Fusarium Species Associated with Root Rot of Lentil (Lens culinaris) in North Dakota

Root rot of lentils is caused by a pathogen complex that includes several Fusarium species as well as Aphanomyces euteiches, Rhizoctonia solani, and Pythium species. Surveys of lentil fields were conducted in 2016 and 2018 in North Dakota to identify Fusarium species associated with root rot. Isolations were performed from lentil roots exhibiting disease, andisolates were identified via morphology and sequencing. In total, 114 fields were surveyed, and 391 Fusarium isolates were collected. A diversity of Fusarium species was recovered, as 10 different species were represented; however, F. oxysporum was the most frequently isolated species, present in 71% of fields. Based on correlation with disease severity data, it is likely that some of these isolates are pathogenic. F. avenaceum was relatively uncommon, unlike previous survey efforts on field pea in North Dakota. Further research is needed to determine how the Fusarium population responsible for root rot of lentil may be affected by cropping practices or seasonal climatic variation. Assessment of the virulence and host range of Fusarium species associated with root rot of lentil will further enhance our understanding of the root rot complex in lentil and the development and integration of effective management practices.