Foraging in Plants: Do Plants Selectively Associate with more Effective Ectomycorrhizal Fungi?

大多数植物和菌根真菌在营养(来自真菌)和碳水化合物(来自植物)之间进行互惠交换。我们认为，植物可以通过在每个环境中选择最有益的菌根真菌物种来促进它们的生长，因此它们的生长、与其他植物的竞争能力以及最终的成功都受到这些相互作用的强烈影响。这一假说假定1)菌根真菌种类对植物生长的益处不同，2)每种真菌种类的有益作用取决于环境条件，3)植物具有“选择”特定真菌种类的能力。这些假设认为不同的真菌将在不同的环境中占优势。我们将通过对树苗和菌根真菌的田间和实验室研究来验证这一假设。首先，我们将调查不同田间环境下与几种林木苗木相关的真菌种类。其次，我们将测试在田间发现的真菌种类，以量化它们在向每种环境中的植物提供营养方面的有效性，并确定对每种环境最有益的真菌。第三，我们将通过在每种环境中种植混合了所有真菌的苗木来测试苗木是否在每种环境中“选择”最有益的真菌。最后，我们将通过操纵田间环境并测试每种植物的真菌互惠伙伴是否根据先前实验产生的预测发生变化，来测试这些过程在自然界中的重要性。

DEB-0108542GoldbergMost plants and mycorrhizal fungi have a mutually beneficial exchange of nutrients (from fungi) and carbohydrates (from plants). We propose that plants can increase their growth by choosing the most beneficial species of mycorrhizal fungus in each environment and therefore that their growth, competitive ability with other plants, and ultimate success is strongly influenced by these mutually positive interactions. This hypothesis assumes that 1) species of mycorrhizal fungi differ in their benefits to plant growth, 2) the beneficial effects of each fungal species depend on environmental conditions, and 3) the plants have the capability of "choosing" a particular fungal species. These assumptions that different fungi will be predominant in different environments. We will test this hypothesis using field and laboratory studies of tree seedlings and mycorrhizal fungi. First, we will survey the fungi species that associate with several species of forest seedlings in different field environments. Second, we will test the fungal species found in the field to quantify how effective they are at providing nutrients to plants in each environment and to determine the most beneficial fungus for each environment. Third, we will test whether seedlings "choose" the most beneficial fungus in each environment by planting seedlings with a mixture of all the fungi in each environment. Finally, we will test the importance of these processes in nature by manipulating the field environments and testing whether the fungal mutualist partners of each plant change according to the predictions generated from the previous experiments.