Clonal integration in homogeneous environments increases performance of Alternanthera philoxeroides
Clonal integration in homogeneous environments increases performance of Alternanthera philoxeroides
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同质环境中的克隆整合提高了空心莲子草的性能
DOI：
10.1007/s00442-015-3338-y
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发表时间：
2015-10-01
期刊：
影响因子：
2.7
通讯作者：
Yu, Fei-Hai
中科院分区：
文献类型：
--
作者：
Dong, Bi-Cheng;Alpert, Peter;Yu, Fei-Hai
当品种在异质环境中经历不同水平的资源利用时，连接品种之间的生理整合可以提高无性系植物的生产性能。一般已经证明或假设克隆整合对同质环境中的克隆表现影响很小。然而，一个概念模型表明，当连接的框架吸收能力不同且外部资源供应高时，集成可以提高同质环境中的性能。我们用水陆两栖植物互花莲子在温室实验中验证了这一假设。在含有3根和2根无根分株的克隆片段中，分株要么保持连通，要么被分成2根分株的基部和2根分株的顶端。为了模拟具有不同资源供应水平的物种的真实、均匀环境，植物在0,20和40 cm的水深下生长。水深对大多数增长指标有积极影响，表明资源供应随深度增加而增加。在水深0 cm处，连接对碎片总生长的影响为负向中性，在水深20和40 cm处，连接对碎片总生长的影响为正向中性；对根尖部分的影响总体为正，且深度越大；对基部的影响一般为负，深度越大，影响越小。结果在很大程度上支持了这一假设，并进一步表明分配和繁殖的克隆整合可能会改变同质环境中资源共享的收益。
Physiological integration between connected ramets can increase the performance of clonal plants when ramets experience contrasting levels of resource availabilities in heterogeneous environments. It has generally been shown or assumed that clonal integration has little effect on clonal performance in homogeneous environments. However, a conceptual model suggests that integration could increase performance in a homogeneous environment when connected ramets differ in uptake ability and external resource supply is high. We tested this hypothesis in a greenhouse experiment with the amphibious plant Alternanthera philoxeroides. Ramets in clonal fragments containing three rooted and two unrooted ramets were either left connected or divided into a basal part with two rooted ramets and an apical part with the other ramets. To simulate realistic, homogeneous environments of the species with different levels of resource supply, plants were grown at 0, 20, or 40 cm of water depth. Water depth had a positive effect on most measures of growth, indicating that resource supply increased with depth. Connection had negative to neutral effects on total growth of fragments at a water depth of 0 cm, and neutral to positive effects at 20- and 40-cm depths; effects on the apical part were generally positive and larger at greater depth; effects on the basal part were generally negative and smaller at greater depth. Results largely supported the hypothesis and further suggest that clonal integration of allocation and reproduction may modify benefits of resource sharing in homogeneous environments.