U.S.-Sweden Cooperative Research: Ecology and Physiology ofAlnus-Frankia Symbiosis

该奖项将支持俄勒冈州立大学的David Myrold博士和瑞典Umea大学植物生理学系的Kerstin Huss-Danell博士在生态学方面的合作研究。该项目将研究与赤杨-弗兰克氏菌共生有关的两个重要问题，即几个因素对土壤中弗兰克氏菌生物量和多样性的影响，以及根瘤赤杨向土壤中释放的固定氮量。特别是，土壤将从一个经过石灰处理、NPK施肥和引进杉木的已建立的研究地点进行采样。将通过植物生物测定和DNA探针法对土壤中的Frankia生物量进行检测。这些实验的结果不仅将为理解Alnus-Frankia共生提供重要的新信息，而且将进一步为一般的放线菌植物提供新的见解。这些植物在生态上很重要，因为它们可以通过迅速改变它们所在系统的氮含量来改变生态系统水平的过程。它们在林业、土地开垦和园艺方面也具有重要意义。这个项目将受益于米罗尔德博士在微生物学方面和胡斯-达内尔博士在植物生理学方面的共同专长。米罗尔德博士还将能够利用瑞典的一个实地选址，这个选址经过了广泛的研究，非常适合拟议中的研究。

This award will support collaborative research in ecology between Dr. David Myrold, Oregon State University and Dr. Kerstin Huss-Danell, Department of Plant Physiology, University of Umea, Sweden. The project will examine two important questions concerning Alnus-Frankia symbiosis, namely the effect of several factors on the biomass and diversity of Frankia in the soil and the amount of fixed N released to the soil by nodulated Alnus. In particular, soil will be sampled from an established research site that has been treated by liming, NPK fertilization and the introduction of alder. This soil will be assayed for Frankia biomass by plant bioassay and DNA probe methods. The results of these experiments will not only provide important new information in understanding Alnus-Frankia symbiosis, but will by extension provide new insight into actinorhizal plants in general. These plants are ecologically important, because they can alter ecosystem level processes by rapidly altering the nitrogen content of the systems in which they occur. They also have importance in forestry, land reclamation and horticulture. This project will benefit from the compleme- ntary expertise of Dr. Myrold in microbiology and of Dr. Huss-Danell in plant physiology. Dr. Myrold will also be able to take advantage of a field site in Sweden which has been extensively studied and is exceptionally well suited to the proposed research.