Abstract

The soil nematode Nacobbus aberrans (Thorne & Allen) is one of the recurrent biotic adversities in crops growing under cover, and its presence in the horticultural area of Río Cuarto, Argentina, is reported from the 1980s to the present day. The use of botanical extracts in combination with biological control agents could be a promising method for the control of this nematode. Nematicidal effects of Pimpinella anisum (anise) and Origanum vulgare (oregano) essential oils (EOs) against second-stage juveniles (J2) of N. aberrans were evaluated in vitro. Fisher LSD tests evidenced significant nematicidal (α = 0.05) effects of the two EOs tested, with LD₁₀₀ of 200 and 600 µL L⁻¹ for anise and oregano, respectively. Compatibility assays between EOs and five nematophagous fungi were microscopically and macroscopically performed on soil extract solid medium (SESM) conditioned at different water activities (0.99 and 0.98 a_w) and incubated at 30, 25 and 20 °C. Purpureocillium lilacinum SR14 was the fungal strain that showed compatibility at levels of spore germination, viability of propagules and growth rate under the different anise oil doses, temperatures and a_w assayed. In conclusion, the integrated application of anise EO with the nematophagous fungus, which combines two action mechanisms, could generate, on the one hand, a rapid larval mortality effect caused by the EO and, on the other hand, a parasitic effect that has the advantage of remaining in time under variable environmental conditions.

Graphic abstract

中文翻译：

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茴香皮平杆菌和牛至精油与线虫性真菌的体外相容性及其对纳豆花粉的影响

摘要

土壤线虫Nacobbus aberrans（Thorne＆Allen）是被遮盖生长的农作物中反复出现的生物逆境之一，据报道，从1980年代至今，它一直存在于阿根廷里奥夸尔托的园艺区。将植物提取物与生物防治剂结合使用可能是控制该线虫的一种有前途的方法。体外评估了茴香皮平菇和茴香牛至精油（EOs）杀线虫对第二代幼虫（J2）的杀线虫作用。Fisher LSD测试表明 ，使用LD ₁₀₀进行测试的两个EO具有明显的杀线虫效果（α = 0.05）茴香和牛至分别为200和600 µL L ^-1。在不同水分活度（0.99和0.98 a _w）条件下，分别在30、25和20°C下孵育的土壤提取物固体培养基（SESM）进行了微观和宏观的EO和五种线虫真菌之间的相容性测定。Purpureocillium lilacinum SR14是真菌菌株，不同的茴香油剂量，温度和下显示出在孢子萌发，繁殖体活力和生长速率的水平兼容性一_瓦特分析。总之，茴香油与线虫真菌的综合应用结合了两种作用机理，一方面可以产生由油酸引起的迅速的幼虫死亡率效应，另一方面，具有油酸的寄生效应。在变化的环境条件下保持时间的优势。

图形摘要