|Manandhar, Gyanu - NEPAL AGRICULTURAL RES. C|
|Manandhar, H - NEPAL AGRICULTURAL RES. C|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 21, 2007
Publication Date: July 21, 2007
Citation: Manandhar, G., Desjardins, A.E., Manandhar, H.K., Busman, M. 2007. Fusarium graminearum: an important pathogen of maize in Nepal, pathogenic variability and mycotoxins (abstract). 25th National Summer Crops Research Workshop, Nepal Agriculture Research Institute. Technical Abstract: Fusarium graminearum is an important pathogen of maize in hills of Nepal. It predominantly occurs on maize grown in cool and humid environment of high hills. The pathogen is also known to infect other cereal crops including wheat and rice causing important diseases. The incidence of ear rot is highest in high hills and can cause considerable loss in crop yield. Significant virulent groups were observed among F. graminearum isolates from maize, rice and wheat during pathogenicity test on Arun-4 variety of maize at Khumaltar in 2001 and 2003. Incidence of ear rot by isolates from maize strains was 38% at severity level of 1.9 in 2001 and also observed increased by many isolates in 2003. Similarly, the incidences of ear rot by isolates from wheat and rice were 26 and 30 percent, respectively at the severity levels of 1.7 and 1.8 in 2001. The disease intensity was observed increased by many isolates in 2003. This test confirmed that F. graminearum isolates from three crops are pathogenic and can cause diseases on other crop. Isolates from maize, wheat and rice were tested for trichothecene mycotoxin production in culture and in plants. The strains were shown by liquid chromatography-mass spectroscopy to produce the trichothecenes deoxynivalenol and nivalenol in culture and in grains from inoculated ears. The virulence of the strains was not related to the trichothecene-production profile of F. graminearum in the study. Both deoxynivalenol-producing strains and nivalenol-producing strains can cause ear rot disease on maize.