Orchids rely strictly on mycorrhizal symbioses for nutrition, including carbon, from seed germination to protocorm growth. However, whether orchids establish symbiotic compatibility selectively with specific mycorrhizal fungi during this early growth period remains to be determined for most species. We examined pair-wise symbiotic compatibility between three terrestrial orchid species, Bletilla striata, Pecteilis radiata, and Spiranthes australis, and five closely related strains of Tulasnella, using a procedure we recently developed for detailed and quantitative evaluation of mycorrhizal symbiosis during post-germination growth. Our analyses revealed significant differences among colonization effects of the Tulasnella strains on the hosts, both at seed germination and during post-germination growth. The effects of the mycorrhizal associations tended to differ by stage, suggesting a variety of determinants for symbiotic compatibility. One Tulasnella strain exhibited high compatibility across the three distantly related host species, implying that inherent properties of mycorrhizal fungi can influence their symbiotic compatibility with a wide range of orchid species.

中文翻译：

---

图兰菌真菌菌株对兰花萌发与幼苗生长后菌根共生的相对有效性

从种子发芽到原球茎生长，兰花严格依靠菌根共生来获取营养，包括碳。然而，对于大多数物种而言，兰花在此早期生长期是否与特定菌根真菌选择性地建立共生相容性尚待确定。我们使用最近开发的用于发芽后生长过程中菌根共生的详细和定量评估的程序，研究了三种陆生兰花物种，白大猩猩，辐射状菌和南方尖齿藻以及五个紧密相关的托拉斯菌菌株之间的成对共生相容性。。我们的分析表明，图拉氏菌的定殖效果之间存在显着差异种子发芽时和发芽后生长期间对寄主的抗性。菌根结合的效果往往因阶段而异，表明存在多种共生相容性的决定因素。一种风铃草菌株在三种遥远相关的宿主物种中表现出高度的相容性，这表明菌根真菌的固有特性可以影响它们与多种兰花物种的共生相容性。