Lodgepole Pine and White Spruce Germination: Effects of Stratification and Simulated Aging

The effects of seed pre-treatment (stratification/prechilling) and simulated aging on germination parameters (germination capacity, speed and value and peak value) were evaluated for several seedlots originating from seed orchard clones of lodgepole pine (Pinus contorta var. latifolia DOUGL. ex LOUD.) and white spruce (Picea glauca (MOENCH) VOSS). Region of origin and stratification had little effect on white spruce, while stratification enhanced germination speed and completeness of lodgepole pine. Broad-sense heritability for germination parameters ranged from 70 to 97% (unstratified) and from 81 to 96% (stratified) for pine, and from 95 to 97% (unstratified) and from 93 to 97% (stratified) for spruce. Simulated aging (short-term storage at high temperature and relative humidity, approximating the physiological effects of long-term storage) resulted in rapid deterioration of white spruce, with very little germination after six days of aging. Lodgepole pine germination increased during the first several aging treatments relative to the control, but germination capacity decreased following twelve days of aging, and was very low after 18 days. White spruce was nondormant and responded primarily to moisture conditions, whereas pine was strongly influenced by maternal effects. These results can be incorporated for more efficacious nursery production practices for commercial reforestation seedling production as well as ex-situ gene conservation strategies.