Effect of Different Ratio of Light Medium on Growth and Photosynthetic Parameters of Picea retroflexa Seedlings

Experiments were conducted on container seedling cultivation of Picea retroflexa on different ratio of peat, coco coir and pearlite in Makekehe Forest Farm, Qinghai province in April, 2015 with local soil as control.Determinations were implemented in May, 2018 on growth traits and photosynthetic parameters.The result demonstrated that height and ground diameter of seedling on light medium was evidently higher than that of the control.Above ground and underground biomass of seedlings on light medium was higher than that of the control.Root surface area, total length and root tip number and root system vigor of seedlings on light medium was much better than that of the control.Photosynthetic efficiency of seedlings on light medium was much higher than that of the control, as well as water use efficiency.Correlation analysis demonstrated that root growth had positive relation with above ground growth of seedlings.The experiment resulted that light medium could promote seedling growth, the best ratio was peat: coco coir: pearlite=7:2:1.