Home site advantage in two long-lived arctic plant species: results from two 30-year reciprocal transplant studies
Home site advantage in two long-lived arctic plant species: results from two 30-year reciprocal transplant studies
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DOI：
10.1111/j.1365-2745.2012.01984.x
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发表时间：
2012-07-01
影响因子：
5.5
通讯作者：
McGraw, James B.
中科院分区：
文献类型：
--
作者：
Bennington, Cynthia C.;Fetcher, Ned;McGraw, James B.
1.相互移植实验旨在量化遗传和环境对表型的影响，是研究局部适应的有力工具。然而，对于长寿物种，特别是那些生长季节较短的生境中的物种，可能需要在新环境中多年的累积效应才能产生适应度差异和表型变化。2.在最初在阿拉斯加内陆建立移植实验30年后，我们回到了两个独立的相互移植实验中，询问在移植后立即观察到的分化模式是否持续存在。我们还询问了早先关于可塑性在缓冲选择对外来基因类型的影响方面的作用的假设是否得到支持。我们调查了沿着雪堤坡度为矮小灌木(Dryas Octopetala)建造的三个移植花园和沿着纬度梯度为形成草丛的莎草(Eriophorum Ovinatum)建造的六个花园的成活和开花情况。对于这两个物种，我们使用方差分析来检测移植回本国的植物相对于移植到异地的植物的适应性优势。3.对于章鱼来说，在移植后的十年中观察到的原始的局部适应模式在三十年后似乎更加强烈，在农田和雪地环境中完全消除了外来生态型。对于阴道棘球绦虫来说，移植后13年，种群存活率的差异并不明显，但在17年后明显。没有证据表明可塑性与外来种群在章鱼或阴道毛虫新栖息地的存活率增加有关。4.综合。我们的结论是，局部适应可能很强，但在短期实验中仍未被发现或被低估。这种基于遗传的种群差异限制了植物种群对气候变化的反应能力。
1. Reciprocal transplant experiments designed to quantify genetic and environmental effects on phenotype are powerful tools for the study of local adaptation. For long-lived species, especially those in habitats with short growing seasons, however, the cumulative effects of many years in novel environments may be required for fitness differences and phenotypic changes to accrue. 2. We returned to two separate reciprocal transplant experiments thirty years after their initial establishment in interior Alaska to ask whether patterns of differentiation observed in the years immediately following transplant have persisted. We also asked whether earlier hypotheses about the role of plasticity in buffering against the effects of selection on foreign genotypes were supported. We censused survival and flowering in three transplant gardens created along a snowbank gradient for a dwarf shrub (Dryas octopetala) and six gardens created along a latitudinal gradient for a tussock-forming sedge (Eriophorum vaginatum). For both species, we used an analysis of variance to detect fitness advantages for plants transplanted back into their home site relative to those transplanted into foreign sites. 3. For D. octopetala, the original patterns of local adaptation observed in the decade following transplant appeared even stronger after three decades, with the complete elimination of foreign ecotypes in both fellfield and snowbed environments. For E. vaginatum, differential survival of populations was not evident 13 years after transplant, but was clearly evident 17 years later. There was no evidence that plasticity was associated with increased survival of foreign populations in novel sites for either D. octopetala or E. vaginatum. 4. Synthesis. We conclude that local adaptation can be strong, but nevertheless remain undetected or underestimated in short-term experiments. Such genetically based population differences limit the ability of plant populations to respond to a changing climate.