Effect of Fusarium tricinctum on Growth of Soybean and a Molecular-based Method of Identification

Abstract

Infection of soybean seedlings by Fusarium tricinctum and effects of isolates on growth and yield were evaluated in laboratory and field experiments in Fargo, North Dakota. Twenty one isolates from soybean roots collected in the field-infected cortical root tissue of soybean seedlings within 40 h at 23°C. In two field experiments conducted in 2012 and 2013, selected isolates significantly reduced emergence by 38 to 59% at three weeks after planting compared with noninoculated control. In 2013, isolates 91-1-8 and 91-319-3 significantly reduced plant height, number of plants with trifoliate leaves, and root biomass, but the reduction was significantly greater with isolate 91-1-8. Percent yield reduction with isolate 91-1-8 was significantly higher (90%) than with isolate 91-319-3 (31%) compared with noninoculated control. Primers specific for F. tricinctum were developed, and the presence of the pathogen in roots was verified in PCR. The problems associated with identification of F. tricinctum are discussed and a method for verifying identification of this species is suggested to aid identification of this pathogen from field samples. Results indicate F. tricinctum may have an important role in soybean root health in the northern soybean production area. 4 August 2014. 15 August 2014.