不同红蓝LED光照强度对紫叶生菜生长及营养品质的影响

Effects of Different Red and Blue LED Light Intensities on the Growth and Nutritional Quality of Purple Leaf Lettuce

为了探索不同红蓝LED光照强度对紫叶生菜生长及营养品质的影响,以紫罗莎品种紫叶生菜为研究对象,在红蓝光比值1∶1不变的条件下研究50μmol/(m^2·s)(RB50)、100μmol/(m^2·s)(RB100)、150μmol/(m^2·s)(RB150)和200μmol/(m^2·s)(RB200)4种光照强度对紫叶生菜生长、营养品质和光合特性的影响。结果表明:在RB150处理下,紫叶生菜生物量最大,具有较高产量,类胡萝卜素含量最高,在定植后25 d,SOD、CAT和POD活性最高,抗氧化能力最强;在RB200处理下,叶片可溶性蛋白含量比RB50和RB100处理分别增加80.30%和40.64%、叶片花青素含量比RB50处理增加51.5倍,叶绿素含量、净光合速率、维生素C含量显著高于其他处理且硝酸盐含量最低,RB200处理可促进紫叶生菜叶绿素a、叶绿素b和叶绿素总量的提高,从而促进光合色素的积累和光合作用的进行。因此,在红蓝光比值1∶1的条件下,光照强度较高时有利于紫叶生菜品质的提高,适当增加光照强度可提高紫叶生菜的生物量以及改善营养品质,可根据生产过程中的不同需求,通过控制植物工厂中光照强度,使得紫叶生菜的光合速率较高并具有优良品质。

In order to explore the effects of different red and blue LED light intensity on the growth and nutritional quality of purple leaf lettuce, purple leaf lettuce ′Purple Rosa′ was used as material in the experiment. Under the 1∶1 ratio of red and blue light condition,four light intensities 50 μmol/(m^2·s)(RB50), 100 μmol/(m^2·s)(RB100), 150 μmol/(m^2·s)(RB150) and 200 μmol/(m^2·s)(RB200) were processed. The growth, nutrient quality and photosynthetic characteristics of lettuce leaves were collected from four light intensities. The results showed that under RB150 treatment, purple leaf lettuce had the largest biomass, higher yield, the highest carotenoid content. At 25 d after transplanting, the highest activity of SOD, CAT and POD and the strongest antioxidant capacity. Under the treatment of RB200, the soluble protein content of leaves increased by 80.30% and 40.64%, and the anthocyanin content of leaves increased by 51.5 times compared with RB50 treatment. Moreover,chlorophyll content, leaf net photosynthetic rate, and vitamin C content of RB200 were significantly higher than other treatments and nitrate content was the lowest. RB200 treatment could promote the increase of chlorophyll a, chlorophyll b and total chlorophyll in purple leaf lettuce, so as to promote the accumulation of photosynthetic pigment and the progress of photosynthesis.Therefore, under the condition of the red and blue light ratio 1∶1, light intensity was higher when the beneficial to the improvement of the quality of purple leaf lettuce, appropriately increased light intensity can enhance purple leaf lettuce biomass and improve the nutritional quality, according to the different requirements in the process of production, by controlling the plant factory in light intensity, make purple leaf lettuce higher photosynthetic rate and excellent quality.