叶用莴苣全株营养累积分配的光谱效应

Spectral Effect for Nutrient Accumulation and Distribution of Whole Lettuce Plant

基于高等植物叶绿素吸收光谱的强弱差异性,分别采用波长(442±9)nm蓝光、(457±7)nm蓝光、(521±14)nm绿光、(627±7)nm红光和(655±11)nm红光光谱发光二极管(LED)光源,以300μmol·m^(-2)·s^(-1)光强对叶用莴苣进行12 h·d^(-1)照射处理3周,以温室自然光为对照,研究具有一定能量供应下叶用莴苣生长和营养累积分配的光谱信号调控效应。红光,尤其是红光655处理的叶面积、鲜质量、干质量显著高于对照57.89%~85.04%;尽管蓝光下全株及叶和根的可溶性蛋白质含量均显著高于对照33.26%~181.23%,可是随着光谱波长的减小,可溶性蛋白质在各器官中的分配更加呈现以叶为主的特征。相比之下,随着光谱波长的增加,可溶性糖在各器官中的分配更加呈现以叶为主的特征。此外,蓝光、红光处理全株以及叶和茎器官的可溶性糖含量显著高于对照97.26%~357.54%;红光下叶中的游离氨基酸含量低于对照52.79%~59.01%,且明显抑制了GOT活性,以及游离氨基酸分配以茎为主和根其次的特征,暗示着红光有利于氨基酸向阴生器官或部位转运分配的倾向。

The seedlings of lettuce（Lactuca sativa L.）were illuminated with blue light（442 ± 9）nm and（457 ± 7）,red light（627 ± 7）nm and（655 ± 11）nm and green light（521 ± 14）nm LEDs（300 μmol · m^-2 · s^-1,12 h photoperiod）respectively,based on the difference of absorption spectrum of chlorophyll in cells of higher plants. Natural light in greenhouse was applied as a control treatment（CK）. After three weeks of illumination,the nutritive accumulation,distribution and growth characteristic in the different parts of lettuce were measured to investigate the regulation effect of LEDs spectrum. The most remarkable increase（57.89%–85.04%）in leaf area,fresh weight and dry weight were detected in the red light655 treatment compared with the CK. Treated with short wavelength of LEDs spectrums,blue light enhanced allocation of soluble proteins in leaf,root and whole-plant,and more soluble proteins were found to centralize in the leaf of lettuce when the wavelength got further shortened（e.g. blue light442）. Meanwhile,the contents of soluble sugar in leaf,stem and whole-plant increased by 97.26%–357.54% under the red and blue irradiation. With the increase of wavelength of LEDs spectrums,more soluble sugar was also recorded in the leaf of lettuce after the illumination of red light 655 treatment. However,the red light reduced the free amino acid content（52.79%–59.01%）and inhibited the GOT activity in leaf of lettuce,which could transfer more free amino acid into stem and then into root. This seems to indicate that red light Abstract. favored the growth of lunar organs or parts of lettuce by transporting and distributing more amino acids.