Abstract: The study of population density, temperature and photoperiod in laboratory conditions induced the development of Ceriodaphnia quadrangula to produce sexual reproduction.It is found that under the suitable conditions, the C. quadrangula are mainly propagated by parthenogenesis, and the population density increases rapidly. Experiments have found that at higher population densities(≥3/mL), the yield of dormant eggs, which are the product of sexual reproduction, increases with population density.When the population density of C. quadrangula is 3/mL, the maximum proportion of individuals in sexual reproduction is 15%. When the population density is 6/mL, the maximum proportion of individuals in sexual reproduction is 19%. When the population density of the daphnia reached 9/mL, the proportion rises to 24%, indicating that high population density is the main factor driving the transformation of parthenogenesis to sexual reproduction. Conditions such as adequate food, appropriate temperature and photoperiod can increase the probability of sexual reproduction in daphnia, which indirectly alters the reproductive- DOI:10.3969/j.issn.1000-1565.2019.03.011方形网纹溞2种生殖模式的转换条件王全晟¹,李婧¹,睢秉键¹,柳峰松^1,2,谢松^1,2(1.河北大学 生命科学学院,河北 保定 071002; 2.河北大学 河北省动物系统学与应用重点实验室,河北 保定 071002)摘 要:在实验室条件下研究了种群密度、温度和光照时长诱导方形网纹溞产生两性生殖的条件.统计发现,在适宜的条件下,方形网纹溞主要繁殖方式是孤雌生殖,种群密度迅速增大.当种群处于较高的密度时(≥3/mL),两性生殖的产物——休眠卵的产量逐渐增加.种群密度为3/mL时,两性生殖的个体占种群数量的最大比例是15%;密度为6/mL时,比例是19%;密度达到9/mL时,比例上升到了24%,这显示高种群密度是促使孤雌生殖向两性生殖转换的主要因素.充足的食物、适宜的温度和光照时长等条件可以提高方形网纹溞两性生殖出现的概率,这是通过对方形网纹溞种群密度的提高而间接地改变其生殖模式的.这表明,种群内因素在方形网纹溞生殖转换的调控机制中起着重要作用.关键词:方形网纹溞;生殖转换;种群密度;温度;光照时长中图分类号:S963.21 文献标志码:A 文章编号:1000-1565(2019)03-0293-09Transformation conditions of two reproductive patterns In Ceriodaphnia quadrangulaWANG Quansheng¹, LI Jing¹,SUI Bingjian¹,LIU Fengsong^1,2,XIE Song^1,2(1. College of Life Sciences, Hebei University, Baoding 071002, China; 2. Key Laboratory of Zoological Systematics and Application, Hebei University, Baoding 071002, China )Abstract:The study of population density, temperature and photoperiod in laboratory conditions induced the development of Ceriodaphnia quadrangula to produce sexual reproduction.It is found that under the suitable conditions, the C. quadrangula are mainly propagated by parthenogenesis, and the population density increases rapidly. Experiments have found that at higher population densities(≥3/mL), the yield of dormant eggs, which are the product of sexual reproduction, increases with population density.When the population density of C. quadrangula is 3/mL, the maximum proportion of individuals in sexual reproduction is 15%. When the population density is 6/mL, the maximum proportion of individuals in sexual reproduction is 19%. When the population density of the daphnia reached 9/mL, the proportion rises to 24%, indicating that high population density is the main factor driving the transformation of parthenogenesis to sexual reproduction. Conditions such as adequate food, appropriate temperature and photoperiod can increase the probability of sexual reproduction in daphnia, which indirectly alters the reproductive- 收稿日期:2018-11-23 基金项目:国家自然科学基金资助项目(31572327);河北省高层次人才项目(CN201701) 第一作者:王全晟(1993—),男,山西大同人,河北大学在读硕士研究生,主要从事水生生物学研究. E-mail:wqs1047829666@163.com 通信作者:柳峰松(1976—),男,河北任丘人,河北大学教授,从事无脊椎动物分子免疫学研究.E-mail:liufengsong@hbu.edu.cn谢松(1964—),男,江西寻乌人,河北大学教授,主要从事水生生物学研究.E-mail:xiesong@hbu.edu.cn第3期王全晟等:方形网纹溞2种生殖模式的转换条件pattern by increasing the population density of daphnia. The results suggest that the intra-population factor should be an important direction in the future study of the molecular mechanism of sex development and transformation of daphnia.

Key words: Ceriodaphnia quadrangula, reproductive conversion, population density, temperature, photoperiod