Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Lesní 322, 25243, Průhonice, Czech Republic.
University of Chemistry and Technology, Technická 5, 166 28, Prague 6-Dejvice, Czech Republic.
Sci Rep. 2021 Feb 15;11(1):3810. doi: 10.1038/s41598-021-81937-7.
Phoma stem canker (caused by the ascomycetes Leptosphaeria maculans and Leptosphaeria biglobosa) is an important disease of oilseed rape. Its effect on endophyte communities in roots and shoots and the potential of endophytes to promote growth and control diseases of oilseed rape (OSR) was investigated. Phoma stem canker had a large effect especially on fungal but also on bacterial endophyte communities. Dominant bacterial genera were Pseudomonas, followed by Enterobacter, Serratia, Stenotrophomonas, Bacillus and Staphylococcus. Achromobacter, Pectobacter and Sphingobacterium were isolated only from diseased plants, though in very small numbers. The fungal genera Cladosporium, Botrytis and Torula were dominant in healthy plants whereas Alternaria, Fusarium and Basidiomycetes (Vishniacozyma, Holtermaniella, Bjerkandera/Thanatephorus) occurred exclusively in diseased plants. Remarkably, Leptosphaeria biglobosa could be isolated in large numbers from shoots of both healthy and diseased plants. Plant growth promoting properties (antioxidative activity, P-solubilisation, production of phytohormones and siderophores) were widespread in OSR endophytes. Although none of the tested bacterial endophytes (Achromobacter, Enterobacter, Pseudomonas, Serratia and Stenotrophomonas) promoted growth of oilseed rape under P-limiting conditions or controlled Phoma disease on oilseed rape cotyledons, they significantly reduced incidence of Sclerotinia disease. In the field, a combined inoculum consisting of Achromobacter piechaudii, two pseudomonads and Stenotrophomonas rhizophila tendencially increased OSR yield and reduced Phoma stem canker.
茎基溃疡病（由子囊菌真菌麦丘病病原菌和大茎点霉引起）是油菜的一种重要病害。本研究调查了茎基溃疡病对油菜根和茎内生菌群落的影响，以及内生菌促进油菜生长和防治病害的潜力。麦丘病病原菌对真菌内生菌群落，特别是细菌内生菌群落的影响较大。优势细菌属为假单胞菌，其次为肠杆菌属、沙雷氏菌属、寡养单胞菌属、芽孢杆菌属和葡萄球菌属。虽然阿克默菌属、果胶杆菌属和鞘脂杆菌属仅从患病植株中分离得到，但数量非常少。健康植株中内生真菌优势属为枝孢属、葡萄孢属和毕赤酵母属，而长梗木霉、镰刀菌属和担子菌（滑菇属、霍尔特曼尼ella 属、伯克霍尔德菌/Thanatephorus 属）仅存在于患病植株中。值得注意的是，大茎点霉病原菌可以从健康和患病植株的茎中大量分离得到。油菜内生菌具有促进植物生长的特性（抗氧化活性、解磷能力、植物激素和铁载体的产生）。尽管在受磷限制的条件下，没有一种测试的内生细菌（阿克默菌属、肠杆菌属、假单胞菌属、沙雷氏菌属和寡养单胞菌属）能促进油菜的生长或控制油菜子叶上的麦丘病，但它们能显著降低菌核病的发病率。在田间，阿克默菌属、假单胞菌属和寡养单胞菌属的混合接种体倾向于增加油菜的产量，并降低茎基溃疡病的发病率。
