NITROGEN SHARING AMONG RAMETS INCREASES CLONAL GROWTH IN FRAGARIA-CHILOENSIS
NITROGEN SHARING AMONG RAMETS INCREASES CLONAL GROWTH IN FRAGARIA-CHILOENSIS
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DOI：
10.2307/1938903
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发表时间：
1991-02-01
期刊：
影响因子：
4.8
通讯作者：
ALPERT, P
中科院分区：
文献类型：
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作者：
ALPERT, P
当克隆植物分株位于光照、水分或土壤养分有效性不同的微生境中时，相互连接的分株之间的资源运输可以促进克隆植物的生长。为了测试这是否也适用于土壤氮的有效性，两个温室实验进行了匍匐茎草本草莓chiloensis（海滩草莓）。首先，准备成对的分株，其中两个分株通过匍匐茎连接，但在单独的盆中生根。成对的分株是：（1）彼此分开，并给出对比的土壤氮水平（高与低）;（2）左连接，并给出对比的土壤氮水平;或（3）左连接，并给出统一的土壤氮水平（都高或都低）。第二，单分株给予高，低，或三个中间水平的土壤氮。维持维管连接分株之间的对比水平的土壤氮导致更大的生产新的匍匐茎和新的分株的分株的低氮水平，并在稍大的叶片生长的分株的低氮水平，如果它也是年轻的连接分株。然而，一个分株高土壤氮增长远远超过一个分株低土壤氮，即使连接。维持分株之间的维管连接给予一个统一的土壤氮水平对生长没有显着的影响。单分株给予较高的土壤氮水平有较大的总质量和组分质量，更多的匍匐茎和新分株，较高的氮浓度，较高的比叶面积，和较高的比例质量的叶片和匍匐茎和新分株。试验结果表明：（1）分株间氮素的运输促进了F.（2）匍匐茎对氮素的运输可能是向顶向或向基向的，但倾向于促进较年轻分株的生长;（3）土壤氮素有效性的提高通过增加对叶片、新匍匐茎和分株的分配而改变植物的构型;（4）分株间的生理整合改变了克隆构型，因为根系获得的氮促进了生根分株及其新分株的生长，而从另一分株获得的氮几乎完全促进新分株的生长。
Transport of resources among connected ramets can increase the growth of clonal plants when ramets are located in microsites with contrasting light, water, or total soil nutrient availability. To test whether this is also true for soil nitrogen availability alone, two greenhouse experiments were conducted using the stoloniferous herb Fragaria chiloensis (beach strawberry). First, pairs of ramets were prepared in which the two ramets were connected by a stolon but rooted in separate pots. Ramets in a pair were: (1) severed from each other and given contrasting levels of soil nitrogen (high vs. low); (2) left connected and given contrasting levels of soil nitrogen; or (3) left connected and given a uniform level of soil nitrogen (both high or both low). Second, single ramets were given the high, the low, or one of three intermediate levels of soil nitrogen. Maintaining the vascular connection between ramets given contrasting levels of soil nitrogen resulted in a greater production of new stolons and new ramets by the ramet given the low nitrogen level, and in slightly greater leaf growth of the ramet given the low nitrogen level if it was also younger than the connected ramet. However, a ramet given high soil nitrogen grew much more than a ramet given low soil nitrogen, even when connected. Maintaining the vascular connection between ramets given a uniform level of soil nitrogen had no significant effect on growth. Single ramets given a higher soil nitrogen level had greater total and component masses, more stolons and new ramets, higher nitrogen concentrations, higher specific leaf area, and a higher proportional mass of leaves and of stolons and new ramets. Experiments suggested that: (1) transport of nitrogen among ramets can increase growth in F. chiloensis, but to a limited extent; (2) transport of nitrogen through a stolon may be either acropetal or basipetal but tends to promote the growth of younger ramets; (3) higher soil nitrogen availability alters plant architecture by increasing allocation to leaves and to new stolons and ramets; and (4) physiological integration among ramets modifies clonal architecture because nitrogen acquired by roots promotes growth of both a rooted ramet and its new ramets, whereas nitrogen acquired from another ramet promotes the growth of new ramets almost exclusively.