© 1995 Heron Publishing—Victoria, Canada
Characterization of the induced response of slash pine to inoculation with bark beetle vectored fungi
Michael P. Popp (1, 2), Jon D. Johnson (1) and Mark S. Lesney (1)
1. Department of Forestry, University of Florida, Gainesville, FL 32611, USA / 2. Department of Opthalmology, Box 100284 JHMHC, University of Florida, Gainesville, FL 32610, USA / Received September 20, 1993
Summary
Six 25- to 30-year-old slash pine, Pinus elliottii Englm. var. elliottii, trees were inoculated with Ophiostoma minus (Hedgc.) H.P. Sydow, O. ips (Rumb.) Nannf or sterile water. Two, 4 and 6 weeks after inoculation, the lengths of developing lesions and the monoterpene
concentration of the necrotic tissue within each lesion were measured. Both sterile and fungal wounding resulted in the development
of lesions in the phloem–outer xylem. At both 4 and 6 weeks after inoculation, lesions induced by O. minus were significantly larger than lesions induced by O. ips or sterile water, whereas the lesions induced by O. ips and sterile water were similar in size at all sampling periods. At 2, 4 and 6 weeks after inoculation, lesions induced by
O. minus had significantly greater concentrations of monoterpenes than lesions induced by O. ips or sterile water. The monoterpene concentration of lesions induced by O. ips was significantly greater than that of lesions induced by sterile water only at the 6-week sampling period. Visual examination
of the lesions indicated that O. minus but not O. ips was inhibiting the development of callus tissue, suggesting that the strain of O. ips was either nonpathogenic or avirulent.
Keywords:
Ceratocystis, monoterpene concentration, Ophiostoma, phloem wounding, Pinus elliottii, xylem wounding.
