LED红蓝光质及其光周期对萝卜苗生长及生物量的影响

Effects of Light Quality and Intensity of LEDs on Growth and Biomass Accumulation of Radish Seedlings

采用LED光源在温度可控的培养室内研究LED红蓝光质及其光周期对萝卜苗期生长与生物量累积的影响。结果表明,红蓝光质比对株高有显著影响,高红蓝比例光质处理促进了生长11天时萝卜的地上部生长,增加了叶片SPAD值(叶绿素含量),而长周期光照对株高无影响或略有提升作用。萝卜苗生长18天时,光质和光周期处理对萝卜苗真叶数量、老叶和新叶SPAD均无显著影响。高红蓝比光质处理下胚轴长度显著高于低红蓝光质比处理;相同红蓝比光质条件下长明期照射处理的下胚轴长度显著高于低红蓝光质比处理。高红蓝光质比处理有利于根长发育,但根直径形成与光周期和光质都有关。低红蓝光质比和短明期处理条件下萝卜地上部鲜重、干重最高,而高红蓝光质比和长明期处理条件下萝卜根鲜重及干重、地上部干重、总干重和根冠比最高。总之,光质和光周期影响萝卜的生长发育,较高的红蓝比与较长的明期有利于提高萝卜地下部生长和产量;反之,有利于地上部生长和产量。

Effects of LED light quality and photoperiod on radish seedling growth and biomass accumulation were investigated in a chamber with controlled temperature. The results showed that high red light to blue light ratio treatments improved shoot growth and leafy SPAD values of radish seedlings 11 d after emergence. However, long lighting period had slight effect on radish shoot height. Light quality and photoperiod had no significant effects on true leafy number, old ＆ new leafy SPAD values of radish seedlings after 18d emergence. Radish seedlings grown under high red light to blue light ratio conditions had longer hypocotyls than those under low red light to blue light ratio conditions. Moreover, low red light to blue light ratio with short lighting period conditions facilitated shoot growth of radish seedlings, while high red light to blue light ratio with long lighting period conditions increased root development of radish seedlings.