Chen Junhui, Akutse Komivi Senyo, Saqib Hafiz Sohaib Ahmed, Wu Xiaolu, Yang Feiying, Xia Xiaofeng, Wang Liande, Goettel Mark S, You Minsheng, Gurr Geoff M
State Key Laboratory of Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China.
Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
Front Microbiol. 2020 Jul 15;11:1519. doi: 10.3389/fmicb.2020.01519. eCollection 2020.
Endophytic fungi are important in diverse plant functions but knowledge of the factors that shape assemblages of these symbionts is lacking. Here, using a culture-dependent approach, we report 4,178 endophytic fungal isolates representing 16 orders isolated from stems, roots and leaves of three cruciferous plant species, Chinese cabbage ( L.), radish ( L.) and white cabbage ( L.), collected from 21 focal fields with different landscape contexts and pesticide uses during four seasons (summer, autumn, winter and spring). The colonization rate of fungi was found to be most strongly affected by season, plant identity and plant tissue. The colonization was highest during autumn, followed by summer, spring and lowest during winter. The colonization was highest in (53.2%), followed by (42.6%), and lowest in (35.0%). The colonization was highest in stems (51.9%) in all plant types, followed by leaves (42.4%) and roots (37.5%). Hypocreales was the dominant order (33.3% of all the isolates), followed by Glomerellales (26.5%), Eurotiales (12.1%), Pleosporales (9.8%) and Capnodiales (6.0%). Fungal endophyte abundance (number of isolates) followed the same pattern as colonization rate, while species richness varied with season and host plant tissue. Ordination analyses showed that the abundance and richness of Hypocreales, Eurotiales and Sordariales were associated with plant roots, while Capnodiales, Pleosporales and Trichosphaeriales were associated with spring. Other environmental factors, elevation, and the proportions of grassland, forest, orchard and waterbodies in the surrounding landscape also exerted effects within some categories of other main effects or for certain fungal taxa. Our results indicate that while fungal endophyte communities of crucifer crops vary strongly with the season, they are also strongly structured by plant identity and plant tissue, to a lesser extent by pesticide use and only weakly by landscape composition. The understanding of the ecological roles of fungal endophytes could contribute to habitat management and consequently improve crop pest management.
内生真菌在多种植物功能中起着重要作用，但对于塑造这些共生体组合的因素仍缺乏了解。在此，我们采用依赖培养的方法，报告了从三种十字花科植物——大白菜（Brassica rapa L.）、萝卜（Raphanus sativus L.）和甘蓝（Brassica oleracea L.）的茎、根和叶中分离出的4178株内生真菌菌株，这些菌株代表16个目，样本采集自21个重点田地，这些田地在四个季节（夏季、秋季、冬季和春季）具有不同的景观背景和农药使用情况。研究发现，真菌的定殖率受季节、植物种类和植物组织的影响最大。定殖率在秋季最高，其次是夏季、春季，冬季最低。大白菜的定殖率最高（53.2%），其次是萝卜（42.6%），甘蓝最低（35.0%）。在所有植物类型中，茎中的定殖率最高（51.9%），其次是叶（42.4%）和根（37.5%）。肉座菌目是优势目（占所有分离菌株的33.3%），其次是球座菌目（26.5%）、散囊菌目（12.1%）、格孢腔菌目（9.8%）和小煤炱目（6.0%）。真菌内生菌丰度（分离菌株数量）与定殖率遵循相同模式，而物种丰富度随季节和宿主植物组织而变化。排序分析表明，肉座菌目、散囊菌目和粪壳菌目的丰度和丰富度与植物根系相关，而小煤炱目、格孢腔菌目和黑孢壳目与春季相关。其他环境因素，如海拔以及周围景观中草地、森林、果园和水体的比例，在某些其他主要影响类别或特定真菌类群中也发挥了作用。我们的研究结果表明，十字花科作物的真菌内生菌群落虽然随季节变化很大，但也受到植物种类和植物组织的强烈影响，在较小程度上受农药使用影响，仅微弱地受景观组成影响。对真菌内生菌生态作用的理解有助于栖息地管理，从而改善作物害虫管理。
