Lilleskov Erik A, Bruns Thomas D
Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkeley, CA 94720, USA.
Present address: USDA Forest Service, North Central Research Station, 410 MacInnes Dr, Houghton, MI 49931, USA.
New Phytol. 2003 Jul;159(1):141-151. doi: 10.1046/j.1469-8137.2003.00794.x.
• Here we investigated whether root colonization dynamics of ectomycorrhizal fungi (EMF) of contrasting life history strategies (i.e. early vs late successional dominants) were affected by resource availability, as mediated either directly via the soil, or indirectly via host nutrition. • In a two phase experiment, Pinus muricata seedlings were co-inoculated with spores of early (Rhizopogon occidentalis) and late (Tomentella sublilacina) successional dominant EMF, with or without squirrel faecal pellets added as a nutrient source, in single chambers (Phase A) subsequently converted to split-root chambers (Phase B). • R. occidentalis colonized seedlings earlier than T. sublilacina. R. occidentalis root tip numbers peaked then declined in both treatments, but earlier in the minus pellet treatment than the plus. T. sublilacina increased steadily regardless of treatment. In the split-root treatment, we found no response by R. occidentalis, and a complex response by T. sublilacina, suggesting that plant nutrition may affect colonization dynamics. • The strategy of R. occidentalis may be to colonize roots early in high resource environments; whereas that of T. sublilacina may be based upon slower colonization rates and greater competitive ability. The effect of nutrient additions on R. occidentalis may be highly dependent upon their timing.
• 在这里，我们研究了具有不同生活史策略（即早期与晚期演替优势种）的外生菌根真菌（EMF）的根系定殖动态是否受到资源可用性的影响，这种影响是通过土壤直接介导的，还是通过宿主营养间接介导的。
• 在一个两阶段实验中，将辐射松幼苗与早期（西方须腹菌）和晚期（浅紫丝膜菌）演替优势EMF的孢子共同接种，在单室（A阶段）中添加或不添加松鼠粪便颗粒作为营养源，随后转换为分根室（B阶段）。
• 西方须腹菌比浅紫丝膜菌更早地定殖于幼苗。在两种处理中，西方须腹菌的根尖数量先达到峰值然后下降，但在无颗粒处理中比有颗粒处理中下降得更早。无论处理如何，浅紫丝膜菌都稳定增加。在分根处理中，我们发现西方须腹菌没有反应，而浅紫丝膜菌有复杂的反应，这表明植物营养可能影响定殖动态。
• 西方须腹菌的策略可能是在高资源环境中早期定殖根系；而浅紫丝膜菌的策略可能基于较慢的定殖速率和更强的竞争能力。添加营养物质对西方须腹菌的影响可能高度依赖于添加时间。
