Nutrient Foraging by Mycorrhizal Roots of Different Morphology: Are Roots and Fungi Complementary?

影响不同植物营养觅食的根系性状知之甚少。 在大多数植物中，根与菌根真菌形成共生关系，这可以提高植物寻找营养的能力。 然而，不同的物种在真菌对养分吸收的促进程度上存在差异，这可能与根系形态有关，包括根直径和根毛丰度。PI假设，具有粗根的树种，根毛很少或较短，在营养丰富的斑块中觅食，严重依赖于菌根真菌，而具有生长更快的根的树种，产生许多长根毛，通过增殖它们的根，增加根毛发育和改变营养吸收速率来觅食营养。 该项目将主要在16种不同树种的14年种植中进行，这些树种的根系形态差异很大，但将在天然林和生长室中进行更多的研究。这项研究将改善植物根系可用于计算植被对元素循环的影响的理论基础，改善植被对气候变化的响应和反馈的预测，并增加对更好地管理作物和树木的食物和纤维所需的根系的理解。 这项研究将有一个强有力的教育组成部分，包括三个研究生的培训，本科生的研究和学生和科学家的国际交流培训。

Root traits that influence nutrient foraging in different plants are poorly understood. In most plants, roots form a symbiotic association with mycorrhizal fungi that may improve the ability of the plant to forage for nutrients. However, species differ in the extent that mycorrhizae can benefit nutrient uptake, and this is likely related to root morphology, including root diameter and root hair abundance. The PIs hypothesize that tree species with coarse roots with few or short root hairs forage in nutrient-rich patches by relying heavily on mycorrhizal fungi, while tree species with more rapidly growing roots that produce many long root hairs forage for nutrients by proliferating their roots, increasing root hair development and altering the rate of nutrient uptake. The project will be primarily conducted in a 14-year-old planting of 16 different tree species that vary widely in root morphology, although additional studies will be conducted in natural forest stands and in growth chambers. This study will improve the theoretical basis by which plant roots can be used for calculating the influence of vegetation on elemental cycles, improve predictions of vegetation responses and feedbacks to climate change, and increase the understanding of roots needed for better management of crops and trees for food and fiber. There will be a strong educational component to this research, including the training of three graduate students, undergraduate training in research and international exchanges of students and scientists.