ARTICLE | doi:10.20944/preprints201811.0408.v1
Subject: Biology, Plant Sciences Keywords: red raspberry; cuticle; stomata; micromorphology; anatomy; ultrastructure elements
Online: 16 November 2018 (11:32:10 CET)
Leaves of Rubus idaeus are a raw material, ingredients of herbal blend and a source of antioxidants. There are no data concerning histochemistry of trichomes and little is known about the leaves structure of this species. The aim of this study was to determine the histochemistry of active compounds and the structure of glandular trichomes, micromorphology, anatomy and ultrastructure of leaves as well as content of elements. To determine the histochemistry of glandular trichomes different chemical compounds were used. The leaves structure was analysed using light, scanning, and transmission electron microscopes. The content of elements was determined with atomic absorption spectrometry and the microanalysis of the epidermis ultrastructure was carried out with transmission electron microscope equipped with a digital X-ray analyser. In glandular trichomes: polyphenols, terpenes, lipids, proteins, and carbohydrates were identified. The main elements in the ultrastructure of the epidermis were: Na, S, Ca, Mg, B, Mo, and Se. In dry matter of leaves K, Mg, Ca, P, and Fe were dominant. Infusions from leaves are safe for health in terms of the Cd and Pb concentrations. Leaves can be a valuable raw material. Non-glandular trichomes prevent clumping of mixed raw materials in herbal mixtures.
ARTICLE | doi:10.20944/preprints201805.0194.v1
Subject: Biology, Horticulture Keywords: ex vitro; internode; light-emitting diodes; stomata; rosette
Online: 14 May 2018 (12:12:07 CEST)
Transferring in vitro-cultured Eustoma seedlings to an ex vitro condition (acclimation) is a big challenge that may expose the seedlings to biotic and abiotic stresses, and affect the internal and external structure of the plants. In addition, in vitro-cultured seedlings of Eustoma are difficult to handle and phenotype and physiological traits such as survival and rosette rate may have altered in the acclimation stage. Therefore, the present study aims to examine the effects of blue, red, and white LED light on the growth and development ex vitro of in vitro-cultured seedlings of Eustoma. The results showed that blue LEDs resulted in greater plant height, internode length, and leaf number, increased upper and lower fresh biomass, and higher chlorophyll content compared with treatment by the other LED lights. Higher stomatal density on the abaxial leaf surface was also observed in the blue LED-treated plants, which also showed a higher survival rate and lower rosette rate. In contrast, the white LED-treated plants had the highest leaf width and internode diameter. Acclimation of the Eustoma plants ex vitro suggests that a combination of blue and white LEDs may be advantageous for better growth and development for large-scale production in a controlled environment.
ARTICLE | doi:10.20944/preprints202206.0021.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: vertical farming; controlled environment; lettuce cultivars; anthocyanin; light quality; LEDs; light recipe; stomata
Online: 1 June 2022 (13:17:55 CEST)
Indoor crop cultivation systems such as vertical farms or plant factories necessitate artificial lighting. Light spectral quality can affect plant growth and metabolism and, consequently, the amount of biomass produced and the value of the produce. Conflicting results on the effects of light spectrum in different plant species and cultivars make it critical to implement a singular lighting solution. In this study we explored the response of green and red leaf lettuce cultivars (’Aquino’, CVg, or ‘Barlach’, CVr, respectively) to long-term blue-enriched light application (WB). Plants were grown for 30 days in a growth chamber with optimal environmental condi-tions (temperature: 20°C, relative humidity: 60%, ambient CO2, Photon Flux Density (PFD) of 260 µmol m-2 s-1 over an 18-h photoperiod). At 15 days after sowing (DAS) white spectrum LEDs (WW) were compared to WB (λPeak = 423 nm) maintaining the same PFD of 260 µmol m-2 s-1. At 30 DAS, both lettuce cultivars resulted adapted to the blue light variant, though the adaptive re-sponse was specific to the variety. Rosette weight, light use efficiency and maximum operating efficiency of PSII photochemistry in the light, Fv/Fm’, were comparable between the two light treatments. Significant light quality effect was detected on stomatal density and conductance (20% and 17% increase under WB, respectively, in CVg) and, on the modified anthocyanin re-flectance index (mARI) (40% increase under WB, in CVr). Net photosynthesis response was gen-erally stronger in CVg compared to CVr; e.g. net photosynthetic rate, Pn, at 1000 µmol m-2 s-1 PPFD increased from WW to WB by 23% in CVg, compared to 18% in CVr. Results obtained suggest the occurrence of distinct physiological adaptive strategies in green and red pigmented lettuce cultivars to adapt to the higher proportion of blue light environment.