Effects of different light intensities on anti-oxidative enzyme activity, quality and biomass in lettuce

Abstract

Weiguo Fu, Pingping Li, Yanyou Wu, Jianjian Tang, 2012. Effects of different light intensities on anti-oxidative enzyme activity, quality and biomass in lettuce. Hort. Sci. (Prague), 39: 129-134.Recently, the worldwide demand for romaine lettuce (Lactuca sativa L.) has been increasing. Thus, regulation measures of supplementary or shading light are often used in the production of lettuce in some regions. However, inconsistent results on the light saturation point of lettuce from previous studies do not facilitate the regulation of light intensity. In the present study, the effects of different light intensities on anti-oxidative enzyme activity, yield and quality of lettuce were investigated. The results reveal the following: (1) judged by the dynamics of anti-oxidative enzyme activity, there was no light stress to occurr in the 100, 200 and 400 μmol/m 2 s treatments, a mild light stress occurred in the 600 μmol/m 2 s treatment, and a serious light stress occurred in the 800 μmol/m 2 s treatment; (2) increased light intensity gradually reduced the contents of soluble protein and nitrate in lettuce, whereas the content of soluble sugar remarkably increased. The biomass of a single plant of lettuce in the 600 µmol/m 2 s treatment was the highest and second highest in the 400 µmol/m 2 s treatment but was the lowest in the 100 µmol/m 2 s treatment. No significant difference in the biomass of single plant was observed between the 400 and 600 µmol/m 2 s treatments. Based on these results, the range of 400 µmol/m 2 s to 600 µmol/m 2 s is a recommendable light intensity for lettuce production.

Cultivar-Specific Performance and Qualitative Descriptors for Butterhead Salanova Lettuce Produced in Closed Soilless Cultivation as a Candidate Salad Crop for Human Life Support in Space

“…Nitrogen use efficiency (NUE) and growth, if not by nitrate/nitrogen itself, can be influenced by light [36]. When light, and in particular DLI, exceeds the light saturation point of lettuce, it can cause photoinhibition and decrease NUE, compromising lettuce growth and development, and significantly affecting fresh yield [37,38]. The optimal DLI for lettuce plants ranges between 10 and 17 mol m 2 d −1 and we used 18.1 DLI to boost lettuce growth.…”

Divergent Leaf Morpho-Physiological and Anatomical Adaptations of Four Lettuce Cultivars in Response to Different Greenhouse Irradiance Levels in Early Summer Season

“…Light fosters lettuce growth only in a specific range of light intensities [19]. Several studies have shown that lettuce grown in summer with light intensity over 600 µmol m −2 s −1 had reduced biomass, leaf area and chlorophyll content [19,20].…”

The Effect of Light on Antioxidant Properties and Metabolic Profile of Chia Microgreens

“…In our study, light caused an increase of carotenoid content in chia seedlings and therefore increased their antioxidative properties. Lower light intensity in a range from 100 to 300 µmol m −2 s −1 had a positive effect on photosynthetic processes [35], increased chlorophyll content [36], and more effective light use [37] in plants. In this study, we used the light intensity of 100 µmol photons m −2 s −1 , which generally has a beneficiary effect on the synthesis of different investigated bioactive compounds and enhances antioxidative properties in chia microgreens.…”