Effects of supplemental lighting treatments on seedling growth of varied provenances in black spruce

To understand the seedling trait performance from different black spruce (Picea mariana) provenances with varied light treatments and to establish efficient propagation technique system with supplemental light, container seedlings of 10 black spruce provenances from Canada were treated by 3 light sources of fluorescent lamp, sunlight dysprosium lamp and tungsten lamp. The results showed that light treatment could inhibit seedling dormancy and promote sustaining growth. The seedling height by using fluorescent light for 8 hrs at midnight for 135 days could be up to 5.47 times compared with control. The effect of light sources was significant on seedling growth, shoot and root formation. The treatment for sunlight dysprosium lamps was best, and fluorescent lamp was more economical and convenient. Besides, the seedling grew well when fluorescent lamp was supplemented for 8 hrs at midnight. There were significant interaction effects on seedling traits between light sources and provenances. It was indicated that there were obvious differences for different black spruce provenances in adapting to light environment. Therefore, it should be paid more attention to select appropriate provenances for introduction experiment. The light source should be selected according to the seedling provenances to achieve the optimum breeding results.