FORMATION OF RESTING SPORES BY LEPTOCYLINDRUS DANICUS (BACILLARIOPHYCEAE) IN A CONTROLLED EXPERIMENTAL ECOSYSTEM 1
FORMATION OF RESTING SPORES BY LEPTOCYLINDRUS DANICUS (BACILLARIOPHYCEAE) IN A CONTROLLED EXPERIMENTAL ECOSYSTEM 1
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在受控实验生态系统中 LEPTOCYLINDRUS DANICUS（硅藻纲）静息孢子的形成 1
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
P. Harrison
中科院分区：
文献类型：
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作者：
C. Davis;J. Hollibaugh;D. Seibert;W. Thomas;P. Harrison
在加拿大不列颠哥伦比亚省Saanich Inlet的CEPEX控制实验生态系统（CEE）中，丹麦细柱藻（Leptocylindrus danicus Cleve）成为浮游植物的优势种，占总浮游植物的70-80%。在6月的第一周，当硝酸盐水平降至0.5 μm以下时，大部分L.存在于CEE中的danicus细胞形成休眠孢子。这些孢子有着厚厚的尖刺，似乎可以不受干扰地沉到CEE的底部。四个连续的培养开始与接种物从CEE和，在24小时内，当N变得耗尽，86%的L。danicus（约占浮游植物总组合的80%）形成休眠孢子。在同一时间从相同接种物开始每日稀释培养，营养素保持在饱和水平，并在N限制培养物中孢子形成事件后持续2周。在营养饱和培养物中未观察到孢子，表明氮限制对于触发孢子形成是必要的。孢子在3 ℃和10 ℃下置于黑暗中。在36和97天后，大部分孢子萌发。214天后，>1%的孢子仍能够萌发。实验室研究L.丹麦分离的CEE证实，N限制是触发孢子形成的主要因素。这些培养物的显微镜观察表明，孢子是由有性繁殖后的孢子缺陷型形成的。
Leptocylindrus danicus Cleve became the dominant phytoplankton species, comprising 70–80% of the total assemblage, in one of the CEPEX Controlled Experimental Ecosystems (CEE) at Saanich Inlet, British Columbia (Canada). In the first week of June, when nitrate levels were reduced below 0.5 μm, the majority of the L. danicus cells present in the CEE formed resting spores. The spores were heavily armored with spines and appeared to sink unmolested to the bottom of the CEE. Four continuous cultures were started with an inoculum from the CEE and, in a 24 h period when N became depleted, 86% of the L. danicus present (∼80% of the total phytoplankton assemblage) formed resting spores. A daily dilution culture with nutrients kept at saturating levels was started at the same time from the same inoculum and continued for 2 wk beyond the spore formation event in the N‐limited cultures. No spores were observed in the nutrient‐saturated culture, indicating that N limitation was necessary to trigger spore formation. Spores were kept in the dark at 3 and 10 C. After 36 and 97 days, a large percentage of the spores germinated. After 214 days, >1% of the spores were still capable of germination. Laboratory studies with L. danicus isolated from the CEE confirmed that N limitation was the primary factor triggering spore formation. Microscope observations of these cultures indicated that the spores were formed by auxospores following sexual reproduction.