光质对烤烟叶片衰老过程中内源激素含量和膜脂过氧化的影响

为明确不同光质对烤烟叶片衰老的作用及对初烤烟叶品质的影响。以云烟87为供试材料,在大田条件下通过覆盖不同颜色滤膜以获得不同光质,研究白光(W)、红光(R)、黄光(Y)、蓝光(B)和紫光(P)5种不同光质对烤烟成熟衰老过程中内源激素和膜脂过氧化的影响。结果表明:与对照(白光)相比,红光可显著提高烟叶中细胞分裂素(CTK)和赤霉素(GA)的含量,有效降低脱落酸(ABA)含量,蓝光和紫光不利于CTK含量的增加却提高了烟叶中ABA的含量,蓝光和紫光处理下生长素(IAA)含量下降趋势早于红光和黄光处理;红光和黄光处理的烟叶中过氧化氢酶(CAT)活性升高,降低了烟叶衰老过程中的过氧化氢(H2O2)含量,使丙二醛(MDA)的含量保持相对较低的水平,从而延缓植株的衰老,蓝光和紫光处理使叶片CAT活性降低,H2O2含量和MDA含量显著高于对照及其他处理,加速了植株的衰老进程;红光处理提高了烟叶的总糖含量、施木克值和钾氯比,黄光处理提高了总氮和烟碱含量,红光和黄光处理降低了蛋白质含量与糖碱比。总体而言,红光处理提高了烟叶中IAA、CTK和GA含量以及CAT活性,减少H2O2、MDA和ABA含量,延缓膜脂过氧化的发生,从而延缓叶片衰老进程,使烟叶的质量得到改善。

Effect of Light Quality on Endogenous Hormone Content and Lipid Peroxidation of Membrane System during Aging Process of Flue-cured Tobacco Leaf

In order to investigate the effects of different light qualities on flue-cured tobacco aging process and flue-cured tobacco leaf guality, this paper studied the effects of 5 different light qualities including white(W), red(R), yellow (Y), blue(B) and purple(P) under field condition by covering different color polyethylene films above tobacco plants, on endogenous hormones, membrane lipid peroxidation in the maturation of flue-cured tobacco leaves taking ‘Yunyan87’ as experimental material. The results indicated that compared with white light (the control), red light could significantly increase the contents of cytokinin (CTK) and gibberellin (GA), while reduced abscisic acid (ABA) content effectively. Blue light and purple light went against the raising of CTK content, but increased ABA content in tobacco leaves. The auxin (IAA) content decline under blue light and purple light treatments was earlier than that under red light and yellow light treatment. Red light and yellow light could increase catalase (CAT) activity and decreased hydrogen peroxide (H2O2) content during flue-cured leaf aging process, and thus maintained the malondiadehyde (MDA) content at a relatively low level, and slowed down the plant aging process. Blue light and purple light treatments decreased CAT activity and made H2O2 and MDA contents higher than the contrast and other treatments, thus speeded up the plant aging process. Red light treatment increased the total sugar content, shmuck value and ratio of potassium and chlorine; yellow light treatment increased the contents of total nitrogen and nicotine; red light and yellow light treatments reduced the protein content and ratio of sugar and nicotine. In general, the contents of IAA, CTK and GA of tobacco leaves and CAT activity were increased, whereas the contents of H2O2, MDA and ABA were reduced under red light treatment. The aging of flue-cured tobacco leaves was delaied, thus the quality of tobacco leaves was improved.