摘要
近年来,随着全球变暖和水体富营养化程度的日趋严重,淡水湖泊藻类水华现象频发;由此引发的微囊藻毒素对水生生物的生态毒性效应备受关注.本实验探究了4个温度(16、20、24和28℃)和3个微囊藻毒素MC-LR浓度(2.0、4.0和6.0μg/ml)对4个品系萼花臂尾轮虫(Brachionus calyciflorus)形态特征的影响.通过2种DNA分类方法——自动条形码查询系统和Yule溯祖模型将萼花臂尾轮虫划分为3个进化种;4个品系轮虫的形态学参数总体随温度升高呈减小趋势.在16℃下,轮虫的形态特征在各品系间未见显著差异;20℃下的昆明品系KMC23形态参数最小,而西宁XN2品系最大;在24℃下,西宁XN2品系的形态参数显著增大;兰州LZB1和西宁XN2品系对温度变化的响应特征相似且在28℃下最小,这可能与两者属于同一进化种有关.4个品系轮虫的卵特征参数对温度变化的响应各有不同.可见,品系和隐种的不同是造成4个轮虫克隆形态学参数对温度差异响应的重要内源性因素.各品系轮虫中,兰州LZB1品系受温度、MC-LR及两者交互作用的影响最为显著,形态可塑性最强.在高温胁迫下,兰州LZB1品系的所有形态学参数均显著减小,但MC-LR浓度对该品系轮虫的形态学参数并未产生显著影响;经低温胁迫后,低浓度的MC-LR没有显著改变兰州LZB1品系轮虫的形态学参数,而高浓度的MC-LR显著降低了轮虫的大部分形态学参数.微囊藻毒素对轮虫形态可塑性的影响受到了内源性因素和外源性因素的综合制约.
With the increasing seriousness of global warming and eutrophication,algal blooms occur frequently in freshwater lakes,and thus initiate ecotoxic effects of microcystins on aquatic organisms. In the present study,the combined effects of temperature（ 16,20,24 and 28℃） and microcystin MC-LR（ 2.0,4.0 and 6.0 μg/ml） on the morphological characteristics of four strains of rotifer Brachionus calyciflorus（ LZB1,XN2,BNB3 and KMC23） were evaluated. According to the two models of DNA taxonomy,three evolutionary species were discriminated in B. calyciflorus groups. Generally,the morphological features in the four rotifer strains decreased with increase temperature. At 16℃,there were no significant differences in morphological indexes among the four strains. The morphological parameters in KMC23 were minimum at 20℃,and the largest was the strain XN2 at 20 and 24℃. Both of LZB1 and XN2 showed similar responses to temperature change,and reached the smallest at 28℃,which could be attributed to ascribing the two strains into the same evolving entity. The responses of egg parameters to temperature change varied among four rotifer strains. It is thus clear that the identity of cryptic species and/or strain is an important endogenous factor which leads to the variant responses of morphological characteristics in rotifer to temperature. Among four B. calyciflorus strains,the effects of temperature,MC-LR and their interaction were the most significant to the morphological features of LZB1 which could hold the greatest capability of phenotypic flexibility. Under the stress of high temperature,all morphological parameters in LZB1 decreased significantly,however,there were no significant effects of MC-LR concentration to morphological features. At low temperature,the MC-LR at low concentration did not affect those indexes in LZB1,and in contrast,the high concentration of MC-LR decreased most of morphological parameters significantly. In summary,the effects of microcystins in water to the morphological flexibility
作者
项贤领
朱凌云
陈莹莹
宛凤英
康琳
席贻龙
XIANG Xianling;ZHU Lingyun;CHEN Yingying;WAN Fengying(College of Life Sciences,Anhui Normal University,Wuhu 241000,P.R.China;Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province,Wuhu 241000,P.R.China;Library of Anhui Normal University,Wuhu 241000,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2018年第4期1027-1040,共14页
Journal of Lake Sciences
基金
国家自然科学基金项目(31470015
31200324)
安徽省自然科学基金项目(1208085QC47
1708085MC79)
重要生物资源保护和利用研究安徽省重点实验室专项基金联合资助
关键词
萼花臂尾轮虫
微囊藻毒素
温度
进化种
品系
形态特征
Brachionus calyc^orus
microcystin-LR
temperature
evolutionary species
strain
morphological characteristic
