Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Alternaria alternata, real cause of black point and differentiating symptoms of two other pathogens associated with wheat (Triticum aestivum) seeds.

Abstract

Grains of wheat demonstrating 3 categories of symptoms of disease were examined to establish the causal fungal pathogen. Grains with dark brown to black discoloration, generally restricted to the area around the embryo (typical black-point symptoms), showed 100% infection by A. alternata. Grains with light brown to dark brown discrete lesions and a dull white spherical or elliptical area in the centre (typical 'eye-spot' symptoms) demonstrated infection by Drechslera sorokiniana [Cochliobolus sativus] alone. Grains with a creamy white or pinkish colour, mostly shrivelled and lighter in weight were infected by Fusarium graminearum [Gibberella zeae].