Pathogenicity of Fusarium spp. associated with root rot and wilt of soybean and evaluation of cultivar resistance

Citation

Wu, L., Strelkov, SE., Kim, YM., Wally, O., and Wang, SF. Pathogenicity of Fusarium spp. associated with root rot and wilt of soybean and evaluation of cultivar resistance. Alberta Regional meeting of the Canadian Phytopathological society, Nov 3-4, 2022, Brooks, AB.

Plain language summary

Fusarium spp. can cause root and stem rot, wilt and sudden death of soybean (Glycine max L.). Surveys in Canada have often identified six species from diseased soybean root samples, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum and F. acuminatum. This study aimed to evaluate the pathogenicity of these species and assess host resistance in a selection of soybean cultivars. Pathogenicity was tested on two cultivars, moderately resistant and susceptible under greenhouse conditions. Twelve isolates (two per species) were inoculated separately into potting medium, and seedling emergence, plant height, root rot severity, and dry root and shoot weight were monitored. Symptoms caused by the different Fusarium spp. varied, and included rotting, girdling and the development of brown and sunken lesions. The virulence of the fungal isolates also varied, with root rot severities ranging from 1.5 to 3.3 on a 0-4 scale. The greatest reduction in emergence of either cultivar was caused by F. avenaceum. Plant height was reduced following inoculation with any of the species, with the exception of F. oxysporum and F. redolens on Susceptible variety. The most virulent isolates of each species were used to screen 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits as for the pathogenicity study. Two cultivars clustered in the resistant group for F. oxysporum, F. redolens, F. graminearum and F. solani, while another two cultivars were most resistant to F. avenaceum or F. acuminatum.

Abstract

Fusarium spp. can cause root and stem rot, wilt and sudden death of soybean (Glycine max L.). Surveys in Canada have often identified six species from diseased soybean root samples, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum and F. acuminatum. This study aimed to evaluate the pathogenicity of these species and assess host resistance in a selection of soybean cultivars. Pathogenicity was tested on two cultivars, ‘Akras’ (moderately resistant) and ‘BISOYI’ (susceptible) under greenhouse conditions. Twelve isolates (two per species) were inoculated separately into potting medium, and seedling emergence, plant height, root rot severity, and dry root and shoot weight were monitored. Symptoms caused by the different Fusarium spp. varied, and included rotting, girdling and the development of brown and sunken lesions. The virulence of the fungal isolates also varied, with root rot severities ranging from 1.5 to 3.3 on a 0-4 scale. The greatest reduction in emergence of either cultivar was caused by F. avenaceum. Plant height was reduced following inoculation with any of the species, with the exception of F. oxysporum and F. redolens on ‘BISOYI’. The most virulent isolates of each species were used to screen 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits as for the pathogenicity study. Two cultivars clustered in the resistant group for F. oxysporum, F. redolens, F. graminearum and F. solani, while another two cultivars were most resistant to F. avenaceum or F. acuminatum.

Publication date

2022-11-03

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