Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2002
Publication Date: 1/1/2003
Citation: Jones, K.A., Rayamajhi, M.B., Pratt, P.D., Van, T.K. 2003. First report of the pathogenicity of colletotrichum gloeosporioides on invasive ferns, lygodium microphyllum and l. japonicum in florida.. Plant Disease.
Interpretive Summary: Both Old-World and Japanese climbing ferns are among the most invasive weeds in Florida. Old-World climbing fern has invaded freshwater habitats in south Florida, while Japanese climbing fern has spread in relatively well-drained habitats from Texas to North Carolina and central Florida. Some plants of both climbing ferns grown in shadehouse and full sunlight developed disease on foliage which caused browning and dieback of severely infected vines. We isolated a foliar fungus from diseased tissue. This fungus caused disease on both fern when sprayed on foliage, and could be developed as a biocontrol agent against the climbing ferns.
Technical Abstract: Lygodium microphyllum (Old World climbing fern) and L. japonicum (Japanese climbing fern) are among the most invasive weeds in Florida. L. microphyllum invades fresh water and moist habitats in south Florida, while L. japonicum has spread in relatively well-drained habitats from Texas to North Carolina and central Florida. Plants of both Lygodium spp. grown in both shadehouse and full sunlight developed spots on pinnules (foliage) resulting in browning and dieback of the severely infected vines. A fungus, Colletotrichum gloeosporioides was consistently isolated from the diseased foliage. This fungus produced abundant conidia on PDA. These conidia were suspended in water and sprayed on healthy plants of both ferns species. Small discolored foliar spots appeared 3 days after fungus inoculation. Within 3 weeks after inoculation, the foliage of L. japonicum developed abundant discolored spots that led to edge browning and wilting of the pinnules. L. microphyllum had similar, but more severe, symptoms, with plants suffering as much as 50% dieback. C. gloeosporioides was consistently reisolated from the symptomatic tissues of both fern species. To our knowledge, this is the first record of C. gloeosporioides pathogenicity on L. microphyllum and L. japonicum.