中文摘要：

在检测到鲫鲤F2产生3种不同大小（直径分别为0．13cm，0．17cm和0．2cm）类型的卵子基础上，进行了F2（♀）×红鲫（♂）及F2（♀）×四倍体鲫鲤（♂）的交配实验。通过染色体计数和流式细胞仪分析，在F2（♀）×红鲫（♂）后代中获得了四倍体、三倍体、二倍体鱼；在F2（♀）×四倍体鲫鲤（♂）后代中获得了四倍体和三倍体鱼。这两个交配组合后代中出现的不同倍性的鱼类为证明鲫鲤F2能产生三倍体、二倍体和单倍体卵子提供了进一步证据。F2（♀）×红鲫（♂）中雄性四倍体鱼的存在说明在四倍体后代中存在基因型为XXXY的个体。对上述两个交配组合后代的四倍体鱼和三倍体鱼的性腺结构观察表明：四倍体鱼是可育的，而三倍体鱼是不育的。作者认为鲫鲤F2能够产生二倍体和三倍体卵子与核内复制机制和生殖细胞的融合有关。

英文摘要：

Based on the presence of three types of eggs with different diameters 0.13, 0.17 and 0.2 cm, we made two crosses： F2 （♀） × diploid red crucian carp （♂）, and F2 （♀）× F10 tetraploid （♂）. The ploidy levels of the progeny of the two crosses were examined by chromosome counting and DNA content measurement by flow cytometer. In the offspring of the former cross, tetraploids, triploids, and diploid were obtained. In the progeny of the latter cross, tetraploids and triploids were observed. The production of the different ploidy level fish in the progeny of the two crosses provided a further evidence that F2 might generate triploid, diploid and haploid eggs. The presence of the male tetraploid found in F2 （♀） × diploid red crucian carp （♂） suggested that the genotype of XXXY probably existed in the tetraploid progeny. The gonadal structures of the tetraploids and triploids indicated that both female and male tetraploids were fertile and the triploids were sterile. We concluded that the formations of different ploidy level eggs from F2 were contributed by endoreduplication and fusion of germ cells.