长、短期连续孤雌生殖对萼花臂尾轮虫生活史和遗传特征的影响

应用单个体培养、聚丙烯酰胺凝胶垂直板电泳技术和特异性染色方法，以具有明显生化遗传差异的3克隆萼花臂尾轮虫（Brachionus calyciflorus）为对象，对长期（世代数大于200）和短期（世代数约为12）连续孤雌生殖后的轮虫进行了生活史特征和等位酶（PGM，GPI，MDH）分析。结果表明，除3克隆轮虫的生殖后期历时和每个雌体一生中所产的后代数在长期和短期连续孤雌生殖后的个体之间均无显著的差异外（P>0.05），其它生活史特征在长期和短期连续孤雌生殖后的个体之间的差异均因轮虫克隆的不同而异。克隆对轮虫的胚胎发育时间、幼体阶段历时、生殖期历时、平均寿命、轮虫每个雌体一生中所产的后代数、幼体大小和幼体的耐饥饿时间均有显著的影响（P<0.05）；连续孤雌生殖历期对轮虫幼体阶段历时、平均寿命、后代混交雌体百分率和幼体的耐饥饿时间均有显著的影响（P<0.05）；而克隆和连续孤雌生殖历期间的交互作用对轮虫的胚胎发育时间、生殖期历时、平均寿命、幼体大小和幼体的耐饥饿时间均有显著的影响（P<0.05）。长期连续孤雌生殖后的轮虫幼体阶段历时和幼体的耐饥饿时间均显著短于短期连续孤雌生殖后的轮虫，平均寿命显著长于短期连续孤雌生殖后的轮虫，后代混交雌体百分率显著高于短期连续孤雌生殖后的轮虫。3克隆轮虫在长期和短期连续孤雌生殖后其3种等位酶的酶谱均未出现明显的改变。

Effects of long- and short-term successive parthenogenesis on life history and genetics characteristics of Brachionus calyciflorus

Life history characteristics and patterns of genetic variation of three Brachionus calyciflorus clones with differently biochemical genetics and different durations of successive parthenogenesis were compared by means of individual culture and vertical polyacrylamide gel electrophoresis of isoenzymes (PGM, GPI, MDH). The results showed that the durations of post-reproductive period and the numbers of offspring produced by per female in her life of all the three rotifer clones after long-term successive parthenogenesis (the number of generations was over 200) were similar with those after short-term successive parthenogenesis (the number of generations was about 12) (P>0.05), but the differences in all the other life history characteristics differed with the rotifer clone. Of all the three rotifer clones, the embryonic developmental times of clone A and clone D were significantly affected by the duration of successive parthenogenesis (P<0.05), and the embryonic developmental time of clone A after long-term successive parthenogenesis was shorter than that after short-term successive parthenogenesis, but the reverse was also true for that of clone D. The durations of juvenile period of clone B and clone D were markedly affected by the duration of successive parthenogenesis (P<0.05), and their durations of juvenile period after long-term successive parthenogenesis were shorter than those after short-term successive parthenogenesis. The duration of reproductive period of clone D was significantly affected by the duration of successive parthenogenesis (P<0.05), and the duration of reproductive period after long-term successive parthenogenesis was longer than that after short-term successive parthenogenesis. The mean lifespans of clone A and clone D were markedly affected by the duration of successive parthenogenesis (P<0.05), and their mean lifespans after long-term successive parthenogenesis were longer than those after short-term successive parthenogenesis. The percentages of mictic daughters of clone A and clone B were significantly affected by the duration of successive parthenogenesis (P<0.05), and their percentages of mictic daughters after long-term successive parthenogenesis were higher than those after short-term successive parthenogenesis. The neonate volume of clone D was markedly affected by the duration of successive parthenogenesis (P<0.05), and the neonate volume after long-term successive parthenogenesis were smaller than that after short-term successive parthenogenesis. The starvation times of neonate of clone A and clone D were significantly affected by the duration of successive parthenogenesis (P<0.05), and their starvation times of neonate after long-term successive parthenogenesis were shorter than those after short-term successive parthenogenesis. Clone affected significantly embryonic developmental time, durations of juvenile and reproductive periods, mean lifespan, number of offspring produced by per female in her life, and volume and starvation time of neonate (P<0.05), duration of successive parthenogenesis affected markedly duration of juvenile period, mean lifespan, percentage of mictic daughters and starvation time of neonate (P<0.05), and the interaction between clone and duration of successive parthenogenesis influenced embryonic developmental time, duration of reproductive period, mean lifespan, and volume and starvation time of neonate (P<0.05). Among the three rotifer clones, the embryonic developmental times, the durations of reproductive period and the numbers of produced offspring of clone A and clone D were all similar, but were shorter or less than those of clone B. The durations of juvenile period and the neonate volumes of clone B and clone D were all similar, but were shorter or larger than those of clone A. The mean lifespan and the starvation time of neonate of clone A were both the shortest, and those of clone B were the longest. Compared with the rotifer produced after short-term successive parthenogenesis, the rotifer produced after long-term successive parthenogenesis had a shorter juvenile period, a shorter starvation time of neonate, a longer mean lifespan, and a higher percentage of mictic daughters. Electromorphs of the three enzymes assayed for the three rotifer clones were the same between the individuals produced by the rotifers after long- and short-term successive parthenogenesis.