Effects of varying light quality from single-peak blue and red light-emitting diodes during nursery period on flowering, photosynthesis, growth, and fruit yield of everbearing strawberry

Abstract

We studied the effects of varying light quality on the flowering, photosynthetic rate and fruit yield of everbearing strawberry plants (Fragaria×ananassa Duch. 'HS138'), which are long-day plants, to increase the efficiency of fruit production in plant factories. The plants were grown under continuous lighting using three types of blue and red LEDs (blue light peak wavelength: 405, 450, and 470 nm; red light peak wavelength: 630, 660, and 685 nm) during the nursery period. All blue light from the various peak LED types promoted more flowering compared with red light (630 and 660 nm except for 685 nm). The longer wavelength among the red light range positively correlated with earlier flowering, whereas the number of days to anthesis did not significantly differ among blue LED treatment wavelengths, irrespective of peak wavelength. The result of a similar experiment using the perpetual flowering Fragaria vesca accession Hawaii-4 representing a model strawberry species showed almost the same pattern of flowering response to light quality. These results suggest that long-day strawberry plants show similar flowering response to light quality. The photosynthetic rate under red light (660 nm) was higher than that under blue light (450 nm). However, the plants grown under red light showed lower photosynthetic capacity than those grown under blue light. Although the light color used to grow the seedlings showed no difference in the daily fruit production, blue light irradiation during the nursery period hastened harvesting because of the advance in flowering.

Effects of overnight radiation with monochromatic far-red and blue light on flower budding and expression of flowering-related and light quality-responsive genes in <I>Eustoma grandiflorum</I>

“…In contrast, the expression of FT and SOC1 homologs was induced by both far-red light and blue light in G. paniculata 'Million Star', which showed the same flowering response to light quality. In addition, although flowering was promoted by both far-red and blue light in long-day strawberry plants, the expression of FT homolog was induced only by blue light Yoshida et al, 2016 . In the present study, the levels of EgFTL and EgSOC1L showed peaks preceding flower bud differentiation in FR and B, suggesting that both genes play a role in flowering in E. grandiflorum, an effect similar to that seen in G. paniculata 'Million Star'. In addition, the later expression of these genes by B in E. grandiflorum compared to that by FR could be associated with weak promotion of flowering by blue light.…”

Deciphering the Metabolic Pathways of Pitaya Peel after Postharvest Red Light Irradiation

“…The peel tissues (2.0 g) were ground and then extracted with 20 mL methanol for 30 min. After centrifugation at 15,000 g for 20 min, the supernatants was collected for the determination of DPPH radical scavenging activity and reducing power according to the method described by Duan et al [8]. Briefly, 0.1 mL of supernatant with 2.9 mL of 0.1 mM DPPH dissolved in methanol solution, and the absorbance was measured at 517 nm to calculate the DPPH radical scavenging activity.…”

“…Light is not only the energy source for plants, but also an essential signal for plant growth and development [7]. Red light could enhance photosynthetic rate of strawberry [8] and function as a global signal in Pseudomonas syringae pv. syringae strain B728a [9].…”

Breeding new varieties for controlled environments

“…The precise timing of production is attractive to growers as they can reach counter-seasonal markets where produce may command a higher retail price. Manipulation of the light environment may provide a means to alter developmental transition to flowering, as light quality has been shown to affect the process in fruit crops (Rantanen et al 2014;Yoshida et al 2016) and flowers (Park et al 2015;Tsukamoto et al 2016). In the case where vegetative plant products are desired, such as herbs, specific light treatments can be implemented to suppress flowering or increase biomass (Stagnari et al 2018).…”