ROW: The Role of Vector Dispersal in Plant Disease Dynamics

尽管昆虫传播的植物病害在自然和农业系统中普遍存在，但人们对植物病原体、昆虫媒介和田间易感植物之间的相互作用知之甚少。本研究的长期目标是了解大麦黄矮病毒（BYDV）的发病动态如何依赖于BYDV分离物、蚜虫载体和寄主植物之间的生物相互作用。三十年来对纽约州伊萨卡市五种典型BYDV分离株相对丰度波动的数据表明，一种媒介特异性分离株（MAV）被一种由几种蚜虫媒介非特异性传播的分离株（PAV）所取代。该项目的目的是评估矢量扩散在驱动位移动力学中的潜在作用。该研究将包括现场和实验室实验，旨在解决以下问题：(1)主要BYDV分离株引起的疾病严重程度如何影响植物对蚜虫的吸引力？(2)不同BYDV分离株侵染植物对两种主要蚜虫载体Sitobion avenae和Rhopalosiphum padi的产酸量、繁殖力和存活率是否有差异？(3)不同菌株侵染植物是否影响田间蚜虫的扩散行为？(4)蚜虫定殖和扩散的差异是否对分离物的传播有显著影响？这项研究对病毒-载体-寄主植物关联的进化具有重要意义，并将为新病毒分离株传播的可能性和基因工程微生物的环境风险评估提供重要信息。

Despite the ubiquity of insect-borne plant diseases in both natural and agricultural systems, relatively little is known about the interactions among plant pathogens, insect vectors, and susceptible plants in the field. The long-term goal of the proposed research is to understand how disease dynamics of the barley yellow dwarf virus (BYDV) depend on the biological interactions between BYDV isolates, aphid vectors, and host plants. Thirty years of data on the fluctuation in relative abundance of the five characterized isolates of BYDV in Ithaca, NY have documented the displacement of a vector specific isolate (MAV) by an isolate transmitted nonspecifically by several aphid vectors (PAV). The objective of this project is to evaluate the potential role of vector dispersal in driving the dynamics of the displacement. The research will consist of field and laboratory experiments designed to address the following questions: (1) How does disease severity induced by the major BYDV isolates affect a plant's attractiveness to aphids? (2) Does plant infection by the various BYDV isolates differentially affect the alate production, fecundity, and survivorship of the two major aphid vectors Sitobion avenae and Rhopalosiphum padi? (3) Does plant infection by different isolates influence aphid dispersal behavior in the field? and (4) Do differences in aphid colonization and dispersal translate into significant effects on isolate spread? This research has implications for the evolution of virus-vector-host plant associations and will contribute vital information on the potential for spread of novel viral isolates and the evaluation of the environmental risks of genetically engineered microorganisms.