不同LED光谱对马铃薯组培苗生长和内源激素变化的影响

Effects of Different LED Light Spectra on Growth and Alterations of Endogenous Hormone of Potato Plantlets Grown in vitro

为研究不同光质对马铃薯组培苗形态生长及内源激素水平的影响,以‘中薯4号’马铃薯组培苗单节茎段为外植体,白色LED光源作对照(CK),探究5种不同光质的LED光源处理即100%红光(RR),100%蓝光(BB),100%绿光(GG),75%红光+25%蓝光(RB)和45%红光+35%蓝光+20%绿光(RBG)对马铃薯组培苗生长和内源激素含量的影响。结果表明,单色光处理显著改变组培苗的生长形态,RR和GG处理下组培苗茎秆纤细;BB处理下的组培苗茎秆粗矮。RB和RBG处理下组培苗在茎长、茎粗、叶面积和根系总长度等形态指标方面均高于CK。BB通过增加各生长期组培苗叶片内源细胞分裂素(IPA、ZR和DHZR)含量,促进叶片生长发育;RR通过提高组培苗根系内源ABA含量,增加根系抗胁迫能力;在整个生长期,RR和GG处理的马铃薯组培苗茎中高浓度的内源GAs和IAA协同作用刺激茎细胞伸长和节间伸长,显著增加了组培苗茎长和节间长。总之,不同LED光谱通过参与调控马铃薯组培苗各器官内源激素的分布进而影响其生长。

Single-stem cuttings of'Zhongshu 4'potato plantlets in vitro were used as the explants,and white LED light was used as the control(CK)to explore the effects of the five LED spectra,namely 100%red light(RR),100%blue light(BB),100%green light(GG),75%red light+25%blue light(RB),and 45%red light+35%blue light+20%green light(RBG),on the growth and endogenous hormone content of potato plantlets cultured in vitro.Potato plantlets in RR and GG treatments were slender with longer internodes.Plantlets stems in BB treatment were shorter.RB and RBG treatments induced healthy potato plantlets in vitro with higher growth parameters including stem length,stem diameter,leaf area and the total root length than those of CK.BB promoted the growth development of leaves by increasing the contents of endogenous cytokinins(IPA,ZR and DHZR)in the leaves of potato plantlets in vitro.RR increased the ABA content in the roots of plantlets,giving rise to the enhancement of the root resistance to stress.In RR and GG treatments,the synergistic effect of high content of endogenous GAs and IAA in the whole growing stages stimulated elongation of stem cells and internodes,which significantly increased the stem length and internode length.In conclusion,different LED spectra are involved in regulating the distribution of endogenous hormones in the organs of potato plantlets in vitro which further affects their growth.