CAJ | 학술논문

在20℃、25℃下,将大型溞和老年低额溞分别按7+3(B组),5+5(C组),3+7(D组)的组合进行混合培养,以及用单种培养(10+0(A组),0+10(E组))作为对照,研究了温度和种间竞争对大型溞种群动态和两性生殖的影响.实验结果表明:在混合培养时,大型溞对老年低额溞产生明显的竞争优势.20℃、25℃下,单种培养的老年低额溞最大种群密度分别为大型溞的2.31和1.97,而在混合培养下老年低额溞的种群密度明显低于大型溞,在实验25d后几乎全部死亡.25℃下两种溞的种群密度之间存在极显著的负相关性(C组:r=-0.508,n=30,P<0.01;D组:r=-0.483,n=30,P<0.01).在20℃、单种培养下,大型溞在首次产幼溞时即出现雄体,且种群密度与雄体密度呈显著的相关性(r=0.678,n=24,P<0.01).大型溞的最大雄体密度(106 ind.(200ml)~(-1))和最大雄体比例(36.8%)均出现在20℃、单种培养下.25℃下,大型溞在混合培养的B组和C组首次产幼溞时即出现雄体,且雄体在混合培养B组的比例达28.2%.大型溞在25℃、单种培养下没有产生卵鞍,在混合培养下总计产生66个卵鞍,其中空卵鞍占51.5%,而在20℃、混合培养下没有卵鞍产生.实验结果暗示:在较高的温度下,种间竞争刺激了大型溞雄体的产生和卵鞍的形成,高密度的雄体有助于大型溞孤雌生殖雌体向两性生殖雌体的转化.
재20℃、25℃하,장대형소화노년저액소분별안7+3(B조),5+5(C조),3+7(D조)적조합진행혼합배양,이급용단충배양(10+0(A조),0+10(E조))작위대조,연구료온도화충간경쟁대대형소충군동태화량성생식적영향.실험결과표명:재혼합배양시,대형소대노년저액소산생명현적경쟁우세.20℃、25℃하,단충배양적노년저액소최대충군밀도분별위대형소적2.31화1.97,이재혼합배양하노년저액소적충군밀도명현저우대형소,재실험25d후궤호전부사망.25℃하량충소적충군밀도지간존재겁현저적부상관성(C조:r=-0.508,n=30,P<0.01;D조:r=-0.483,n=30,P<0.01).재20℃、단충배양하,대형소재수차산유소시즉출현웅체,차충군밀도여웅체밀도정현저적상관성(r=0.678,n=24,P<0.01).대형소적최대웅체밀도(106 ind.(200ml)~(-1))화최대웅체비례(36.8%)균출현재20℃、단충배양하.25℃하,대형소재혼합배양적B조화C조수차산유소시즉출현웅체,차웅체재혼합배양B조적비례체28.2%.대형소재25℃、단충배양하몰유산생란안,재혼합배양하총계산생66개란안,기중공란안점51.5%,이재20℃、혼합배양하몰유란안산생.실험결과암시:재교고적온도하,충간경쟁자격료대형소웅체적산생화란안적형성,고밀도적웅체유조우대형소고자생식자체향량성생식자체적전화.
Under isolated and mixed cultures of Daphnia magna and Simocephalus vetulus, the effect of temperature and interspeific competition on populaiton dynamics and sexual reproduction of D. magna was investigated. The mixed cultures included three density combinations: A, 7D+3S;B, 5D+5S;C, 3D+7S. The results showed D. magna had a competitive advantage over S. vetulus under all mixed cultures. At 20℃ and 25℃, maximal population densities of S. vetulus were 2.31 and 1.97 times than one of D. magna under isolated cultures, respectively. But population density of S. vetulus was much lower than one of D. magna under mixed cultures, and S. vetulus died away after twenty-five days. Negative relationships between the population densities of D. magna and S. vetulus were significant (C: r=-0.508, n=30, P<0.01;D: r=-0.483, n=30, P<0.01). Males of D. magna occurred in all density combinations during the experiment. The population density of D. magna was positively correlated with its male density (r=0.678, n=24, P<0.01) under 20℃ and isolated cultures, and males of D. magna were induced at first reproducion. Maximal male density (106 ind.(200ml)~(-1)) and maximal male percentage (36.8%) appeared under 20℃ and isolated culture. The males of D. magna appeared at first reproduction in B and C combinations at 25℃, and the proportions reached 28.2% in B combinations.No ephippia were produced by D. magna under isolated culutres at 25℃ and mixed cultures 20℃, while there were 66 ephippia under mixed cultures at 25℃, among which 51.5% was empty. The results indicated that the interspecific competition induced the production of males and the formation of ephippia in D. magna, and high density of males might promote to switch from parthenogenic females to sexual females in D. magna.