Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
Plant Dis. 2023 Jun;107(6):1785-1793. doi: 10.1094/PDIS-07-22-1551-RE. Epub 2023 May 24.
Phytophthora root and stem rot (PRR), caused by , is one of the most devastating oomycete diseases of soybean in Illinois. Single resistant genes () are used to manage this pathogen but has adapted to , causing failure of resistance in many regions. In addition to , recent reports indicate that could also cause root rot in soybean. Soil samples and symptomatic plants were collected across 40 Illinois counties between 2016 and 2018. (77%) was more abundant than (23%) across Illinois fields. Both species were characterized by virulence, aggressiveness, and fungicide sensitivity. Virulence of all isolates was evaluated using the hypocotyl inoculation technique in 13 soybean differentials. Aggressiveness was evaluated in the greenhouse by inoculating a susceptible cultivar and measuring root and shoot dry weight. On average, isolates were able to cause disease on six soybean differentials. was more aggressive than . All isolates were sensitive to azoxystrobin, ethaboxam, mefenoxam, and metalaxyl. The characterization of the population of species associated with PRR will inform management decisions for this disease in Illinois.
大豆疫霉根腐和茎腐病（PRR）由引起，是伊利诺伊州大豆最具破坏性的卵菌病害之一。单一抗性基因（）被用于防治该病原体，但已适应，导致许多地区的抗性失效。除了，最近的报告表明也可能导致大豆根腐病。2016 年至 2018 年期间，在伊利诺伊州的 40 个县收集了土壤样本和有症状的植物。在伊利诺伊州的田间，（77%）比（23%）更为丰富。这两个物种都具有毒性、侵袭性和杀菌剂敏感性。使用 13 种不同的大豆品种的下胚轴接种技术评估了所有分离物的毒性。通过接种易感品种并测量根和茎的干重来评估温室中的侵袭性。平均而言，分离物能够在六种大豆品种上引起疾病。比更具侵袭性。所有分离物对唑菌酯、乙氧呋草黄、甲霜灵和精甲霜灵敏感。与 PRR 相关的种群体的特征将为伊利诺伊州该病害的管理决策提供信息。
