Relationship of pathogenicity to tobacco leaves and toxicity to chickes of isolates of Alternaria longipes.

One hundred thirty-seven single-conidium isolates of Alternaria longipes were tested for pathogenicity to tobacco leaves and for toxicity to 1-day-old chicks. Of 58 isolates pathogenic to tobacco, 43 (74.3%) had a significant effect on test chicks. Of 79 nonpathogenic isolates, 59 (74.7%) were nontoxic, 7 were toxic, and 13 were lethal. A relationship between pathogenicity and toxicity is suggested.