Correlation between black point symptoms and fungal infestation and seedling viability of wheat kernels

The level of occurrence of black point, the spectrum of fungal species and damage to wheat seedling vigour associated with it were assessed during 2003 and 2004 in the Slovak Republic. The incidence of black point kernels ranged between 0.2-2.4% in 2003 and 24.2-34.3% in 2004. The kernels' fungal contamination varied from 60% to 100%. Alternaria spp., F. poae and F. culmorum were isolated from all localities and all subsamples. Stemphylium vesicarium, Fusarium culmorum, F. graminearum, F. avenaceum, F. sporotrichioides, Microdochium nivale, Epicoccum nigrum, Penicillium spp., Aspergillus niger, Rhizopus nigricans and Cochliobolus sativus were isolated less frequently. Fungi of the genus Alternaria were the most dominant, followed by Fusarium and Microdochium among which F. poae was dominant. Irrespective of incubation temperature, the germinative capacity and coleoptile growth rate of discolored kernels were affected more in the wet and cold year 2004. The inhibition of germination and seedling viability was more pronounced at the incubation temperature 22°C than at 15°C. Inhibition of coleoptile growth rate was 0.12-3.12% in black point kernels collected in 2003, and 0.24-9.28% in those collected in 2004.