Photosynthetic and growth responses of green and purple basil plants under different spectral compositions (original) (raw)
Related papers
Plants
Indoor farming of basil (Ocimum basilicum L.) under artificial lighting to support year-round produce demand is an area of increasing interest. Literature data indicate that diverse light regimes differently affect downstream metabolic pathways which influence basil growth, development and metabolism. In this study, basil was grown from seedlings to fully developed plants in a microcosm, an innovative device aimed at growing plants indoor as in natural conditions. Specifically, the effects of white (W) and blue-red (BR) light under a photosynthetic photon flux density of 255 μmol m−2 s−1 on plant growth, photochemistry, soluble nutrient concentration and secondary metabolism were investigated. Plants grew taller (41.8 ± 5.0 vs. 28.4 ± 2.5 cm) and produced greater biomass (150.3 ± 24.2/14.7 ± 2.0 g vs. 116.2 ± 28.3/12.3 ± 2.5 g fresh/dry biomass) under W light compared to BR light. The two lighting conditions differently influenced the soluble nutrient concentration and the transloca...
Agronomy
Light is a crucial element for plant growth and production. High-pressure sodium (HPS) lamps are considered not very electrically efficient as they generate high radiant heat, and as a consequence, there has been a lot of interest in replacing HPS lamps with new more efficient lighting sources in the form of light-emitting diodes (LEDs). LEDs have a linear photon output with the electrical input current, and this great feature allows the design of lighting arrays that match the plant’s needs. In the current study, light spectrum absorbance of pigments extracted from 14 plant species was analyzed. Two absorbance peaks were observed in the Photosynthetically Active Radiation (PAR) region: one at 435 nm and the other at 665 nm. The light spectrum array was designed to produce the spectrum absorbed by basil pigments. This included the use of new wavelengths of 435 ± 5 nm to cover the blue region. Moreover, the ratio between blue and red was considered to match the absorbance of basil pi...
Seasonal Efficiency of Supplemental LED Lighting on Growth and Photomorphogenesis of Sweet Basil
Frontiers in Plant Science
For decisions on supplemental lighting a quantitative knowledge of the plants' responses to light under varying conditions is fundamental. In this study, we developed light dose-response curves of growth and morphological traits forOcimum basilicumL. and examined the effects of light color (blue, red, and white plus far-red) and natural environment (season) on these curves. Four greenhouse experiments were conducted throughout the year to determine the efficiencies of the light regimes on growth and their effects on plant morphology. A special aspect was the photosynthetic efficiency of far-red light. Linear and monomolecular relationships were found for the relationships between plant traits and supplemental light dose. Traits related to biomass productivity increased linearly with light dose whereas some morphological characters showed a saturation behavior. Red light and white plus far-red light were more efficient in plant dry weight production than blue light, and the plant...
Photosynthetica
Comparative studies of the adaptation of green-and purple-leaved Ocimum basilicum varieties, which differ in carotenoid and anthocyanin contents, to high-intensity light have been carried out. The plants were grown for 21 d under white lightemitting diode providing different light intensities [300, 550, and 1,350 µmol(photon) m-2 s-1 ]. During the experiment, fresh mass and relative water content, photosynthetic pigment and anthocyanin content, amount of total free phenolic compounds, and the contents of thiobarbituric acid reactive substances and H2O2 were analysed. The fluorescent parameters, which characterized the PSII activity in the leaves (Fv/Fm, Y(II)), as well as the efficiency of dissipation of absorbed energy into heat (Y(NPQ),Y(NO)) and the fraction of the PSII open centres (qL), were determined. The obtained results are consistent with the concept of the important role of not only anthocyanin but also carotenoids in plant adaptation to high-intensity light.
Horticulturae, 2024
Basil is a culinary herb in high demand all year round, either fresh, dried, or frozen. Field basil crops are commercially predominant, while greenhouse crops can cover the demand for fresh basil during the off-season. The leaf aspect of basil has great importance for the food industry, and a great diversity of genotypes has been created. The aim of this research was to conduct a comparative characterization of 12 basil genotypes (green and purple leaf) that present interest for breeding programs from a national germplasm collection. The study examines the accumulation of photosynthetic pigments in basil cultivated in field versus greenhouse conditions as indicators of plant performance and herb quality from the perspective of ensuring fresh plant material all year round. The experimental median indicated that photosynthetic leaf pigments accumulated in higher concentrations in the field relative to the greenhouse conditions, in descending order: β-carotene, lutein, chlorophyll a, and chlorophyll b. The trend was not as consistent for chlorophyll b, since four out of twelve genotypes presented higher levels in the greenhouse than in the field, while the overall values were not much lower in the greenhouse than the field (16.82%). All genotypes accumulated much higher carotenoid contents in field conditions relative to greenhouse conditions (>200%) and could also provide better nutritional advantages given their demonstrated health benefits. The differences in photosynthetic leaf pigments have both nutritional (the carotenoids), shelf-life, and processing relevance (chlorophylls) and serve as quality markers.
Frontiers in Plant Science
Indoor plant cultivation can result in significantly improved resource use efficiency (surface, water, and nutrients) as compared to traditional growing systems, but illumination costs are still high. LEDs (light emitting diodes) are gaining attention for indoor cultivation because of their ability to provide light of different spectra. In the light spectrum, red and blue regions are often considered the major plants' energy sources for photosynthetic CO 2 assimilation. This study aims at identifying the role played by red:blue (R:B) ratio on the resource use efficiency of indoor basil cultivation, linking the physiological response to light to changes in yield and nutritional properties. Basil plants were cultivated in growth chambers under five LED light regimens characterized by different R:B ratios ranging from 0.5 to 4 (respectively, RB 0.5 , RB 1 , RB 2 , RB 3 , and RB 4), using fluorescent lamps as control (CK 1). A photosynthetic photon flux density of 215 µmol m −2 s −1 was provided for 16 h per day. The greatest biomass production was associated with LED lighting as compared with fluorescent lamp. Despite a reduction in both stomatal conductance and PSII quantum efficiency, adoption of RB 3 resulted in higher yield and chlorophyll content, leading to improved use efficiency for water and energy. Antioxidant activity followed a spectral-response function, with optimum associated with RB 3. A low RB ratio (0.5) reduced the relative content of several volatiles, as compared to CK 1 and RB ≥ 2. Moreover, mineral leaf concentration (g g −1 DW) and total content in plant (g plant −1) were influences by light quality, resulting in greater N, P, K, Ca, Mg, and Fe accumulation in plants cultivated with RB 3. Contrarily, nutrient use efficiency was increased in RB ≤ 1. From this study it can be concluded that a RB ratio of 3 provides optimal growing conditions for indoor cultivation of basil, fostering improved performances in terms of growth, physiological and metabolic functions, and resources use efficiency.
Improved red and blue ratio in LED lighting for indoor cultivation of basil
Acta Horticulturae, 2020
Indoor farming systems are claimed to improve plant resource use efficiency (including water) as compared to traditional growing systems. However, electricity costs associated with plant lighting are still limiting the growth of the sector. Light emitting diodes (LEDs) may provide elevate electricity use-efficiency, while also allowing for adjusting light spectral properties to the plant needs. The goal of this study is to identify the role played by red:blue (RB) ratio on the water and energy resource use efficiency of indoor basil cultivation, linking the light physiological response to changes in yield. Basil plants were cultivated in growth chamber under LED lights supplying 5 different RB ratio regimens (respectively, RB0.5, RB1, RB2, RB3, and RB4) and against fluorescent lamps as control (FL1). In all treatments light supplied provided a PPFD of 215 μmol m-2 s-1 and a photoperiod of 16 h of light per day. Greater biomass production was associated with LEDs lighting as compared with fluorescent lamp, with best performances observed using RB≥2. Adoption of RB2 and RB3 improved also the plant's capacity to transform resources, resulting in greatest energy use efficiency. Decreasing RB ratio increased leaf stomatal conductance, therefore leading to low water use efficiency under RB<2. From this study it can be concluded that a RB ratio of 2 or 3 improves water and energy use efficiency in indoor cultivation of basil.
Agriculture, 2019
The aim of this study was to evaluate the growth characteristics and pigment content of tomato plantlets grown under various ratios of red (R) (661 nm) and blue (B) (449 nm) LED light. In this study, three different ratios of R and B (RB) light such as 5:01, 10:01, and 19:01 along with R (100%) were used. The photosynthetic photon flux density (PPFD), and photoperiod of the growth chamber was 120 ± 5 μmol m−2s−1 and 16/8 h (day/night), respectively. Tomato plantlets were cultured for six weeks in the growth chamber. It was shown that tomato plantlets had higher photosynthesis rate, higher pigments content, higher growth characteristics (e.g., number of leaves, leaf area, shoot number, root number, root length, dry, and fresh mass), and greater surviving rate under the R:B = 10:01 ratio among the treatments. The plantlets showed at least a threefold decrease in photosynthesis rate, as well as a significant abnormal stem elongation when grown under 100% R light. It is concluded that t...
Plants, 2019
The aim of this study was to investigate the different combinations of red (R) and blue (B) light emitting diode (LEDs’) lighting effects on growth, pigment content, and antioxidant capacity in lettuce, spinach, kale, basil, and pepper in a growth chamber. The growth chamber was equipped with R and B light percentages based on total light intensity: 83% R + 17% B; 91% R + 9% B; 95% R + 5% B; and control was 100% R. The photosynthetic photon flux density (PPFD), photoperiod, temperature, and relative humidity of the growth chamber were maintained at 200 ± 5 μmol m−2 s−1, 16 h, 25/21 ± 2.5 °C, and 65 ± 5%, respectively. It is observed that the plant height of lettuce, kale, and pepper was significantly increased under 100% R light, whereas the plant height of spinach and basil did not show any significant difference. The total leaf number of basil and pepper was significantly increased under the treatment of 95% R + 5% B light, while no significant difference was observed for other pl...
Agronomy, 2019
Light is a crucial element for plant growth and production. In areas where natural light is not sufficient for optimal plant growth and production, high pressure sodium (HPS) light sources are widely used. However, HPS lamps are considered not very electrically efficient generating high radiant heat and as a consequence, there has been a lot of interest in replacing HPS lamps with new more efficient lighting sources in the form of light-emitting diodes (LEDs). The effects of three lighting sources (White LED, Blue/Red LED and HPS) on the growth, development and on the essential oil yield and quality of sweet basil and bush basil were investigated. There was a clear advantage to the Blue/Red (452 nm and 632 nm, respectively) LED on virtually all growth and physiological parameters measured for both basil species. The HPS lighting system always performed least effectively in all comparisons. Combining increases in plant yield and increases in oil yield the Blue/Red LED array outperfor...