个较好指标。

In this study,loach were obtained from four areas of Hubei Province （Wuhan,Shashi,Enshi, Zhijiang）. The chromosome number of loach from four populations was determined by the PHA colchicine hypotonic-air drying technique. It was found that loach from Wuhan and Shashi were tetraploid, and those from Enshi and Zhijiang were diploid. Blood smears were prepared, stained with Wright＇s-Giemsa fluid. Cell length,cell width,nucleus length and nucleus width were recorded under 1 000 magnification. Surface area and volume of both the erythrocytes and nucleus were computed by following the formula for ellipsoids or oblate spheroids. Through discrimination analysis, results showed that tetraploid loach had significantly larger erythrocytes and nuclear measurements than those of diploid loach. The accuracy and reliability of this technique for identifying diplods and tetraploids were over 90% in the loach. It was found that erythrocyte measurement was more convenient than chromosome counting. Therefore, it is concluded that erythrocyte size measurement can be cited as a good means for identification of ploidy in M. anguillicaudatus.