红蓝LED光源对马铃薯组培苗形态生长、光合色素含量及矿质元素积累的影响

Effects of Red and Blue LED Light Source on Morphological Growth,Photosynthetic Pigment Content and Mineral Element Accumulation of Potato Plantlets Cultured in vitro

以‘中薯7号’马铃薯品种为试验材料,以脱毒马铃薯组培苗单节茎段为外植体,采用100μmol/m2·s光强的白(对照)、红、蓝及红蓝光组合4种LED光谱作照明光源培养马铃薯组培苗,研究不同LED光质对马铃薯组培苗生长及矿质元素积累的影响。结果表明,红光引起马铃薯组培苗茎秆伸长变细,增加其节间长和茎节数,降低壮苗指数;蓝光诱导组培苗茎秆矮化加粗,促进干物质积累,增加壮苗指数。蓝光和红蓝光组合显著增加叶绿素a/b的值,红光则显著降低该值。与白光相比,红光抑制马铃薯组培苗对Ca、Fe、Zn和Cu的吸收,并增加上述元素在茎中的分配率,降低其在叶中的分配率;蓝光抑制组培苗对Ca和Mn的吸收,促进P、Zn和Fe的吸收,提高P和Zn在根中的分配率,减少其在茎中的分配率。红蓝光组合增加K、P、Mg、Mn在组培苗中的总积累量,改变Ca和Fe元素在组培苗各器官中的分配情况。因此,光质显著影响马铃薯组培苗的生长和矿质元素的积累:蓝光和红蓝光组合通过增加健苗指数和P元素的积累,促进马铃薯组培苗健壮生长;红光一定程度上造成马铃薯组培苗的遮荫反应并抑制Ca等矿质元素的积累,不利于组培苗生长。研究为光源调控马铃薯组培苗生长和矿质元素代谢提供相关数据支撑和理论依据,同时为马铃薯组培苗快繁中人工光源的选择提供相关参考。

In the present study,with the variety'Zhongshu 7'as the experimental material and single node cuttings of virus-free potato plantlets used as explants,the potato plantlets in vitro were cultured under white(used as the control),red,blue and the combination of red and blue LED light spectra with 100μmol/m2·s illumination intensity to understand the effects of different LED light qualities on the growth and mineral element accumulation and distribution of potato plantlets cultured in vitro.The results indicated that red light induced elongated and slender stems of potato plantlets cultured in vitro with significantly increased internode length and internode number,but decreased health index.On the contrary,blue light produced dwarf and sturdy plantlets,facilitated dry matter accumulation and increased health indexes.Blue light and the combination of red and blue light spectrum significantly increased the value of chlorophyll a/b,however,red light significantly decreased the ratio.Compared with white light,red light inhibited the absorption of Ca,Fe,Zn and Cu,but increased these mineral elements to distribute to the stems rather than leaves in potato plantlets in vitro.Blue light reduced the absorption of Ca and Mn and promoted the absorption of P,Zn and Fe with elevated distribution ratio of P and Zn in roots and decreased that in stems of potato plantlets in vitro.The combination of red and blue light increased the total accumulation of K,P,Mg and Mn in potato plantlets in vitro and altered the distribution of Ca and Fe in plantlets organs obviously.Therefore,different LED light qualities significantly affect the growth and mineral element accumulation of potato plantlet cultured in vitro.In summary,blue light and the combination of blue and red light promoted potato plantlets in vitro growth by increasing the health indexes and P element accumulation.To some extent,red light caused the shade reaction and inhibited the accumulation of Ca and other mineral elements,which was not conducive to the growth of potato plantlets cultured in vitro.This study provides data supports and theoretical basis for light regulation of potato plantlets growth and mineral element metabolism and also supplies relevant reference for the selection of artificial light source in the rapid propagation of potato plantlets cultured in vitro.