人工气候室控制条件下青葱对LED光质的响应特性

Response Characteristics of Green Onion(Allium fistulosum L.)to LED Light Quality Under Artificial Climate Chamber

【目的】研究人工气候室控制条件下青葱生长、产品品质及光合特性对不同光质的响应特性,优化青葱工厂化生产光环境调控参数,提高以鲜嫩绿叶为产品的青葱生产效率。【方法】在人工气候室LED控制光源条件下,以‘章丘’和‘天光’2个不同品种大葱为试验材料,将苗高15 cm左右、具2—3片真叶的穴盘中大葱幼苗,分别置于蓝光(B)、红光(R)、绿光(G)、黄光(Y)、白光(W)等5种不同光质条件下进行培养,光照强度均控制在(301.6±12.7)μmol·m^-2·s^-1,光照时间为12 h/d,昼/夜温度分别控制在25℃/18℃。分别在试验处理0、10、20、30和40 d时取样,测定不同光质处理的青葱叶片光合作用参数,以及培养40 d时青葱的生长量和产品品质。【结果】青葱的生长量、产品品质、叶片色素含量、净光合速率(Pn)、表观量子效率(AQY)和RuBP最大再生速率均以白光显著优于各单色光处理。培养40 d时,白光处理青葱单株鲜重为25.21 g,分别比蓝光、红光、绿光、黄光处理增加了7.83%、20.28%、35.68%和60.78%;其叶片Pn为7.63μmol·m^-2·s^-1,分别比蓝光、红光、绿光和黄光处理提高了11.39%、24.07%和39.23%和59.62%;叶片光饱和光合速率(Pmax)达13.29μmol·m^-2·s^-1,分别较蓝光、红光、绿光和黄光处理增加了5.39%、9.47%、15.57%和21.48%;光饱和点(LSP)除白光处理较高外,其他单色光处理间无显著差异;而光补偿点(LCP)则以黄光较高,绿光、红光次之,蓝光、白光较低。不同单色光处理间也存在显著差异,以蓝光处理青葱单株鲜重较高,黄光处理较低,分别达24.22和16.52 g,绿光、红光居中;蓝光处理青葱叶片Pn、AQY、光饱和光合速率(Pmax)、羧化效率(CE)以及RuBP最大再生速率也显著高于其他单色光处理。青葱假茎可溶性糖、粗纤维、丙酮酸、可溶性蛋白、游离氨基酸和干物质含量等品质指标均以白光处理显著高于各单色光处理,但各单色光处理之间则以蓝光处理较高,其他依次为红光、绿光、黄光。【结论】全光谱的白光处理最有利于青葱生长,表现为叶片光合效率较高,产品品质较优;各单色光处理则以蓝光效应较高,红光次之,黄光、绿光较差,反映青葱对白光、蓝光光能利用能力较强。

【Objective】The purpose was to explore the response characteristics of green onion growth,product quality and photosynthetic characteristics of green onions to different light qualities,and to provide technical parameters for optimizing the regulation of light environment in industrial production of green onions and improve the production efficiency of green onions based on fresh green leaves.【Method】Under the condition of LED light source in artificial climate chamber,two different varieties of green onion‘Zhangqiu’and‘Tianguang’were used as experimental materials.The seedlings of green onion with about 15 cm in seedling height and 2-3 pieces of true leaves were cultured under five different light qualities,including blue light(B),red light(R),green light(G),yellow light(Y)and white light(W).The light intensity was controlled at(301.6±12.7)μmol·m^-2·s^-1,the light time was 12 h/d,and the day/night temperature was controlled at 25℃/18℃,respectively.Samples were taken at 0,10,20,30 and 40 days after treatment,and the photosynthetic parameters of green onions treated with different light quality were measured,as well as the growth and product quality of green onion at 40 days of culture.【Result】The growth,product quality,leaf pigment content,photosynthetic rate(Pn),apparent quantum efficiency(AQY)and Ru BP maximum regeneration rate of green onion under W were significantly better than those under monochromatic light.After 40 days of culture,the fresh weight(FW)per plant of green onion treated with W was 25.21 g,which was 7.83%,20.28%,35.68%and 60.78%higher than B,R,G and Y,respectively.The Pn under W was 7.63μmol·m^-2·s^-1,which was 11.39%,24.07%,39.23%and 59.62%higher than B,R,G and Y,respectively.The photo-saturated photosynthetic rate(Pmax)under W reached 13.29μmol·m^-2·s^-1,which was 5.39%,9.47%,15.57%and 21.48%higher than B,R,G and Y,respectively.There was no significant difference in light saturation point(LSP)among other monochromatic light,while the light compensation point(LCP)was higher in Y,followed by G and R,and lower in B and W.There were also significant differences among different monochromatic light,the FW per plant of B was significantly higher than Y,which reached 24.22 g and 16.52 g,respectively,G and R were in the middle.Pn,AQY,Pmax,carboxylation efficiency(CE)and maximum regeneration rate of Ru BP of green onion leaves treated with B were also significantly higher than those of other monochromatic light.The quality indexes in green onion,such as soluble sugar,crude cellulose,pyruvate,soluble protein,free amino acid and dry matter in W,were significantly higher than those in monochromatic light.However,the B was higher among the monochromatic light,and the others were red light,green light,and yellow light in order.【Conclusion】The W was the most beneficial to the growth of green onions,which showed that the photosynthetic efficiency of leaves was higher and the product quality was better,and the effect of each monochromatic light treatment was higher than B,followed by R,Y and G.It reflected that green onions had strong utilization ability to W and B,which laid a foundation for further study on the formation of yield and quality of green onions by compound light.