Vogler, D. R., Kinloch, B. B., Jr., Libby, W. J., Cobb, F. W., Jr., and Popenuck, T. L. 1992.
Department of Plant Pathology, University of California,
Berkeley, CA 94720, and
U.S.D.A., Forest Service, Institute of Forest Genetics, Berkeley, CA 94701.
Phytopathology 82:1097. (1992)
Ortets (seedlings) of radiata pine (Pinus radiata D. Don) planted in a common garden experiment at Lafayette, CA in 1982 and exposed to natural inoculum of western gall rust (WGR; Peridermium harknessii J. P. Moore) exhibited a range of susceptibility to infection over the ensuing decade. To test the consistency and repeatability of host response, we field-tested ramets (rooted cuttings) of clones derived from both field- susceptible and field-resistant ortets. Clones were chosen to represent each of the five native radiata populations, as well as U.S. mainland-Mexican island hybrids and Australia-New Zealand selects. Two ramets of each of 24 clones were planted in blocks in each of four plantations at Lafayette, CA in 1988, and observed for three years. Clonal response to WGR was generally consistent between the 1982 and 1988 experiments, and highly consistent within the 1988 experiment. Differences among clones were dramatic, with some ramets having few or no galls adjacent to others with 300 or more.