Supplementing light in the night can efficiently promote the seedlings growth of Picea crassifolia,but the families genetic variation with supplemental light and the relationship between seedlings growth and mineral elements content were not clear. In this study,we explore the effects of extending lighting time on seedling growth and nutrition absorption,and analyze the response of the family genetic difference to light supplemental. The biomass and mineral element content of nine families from superior trees in P. crassifolia with supplemental light were investigated in growing and bud set period. The results showed that biomass and mineral element content were significantly affected by family, lighting time and interacted by family and lighting time. The biomass of P. crassifolia was increased with supplemental light treatment,and the aboveground biomass and underground biomass were 2. 01 and 1. 54 times higher than that of the control,respectively. The seedlings with higher growth rate had lower N:P ratio which was mainly affected by the P content. The N:P ratio of seedlings with supplemental light (7. 71) was significantly lower than that of the control (9. 05) in July. There was a significant negative correlation between the P content and the aboveground biomass. With increased seedling growth promoted by supplemental light,the P content was probably diluted in synthesizing RNA and protein. Thus,it is necessary to apply phosphate fertilizer to seedlings with supplemental light. The family genetic differentiation and phenotypic plasticity to lighting time together brought about the different responses of different families in biomass and nutrient element content to the supplemental light,which makes it possible to select superior family under supplemental light.
展开▼
