Muvea Alexander M, Meyhöfer Rainer, Subramanian Sevgan, Poehling Hans-Michael, Ekesi Sunday, Maniania Nguya K
Institute of Horticultural Production Systems, Section Phytomedicine, Leibniz Universität Hannover, Hannover, Germany; Plant Health Division, IPM cluster, International Centre of Insect Physiology and Ecology, Nairobi, Kenya.
Institute of Horticultural Production Systems, Section Phytomedicine, Leibniz Universität Hannover, Hannover, Germany.
PLoS One. 2014 Sep 25;9(9):e108242. doi: 10.1371/journal.pone.0108242. eCollection 2014.
Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci.
内生真菌生活在寄主植物组织内，不会引起任何可见的感染症状，它们是介导植物与食草动物相互作用的重要共生生物。西花蓟马（Lindeman）是洋葱（Allium cepa L.）的主要害虫之一，洋葱是一种在全球广泛种植的重要经济作物。然而，关于洋葱内生菌定殖及其对以洋葱为食的蓟马生物学特性影响的信息却很缺乏。我们使用两种接种方法测试了选定的真菌内生菌分离株在洋葱植株上的定殖情况。还研究了接种内生菌对侵染洋葱的西花蓟马的影响。我们研究中使用的七种真菌内生菌能够通过种子接种或幼苗接种方法在洋葱植株上定殖。与幼苗接种相比，种子接种使所有测试内生菌接种后的平均回收率提高了1.47倍。与接种尖孢镰刀菌ICIPE 717和对照处理的植株相比，在接种粉红粘帚霉ICIPE 707、棘孢木霉M2RT4、绿色木霉ICIPE 710、哈茨木霉709、李氏肉座菌F3ST1和镰刀菌属ICIPE 712分离株的植株上观察到较少的蓟马。与其他处理相比，被粉红粘帚霉ICIPE 707、棘孢木霉M2RT4、绿色木霉ICIPE 710和李氏肉座菌F3ST1定殖的洋葱植株上的取食穿刺显著减少。在所测试的分离株中，西花蓟马在李氏肉座菌F3ST1和粉红粘帚霉ICIPE 707接种的植株上产卵数量最少。这些结果扩展了关于真菌内生菌在洋葱上定殖及其对西花蓟马影响的知识。
