Dickie Ian A, Guza Rebecca C, Krazewski Sarah E, Reich Peter B
Department of Forest Resources, University of Minnesota, Saint Paul, MN 55108, USA.
New Phytol. 2004 Nov;164(2):375-382. doi: 10.1111/j.1469-8137.2004.01177.x.
• Ectomycorrhizal infection of Quercus seedlings can be low at a distance from established ectomycorrhizal vegetation. Here we investigate whether Helianthemum bicknellii, a herbaceous ectomycorrhizal perennial of prairies and oak savannas, creates patches of elevated ectomycorrhizal infection of Quercus seedlings. • We performed two studies. First, ectomycorrhizas of H. bicknellii were compared with ectomycorrhizas of Quercus spp. Second, soil bioassays were conducted with Quercus macrocarpa seedlings grown in soils from near H. bicknellii; near established Quercus spp.; or distant from ectomycorrhizal vegetation. • Eight species associated with H. bicknellii were identified: Cenococcum geophilum, Russula aff. amoenolens, an unknown Pezizalean fungus, Laccaria laccata, Tomentella sp., Lactarius mutabilis, Russula aff. pectinatoides, and Cortinarius sp. Internal transcribed spacer restriction fragment length polymorphism (ITS RFLP) patterns of all species except Cortinarius sp. matched to ectomycorrhiza from Quercus. In the bioassay, ectomycorrhizal infection was higher in near-Helianthemum soils than in distant soils, but lower than in near-Quercus soils. • These results demonstrate that H. bicknellii, a common herbaceous plant of oak savannas, shares ectomycorrhizal partners with Quercus and provides patches of increased ectomycorrhizal infection of Quercus seedlings.
• 距离已有的外生菌根植被较远时，栎属幼苗的外生菌根感染率可能较低。在此，我们研究草原和栎树稀树草原上的多年生草本外生菌根植物比克内尔半日花是否会形成栎属幼苗外生菌根感染率升高的斑块。
• 我们进行了两项研究。首先，将比克内尔半日花的外生菌根与栎属物种的外生菌根进行比较。其次，用在比克内尔半日花附近、已有的栎属物种附近或远离外生菌根植被的土壤中生长的大果栎幼苗进行土壤生物测定。
• 鉴定出与比克内尔半日花相关的8个物种：土生空团菌、近香黄红菇、一种未知的盘菌纲真菌、乳白红菇、绒盖牛肝菌属、易变乳菇、近梳状红菇和丝膜菌属。除丝膜菌属外，所有物种的内转录间隔区限制性片段长度多态性（ITS RFLP）模式均与栎属的外生菌根匹配。在生物测定中，靠近比克内尔半日花的土壤中外生菌根感染率高于远离的土壤，但低于靠近栎属的土壤。
• 这些结果表明，栎树稀树草原上的常见草本植物比克内尔半日花与栎属共享外生菌根共生伙伴，并为栎属幼苗提供外生菌根感染率增加的斑块。
