发光二极管(LED)光质对金秋砂糖橘幼苗生长发育和光合特性的影响

为阐明不同发光二极管(LED)光质对金秋砂糖橘生长发育和光合特性的影响,以金秋砂糖橘容器苗为试验材料,设置LED红光(R)、蓝光(B)、红蓝复合光(RB11、RB21、RB41、RB81)共6种光质处理,并以LED白光(W)为对照组.处理2个月后研究新梢茎叶形态、生物量、光合色素含量和光合特征参数变化,并对相关指标进行...

Effects of different light-emitting diode (LED) light quality on growth,development and photosynthetic characteristics of Jinqiu Shatangju seedlings

In order to clarify the influence of different light-emitting diode (LED) light quality on growth, development and photosynthetic characteristics of Jinqiu Shatangju, Jinqiu shatangju container seedlings with trifoliate orange as the rootstock were used as the experimental materials, six light quality treatments red light (R), blue light (B), red and blue composite light (RB11, RB21, RB41, RB81)] were set up in this study with white light (W) as the control. Phenotypic index, biomass, photosynthetic pigment content and photosynthetic characteristic parameters of the newly grown stems and leaves were measured after two months treatment, and the principal component analysis was performed on the relevant indicators. The results showed that red light significantly promoted elongation of new shoots, increased the number of leaves, leaf area and biomass, and inhibited thickening of stems and leaves, while effect of blue light was opposite to that of red light. Low proportion of red light also significantly promoted the elongation of new shoots, made stem thicker, increased number of leaves, leaf area and biomass, however, as the proportion of red light increased, growth trend was significantly reduced. Stem length, stem thickness, number of leaves and leaf area of compound light RB11 were 1.97 times (P<0.05), 1.14 times (P>0.05), 2.05 times (P<0.05), 1.84 times (P<0.05) of the control, respectively. Fresh weight and dry weight of new shoots were 1.68 times (P<0.05), 1.88 times (P<0.05) of the control. Fresh weight of leaves and stems, dry weight of leaves and stems were 1.46 times (P>0.05), 3.00 times (P<0.05), 1.68 times (P<0.05), 3.06 times (P<0.05) of the control. Red light and blue light all lead to a significant decrease in photosynthetic pigment content and net photosynthetic rate (P_n), while red-blue composite light promoted increase of chlorophyll b (chlb), carotenoid (car) content and P_n. In addition, increasing the proportion of red light, content of chlorophyll and car, as well as chla/chlb and P_n showed significant decreasing trend. All treatment light led to a decreasing trend in stomatal conductance (G_s) (except RB41 treatment) and transpiration rate (T_r) (except RB21 and RB41 treatments). Through principal component analysis, it could be found that the red-blue 1:1 compound light (RB11) was more conducive to growth and development, material accumulation and photosynthesis of new shoots of Jinqiu Shatangju. This study provided a theoretical basis for establishment of LED light supplement technology for rapid propagation of Jinqiu Shatangju seedlings.