Abstract:
The main afforestation trees for barren mountains at different altitudes in Yunnan, namely
Pinus kesiya var.
Langbianensis,
Pinus yunnanensis and
Pinus densata, were selected as the objects of this study. The relevant parameters of seed germination, seedling growth and biomass accumulation were determined by using RL, BL and WL(CK) as the light sources. Furthermore, the relationship between hypocotyl elongation and
HY5 expression was analyzed. The results showed that RL can promote the seed germination and seedling growth of 3 pine trees, which increased by 23.70% and 14.02% for
P.
kesiya var.
langbianensis, 11% and 11.61% for
P.
yunnanensis, 9.37% and 11.35% for
P.
densata, respectively. However, the chlorophyll content of needles in three pine seedlings (
P.
kesiya,
P.
yunnanensis and
P.
densata decreased by 15.30% and 8.78%, respectively) was reduced under the RL, and RL had no significant effects on biomass accumulation. The chlorophyll content and biomass accumulation of three pine seedlings were increased under BL, which increased by 3.27%, 11.72% and 2.28% in
P.
kesiya var.
langbianensis,
P.
yunnanensis and
P.
densata, respectively. On the other hand, it inhibited the seed germination and seedling growth of
P.
yunnanensis and
P.
densata, but promoted the growth of
P.
kesiya var.
langbianensis. The hypocotyl elongation was negatively correlated with
HY5 expression in three pine seedlings under RL and BL light. The seed germination and seedling growth of
P.
kesiya var.
langbianensis showed RL > BL > WL under different light quality, while that of
P.
yunnanensis and
P.
densata showed RL > WL > BL.