Cairney John W G, Ashford Anne E
Mycorrhiza Research Group, Centre for Horticulture and Plant Sciences, University of Western Sydney, Parramatta Campus, Locked Bag 1797, PENRITH SOUTH DCL, NSW 1797, Australia.
School of Biological Science, University of New South Wales, Sydney 2052, Australia.
New Phytol. 2002 May;154(2):305-326. doi: 10.1046/j.1469-8137.2002.00398.x.
Epacrids, a group of southern hemisphere plants formerly considered members of the separate family Epacridaceae, are in fact most closely allied to the Vaccinioid tribe (Ericaceae). Epacrids and other extant ericoid mycorrhiza-forming plants appear to have a monophyletic origin. In common with many Ericaceae they form ericoid mycorrhizas. ITS sequence data indicate that the fungi forming ericoid mycorrhizas with epacrids and other extant Ericaceae are broadly similar, belonging to a poorly defined group of ascomycetes with phylogenetic affinities to Helotiales. The basic development and structure of ericoid mycorrhizal infections in epacrids is similar to other Ericaceae. However, data are limited on the structure and physiology of both hair roots and ericoid mycorrhizas for all Ericaceae. Relatively little is known about the functional significance of ericoid mycorrhizas in epacrids in southern hemisphere habitats that are often poor in organic matter accumulation. However the abilities of fungal endophytes of epacrids to utilize organic N and P substrates equal those of endophytes from northern hemisphere heathland plant hosts. Investigations using N/ C-labelled organic N substrates suggest that mycorrhizal endophytes are important, at least, to the N nutrition of their epacrid hosts in some habitats. Contents Summary 305 I. Epacrid plant hosts 306 II. Evolution of ericoid mycorrhizas in epacrids 306 III. Epacrid hair roots and their mycorrhizal associations 307 IV. Seasonality and incidence of mycorrhizal infection 310 V. Structure and development of mycorrhizal associations 311 VI. Nature of the mycorrhizal fungal endophytes 315 VII. Community and population biology of mycorrhizal endophytes 318 VIII. Functional aspects of mycorrhizas in epacrids 319 IX. Conclusions 322 Acknowledgements 322 References 322.
澳石南属植物，这是一组以前被认为属于独立的澳石南科的南半球植物，实际上与越桔族（杜鹃花科）关系最为密切。澳石南属植物和其他现存的形成石楠状菌根的植物似乎有一个单系起源。与许多杜鹃花科植物一样，它们形成石楠状菌根。ITS序列数据表明，与澳石南属植物和其他现存杜鹃花科植物形成石楠状菌根的真菌大致相似，属于一组定义不明确的子囊菌，与柔膜菌目有系统发育亲缘关系。澳石南属植物中石楠状菌根感染的基本发育和结构与其他杜鹃花科植物相似。然而，关于所有杜鹃花科植物的毛根和石楠状菌根的结构和生理学的数据都很有限。对于南半球栖息地中通常有机物积累较少的澳石南属植物，人们对其石楠状菌根的功能意义了解相对较少。然而，澳石南属植物的真菌内生菌利用有机氮和磷底物的能力与北半球石南荒原植物宿主的内生菌相当。使用氮/碳标记的有机氮底物进行的研究表明，菌根内生菌至少在某些栖息地对其澳石南属宿主的氮营养很重要。内容摘要305 一、澳石南属植物宿主306 二、澳石南属植物中石楠状菌根的进化306 三、澳石南属植物的毛根及其菌根关联307 四、菌根感染的季节性和发生率310 五、菌根关联的结构和发育311 六、菌根真菌内生菌的性质315 七、菌根内生菌的群落和种群生物学318 八、澳石南属植物中菌根的功能方面319 九、结论322 致谢322 参考文献322
