Hebert P D
Genetics. 1974 Jun;77(2):335-41. doi: 10.1093/genetics/77.2.335.
In temporary habitats populations of the cyclical parthenogen, Daphnia magna, are re-established each year from sexual eggs and reproduce parthenogenetically for two or at most three generations. The genetic effects of this breeding system have been investigated by analyzing allozyme frequencies in nineteen intermittent populations.-Genotypic frequencies at polymorphic loci were ordinarily found to be in good agreement with Hardy-Weinberg proportions and disequilibria between loci were not observed. Although significant changes in gene frequencies were observed both during and between successive cycles, there was no evidence of the marked instability of genotype frequencies characteristic of permanent populations. The recombinational degradation of genotypes at the end of each annual cycle in temporary habitats effectively prevents the genotypic structuring which develops when continued parthenogenesis is possible.
在临时生境中，周期性孤雌生殖的大型溞种群每年都由有性卵重新建立，并进行两代或至多三代的孤雌生殖。通过分析19个间歇性种群的等位酶频率，对这种繁殖系统的遗传效应进行了研究。多态位点的基因型频率通常与哈迪-温伯格比例高度一致，并且未观察到位点间的不平衡。尽管在连续周期内和周期之间都观察到了基因频率的显著变化，但没有证据表明永久种群基因型频率具有明显的不稳定性。在临时生境中，每个年度周期结束时基因型的重组降解有效地阻止了在可能持续进行孤雌生殖时所形成的基因型结构。
