Beneficial root microbes may mitigate negative effects of crop pests by enhancing plant tolerance or resistance. We used a greenhouse experiment to investigate impacts of commercially available microbial root inoculants on growth and biomass allocation of wheat (Triticum aestivum L. [Cyperales: Poaceae]) and on survival and growth of the gall-inducing wheat pest Hessian fly, Mayetiola destructor (Say). A factorial design was used, with two near-isogenic wheat lines (one susceptible to Hessian fly, the other resistant), two levels of insect infestation (present, absent), and four inoculants containing: 1) Azospirillum brasilense Tarrand et al. (Rhodospirillales: Azospirillaceae), a plant growth-promoting bacterium, 2) Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) (Glomerales: Glomeraceae), an arbuscular mycorrhizal fungus, 3) A. brasilense + R. intraradices, and 4) control, no inoculant. Larval feeding stunted susceptible wheat shoots and roots. Plants had heavier roots and allocated a greater proportion of biomass to roots when plants received the inoculant with R. intraradices, regardless of wheat genotype or insect infestation. Plants receiving the inoculant containing A. brasilense (alone or with R. intraradices) had comparable numbers of tillers between infested and noninsect-infested plants and, if plants were susceptible, a greater proportion of aboveground biomass was allocated to tillers. However, inoculants did not impact density or performance of Hessian fly immatures or metrics associated with adult fitness. Larvae survived and grew normally on susceptible plants and mortality was 100% on resistant plants irrespective of inoculants. This initial study suggests that by influencing plant biomass allocation, microbial inoculants may offset negative impacts of Hessian flies, with inoculant identity impacting whether tolerance is related to root or tiller growth.

中文翻译：

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微生物接种剂对诱导瘿麻蝇（双翅目：Cecidomyiidae）攻击的小麦的植物生长和生物量分配有不同的影响

有益的根系微生物可以通过增强植物耐受性或抗性来减轻作物害虫的负面影响。我们使用温室实验来研究市售微生物根接种剂对小麦（Triticum aestivum L. [Cyperales: Poaceae]）的生长和生物量分配的影响，以及对诱导瘿的小麦害虫 Hessian 蝇、Mayetiola destructor 的存活和生长的影响（说）。使用了因子设计，具有两个近等基因的小麦品系（一个易受黑森蝇的影响，另一个抗性）、两个级别的昆虫侵扰（存在、不存在）和四种接种剂，其中包含：1) Azospirillum brasilense Tarrand 等。(Rhodospirillales: Azospirillaceae)，一种植物生长促进细菌，2) Rhizophagus intraradices (NC Schenck & GS Sm.) (Glomerales: Glomeraceae)，一种丛枝菌根真菌，3) A. brasilense + R. intraradices，和 4) 对照，无接种剂。幼虫喂养发育不良的小麦芽和根。无论小麦基因型或昆虫侵染情况如何，当植物接受含有 R.intraradices 的接种剂时，植物具有更重的根并为根分配更大比例的生物量。接受含有 A. brasilense（单独或与 R.intraradices）接种剂的植物在受侵染和未受害虫侵染的植物之间具有相当数量的分蘖，如果植物易感，则将更大比例的地上生物量分配给分蘖。然而，接种剂不会影响 Hessian 苍蝇幼虫的密度或性能或与成年健康相关的指标。幼虫在易感植物上存活并正常生长，无论接种剂如何，在抗性植物上的死亡率均为 100%。