Endophytic colonisation of tomato by the entomopathogenic fungus Beauveria bassiana: the use of different inoculation techniques and their effects on the tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae)
Endophytic colonisation of tomato by the entomopathogenic fungus Beauveria bassiana: the use of different inoculation techniques and their effects on the tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae)
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DOI：
10.1515/jppr-2017-0045
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发表时间：
2017-01-01
影响因子：
1.1
通讯作者：
Clara Scorsetti, Ana
中科院分区：
文献类型：
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作者：
Allegrucci, Natalia;Silvana Velazquez, Maria;Clara Scorsetti, Ana
真菌昆虫病原体可以自然地调节各种昆虫的种群。球孢白僵菌（Bals.-Criv.）Vuill。也能内生地在不同的植物上定植。昆虫病原的内生定植可能是真菌与昆虫间间接相互作用的一个来源，并且与真菌控制害虫的能力有关。番茄叶螨（Tuta absoluta, Meyrick）被认为是番茄（Solanum lycopersicum L.）最具破坏性的害虫之一，其难以控制是由于其采虫习性，生命周期短，繁殖能力高。本研究的目的是：(1)采用叶片喷施、种子浸种和根浸种三种不同的技术接种番茄球孢白僵菌；(2)评价球孢白僵菌接种后对番茄叶片消耗和绝对白僵菌死亡率的影响。接种后7、14、28 d分别测定球孢白僵菌的定殖率。采用的所有接种技术都可以恢复球孢白僵菌，尽管我们的结果显示技术之间存在显着差异。以叶片喷施效果最好，接种后第7天的定殖率最高。我们还评估了(i)直接接触球孢白僵菌孢子对绝对白僵菌死亡率的影响，以及（ii）间接接触接种了球孢白僵菌的植株组织对番茄叶片消耗和死亡率的影响。死亡率生物测定表明，球孢白僵菌通过直接接触或间接食入接种过的番茄叶片感染绝对白僵菌。与间接接触相比，直接接触的死亡率更高，中位生存时间（MST）更低。不同处理与对照组接触球孢白僵菌后绝对白僵菌死亡率差异有统计学意义。结果表明，番茄内生球孢白僵菌的接种为进一步研究内生球孢白僵菌对绝对白僵菌的毒力提供了基础。
Fungal entomopathogens can naturally regulate populations of various insects. The entomopathogen Beauveria bassiana (Bals.-Criv.) Vuill. is also able to endophytically colonize different plants. Endophytic colonization by entomopathogens may provide a source of indirect interactions between fungi and insects and has been associated with the ability of the fungus to control insect pests. The tomato leaf miner, Tuta absoluta (Meyrick) is considered one of the most devastating pests of tomato (Solanum lycopersicum L.) and its difficult control is due to its miner habit, short life cycle, and high reproductive capacity. The aims of this study were: (i) to use three different techniques, i.e. leaf spraying, seed immersion and root dipping, for the endophytic inoculation of B. bassiana in tomato plants; and (ii) to assess the effect of B. bassiana on tomato leaf consumption and mortality of T. absoluta after inoculation. The percentage of colonization by B. bassiana was assessed 7, 14 and 28 days after inoculation. All inoculation techniques employed allowed the recovery of B. bassiana, although our results showed significant differences between techniques. Leaf spraying was the most effective, with the highest percentage of colonization recorded 7 days after inoculation. We also evaluated (i) the effect on the mortality of T. absoluta by direct contact with conidia of B. bassiana, and (ii) the effect on tomato leaf consumption and mortality by indirect contact through ingestion of inoculated plant tissues with B. bassiana. Mortality bioassays showed that B. bassiana infected T. absoluta, either by direct contact or indirectly, via ingestion of inoculated tomato leaves. Direct contact showed a higher percentage of mortality and a lower median survival time (MST) than indirect contact. Significant differences in the mortality percentages of T. absoluta after exposure with B. bassiana were found among the treatments and the control. Our results suggest that the endophytic inoculation of B. bassiana in tomato crops provides the basis for further investigation, which should focus on the virulence of the endophytic B. bassiana against T. absoluta.