Genetic variation was comparatively analyzed between the artificially induced diploid gynogen population from F10 allotetraploid hybrids of red crucian carp (U) (Carassius auratus red var., 2n=100) common carp (h) (Cyprinus carpio L.,2n=100) and the normal F10 allotetraploid hybrid population used as the control, using random amplified polymorphicDNA (RAPD) assay and microsatellite analysis. The specific 600-bp fragment for diploid gynogen population wasdetected by S45 and the specific 900-bp fragment for allotetraploid F10 hybrid population was detected by S134. Theresults from RAPD assay and microsatellite analysis were in agreement with each other, that is to say, the diploid gynogens presented lower level of polymorphism than allotetraploid F10 hybrids. Furthermore, as expected, microsatellite analysis revealed more detailed information on genetic diversity than RAPD assay. The mean percentage of polymorphic loci (12.71%) and Shannon's index of phenotypic diversity (0.25) from RAPD data for diploid gynogen population were significantly lower than those (30.69% and 0.63, respectively) for F10 allotetraploid hybrid population. The mean number of alleles per microsatellite locus (1.73) in diploid gynogen population was considerably lower than that (2.55) in F10 allotetraploid hybrid population. The average observed (0.36) and expected heterozygosity (0.26) in diploid gynogen population were lower than those (0.58 and 0.40, respectively) in F10 allotetraploid hybrid population, indicating that the diploid gynogens presented lower genetic diversity than the allotetraploids. In addition, the mean effective number of alleles at 11 microsatellite loci (1.60) in diploid gynogen population was lower than that (1.88) in F10 allotetraploid hybrid population. The significant differences between two populations in the average observed and expected heterozygosity,mean number of alleles and effective number of alleles, suggested that the effect of gynogenesis resulted in rather higher genetic homogeneity in diploid gynogens. The comparative RAPD analysis of diploid gynogens and their parents was performed with 34 primers. The identical RAPD pattern was detected between diploid gynogens and their female parent,however, some clear specific RAPD bands were detected between diploid gynogens and their male parents, but not detected in their female parent. The result indicated that heterologous genetic material had incorporated into diploid gynogenetic fish (G1).

二倍体雌核发育第1代（G1）产生的二倍体卵子经紫外线灭活的散鳞镜鲤精子诱导，无需染色体加倍处理，发育成二倍体雌核发育第2代（G2）；G1产生的二倍体卵子与雄性异源四倍体鲫鲤（AT）产生的二倍体精子结合，形成新型两性可育的异源四倍体鲫鲤（G1×AT）。对G2和新四倍体（G1×AT）的体细胞染色体数目、生殖细胞染色体行为及性腺结构、外形、生长速度等生物学特征进行了研究。结果表明:G2体细胞染色体数目为2n=100。在6～12月龄G2中，没有发现性成熟的个体，组织学切片结果表明，G2性腺处于卵原细胞增殖阶段，与1龄G1的性腺发育相似，性腺发育迟缓。对6～8个月龄G2性腺染色体制片进行观察，结果表明，G2生殖细胞的染色体没有二价体的形成，只有有丝分裂的迹象，其有丝分裂中期不但有2n=100的染色体分裂相，还有4n=200的染色体分裂相，甚至有接近8n（380）的分裂相，说明1龄G2的性腺中存在2n、4n等多种类型的生殖细胞，其中4n的生殖细胞经正常的减数分裂后可产生二倍体卵子。核内复制（pre2meioticendoreduplication）学说可以较好地解释这种不减半配子产生的现象。新四倍体（G1×AT）体细胞染色体数目为4n=200，雌雄新四倍体（G1×AT）具有正常的性腺发育，在繁殖季节从1龄G1×AT的雌、雄个体中可分别挤出成熟的卵子和精液。对6～8个月龄新四倍体（G1×AT）的性腺染色体制片观察表明，精母细胞染色体进行频繁的减数分裂，同源染色体两两配对形成100个二价体，没有观察到单价体、三价体、四价体，表明它们能形成稳定的二倍体配子。这种两性可育、生长较快的新四倍体（G1×AT）丰富了已有四倍体的种类。