LED光质对猴樟幼苗生长和光合特性的影响

为研究不同光质对猴樟生长及光合作用的影响,对猴樟幼苗开展了LED光源控制试验。设置红光、蓝光、红蓝（7:3）复合光和白光（对照）4个处理,测定了猴樟的生物量、光合参数和叶绿素荧光参数等指标,并运用主成分分析法对4种光质进行了综合评价。结果表明,处理5个月后,与白光相比,红光除增大了最大光化学效率（F_v/F_m）之外,其在猴樟苗的株高、地径、生物量、净光合速率（P_n）和水分利用效率（WUE）上都显著减小,即红光抑制了猴樟苗的生长和表观光合作用。蓝光下猴樟苗生长性状与白光类似,但P_n和F_v/F_m 减小,Y（NO）增大,说明蓝光显著抑制光合。红蓝光下除了地径减小、叶生物量增大之外,其余指标与白光没有明显差异。4种光质对猴樟苗的综合效应优劣顺序为白光＞红蓝光＞蓝光＞红光。白光下综合表现最优,红光下最差。猴樟设施化育苗中应首选白光和红蓝光等复合光源。

Effects of LED light quality on the growth and photosynthetic characteristics of Cinnamomum bodinieri seedlings

In order to study the effects of different light qualities on the growth and photosynthesis of Cinnamomum bodinieri seedlings, LED light source control experiments were carried out. Four treatments of red light, blue light, red-blue (7:3) composite light and white light (control) were set up. The biomass, photosynthetic parameters and chlorophyll fluorescence parameters of C. bodinieri were measured. The principal component analysis was used to comprehensively evaluate the four light qualities. The results showed that after 5 months of treatments, compared with white light, red light increased the maximum photochemical efficiency (F_v/F_m), but it significantly decreased the plant height, ground diameter, biomass, net photosynthetic rate (P_n) and water use efficiency (WUE), that is, red light inhibited the growth and apparent photosynthesis of C. bodinieri. The growth traits of C. bodinieri seedlings under blue light were similar to those under white light with the decrease of P_n and F_v/F_m and the increase of the Y (NO), indicating that blue light significantly inhibited the photosynthesis. In addition to the decrease of ground diameter and the increase of leaf biomass, there was no significant difference between red-blue light and white light. The comprehensive effects of four light qualities on C. bodinieri seedlings were white light > red-blue light > blue light > red light. The result indicated that comprehensive performance of C. bodinieri treated with the white light was the best, and which treated with the red light was the worst. Composite light sources such as white light and red-blue light should be preferred in facility seedling raising of C. bodinieri.