Leaf and whole-plant gas exchange and water-use efficiency of chrysanthemums under HPS and LEDs during the vegetative and flower-induction stages

Abstract

The effects of light quality on photosynthesis and transpiration of chrysanthemums during the vegetative and flowering stages are not known. Leaf and whole-plant CO2 and H2O exchanges of chrysanthemums during long-day (LD) and short-day (SD) photoperiods were measured under varying intensity levels of high-pressure sodium (HPS) and different monochromatic and multicolour light-emitting diode (LED) lights. All light sources induced leaf photosynthesis effectively, including green and orange LEDs. During both LD and SD, HPS, white, and notably orange light produced high rates of photosynthesis, whereas blue light had the lowest rates. In addition, there were only subtle changes in the response of leaf functions to light quality during flowering induction. Diurnal patterns of whole-plant net C exchange rate were similar under HPS and two commercial LED lights, one red–blue (RB) and one red–white (RW), during both LD and SD. The RB and RW LED lights were as effective at maintaining whole-plant C gain during the day as traditional HPS lights. However, in comparison to HPS, the RB and RW LEDs increased whole-plant transpiration and decreased water-use efficiency (WUE). A decrease in WUE under these LEDs was not evident from the leaf measurements, which emphasizes the importance of examining responses to light quality at the whole-plant level as well and not at the leaf level alone. In commercial production, the wavelength of supplementary lighting may heavily influence WUE and subsequent nutrient uptake, and ultimately growth and quality of cut flower crops.

Spectral effect of streetlamps on urban trees: A simulated study on tissue water, nitrogen, and carbohydrate contents in maple and oak

“…The spectrum from RB light in our study resulted in a decline of whole-plant water content in maple seedlings compared to the control. These results concur with those found on vegetative and flower crops [ 56 , 57 ]. In addition, a white light spectrum was found to indicate an increase in transpiration rate and internal CO 2 concentration and a subsequent decrease in WUE in tomato ( Solanum lycopersicum ) plants.…”

“…These meant that the process of producing and accumulating biomass and carbohydrate was accompanied by the consumption of tissue water. Lighting spectra can promote the gas exchange to elevate C assimilation for carbohydrate and biomass accumulation, which would decrease WUE through increasing transpiration [ 56 , 57 ]. The spectrum from RB light in our study resulted in a decline of whole-plant water content in maple seedlings compared to the control.…”

Blue Light Improves Stomatal Function and Dark-Induced Closure of Rose Leaves (Rosa x hybrida) Developed at High Air Humidity

“…An important aspect of the commercial application of LEDs as supplementary lighting is how plant production can be optimized. However, attention has also been placed on other important processes like content of phytochemicals, water use efficiency (WUE), field performance and postharvest behavior (Arve et al, 2015b;Riikonen, 2016;Lanoue et al, 2017;Ahmadi et al, 2019;Leonardos et al, 2019). In spite of the progress in research on light regulation of stomatal movement, there is a lack of information on the interaction between light quality and other environmental factors.…”

LED-Induced Carotenoid Synthesis and Related Gene Expression in Brassica Microgreens

“…In most cases, the accumulation of xanthophylls and carotenes was dose-dependent, and these effects can be the result of biochemical transformation in response to increased light intensity or the conversion to zeaxanthin from violaxanthin under strong short-energy BL (Figure ). ,, TCC and α-carotene in the flavedo of citrus fruits were decreased under rLED, while both bLED and aLED had higher rates of carbon export in tomato leaves. , In another report, chrysanthemum grown under OL had higher photosynthetic maximums compared to bLED . These findings suggest that an individual species can respond variably to LED, and therefore, different strategies may be deployed when targeting enhanced carotenoid photosynthesis in vegetable plants.…”