2Centro Tecnológico de Investigación del Champiñón de La Rioja (CTICH), Autol, Spain.
1Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1, UK.
Microbiology (Reading). 2019 Jun;165(6):611-624. doi: 10.1099/mic.0.000792. Epub 2019 Apr 17.
The casing material required in mushroom cultivation presents a very rich ecological niche, which is inhabited by a diverse population of bacteria and fungi. In this work three different casing materials, blonde peat, black peat and a 50 : 50 mixture of both, were compared for their capacity to show a natural suppressive response against dry bubble, Lecanicillium fungicola (Preuss) Zare and Gams, and wet bubble, Mycogone perniciosa (Magnus) Delacroix. The highest mushroom production was collected from crops cultivated using the mixed casing and black peat, which were not significantly different in yield. However, artificial infection with mycoparasites resulted in similar yield losses irrespective of the material used, indicating that the casing materials do not confer advantages in disease suppression. The composition of the microbiome of the 50 : 50 casing mixture along the crop cycle and the compost and basidiomes was evaluated through next-generation sequencing (NGS) of the V3-V4 region of the bacterial 16S rRNA gene and the fungal ITS2 region. Once colonized by Agaricus bisporus, the bacterial diversity of the casing microbiome increased and the fungal diversity drastically decreased. From then on, the composition of the casing microbiome remained relatively stable. Analysis of the composition of the bacterial microbiome in basidiomes indicated that it is highly influenced by the casing microbiota. Notably, L. fungicola was consistently detected in uninoculated control samples of compost and casing using NGS, even in asymptomatic crops. This suggests that the naturally established casing microbiota was able to help to suppress disease development when inoculum levels were low, but was not effective in suppressing high pressure from artificially introduced fungal inoculum. Determination of the composition of the casing microbiome paves the way for the development of synthetic casing communities that can be used to investigate the role of specific components of the casing microbiota in mushroom production and disease control.
蘑菇栽培中所需的外壳材料提供了一个非常丰富的生态位，其中栖息着多种细菌和真菌。在这项工作中，比较了三种不同的外壳材料，即金发藓泥炭、黑泥炭和两者的 50∶50 混合物，以评估它们对干性疱病（Lecanicillium fungicola (Preuss) Zare and Gams）和湿性疱病（Mycogone perniciosa (Magnus) Delacroix）的天然抑制反应能力。从使用混合外壳和黑泥炭种植的作物中收获了最高的蘑菇产量，其产量没有显著差异。然而，无论使用何种材料进行人工接种真菌，都会导致相似的产量损失，表明外壳材料在疾病抑制方面没有优势。通过对 V3-V4 区细菌 16S rRNA 基因和真菌 ITS2 区的下一代测序（NGS），评估了 50∶50 外壳混合物沿作物周期以及堆肥和菌盖的微生物组组成。一旦被双孢蘑菇定殖，外壳微生物组的细菌多样性增加，真菌多样性急剧下降。从那时起，外壳微生物组的组成保持相对稳定。对菌盖中细菌微生物组组成的分析表明，它受到外壳微生物群的高度影响。值得注意的是，即使在无症状的作物中，使用 NGS 也能在未接种的堆肥和外壳对照样本中持续检测到 L. fungicola。这表明，当接种物水平较低时，天然建立的外壳微生物群能够帮助抑制疾病的发展，但在抑制高浓度人工引入的真菌接种物方面效果不佳。确定外壳微生物组的组成为开发合成外壳群落铺平了道路，这些群落可用于研究外壳微生物群的特定成分在蘑菇生产和疾病控制中的作用。
