团头鲂同源四倍体、倍间三倍体与二倍体红细胞的形态特征比较

通过比较同源四倍体、倍间三倍体与二倍体团头鲂（Megalobrama amblycephala）的红细胞、红细胞核的形态大小差异，探讨不同倍性团头鲂的红细胞形态遗传特征。结果表明：（1）团头鲂多倍体（同源4n和倍间3n）的红细胞数量显著低于二倍体（2n）团头鲂（P〈0．05）。其中，倍间三倍体团头鲂每毫升血液的红细胞数为二倍体的78．95％，而同源四倍体的红细胞数量下降幅度较大，仅为2n团头鲂的56．87％。（2）团头鲂同源四倍体、倍间三倍体的红细胞短径和长径、核短径和长径、红细胞表面积、红细胞体积和核体积均依倍性增加而显著增大（P〈0．05）；其中，又以核体积增大最为显著，同源四倍体、倍间三倍体的核体积分别为2n团头鲂的1．97倍和1．39倍。（3）团头鲂同源四倍体每毫升血液红细胞的总体积和总表面积，均明显低于二倍体和倍间三倍体团头鲂（P〈0．05）；倍间三倍体每毫升血液红细胞的总体积要多于二倍体团头鲂（P〈0．05），但红细胞的总表面积在倍间三倍体与二倍体团头鲂间不存在显著差异（P〉0．05）。（4）在团头鲂同源四倍体中还观察到一定比例的异常红细胞现象。

Morphological differences of erythrocyte in autotetraploid,interploid 3n of blunt snout bream,Megalobrama amblycephala

Blunt snout bream(Megalobrama amblycephala) is herbivorous and is widely favored in China as a delicacy.Since the 1960s,bream has been accepted as a principal species in Chinese freshwater fish polyculture systems.Based on the good breed "Pujiang No.1" blunt snout bream(selected strain F6),fertile autotetraploid founders have been produced by precise suppression of the first mitotic cleavage of the embryo by thermal shock in 1999.Interploid triploids used in this study were produced by mating tetraploid females with diploid males or by mating diploid females with tetraploid males in 2002 and 2003.In this study,the morphological paiameters of erythrocyte and nuclei were compared among autotetraploid,interploid 3n and 2n blunt snout bream.The results show as follows.(1)Polyploids has significantly lower erythrocyte number than 2n control(P<0.05).The erythrocyte number per milliliter blood in interploid 3n and autotetraploid is 78.95% and 56.87% of that of 2n control,respectively,with a sharper decrease in autotetraploid.(2)The long and short diameter of erythrocytes and nuclei,the erythrocyte surface area,and the nuclear and erythrocyte volume in autotetraploid and interploid 3n increase significantly(P<0.05) due to the polyploidy of chromosome sets.Among them,the erythrocyte nuclear volume in autotetraploid and interploid 3n increase extremely,which are as 1.97 and 1.39 times as that of diploids.(3)The values of total erythrocyte volume and total surface area per milliliter blood are significantly(P<0.05) lower in autotetraploid than those in interploid 3n and 2n control.The total erythrocyte volume per milliliter blood in interploid 3n is significantly(P<0.05) higher than that of 2n control,while the total erythrocyte surface area per milliliter blood is not significantly(P>0.05) different between interploid 3n and 2n control.(4)Some abnormal erythrocytes were observed in autotetraploid.Morphological differences of erythrocyte in autotetraploid,interploid 3n may exert positive or negative effects on the survivals and aquacultural performances in these polyploidy fish.Journal of Fishery Sciences of China,2006,13(6):891-896]