© 2006 Plant Management Network.
Lilium lancifolium is Discovered as a New Host of Botryosphaeria parva in Georgia
Jason E. Woodward, Department of Plant Pathology and Microbiology, Texas A&M University, Lubbock 79403; Sara K. Gremillion, Jason H. Brock, Robert C. Kemerait, David B. Langston, Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31794; and Jean L. Williams-Woodward, Department of Plant Pathology, University of Georgia, Athens 30602
Corresponding author: Sara K. Gremillion. firstname.lastname@example.org
Woodward, J. E., Gremillion, S. K., Brock, J. H., Kemerait, R. C., Langston, D. B., and Williams-Woodward, J. L. 2006. Lilium lancifolium is discovered as a new host of Botryosphaeria parva in Georgia. Online. Plant Health Progress doi:10.1094/PHP-2006-1127-02-BR.
In September 2005, diseased tiger lily (Lilium lancifolium Thunb.) plants were collected from a residential landscape in Tifton, GA. Initial symptoms were evident on all plants and consisted of elongated, water-soaked lesions on receptacles and stems. Within necrotic tissue, black, erumpent pycnidia were visible. Microscopic evaluations of diseased tissue revealed hyaline, aseptate, smooth-walled, fusoid conidia. No spermatia (microconidia) were found. The mean conidial dimensions (n = 50) were 18.0 × 5.8 µm; the extreme range was 17 to 23 × 5 to 7 µm. These characteristics are consistent with Fusicoccum parvum Pennycook & Samuels, anamorph of Botryosphaeria parva Pennycook & Samuels (1,2). The teleomoph stage was not observed on diseased tissue. Infected stems were surface disinfested in 0.5% sodium hypochlorite for 1 min and plated on potato dextrose agar (PDA). A total of ten fungal isolates were recovered and sub-cultured on PDA. Healthy tiger lily plants were inoculated using two B. parva isolates, designated Bp I and II. Preliminary experiments indicated that wounding was required for disease development and inoculations using agar plugs resulted in more uniform disease development than inoculations with spore suspensions. For subsequent inoculations, flowers were removed at the receptacle, and stems were inoculated with PDA plugs containing each isolate. Control plants were inoculated with sterile PDA plugs. Agar plugs were secured with parafilm strips, and plants were maintained at 28°C for a 12-h photoperiod for 7 days. The experiment was conducted twice. Symptoms identical to those observed in the landscape developed for all inoculations, while controls remained healthy. Lesions were measured, and data from the two trials were pooled (n = 8). Mean lesion lengths were 2.7 and 2.1 cm for the Bp I and II isolates, respectively. Koch’s postulates were fulfilled by re-isolating the fungus from symptomatic tissue. Fungal isolate DNA was extracted, and the ITS region including ITS1, 5.8S rRNA, and ITS2 was amplified using established primers (3). Portions of the ITS sequences from Bp I and Bp II have been deposited in the NCBI database (Acc. No. DQ499154 and DQ499155, respectively). A BLAST search of the aforementioned ITS sequence revealed complete homology with B. parva. Botryosphaeria spp. are important fungal pathogens of many plants throughout the world. While Botryosphaeria spp. are associated with diseases of woody plants, reports of their occurrence on monocots are rare. The Koch’s postulate and molecular study conducted confirm that B. parva is capable of causing disease on tiger lily.
1. Pennycook, S. R., and Samuels, G. J. 1985. Botryosphaeria and Fusicoccum species associated with ripe fruit rot of Actinidia deliciosa (Kiwifruit) in New Zealand. Mycotaxon. 24:445-458.
2. Slippers, B., Johnson, G. I., Crous, P. W., Coutinho, T. A., Wingfield, B. D., and Wingfield, M. J. 2005. Phylogenetic and morphological re-evaluation of the Botryosphaeria species causing diseases of Mangifera indica. Mycologia. 97:99-110.
3. White, T. J., Bruns, T., Lee, S., and Taylor, J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. Pages 315-322 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis, D. H. Gelfand, J. J. Sninsky, and T. J. White, ed. Academic Press Inc., New York, NY.