Quantifying airborne dispersal routes of pathogens over continents to safeguard global wheat supply
Quantifying airborne dispersal routes of pathogens over continents to safeguard global wheat supply
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DOI：
10.1038/s41477-017-0017-5
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发表时间：
2017-10-01
期刊：
影响因子：
18
通讯作者：
Gilligan, C. A.
中科院分区：
文献类型：
--
作者：
Meyer, M.;Cox, J. A.;Gilligan, C. A.
传染性作物疾病在广大农业地区蔓延，对粮食安全构成威胁。专性病原真菌小麦柄锈菌（Puccinia graminis f.）的攻击性菌株。在东非和中东发现了引起作物病害小麦秆锈病的小麦秆锈菌（Pgt），在那里它们导致了巨大的经济损失并威胁到农民的生计。全球大多数商业种植的小麦品种对这些新出现的菌株敏感，这对全球小麦生产构成风险，因为传播疾病的真菌孢子可以通过风传播到各个地区甚至大陆1 -11。有针对性的监测和控制需要了解病原体的空气传播，但远距离传播的复杂性对定量研究提出了重大挑战12 -14。我们结合联合收割机国际实地调查，全球气象数据，拉格朗日扩散模型和高性能计算资源来模拟一组疾病爆发情景，追踪十多年来动态变化的宿主和环境景观中数十亿真菌孢子的随机轨迹。这是对南部/东部非洲、中东和中亚/南亚所有小麦生产国孢子传播频率和数量的首次定量评估。我们确定了与先前假设的小麦锈病流行区（以地方病和接种物自由移动为特征）10，15在地理上相对应的高空气传播连通性区域，以及相关病原体种群遗传相似性区域16，17。我们量化的情况下（路线，时间，爆发规模），致命的病原体菌株，如'Ug 99' 5，6构成威胁，从东非的长途传播到巴基斯坦和印度的大小麦产区。总结了该领域所有国家的长期平均孢子传播趋势（主要方向、频率、数量）（补充数据）。我们的机制建模框架可以应用于其他地理区域，适用于其他病原体，并用于实时提供风险评估。
Infectious crop diseases spreading over large agricultural areas pose a threat to food security. Aggressive strains of the obligate pathogenic fungus Puccinia graminis f. sp. tritici (Pgt), causing the crop disease wheat stem rust, have been detected in East Africa and the Middle East, where they lead to substantial economic losses and threaten livelihoods of farmers. The majority of commercially grown wheat cultivars worldwide are susceptible to these emerging strains, which pose a risk to global wheat production, because the fungal spores transmitting the disease can be wind-dispersed over regions and even continents1-11. Targeted surveillance and control requires knowledge about airborne dispersal of pathogens, but the complex nature of long-distance dispersal poses significant challenges for quantitative research12-14. We combine international field surveys, global meteorological data, a Lagrangian dispersion model and high-performance computational resources to simulate a set of disease outbreak scenarios, tracing billions of stochastic trajectories of fungal spores over dynamically changing host and environmental landscapes for more than a decade. This provides the first quantitative assessment of spore transmission frequencies and amounts amongst all wheat producing countries in Southern/East Africa, the Middle East and Central/South Asia. We identify zones of high air-borne connectivity that geographically correspond with previously postulated wheat rust epidemiological zones (characterized by endemic disease and free movement of inoculum) 10,15, and regions with genetic similarities in related pathogen populations16,17. We quantify the circumstances (routes, timing, outbreak sizes) under which virulent pathogen strains such as 'Ug99' 5,6 pose a threat from long-distance dispersal out of East Africa to the large wheat producing areas in Pakistan and India. Long-term mean spore dispersal trends (predominant direction, frequencies, amounts) are summarized for all countries in the domain (Supplementary Data). Our mechanistic modelling framework can be applied to other geographic areas, adapted for other pathogens and used to provide risk assessments in real-time.