Zettler Lawrence W, Rajaovelona Landy, Yokoya Kazutomo, Kendon Jonathan P, Stice Andrew L, Wood Amanda E, Sarasan Viswambharan
Department of Biology, Illinois College, 1101 West College Ave., Jacksonville, IL, 62650, USA.
Kew Madagascar Conservation Centre, Lot #J131B, Ambodivaonjo-Ivandry, 101, Antananarivo, Madagascar.
Bot Stud. 2017 Nov 28;58(1):54. doi: 10.1186/s40529-017-0209-3.
Tropical orchids need more study with respect to their mycorrhizal associations. For researchers in distant countries who aspire to study these orchids augmenting their conservation, the great distances involved, coupled with limited funds, pose formidable challenges. These challenges are sometimes exacerbated by political unrest, delays in securing permits, unexpected hardships, and the risk that the biological samples collected (e.g., roots harboring mycorrhizal fungi) will not survive long-distance transport.
We describe a protocol for the collection and transport of root samples from Madagascar orchids to labs in the United Kingdom (Kew) and the United States (Illinois) where Rhizoctonia-like fungi were subsequently isolated. Three separate trips were made spanning 4 years (2012-2015), with emphasis on the collection of roots from epiphytic, lithophytic, and terrestrial orchids inhabiting the Itremo Massif of the Central Highlands. Collectively, the trips to Madagascar resulted in the isolation of all major groups of Rhizoctonia-like fungi (Ceratobasidium, Tulasnella, Sebacina) from all three orchid growth forms (terrestrials, epiphytes and lithophytes). Sampling of terrestrial and epiphytes during the rainy season (January) yielded best results.
Our study demonstrates that peloton-forming fungi in root samples can retain viability up to 3 weeks after collection.
热带兰花的菌根共生关系需要更多研究。对于那些渴望研究这些兰花以加强其保护的遥远国家的研究人员来说，路途遥远加上资金有限，构成了巨大挑战。有时，政治动荡、获取许可证的延误、意外困难以及所采集生物样本（例如含有菌根真菌的根）无法在长途运输中存活的风险，会使这些挑战更加严峻。
我们描述了一种从马达加斯加兰花采集根样本并运往英国（邱园）和美国（伊利诺伊州）实验室的方案，随后在这些实验室分离出了类似丝核菌的真菌。在4年（2012 - 2015年）间进行了三次单独行程，重点采集了栖息于中央高原伊特雷莫地块的附生、石生和地生兰花的根。总体而言，前往马达加斯加的行程从所有三种兰花生长形式（地生、附生和石生）中分离出了所有主要类群的类似丝核菌的真菌（角担菌属、土赤壳属、角形孢属）。在雨季（1月）对地生和附生植物进行采样取得了最佳结果。
我们的研究表明，根样本中形成菌丝球的真菌在采集后长达3周仍可保持活力。
