Muvea Alexander Mutua, Subramanian Sevgan, Maniania Nguya Kalemba, Poehling Hans-Michael, Ekesi Sunday, Meyhöfer Rainer
Section of Phytomedicine, Institute of Horticultural Production Systems, Leibniz Universität Hannover, Hanover, Germany.
Plant Health Division, International Centre of Insect Physiology and Ecology, Nairobi, Kenya.
Front Plant Sci. 2018 Dec 6;9:1785. doi: 10.3389/fpls.2018.01785. eCollection 2018.
In agricultural ecosystems, insect pests, pathogens, weather patterns, and reduced soil fertility pose major challenges to crop productivity and are responsible for significant yield losses worldwide. (IYSV) vectored by Lindeman, is a major hindrance to onion production in eastern Africa. Control measures often rely on insecticides with deleterious effects. Endophytes are one key alternative as they can play important roles in mediating induced systemic resistance. Hence, we examined the potential effect of endophytic fungus (F3ST1) on feeding and replication of IYSV on endophyte-colonized (E+) and endophyte-free (E-) onion plants. For more precise assessment, replication was also tested using leaf disk bioassays and individual thrips. The number of feeding punctures was significantly lower in E+ as compared to E- plants. Disease level was significantly lower in E+ as compared to E- plants for four weeks post-exposure to thrips. IYSV replication was reduced by 2.5-fold in endophytic treatment on both whole plant and leaf disk assays. showed 2 times higher feeding activities on endophyte-free onion leaf disks as compared to the endophyte-inoculated leaf disks. Our results suggest potential utility of the endophytes to reduce feeding damage and virus infection on onion plants. Further studies should be conducted to elucidate the secondary metabolites involved in such endophyte-thrips-virus mediated interaction and determine whether the interactions extend for this and other onion varieties and viruses under field conditions.
在农业生态系统中，害虫、病原体、天气模式以及土壤肥力下降对作物生产力构成了重大挑战，并在全球范围内导致了巨大的产量损失。由林德曼传播的（番茄潜叶蛾病毒）是东非洋葱生产的主要障碍。控制措施通常依赖于具有有害影响的杀虫剂。内生菌是一种关键的替代方法，因为它们在介导诱导系统抗性方面可以发挥重要作用。因此，我们研究了内生真菌（F3ST1）对内生菌定殖（E+）和无菌内生菌（E-）洋葱植株上番茄潜叶蛾病毒取食和复制的潜在影响。为了进行更精确的评估，还使用叶盘生物测定法和单个蓟马对复制情况进行了测试。与E-植株相比，E+植株上的取食穿刺数量显著减少。在接触蓟马四周后，E+植株的病害水平与E-植株相比显著降低。在全株和叶盘试验中，内生菌处理使番茄潜叶蛾病毒的复制减少了2.5倍。与接种内生菌的叶盘相比，（某种情况未明确）在无菌内生菌的洋葱叶盘上的取食活性高出2倍。我们的结果表明内生菌在减少洋葱植株取食损伤和病毒感染方面具有潜在效用。应进一步开展研究，以阐明参与这种内生菌-蓟马-病毒介导相互作用的次生代谢物，并确定这种相互作用在田间条件下是否也适用于该洋葱品种及其他品种和病毒。
