萼花臂尾轮虫有性生殖、种群增长和休眠卵产量间的关系

Relationship between sexual reproduction,population growth and resting egg production of freshwater rotifer Brachionus calyciflorus.

利用种群指数增长和Logistic增长模型 ,通过计算机模拟研究了萼花臂尾轮虫有性生殖发生的频率、后代中的混交雌体百分率对种群增长和休眠卵产量的影响 .在所模拟的参数范围内 ,随有性生殖发生频率由 10 0 %减小到 2 0 % ,获得最大休眠卵产量所需的混交雌体百分率由 9%增大到 6 9% ;随密度制约作用的增大 (环境容纳量K值由 10 0 0减小到 10 0 ) ,该混交雌体百分率由 18%增大到 6 9% ,休眠卵产量由10 72 .10降低至 133.6 7.种群的内禀增长率与获得最大休眠卵产量所需的混交雌体百分率间呈曲线相关 .当有性生殖发生得越频繁、种群增长所受的密度制约作用较小时 ,后代中 10 %～ 30 %的个体为混交雌体时的种群中休眠卵产量较大 .

Using exponential and logistic growth models,the effects of sexual reproduction frequency and the proportion of a female's daughters reproducing sexually on population growth rate and resting egg production of freshwater rotifer Brachionus calyciflorus were examined by computer simulation. Within the parameters of the simulation,the percentage of micitc females in the offspring required for maximum resting egg production increased from 9% to 69%,when the frequency of sexual reproduction decreased from 100% to 20%. The increase of density dependent limitation (the value of K decreased from 1000 to 100) made this percentage increase from 18% to 69%,and resting egg production decrease from 1072.10 to 133.67. The relationship between the population growth rate (r) and the optimum percentage of mictic females in the offspring required for maximum resting egg production was best described by curvilinear regression. When sexual reproduction became more frequent and density dependent decreased,The population with the percentage of mictic females in the offspring in 10～30% had a bigger resting egg production.