Isozyme analysis in Crossocheilus bamaensis and Discogobio tetrabarbatus

Horizontal starch gel electrophoresis was used to investigate the isozyme genetic difference in Crossocheilus bamaensis and Discogobio tetrabarbatus.Ten enzymes were investigated for two speices.Of 13 loci of Discogobio tetrabarbatus,only MPI was polymorphic.The proportion of polymorphic was 0.0769, the average observed heterozygosities was 0, and the expected heterozygosities was 0.0059. The average effective number of alleles is 1.1361. Of thirteen loci ofCrossocheilus bamaensis, MPI and MDH-2 were polymorphic.MPI genetic deviation index is -0.2535,that showes heterozygous deletion,but MDH-2 genetic deviation index is 0.024,which means that there is serious surplus of heterozygotes.There were no polymorphism was found in loci AAT、PGM、LDH、IDHP、SOD-1、SOD-2、SOD-3、G3PDH、MDH-1、LAP and EST.The proportion of polymorphic was 0.1538,the average observed heterozygosities of them was 0.0301,and the expected heterozygosities was 0.0391.The average effective number of alleles is 0.9609.The Nei′s genetic distance between two species was 0.7353 and there were complete gene replacement in loci AAT,PGM,LDH,MPI,LAP and EST between Discogobio tetrabarbatus and Crossocheilus bamaensis,which can be used in identification of two species.