Suwannarach Nakarin, Kumla Jaturong, In-On Ammarin, Lumyong Saisamorn
Research Center of Microbial Diversity and Sustainable Utilization, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
J Fungi (Basel). 2021 Apr 13;7(4):293. doi: 10.3390/jof7040293.
Truffles ( spp.) are well-known as edible ectomycorrhizal mushrooms, and some species are one of the most expensive foods in the world. During the fruiting process, truffles produce hypogeous ascocarps; a trained pig or dog is needed to locate the ascocarps under the ground. Truffles in northern Thailand have been recorded in association with and . In this study, we investigated the soil mycobiota diversity of soil samples from both of these truffle host plants in native forests using environmental DNA metabarcoding to target the internal transcribed spacer 1 (ITS1) region of the rDNA gene for the purposes of investigation of truffle diversity and locating truffles during the non-fruiting phase. In this study, a total of 38 soil samples were collected from different locations. Of these, truffles had been found at three of these locations. Subsequently, a total of 1341 putative taxonomic units (OTUs) were obtained. The overall fungal community was dominated by phylum-level sequences assigned to Ascomycota (57.63%), Basidiomycota (37.26%), Blastocladiomycota (0.007%), Chytridiomycota (0.21%), Glomeromycota (0.01%), Kickxellomycota (0.01%), Mortierellomycota (2.08%), Mucoromycota (0.24%), Rozellomycota (0.01%), Zoopagomycota (0.003%), and unidentified (2.54%). The results revealed that six OTUs were determined to be representative and belonged to the genus . OTU162, OTU187, OTU447, and OTU530 belonged to . , . , , and . , whereas OTU105 and OTU720 were acknowledged as unrecognized species. From 38 locations, OTUs of truffles were found in 33 locations (including three previously known truffle locations). Thus, 30 collection sites were considered new locations for . , , and other unrecognized species. Interestingly, at 16 new locations, mature ascocarps of truffles that were undergoing the fruiting phase were located underground. All 16 truffle samples were identified as based on morphological characteristics and molecular phylogenetic analysis. However, ascocarps of other truffle species were not found at the new OTUs representative locations. The knowledge gained from this study can be used to lead researchers to a better understanding of the occurrence of truffles using soil mycobiota diversity investigation. The outcomes of this study will be particularly beneficial with respect to the search and hunt for truffles without the need for trained animals. In addition, the findings of this study will be useful for the management and conservation of truffle habitats in northern Thailand.
块菌（松露属）是著名的可食用外生菌根真菌，有些品种是世界上最昂贵的食物之一。在结实过程中，块菌会产生地下子囊果；需要训练有素的猪或狗来在地下找到这些子囊果。泰国北部的块菌已被记录与[具体植物名称1]和[具体植物名称2]有关。在本研究中，我们使用环境DNA宏条形码技术，以rDNA基因的内转录间隔区1（ITS1）区域为目标，调查了原生森林中这两种块菌寄主植物土壤样本的土壤真菌群落多样性，目的是在非结实阶段调查块菌多样性并定位块菌。在本研究中，从不同地点共采集了38个土壤样本。其中，在三个地点发现了块菌。随后，共获得了1341个假定分类单元（OTU）。总体真菌群落以归属于子囊菌门（57.63%）、担子菌门（37.26%）、芽枝霉门（0.007%）、壶菌门（0.21%）、球囊菌门（0.01%）、被孢霉门（0.01%）、被孢霉门（2.08%）、毛霉门（0.24%）、罗兹菌门（0.01%）、虫霉门（0.003%）以及未鉴定（2.54%）的门水平序列为主。结果显示，有6个OTU被确定为具有代表性且属于[具体属名]属。OTU162、OTU187、OTU447和OTU530属于[具体种名1]、[具体种名2]、[具体种名3]和[具体种名4]，而OTU105和OTU720被认为是未被识别的[具体属名]物种。在38个地点中，在33个地点发现了块菌的OTU（包括三个先前已知的块菌地点）。因此，30个采集地点被认为是[具体属名]、[具体种名1]和其他未被识别的[具体属名]物种的新地点。有趣的是，在16个新地点，处于结实阶段的成熟块菌子囊果被发现在地下。根据形态特征和分子系统发育分析，所有16个块菌样本均被鉴定为[具体种名]。然而，在新的OTU代表性地点未发现其他块菌物种的子囊果。本研究获得的知识可用于引导研究人员通过土壤真菌群落多样性调查更好地了解块菌的出现情况。本研究的结果对于无需训练有素的动物来寻找和采集块菌将特别有益。此外，本研究的发现将有助于泰国北部块菌栖息地的管理和保护。
