Interactive effects of arbuscular mycorrhiza, wheat cultivar, and water regime on cereal aphid performance

Background and Aims Arbuscular mycorrhizal fungi (AMF) play important roles in improving plant water relations, nutrient acquisition, and tolerance to abiotic stress. However, the effects of AMF-mediated changes in wheat physiology under drought on aboveground herbivores remain poorly understood. This study investigated how Claroideoglomus etunicatum , wheat genotype, and water availability influence the performance of the cereal aphid Sitobion avenae . Methods A factorial experiment comprising two wheat varieties (drought-non-susceptible Yunhan-618 and drought-susceptible Xinong-1376), two AMF treatments (mycorrhizal and non-mycorrhizal), and two water regimes (well-watered and water-deficit stress) was conducted. Root colonization, aphid developmental time, lifespan, fecundity, adult weight, water content, honeydew production, and host preference were evaluated. Results Claroideoglomus etunicatum colonization was significantly higher in Yunhan-618 than Xinong-1376 under water-deficit stress. Water deficit prolonged aphid development, particularly on mycorrhizal Yunhan-618 plants. Aphid lifespan was shorter on mycorrhizal plants, whereas fecundity, honeydew production, adult weight, and water content were generally higher on non-mycorrhizal plants, especially under well-watered conditions. Host preference also shifted over time in response to AMF colonization and water availability. Conclusion The findings demonstrate that interactions among AMF, wheat genotype, and water regime influence the performance and behavior of S. avenae . AMF-induced changes in host plants may indirectly affect herbivore fitness, providing insights into plant–microbe–insect interactions and supporting the development of sustainable pest management strategies for water-limited agroecosystems.