白蓝LED补光对温室甜瓜幼苗生长发育的影响

Effects of Supplementary White and Blue LED Light on Growth and Development of Greenhouse-Grown Muskmelon Seedlings

为改善甜瓜幼苗在温室弱光环境下易出现徒长的现象,培育株型紧凑的优质壮苗、确定适宜幼苗生长的补光调控策略至关重要。本试验在补充相同日累积光照量的条件下,使用白色或白蓝LED补充不同比例的蓝光(28.5%、38.5%、48.5%、58.5%和68.5%),以未补光作为对照(CK),研究其对温室甜瓜幼苗生长发育的影响。结果表明:白色与一定比例蓝色LED组合补光可显著影响甜瓜幼苗形态,随着补充蓝光比例的增大,甜瓜幼苗下胚轴长逐渐降低,蓝光比例为48.5%(WB20)、58.5%(WB30)和68.5%(WB40)时下胚轴长分别比CK降低31.8%、36.4%和34.1%;与CK相比,蓝光比例为48.5%(WB20)和58.5%(WB30)培育的甜瓜幼苗壮苗指数分别提高125.8%和118.2%,地上部干重分别增加81.1%和69.0%,POD活性分别增加130.8%和197.2%;此外,蓝光比例为58.5%(WB30)时,甜瓜幼苗的根表面积与CK相比增加66.8%。可见,增补适当比例蓝光能够促进甜瓜幼苗生长并抑制下胚轴伸长,且蓝光比例为48.5%~58.5%的白蓝LED组合对培育温室甜瓜壮苗效果显著。

In order to improve the quality of greenhouse-grown muskmelon seedlings in weak light environment and obtain high-quality and strong seedlings with compact plant type, it is important to determine appropriate supplementary light strategy. In this experiment, the white and blue LEDs with different proportions of blue light(28.5%, 38.5%, 48.5%, 58.5% and 68.5%) were used to study their effects on growth and development of muskmelon seedlings in greenhouse based on the same cumulative daily light amount. The treatment without supplementary light was used as control(CK). The results indicated that different blue proportions created by white and blue LEDs had significant effects on morphology of muskmelon seedlings. The hypocotyl length of muskmelon seedlings gradually decreased with the increase of blue light proportion. Compared with CK, the hypocotyl length decreased by 31.8%, 36.4% and 34.1% under the blue light proportion of 48.5%(WB20), 58.5%(WB30) and 68.5%(WB40), respectively;the strong seedling index under 48.5%(WB20) and 58.5%(WB30) blue light increased by 125.8% and 118.2%, the aboveground dry weight increased by 81.1% and 69.0%, and the POD activity increased by 130.8% and 197.2%, respectively. In addition, the root surface area of muskmelon seedlings under 58.5% blue light(WB30) increased by 66.8% compared with CK. In conclusion, the addition of proper proportion of blue light could promote the growth of melon seedlings and inhibit the hypocotyl elongation, and the combinations of white and blue LEDs with the blue light ratio as 48.5%~58.5% had significant effects on cultivating strong muskmelon seedlings in greenhouse.