Genetic Improvement of Red Pine and Eastern White Pine

Abstract

Present knowledge of the genetics of red and white pine is reviewed. The adequacy of the existing program is discussed and suggestions are made concerning the direction that future programs should follow.Red pine is genetically the least variable of any of the tree species that have been intensively studied. Genetic improvement of the species will be difficult, but by no means impossible. The expected improvement will be small in comparison to that which can be made with other coniferous species, but even a modest improvement may be economically justified where the species is potentially valuable in reforestation. Future research with red pine should concentrate on locating, producing, and utilizing additional genetic variation by: interprovenance and interspecific hybridization; individual tree selection with emphasis on growth rate, branch habit, and site adaption; and long-term studies with mutagenic agents.White pine is a genetically variable species in which considerable improvement can be made in growth characteristics, and in resistance to white pine blister rust, Cronartium ribicola Fischer, and to white pine weevil, Pissodes strobi (Peck). A good deal of effort has been expended on developing white pines resistant to blister rust. This resistance appears to be controlled by a large number of small-effect genes. White pine seed orchards have been established for the production of rust-resistant materials. Future work should emphasize combining rust resistance with weevil resistance into types with superior growth rate and growth form.