Jiang Jr-Hau, Lee Yung-I, Cubeta Marc A, Chen Lung-Chung
Department of Plant Pathology, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung, Taiwan.
Mycorrhiza. 2015 Aug;25(6):431-45. doi: 10.1007/s00572-014-0616-1. Epub 2015 Jan 11.
The medicinal effects and techniques for cultivating Anoectochilus formosanus are well-documented, but little is known about the mycorrhizal fungi associated with A. formosanus. Rhizoctonia (Thanatephorus) anastomosis group 6 (AG-6) was the most common species isolated from fungal pelotons in native A. formosanus and represented 67% of the sample. Rhizoctonia (Ceratobasidium) AG-G, P, and R were also isolated and represent the first occurrence in the Orchidaceae. Isolates of AG-6, AG-R, and AG-P in clade I increased seed germination 44-91% and promoted protocorm growth from phases III to VI compared to asymbiotic treatments and isolates of AG-G in clade II and Tulasnella species in clade III. All isolates in clades I to III formed fungal pelotons in tissue-cultured seedlings of A. formosanus, which exhibited significantly greater growth than nonmycorrhizal seedlings. An analysis of the relative effect of treatment ([Formula: see text]) showed that the low level of colonization ([Formula: see text]) by isolates in clade I resulted in a significant increase in seedling growth compared to isolates in clades II (0.63-0.82) and III (0.63-0.75). There was also a negative correlation (r = -0.8801) with fresh plant weight and fungal colonization. Our results suggest that isolates in clade I may represent an important group associated with native populations of A. formosanus and can vary in their ability to establish a symbiotic association with A. formosanus. The results presented here are potentially useful for advancing research on the medicinal properties, production, and conservation of A. formosanus in diverse ecosystems.
台湾金线莲的药用功效及栽培技术已有充分记载，但对于与其相关的菌根真菌却知之甚少。丝核菌（角担菌属）融合群6（AG - 6）是从原生台湾金线莲的真菌菌丝球中分离出的最常见物种，占样本的67%。丝核菌（角担菌属）AG - G、P和R也被分离出来，这是在兰科植物中首次发现。与非共生处理以及进化枝II中的AG - G分离株和进化枝III中的土赤壳属物种相比，进化枝I中的AG - 6、AG - R和AG - P分离株使种子发芽率提高了44 - 91%，并促进了原球茎从III期到VI期的生长。进化枝I至III中的所有分离株在台湾金线莲组培苗中形成了真菌菌丝球，这些组培苗的生长明显优于非菌根苗。对处理的相对效应（[公式：见原文]）分析表明，与进化枝II（0.63 - 0.82）和III（0.63 - 0.75）中的分离株相比，进化枝I中分离株的低定殖水平（[公式：见原文]）导致幼苗生长显著增加。鲜重与真菌定殖之间也存在负相关（r = -0.8801）。我们的结果表明，进化枝I中的分离株可能代表了与台湾金线莲原生种群相关的一个重要群体，并且它们与台湾金线莲建立共生关系的能力可能有所不同。本文给出的结果可能有助于推进对台湾金线莲在不同生态系统中的药用特性、生产和保护的研究。
