Chatterton Syama, Schwinghamer Timothy D, Pagé Antoine, Davidson Robyne Bowness, Harding Michael W, Banniza Sabine
Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
Aquatic and Crop Resource Development, National Research Council Canada, Montreal, QC, Canada.
Front Plant Sci. 2023 May 9;14:1115420. doi: 10.3389/fpls.2023.1115420. eCollection 2023.
The oomycete pathogen, , was implicated for the first time in pea and lentil root rot in Saskatchewan and Alberta in 2012 and 2013. Subsequent surveys from 2014 to 2017 revealed that root rot (ARR) was widespread across the Canadian prairies. The absence of effective chemical, biological, and cultural controls and lack of genetic resistance leave only one management option: avoidance. The objectives of this study were to relate oospore levels in autoclaved and non-autoclaved soils to ARR severity across soil types from the vast prairie landscape and to determine the relationship of measured DNA quantity of using droplet digital PCR or quantitative PCR to the initial oospore inoculum dose in soils. These objectives support a future end goal of creating a rapid assessment method capable of categorizing root rot risk in field soil samples to aid producers with pulse crop field selection decisions. The ARR severity to oospore dose relationship was statistically significantly affected by the soil type and location from which soils were collected and did not show a linear relationship. For most soil types, ARR did not develop at oospore levels below 100/g soil, but severity rose above this level, confirming a threshold level of 100 oospores/g soil for disease development. For most soil types, ARR severity was significantly higher in non-autoclaved compared to autoclaved treatments, demonstrating the role that other pathogens play in increasing disease severity. There was a significant linear relationship between DNA concentrations measured in soil and oospore inoculum concentration, although the strength of the relationship was better for some soil types, and in some soil types, DNA measurement results underestimated the number of oospores. This research is important for developing a root rot risk assessment system for the Canadian prairies based on soil inoculum quantification, following field validation of soil quantification and relationship to root rot disease severity.
卵菌病原体于2012年和2013年首次在萨斯喀彻温省和艾伯塔省的豌豆和扁豆根腐病中被发现。2014年至2017年的后续调查显示，根腐病（ARR）在加拿大大草原广泛存在。由于缺乏有效的化学、生物和栽培防治措施，且缺乏遗传抗性，只剩下一种管理选择：避免。本研究的目的是将高压灭菌和未高压灭菌土壤中的卵孢子水平与广大草原景观中不同土壤类型的ARR严重程度相关联，并使用液滴数字PCR或定量PCR确定所测的DNA量与土壤中初始卵孢子接种剂量之间的关系。这些目标支持了一个未来的最终目标，即创建一种快速评估方法，能够对田间土壤样本中的根腐病风险进行分类，以帮助生产者做出豆类作物田间选择决策。ARR严重程度与卵孢子剂量的关系在统计学上受到所采集土壤的类型和地点的显著影响，且未呈现线性关系。对于大多数土壤类型，当卵孢子水平低于100个/克土壤时，ARR不会发生，但严重程度在该水平以上会上升，证实了疾病发生的阈值水平为100个卵孢子/克土壤。对于大多数土壤类型，与高压灭菌处理相比，未高压灭菌处理中的ARR严重程度显著更高，这表明其他病原体在增加疾病严重程度方面所起的作用。土壤中测得的DNA浓度与卵孢子接种物浓度之间存在显著的线性关系，尽管某些土壤类型的关系强度更好，且在某些土壤类型中，DNA测量结果低估了卵孢子数量。在对土壤定量及其与根腐病严重程度的关系进行田间验证之后，本研究对于基于土壤接种物定量开发加拿大大草原根腐病风险评估系统具有重要意义。
