Submitted to: Acta Horticulturae
Publication Type: Abstract Only
Publication Acceptance Date: July 9, 2000
Publication Date: N/A
Technical Abstract: Colletotrichum species cause serious diseases of fruits and vegetables worldwide. Three species, C. acutatum, C. fragariae, and C. gloeosporioides, are major pathogens of strawberry. Thirty-eight Colletotrichum isolates representing 9 species collected from 12 hosts were inoculated onto strawberry, blueberry, blackberry, muscadine grape, tomato and pepper. Leaf and stem or petiole tissues of each host were wound inoculated and plants were incubated at 100% RH and 25C for 48 hr. Symptoms were rated after 20 days. The 4 C. fragariae isolates were most aggressive causing lesion development at 43% of inoculation sites. Each host developed more lesions on stems than on leaves. Strawberry was the most susceptible host with 63% of petiole and 15% of leaf inoculations resulting in lesion development. Pepper was the most resistant host with no symptom development on leaves or stems following inoculation with any isolate. Lesion development with all 38 isolates on stem tissues for the other hosts was: blueberry 35%, muscadine grape 26%, blackberry 19% and tomato 13%. Isolates obtained from fruit generally did not cause leaf or stem symptoms. The most aggressive C. acutatum isolate came from tomato and caused more severe petiole lesions on strawberry than the 3 C. acutatum isolates obtained from strawberry. These results suggest that primary anthracnose infections in strawberry fields might sometimes originate from other diseased fruit or vegetable hosts.