Pine In British Columbia Research Articles

MELAMPSORA INFECTION OF PINE IN BRITISH COLUMBIA

A rust fungus, discovered infecting ponderosa pine (Pinus ponderosa Laws.) at Telkwa, B.C. in 1960 and reported to be the European pine twist rust, Melampsora pinitorqua Rostr., is shown to be the native rust M. albertensis Arth., which was previously thought to have Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) as its only coniferous host. Four other pines are shown to be susceptible to the rust: lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), jack pine (P. banksiana Lamb.), red pine (P. resinosa Ait.), and Scots pine (P. sylvestris L.).Melampsora occidentalis Jacks. was shown to be able to infect ponderosa and lodgepole pines as well as its previously known host, Douglas fir.Only current year's germinants or current year's shoots of very young pines appeared susceptible to these rusts.These are the first records of a species of Uredinales infecting two coniferous genera and it is suggested that other examples may be found by closer observation of younger age classes of hosts.The rust is not considered a special hazard to pine in British Columbia at the present time.