Identification of Key Root Volatiles Signaling Preference of Tomato over Spinach by the Root Knot Nematode Meloidogyne incognita
Identification of Key Root Volatiles Signaling Preference of Tomato over Spinach by the Root Knot Nematode Meloidogyne incognita
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DOI：
10.1021/acs.jafc.8b03257
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发表时间：
2018-07-18
影响因子：
6.1
通讯作者：
Torto, Baldwyn
中科院分区：
文献类型：
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作者：
Murungi, Lucy Kananu;Kirwa, Hillary;Torto, Baldwyn
南方根结线虫（Meloidogyne incognita（Kofoid and白色）Chitwood）是撒哈拉以南非洲地区番茄（Solanum lycopersicum）和菠菜（Spinacea oleracea）的重要害虫。在东非，这两种作物在经济上很重要，小农户通常间作。寄主植物挥发性物质在M.目前尚不清楚这两种商品之间的相互作用。在这里，我们调查的嗅觉基础吸引番茄和菠菜根的感染性第二阶段的青少年（J2 s）。无名氏在嗅觉仪测定，J2被吸引到根挥发物从两种作物在潮湿的沙子（对照），但在选择测试中使用的两种寄主植物，番茄根的挥发物更有吸引力比菠菜释放。采用固相微萃取（SPME）纤维对根挥发物进行采样，并通过气相色谱/质谱（GC/MS）分析，共鉴定出8种组分，其中5种组分的含量最高。（2-异丙基-3-甲氧基吡嗪，2-（甲氧基）-3-（1-甲基丙基）吡嗪，十三烷，α-和β-雪松烯）发生在两种植物的根排放的挥发物，与三个（δ-3-<$烯、香桧烯和水杨酸甲酯）是番茄根挥发物特有的。在一系列的生物测定中，水杨酸甲酯对番茄的吸引力有很大的贡献，而2-异丙基-3-甲氧基吡嗪和十三烷对菠菜的吸引力有贡献。M.与单独的菠菜挥发物相比，当水杨酸甲酯与番茄挥发物结合时，无名氏J2也更容易被天然菠菜根挥发物吸引，这表明番茄挥发物中水杨酸甲酯的存在强烈有助于其对菠菜的偏好。我们的研究结果表明，由于番茄和菠菜的根对M。通过对根结线虫的研究，确定这两种植物物种的化学吸引力较低的品种可能有助于管理根结线虫。
The root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood, is a serious pest of tomato (Solanum lycopersicum) and spinach (Spinacea oleracea) in sub-Saharan Africa. In East Africa these two crops are economically important and are commonly intercropped by smallholder farmers. The role of host plant volatiles in M. incognita interactions with these two commodities is currently unknown. Here, we investigate the olfactory basis of attraction of tomato and spinach roots by the infective second stage juveniles (J2s) of M. incognita. In olfactometer assays, J2s were attracted to root volatiles from both crops over moist sand (control), but in choice tests using the two host plants, volatiles of tomato roots were more attractive than those released by spinach. Root volatiles sampled by solid phase microextraction (SPME) fiber and analyzed by gas chromatography/mass spectrometry (GC/MS) identified a total of eight components, of which five (2-isopropyl-3-methoxypyrazine, 2-(methoxy)-3-(1-methylpropyl)pyrazine, tridecane, and alpha- and beta-cedrene) occurred in the root-emitted volatiles of both plants, with three (delta-3-carene, sabinene, and methyl salicylate) being specific to tomato root volatiles. In a series of bioassays, methyl salicylate contributed strongly to the attractiveness of tomato, whereas 2-isopropyl-3-methoxypyrazine and tridecane contributed to the attractiveness of spinach. M. incognita J2s were also more attracted to natural spinach root volatiles when methyl salicylate was combined than to spinach volatiles alone, indicating that the presence of methyl salicylate in tomato volatiles strongly contributes to its preference over spinach. Our results indicate that since both tomato and spinach roots are attractive to M. incognita, identifying cultivars of these two plant species that are chemically less attractive can be helpful in the management of root knot nematodes.