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Perennation of Alternaria longipes and the early stages of its development on tobacco
Author(s) -
NORSE D.,
WHEELER B. E. J.
Publication year - 1971
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1971.tb02905.x
Subject(s) - biology , alternaria , conidium , inoculation , seedling , pathogenicity , potato dextrose agar , horticulture , agar , botany , microbiology and biotechnology , bacteria , genetics
SUMMARY Alternaria longipes (Ell. &Ev.) Mason survived on autoclaved maize stems for 6 months without losing its pathogenicity, but rapidly lost viability on non‐autoclaved stems and could not be re‐isolated 4 months after inoculation. In laboratory tests it infected both living and dead maize leaves. Some Alternaria isolates from non‐solanaceous hosts infected tobacco leaves kept at high humidities for 10 days after inoculation, but not when this incubation period was reduced to 48 h. In the field, perennation on plants other than tobacco is unlikely to be important as a source of inoculum. Pathogenicity of Alternaria isolates was maintained from one season to the next when stored as conidia in sterile soil, or as dried, infected tobacco leaves; some isolates maintained on agar slopes under oil were still pathogenic after 5 years. Alternaria conidia collected from the surface of tobacco seedlings, and isolates from apparently healthy seedling leaves were pathogenic to mature tobacco. In the field conidia were detected on tobacco leaves soon after these emerged, and epiphytic colonies were occasionally found well in advance of symptoms. Many latent infections were also detected up to 5 weeks in advance of symptoms. Visual development of latent infections closely coincided with the end of leaf expansion.