不同光质配比对杉木幼苗光合生理特征的影响

Effects of different light quality ratios on photosynthetic and physiological characteristics of Chinese fir seedlings

【目的】通过研究不同光质下杉木幼苗叶绿体超微结构、光合色素含量及光合相关参数,揭示杉木幼苗对不同光质的响应差异,为杉木培育提供理论依据。【方法】以1年生优良无性系020扦插苗为材料,利用LED智能调光台为人工光源,设置白光(CK)、红光(R)、蓝光(B)、红蓝光(R∶B=1∶1)4个处理,每个处理3个重复,通过透射电镜观察叶绿体结构,并测定光合参数和光合色素。【结果】白光、红蓝复合光处理下的净光合速率、气孔导度、蒸腾速率高于红光和蓝光处理。其中,白光处理比红光处理分别高130.61%、204.05%、112.14%,比蓝光处理分别高37.80%、31.34%、49.91%,而红蓝复合光处理比红光分别高89.02%、176%、51.09%,比蓝光处理分别高13.07%、18.96%、6.81%。白光处理和红光处理下幼苗叶片胞间CO高于蓝光和红蓝复合光处理。其中,白光处理比蓝光和红蓝复合光处理高6.32%、5.10%,红光处理比蓝光和红蓝复合光处理高4.18%、3.01%。光合色素在红蓝复合光处理下最低,分别比其余3种处理低27.81%、26.51%、15.52%。叶绿素比值在红光处理下最低,分别比其余3种处理低3.32%、1.90%、3.79%,而在红蓝复合光处理下最大,并显著高于其余3种处理。观察叶绿体超微结构得出,红蓝复合光下细胞壁更加完整平滑,基粒、基质片层及其结构更加完整。【结论】不同光质处理下杉木幼苗光合特性存在较大差异。蓝光以及掺杂一定比例的红蓝光是杉木幼苗良种壮苗的理想光质。

【Objective】The present study aimed to reveal differences in the response of fir seedlings to different light qualities by studying chloroplast ultrastructure, photosynthetic pigment content and photosynthesis-related parameters of fir seedlings under different light qualities to provide a theoretical basis for fir cultivation. 【Method】 The 1-year-old excellent clone 020 cuttings were used as the material, and LED intelligent dimming table was used as the artificial light source. Four treatments were set up, including white light(CK), red light(R), blue light(B) and red and blue combined light(R∶B=1∶1), with three replicates in each treatment. The chloroplast structure was observed by transmission electron microscope, and the related photosynthetic parameters and photosynthetic pigments were determined.【Result】The net photosynthetic rate, stomatal conductance, and transpiration rate under white light and red-blue composite light treatments were higher than those under red light treatment and blue light treatment. Among them, the white light treatment was 130.61%, 204.05% and 112.14% higher than that of the red-light treatment, 37.80%, 31.34% and 49.91% higher than that of the blue light treatment, respectively, while the red-blue composite light treatment was 89.02%, 176% and 51.09% higher than that of the red light, 13.07%, 18.96% and 6.81% higher than that of the blue light treatment, respectively. The intercellular COof seedling leaves under white light treatment and red-light treatment was higher than that of blue light treatment and red-blue composite light treatment. Among them, the white light treatment was 6.32% and 5.10% higher than that of the blue light and red-blue composite light treatments, and the red-light treatment was 4.18% and 3.01% higher than that of the blue light and red-blue composite light treatments. Photosynthetic pigments were the lowest in the red and blue combined light treatment, 27.81%, 26.51% and 15.52% lower than that of the remaining three treatments, respectively. Chlorophyll ratios were the lowest under red light treatment, 3.32%, 1.90% and 3.79% lower than that of the remaining three treatments, respectively, while they were maximum under red-blue complex light treatment, significantly higher than that of the remaining three treatments. The observation of chloroplast ultrastructure yielded that the cell wall was more complete and smoother under red and blue combined light, and the basal granules, stromal lamellae and their structures were more complete.【Conclusion】The photosynthetic characteristics of fir seedlings differed greatly under different light quality treatments. Blue light as well as red and blue light mixed with a certain proportion were the ideal light quality for good and strong cedar seedlings.