镰刀菌的无症状寄主范围包括玉米,我们假设与大豆轮作的常见作物可能会改变F.virguliforme种群动态和疾病管理。基于田间的方法探索了不同耕作和残留管理下玉米和大豆根上的F.virguliforme定植的时间动态。实验是在爱荷华州进行的,印第安纳州,密歇根州,威斯康星州,美国和安大略省,加拿大从2016年到2018年。在种植后1至16周的连续时间点对玉米和大豆根进行取样。从所有根中提取DNA,并通过实时定量PCR分析F.virguliforme定量。试验在玉米和大豆之间轮换,在几个实验设计中包含2乘2的耕作因子(无耕作或耕作)和玉米残留物(有或没有)。2016年,在接种的爱荷华州中检测到少量(每10mg根组织约100fg)。印第安纳州,和密歇根州的位置和未经接种的威斯康星州玉米田。然而,2017年,在爱荷华州检测到更高水平的F.virguliformeDNA,印第安纳州,和密歇根州不同的采样时间点。在试验和地点之间,耕作实践对F.virguliforme根定植和猝死综合征(SDS)叶面症状的影响不一致。然而,残留管理不会改变F.virguliforme对玉米或大豆的根定植。2016年,含玉米残渣的地块在爱荷华州的SDS叶面疾病指数更高。然而,这一趋势在整个站点年份都没有观察到,表明玉米残留物可能偶尔增加SDS叶面症状,具体取决于疾病水平以及土壤和天气因素。
The asymptomatic host range of Fusarium virguliforme includes corn, a common crop rotated with soybean that we hypothesize may alter F. virguliforme population dynamics and disease management. A field-based approach explored the temporal dynamics of F. virguliforme colonization of corn and soybean roots under different tillage and residue managements. Experiments were conducted in Iowa, Indiana, Michigan, and Wisconsin, United States and Ontario, Canada from 2016 to 2018. Corn and soybean roots were sampled at consecutive timepoints between 1 and 16 weeks after planting. DNA was extracted from all roots and analyzed by real-time quantitative PCR for F. virguliforme quantification. Trials were rotated between corn and soybean, containing a two-by-two factorial of tillage (no-tilled or tilled) and corn residue (with or without) in several experimental designs. In 2016, low amounts (approximately 100 fg per 10 mg of root tissue) of F. virguliforme were detected in the inoculated Iowa, Indiana, and Michigan locations and noninoculated Wisconsin corn fields. However, in 2017, greater levels of F. virguliforme DNA were detected in Iowa, Indiana, and Michigan across sampling timepoints. Tillage practices showed inconsistent effects on F. virguliforme root colonization and sudden death syndrome (SDS) foliar symptoms among trials and locations. However, residue management did not alter root colonization of corn or soybean by F. virguliforme. Plots with corn residue had greater SDS foliar disease index in Iowa in 2016. However, this trend was not observed across the site-years, indicating that corn residue may occasionally increase SDS foliar symptoms depending on the disease level and soil and weather factors.