Sapkota Rumakanta, Knorr Kamilla, Jørgensen Lise Nistrup, O'Hanlon Karen A, Nicolaisen Mogens
Department of Agroecology, Faculty of Science and Technology, Aarhus University, Forsøgsvej 1, DK4200, Slagelse, Denmark.
Slotsvaenget 11, 3400, Hillerød, Denmark.
New Phytol. 2015 Sep;207(4):1134-44. doi: 10.1111/nph.13418. Epub 2015 Apr 21.
The phyllosphere mycobiome in cereals is an important determinant of crop health. However, an understanding of the factors shaping this community is lacking. Fungal diversity in leaves from a range of cultivars of winter wheat (Triticum aestivum), winter and spring barley (Hordeum vulgare) and a smaller number of samples from oat (Avena sativa), rye (Secale cereale) and triticale (Triticum × Secale) was studied using next-generation sequencing. The effects of host genotype, fungicide treatment and location on fungal communities were explored. In total, 635 251 fungal internal transcribed spacer (ITS) reads were obtained from 210 leaf samples. Visual disease assessments and relative read abundance of Zymoseptoria tritici and Ramularia collo-cygni were strongly positively related. Crop genotype at the species level explained 43% of the variance in the total dataset, followed by fungicide treatment (13%) and location (4%). Indicator species, including plant pathogens, responding to factors such as crop species, location and treatment were identified. Host genotype at both the species and cultivar level is important in shaping phyllosphere fungal communities, whereas fungicide treatment and location have minor effects. We found many host-specific fungal pathogens, but also a large diversity of fungi that were relatively insensitive to host genetic background, indicating that host-specific pathogens live in a 'sea' of nonspecific fungi.
谷物叶际真菌群落是作物健康的重要决定因素。然而，目前尚缺乏对影响该群落形成因素的了解。利用新一代测序技术，研究了一系列冬小麦（普通小麦）、冬大麦和春大麦（大麦）品种叶片中的真菌多样性，并对少量燕麦（燕麦）、黑麦（黑麦）和小黑麦（小麦×黑麦）样本进行了研究。探讨了宿主基因型、杀菌剂处理和地理位置对真菌群落的影响。共从210个叶片样本中获得了635251条真菌内转录间隔区（ITS）序列读数。小麦黄斑叶枯病菌和大麦网斑病菌的病情目测评估结果与相对序列读数丰度呈显著正相关。物种水平上的作物基因型解释了整个数据集中43%的变异，其次是杀菌剂处理（13%）和地理位置（4%）。确定了对作物种类、地理位置和处理等因素有响应的指示物种，包括植物病原体。物种和品种水平上的宿主基因型对叶际真菌群落的形成都很重要，而杀菌剂处理和地理位置的影响较小。我们发现了许多宿主特异性真菌病原体，但也有大量对宿主遗传背景相对不敏感的真菌，这表明宿主特异性病原体生活在非特异性真菌的“海洋”中。
