Relative Light Intensity Research Articles

Physiological and Transcriptomic Variability Indicative of Differences in Key Functions Within a Single Coral Colony

Polyps in different locations on individual stony coral colonies experience variation in numerous environmental conditions including flow and light, potentially leading to transcriptional and physiological differences across the colony. Here, we describe high-resolution tissue and skeleton measurements and differential gene expression from multiple locations within a single colony ofStylophora pistillata, aiming to relate these to environmental gradients across the coral colony. We observed broad transcriptional responses in both the host and photosymbiont in response to height above the substrate, cardinal direction, and, most strongly, location along the branch axis. Specifically, several key physiological processes in the host appear more active toward branch tips including several metabolic pathways, toxin production for prey capture or defense, and biomolecular mechanisms of biomineralization. Further, the increase in gene expression related to these processes toward branch tips is conserved betweenS. pistillataandAcroporaspp. The photosymbiont appears to respond transcriptionally to relative light intensity along the branch and due to cardinal direction. These differential responses were observed across the colony despite its genetic homogeneity and likely inter-polyp communication. While not a classical division of labor, each part of the colony appears to have distinct functional roles related to polyps’ differential exposure to environmental conditions.

Forest structure drives changes in light heterogeneity during tropical secondary forest succession.

Light is a key resource for tree performance and hence, tree species partition spatial and temporal gradients in light availability. Although light distribution drives tree performance and species replacement during secondary forest succession, we yet lack understanding how light distribution changes with tropical forest development.This study aims to evaluate how changes in forest structure lead to changes in vertical and horizontal light heterogeneity during tropical forest succession.We described successional patterns in light using a chronosequence approach in which we compared 14 Mexican secondary forest stands that differ in age (8–32 years) since agricultural abandonment. For each stand, we measured vertical light profiles in 16 grid cells, and structural parameters (diameter at breast height, height and crown dimensions) for each tree.During succession, we found a rapid increase in stand size (basal area, crown area and length) and stand differentiation (i.e. a gradual leaf distribution along the forest profile), which leads to fast changes in light conditions and more light heterogeneity. The inflection points of the vertical light gradient (i.e. the absolute height at which 50% relative light intensity is attained) rapidly moved towards higher heights in the first 20 years, indicating that larger amounts of light are intercepted by canopy trees. Light attenuation rate (i.e. the rate of light extinction) decreased during succession due to slower accumulation of the crown area with height. Understorey light intensity and heterogeneity slightly decreased during succession because of an increase in crown size and a decrease in lateral gap frequency. Understorey relative light intensity was 1.56% at 32 years after abandonment.Synthesis. During succession, light conditions changed linearly, which should lead to a continuous and constant replacement of species. Especially in later successional stages, stronger vertical light gradients can limit the regeneration of light‐demanding pioneer species and increase the proportion of shade‐tolerant late‐successional species under the canopy. These changes in light conditions were largely driven by the successional changes in forest structure, as basal area strongly determined the height where most light is absorbed, whereas crown area, and to a lesser extent crown length, determined light distribution.

Effects of polymers concentration on EHL film-forming in point contacts

Purpose This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact under pure rolling. Design/methodology/approach By using the relative light intensity method, the film thickness is calculated from the interferometer images which are captured by multiple-contact optical elastohydrodynamic lubricated test rig. Findings The test results reveal that polymers, both PMA and PIB, have a significant contribution to the film-forming capability of base oils and the film thickness increases with concentration. The forming-film capabilities for PMA and PIB in base oils are similar at low concentration, while PIB gives a higher film thickness than PMA at high concentration. Shear-thinning phenomenon are observed in all polymer-based oils. Originality/value The polymer usually as an additive is added into the low viscosity base oils to improve the properties of lubricant oil. This paper reports the lubricated properties of PMA and PIB with different concentrations in base oils and to evaluate their functional mechanism in a point contact. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0263/

Melanin pigmented gingival tissue impairs red-light lateral scattering for antimicrobial photodynamic therapy.

Gingival melanin pigmentation is present in many African and Oriental descendant people and its occurrence in patients may interfere with the absorption and scattering of therapeutic doses of light. Antimicrobial photodynamic therapy (aPDT) is used as an adjunctive treatment for periodontitis and light irradiation may be impaired by tissue size and its melanin content. The aim of this clinical study was to measure the red-light attenuation in gingival tissue naturally pigmented with melanin. Ten patients with melanized gingival tissue were selected and irradiated by 100 mW red laser. The patients were photographed in frontal and incisal regions with a T2i camera (Canon, Japan) with 100 mm macro lens, 35 mm focal length, aperture f22, 1/100 shutter speed and ISO 200. Three randomly selected sites of each patient were used for evaluations and the irradiation values were assessed in the IMAGEJ software (NIH, Wayne Rasband, USA). Intensity in pixels was quantified in relation to the distance from the light incident point. Data were normalized and the results were presented as relative light intensity as a function of distance. The results demonstrated that red laser light is exponentially attenuated as a function of lateral distance and loses approximately 50 % of its intensity by 2.23 mm. On the other hand, the light travels 3 mm in depth to decay 50 %. In conclusion, our data suggest that melanin presence decreases optical pathway and irradiation protocols for antimicrobial photodynamic therapy in gingival tissue should consider light attenuation and depth of periodontal pockets so that efficient illumination of the target tissue occurs. Periodontal pockets bigger than 6 mm should be irradiated with more than one point.

Effects of soil water content and light intensity on the growth of Molinia japonica in montane wetlands in South Korea

BackgroundMontane wetlands are unique wetland ecosystems with distinct physicochemical characteristics, and Molinia japonica often makes dominant communities in montane wetlands in South Korea. In order to figure out the environmental characteristics of M. japonica habitats and the major factors for the growth of M. japonica, field surveys were conducted in five wetlands from September to October 2019. Also, soil was collected at every quadrats installed in surveyed wetlands to analyze the physicochemical features.ResultsThe relative coverage of M. japonica was higher in low latitude wetlands than in high latitude. Redundancy analysis showed that soil water content had the strongest effect on the growth of M. japonica (F = 23.0, p < 0.001). Soil water content, loss on ignition, and relative light intensity showed a high correlation with the density (R = 0.568, 0.550, 0.547, respectively, p < 0.01) and the coverage of M. japonica (R = 0.495, 0.385, 0.514, respectively, p < 0.01). Soil water content, loss on ignition, and pH were highly correlated with each other.ConclusionsMolinia japonica lives in acidic wetlands at high altitude in temperate zone of low latitude, with peat layer placed on the floor. Also, M. japonica prefers open spaces to secure enough light for photosynthesis. High shoot production of M. japonica resulted in adding new peat material in every year, and this layer enforces the environmental characteristics of M. japonica habitats. This study may provide insights for further understanding of the method how wetlands maintain acidic condition by itself in montane wetlands in temperate zone.

Spatio-temporal measurements of overshoot phenomenon in pulsed inductively coupled discharge* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11675039, 11875101, 11935005, and 12075049) and the Fundamental Research Funds for the Central Universities of China (Grant Nos. DUT18TD06 and DUT20LAB201).

Pulse inductively coupled plasma has been widely used in the microelectronics industry, but the existence of overshoot phenomenon may affect the uniformity of plasma and generate high-energy ions, which could damage the chip. The overshoot phenomenon at various spatial locations in pulsed inductively coupled Ar and Ar/CF4 discharges is studied in this work. The electron density, effective electron temperature, relative light intensity, and electron energy probability function (EEPF) are measured by using a time-resolved Langmuir probe and an optical probe, as a function of axial and radial locations. At the initial stage of pulse, both electron density and relative light intensity exhibit overshoot phenomenon, i.e., they first increase to a peak value and then decrease to a convergent value. The overshoot phenomenon gradually decays, when the probe moves away from the coils. Meanwhile, a delay appears in the variation of the electron densities, and the effective electron temperature decreases, which may be related to the reduced strength of electric field at a distance, and the consequent fewer high-energy electrons, inducing limited ionization and excitation rate. The overshoot phenomenon gradually disappears and the electron density decreases, when the probe moves away from reactor centre. In Ar/CF4 discharge, the overshoot phenomenon of electron density is weaker than that in the Ar discharge, and the plasma reaches a steady density within a much shorter time, which is probably due to the more ionization channels and lower ionization thresholds in the Ar/CF4 plasma.

Effects of thinning and reshaping on canopy micro-domain environment and leaf physiological characteristics in dense Fuji apple orchard on Loess Plateau of eastern Gansu, China

We examined the effects of thinning and reshaping on the canopy micro-domain environment, leaves micro-structure, physiological characteristics and photosynthetic capacity of 16 year-old Fuji apple dense orchards by measuring canopy relative light intensity, temperature, relative humidity, leaf chlorophyll content, micro-structure, and photosynthetic fluorescence. After thinning and reshaping, relative light intensity and temperature of tree canopy were significantly improved, and the distribution was balanced. Effective light intensity (&gt;30%) was 57% higher than that of control (thinning and reshaping, CK), and temperature increased by 1.1 ℃. Due to the improvement of relative light intensity and temperature in the canopy, leaf chlorophyll, leaf thickness, and palisade tissue thickness of thinning trees were increased by 8.7%, 5.4%, and 9.2%, respectively. Net photosynthetic rate, transpiration rate and stomatal conductance of the leaves were also significantly increased, being 12.6%, 17.1% and 7.3% higher than CK, respectively. Leaf photosynthesis capacity of both treatments was limited by non-stomatal factors. After thinning and reshaping, Fm (maximum fluorescence) and qN(non-photochemical quenching coefficient) of PSⅡ in leaves were increased by 1.5% and 2.1%. Leaves did not suffer strong light photoinhibition, with ABS/RC (unit reaction center absorbs light energy), ETo/RC (energy used for electron transfer captured by unit reaction center) and TRo/RC (energy captured by the unit reaction center to reduce QA) of leaves being significantly improved. The physiological characteristics of leaves were closely related to light and temperature environment. After thinning, light and temperature of the orchard canopy were improved, which promoted leaves growth and development, improved foliar micro-structure and photosynthetic efficiency. Thinning and reshaping were suitable strategies for the adjustment and optimization of Fuji orchard density in Loess Plateau of eastern Gansu.

Design of temperature humidity and illumination control system for indoor flowers

In order to improve the automation of indoor flower environment monitoring, enable the flowers grow in the best environment, this paper designs an automatic control system of temperature, humidity and illumination based on STC89C52 single chip microcomputer. Temperature sensor DS18B20 is applied to sense indoor air temperature, meantime, YL-69 soil moisture sensor and photosensitive resistance are used to sense soil relative humidity and light intensity respectively. Temperature, humidity and light intensity are transmitted to single chip microcomputer for analysis and processing, and the results are displayed by OLED display module. The upper and lower limits of environmental parameters are manually preset through the keyboard. When the temperature and light intensity exceed the upper limit, the system can send out alarm signals and output control signals to drive the corresponding actuator to work; when the soil moisture is lower than the lower limit, the system will automatically alarm and water automatically; when the humidity reaches the upper limit, watering will be stopped to ensure the indoor environmental parameters in the best value suitable for flower growth. The system has been tested and debugged. The results show that the control system can effectively process and display the flower environment information, achieving the purpose of automatically adjusting and controlling the temperature, humidity and illumination of flowers, has strong promotion value.

Adjustable unidirectional beam splitters in two dimensional photonic crystals

The splitting properties are investigated in two dimensional silicon photonic crystals by adjusting the interface of the structure. Introducing elliptical air holes with optimized parameters on the heterointerface, the forward transmittance is significantly improved in a wide frequency range. Correspondingly, the unidirectional two-beam splitter is realized and the relative light intensities of each beam can be continuously adjusted by modulating the area ratio (AR) of elliptical air holes. Furthermore, the output beams can be changed into three and five beams by alternately introducing elliptical air holes on the monolayer output interface. Not only the forward light intensities of each beam can be continuously adjusted, but also the reverse can be tuned simultaneously by modulating the shape of elliptical air holes. Particularly, the light transmission behaviors along two opposite directions are significantly different. Moreover, the elliptical-shaped air holes have more structural freedoms and increase the design flexibility of the devices. The performance of the splitter is found to be very encouraging in the complex photonic integrated circuits.

An Optimization Model for Environmental Ergonomics Assessment in Bioproduction of Food SMEs

Environmental ergonomics in bioproduction of food Small Medium-sized Enterprises (SMEs) become a concern and need to be optimized. An optimization model was developed using a Genetic Algorithm (GA). The weight of an Artificial Neural Network Model was used as a fitness function for GA. The research objectives were: 1) To design an environmental ergonomic assessment system for bioproduction of Food SMEs, 2) To develop an optimization model for environmental ergonomic assessment using a Genetic Algorithm. GA is utilized to search optimal set points of environmental ergonomics based on the predicted fitness values. Each chromosome of GA represents the environmental ergonomics value. The parameters were heart rate, bioproduction temperature, distribution of bioproduction relative humidity and light intensity. The target of the optimization model was the bioproduction temperature set points. The research result indicated the model generated optimum values of environmental ergonomics parameter in bioproduction of food SMEs. The parameters could be used to provide standard workplace environment for the sustainability of food SMEs.

First Report of Powdery Mildew Caused by Podosphaera xanthii on Hulless Cucurbita pepo of Inner Mongolia and Xinjiang Autonomous Region in China.

Hulless Cucurbita pepo is an annual herb in the Cucurbitaceae family and is one of the main economic vegetable crops in China, and is a raw material for cosmetics and health care products. It is also called hulless pumpkin because its seeds have no seed coat, which is a rare variation of the Cucurbita. In July 2010, powdery mildew was observed on hulless Cucurbita pepo 'Tianran' in fields of Wuwei District, China(Liang et al.2010). Disease incidence when first observed was 65.67%, but increased to 100% in July 2019. Early disease symptoms appeared as circular or irregular white powdery areas on both leaf surfaces. At later infection stages, entire leaves，petioles, and stems were covered with white fungal mycelia that resulted in leaf yellowing and senescence，but not defoliation . Fungal hyphae were septate, branched and flexuous to straigh. Conidiophores were unbranched, straight and grew vertically to the mycelium. Conidiophore foot cells of the were cylindrical with slight constriction at basal septa and followed by one to four short cells that eventually became conidia. Conidia were barrel-shaped with ends darker than the middle and measured 20 to 32 × 12 to 19μm.T Cleistothecium formed at 20 ℃, 70% relative humidity and light intensity of 4,400 lx. They were scattered, spherical, dark brown, with parietal cells irregularly rectangular or polygonal, and 70 to 75×90 to 95μm in diameter. Cleistothecia had four to eight appendages that were colorless to partially brown, each with three to five septa and lengths 0.5 to 3.0 times the diameter of cleistothecia. The powdery mildew fungus was tentatively identified as Podosphaera xanthii and showed characteristics similar to those reported by others (Cui et al. 2018; Choi et al. 2020). rDNA was extracted from pools of fungus conidia and the ITS region amplified using primers ITS 1:5'-TCCGTAGGT GAACCTGCGG-3'/ITS 4:5'-TCCTCCGCTTATTGATATGC-3' and then sequenced. BLASTn analysis of the 540-bp (MT250855) amplicon revealed 100% sequence identity with respective rDNA sequences of Podosphaera xanthii isolates from Momordica charantia(AB774158.1). Based on the morphological characteristics and ITS sequences, the fungal species was identified as P. xanthii .Pathogenicity of the powdery mildew fungus was tested by dusting conidia from infected hulless pumpkin leaves onto three asymptomatic plants. Three noninoculated plants was used as a controls. The Infection process of P.xanthii on pumpkins observed that the conidia began to germinate at 12h after inoculation.Twenty four to 72 h post inoculation, powdery mildew mycelia appeared on inoculated leaves. After 73 to 96 h, chains of conidia formed and these germinated to form secondary infection sites. In later stages of the disease cycle, dark brown cleistothecia formed on the yellowing plant foliage. Fungus morphology from inoculated leaves was identical to that observed on original naturally infected plants. Uninoculated plants remained healthy. Powdery mildew caused by P. xanthii is a major foliage disease that affects members of the Cucurbitaceae family worldwide. The fungus has previously been reported from China on Cucurbita moschata (DQ490752), Cucurbita maxima (DQ490759), Cucurbita pepo(DQ490750), Cucumis sativus(DQ490755)(Park et al.2010; Liang et al.2007) and Cucurbita maxima, Abelmoschus esculentus (okra), Sechium edule (mirliton, vegetable pear), and Lagenaria siceraria (bottle gourd) (Choi et al. 2020; Fan et al. 2019; Xu et al. 2020; Cui et al. 2018).To our knowledge, this is the first report on the occurrence of P. xanthii on hulless Cucurbita pepo in China.

Multi Frequency on RGB Lighting LED Driver Technique

In this paper, we conducted RGB incident light intensity of the high power white lighting LED. The current control 50% duty cycle pulse signal source with appropriate semiconductor carrier frequency response are supply to the RGB white lighting LED. Although, the carrier relaxation time of the red blue and green light in the white lighting LED are not the same value which depend on the carrier different of the energy level. The measurement show that the lowest duty cycle appropriate pulse signal for only blue or UV base white LED give more relative light intensity than normal (low frequency) signal within 11%.

Effects of bagging or the combination of umbrella and bag treatments on anthocyanin accumulation in the berry skin of ‘Kyoho’ (Vitis labruscana) Grape

The object of this study was to investigate the influence of bagging or the combination of umbrella and bags on berry composition, especially anthocyanin accumulation, in ‘Kyoho’ (V. labruscana) berry skins. Five different colors and bag materials commonly used in production were chosen for this study: white, green, yellow, nonwoven and transparent, and the umbrellas were made of plastic material. The composition and content of anthocyanins in the berry skin of ‘Kyoho’ were analyzed by HPLC-MS. The results showed that bagging or a combination of umbrella and bags on anthocyanin concentration in ‘Kyoho’ grapes showed inconsistent effects that depended on the colors and materials of the bags and the use of an umbrella or not. Compared with the control, the inhibition effects of white, green and yellow bags on the soluble solids content and the total and individual anthocyanin concentrations in ‘Kyoho’ grapes reached significant levels; effects of green and yellow bags were the most significant among them. The plastic umbrella used in this study also presented a lower relative light intensity and produced more even-colored clusters. White, green, and yellow bags and combinations of umbrella and bags significantly increased some stable anthocyanin proportions to varying degrees, such as coumaroylated and methylated anthocyanins, compared to the control.

Floquet higher-order exceptional points and dynamics in PT-symmetric quadrimer waveguides

We investigate the effect of periodic modulation on PT-symmetry recovery, higher-order exceptional points (EPs) and dynamics for a periodically modulated PT-symmetric quadrimer waveguide system. It is analytically and numerically revealed that the periodic modulation not only can restore the broken PT symmetry, but also can manipulate the PT symmetry by tuning modulation amplitude. Furthermore, we found that multiple EPs can emerge, and as the modulation amplitude vary, these EPs can collide and merge, leading to higher-order Floquet singularities. By defining average relative light intensity distribution, we explore the dynamical characteristics nearby these EPs. It is found that we can control the light tunneling direction of optical quadrimer waveguide via periodic modulation and proper choice of gain/loss parameters.

Optical modulation of repaired damage site on fused silica produced by CO2 laser rapid ablation mitigation**Project supported by the National Natural Science Foundation of China (Grant Nos. 51775147 and 51705105), the Science Challenge Project of China (Grant No. TZ2016006-0503-01), the Young Elite Scientists Sponsorship Program by CAST (Grant No. 2018QNRC001), the China Postdoctoral Science Foundation funded project (Grant Nos. 2018T110288

CO2 laser rapid ablation mitigation (RAM) of fused silica has been used in high-power laser systems owing to its advantages of high efficiency, and ease of implementing batch and automated repairing. In order to study the effect of repaired morphology of RAM on laser modulation and to improve laser damage threshold of optics, an finite element method (FEM) mathematical model of 351 nm laser irradiating fused silica optics is developed based on Maxwell electromagnetic field equations, to explore the 3D near-field light intensity distribution inside optics with repaired site on its surface. The influences of the cone angle and the size of the repaired site on incident laser modulation are studied as well. The results have shown that for the repaired site with a cone angle of 73.3°, the light intensity distribution has obvious three-dimensional characteristics. The relative light intensity on z-section has a circularly distribution, and the radius of the annular intensification zone increases with the decrease of z. While the distribution of maximum relative light intensity on y-section is parabolical with the increase of y. As the cone angle of the repaired site decreases, the effect of the repaired surface on light modulation becomes stronger, leading to a weak resistance to laser damage. Moreover, the large size repaired site would also reduce the laser damage threshold. Therefore, a repaired site with a larger cone angle and smaller size is preferred in practical CO2 laser repairing of surface damage. This work will provide theoretical guidance for the design of repaired surface topography, as well as the improvement of RAM process.

Combined modulation of incident laser light by multiple surface scratches and their effects on the laser damage properties of KH2PO4 crystal.

Manufacturing-induced surface defects are deemed as a potential source, leading the laser-induced damage threshold (LIDT) of the actual KDP crystal optics to be much lower than the intrinsic one. However, the underlying mechanisms have not been fully recognized. We explore the combined modulation of incident laser light by multiple scratches and their effects on laser damage performance of KDP optics by modeling the light intensifications and performing a laser damage test. Under the combined modulation of multiple scratches, enhanced hot spots are generated due to the focusing effects of convex lens profiles surrounded by the neighboring scratches. The combined modulation actions are much stronger than that of a single scratch. The relative light intensities (IRs) caused by multiple scratches can reach up to two times, and the number of hot spots (IPs) are four times as large as those by a single scratch. The IRs exhibit a general, increasing tendency as the scratch density increases. But for the case of double total reflections of rear-surface scratches, the totally reflected lights are transmitted through neighboring scratches, resulting in decreasing tendency of IRs. The tested LIDTs and optical transmittances of multiple scratches present a gradual, decreasing tendency with the increase of scratch density, which agrees with the simulation results. Besides, the simulated light intensifications could well explain the locations of laser damage, which further verify the role of multiple scratches in lowering the laser damage resistance.

Morpho-anatomical adaptation of lesser yam (Dioscorea esculenta) on different planting pattern and relative light intensity in Java community forest

Lesser yam (Dioscorea esculenta) is traditionally cultivated as a valuable crop species in a various planting pattern of teak-based agroforestry (AF) system in Watubonang village, Sukoharjo District, Central Java. Different planting pattern contributes to various light intensity which is associated with plant morphological and anatomical changes and directly affect to yam tuber production. Research site was selected by mean of purposive sampling method with three yam planting patterns, i.e. yam monoculture (Y), yam in trees along border (TAB) and yam in full teak trees (T-Y), in three replicates of 20 m x 20 m plots. In each plot, four subplots were established to investigate relative light intensity and take leaf samples. Changes in morphological and anatomical characteristics of yam to different planting pattern and relative light intensity (RLI) were studied, including leaf size, leaf color, tendril and internode length, chlorophyll content and stomatal density. The result showed that RLI were significantly different among planting pattern (Y: 78.66%, TAB: 66.94%, T-Y: 34.05%). Planting pattern and interaction between planting pattern and RLI significantly affected yam morphological and anatomical characteristics (of leaf size, tendril & internode length, and stomatal density) at P < 0.05. Leaf size, tendril and internode length increased with decreasing of RLI in TAB, but opposite adaptation was found in T-Y planting pattern. Higher RLI resulted in reductions of chlorophyll a and chlorophyll b content, and therefore increased of chlorophyll a:b ratio. Leaf color of yam grown under high RLI (Y) were light green, while those grown under shaded condition with relatively low light intensity (TAB, T-Y) were dark green that may related to the foliar chlorophyll content. Hence, a trend of decreasing stomatal density was found associated with lower RLI (Y: 35 stomatal/mm2, TAB: 25 stomatal/mm2, T-Y: 19 stomatal/mm2). Approximately 50-60% of RLI is suggested to be an optimum intensity for yam cultivation to support yam tuber production. Agroforestry practice by applying pruning and managing planting density are needed to reach the optimum light.

Anatomy adaptation of Ketak (Lygodium circinatum (Burm.) Sw) to relative light intensity in agroforestry systems, on Senaru Education Forest, West Nusa Tenggara

Ketak requires other plant as a climbing host for tendrils in order to get light. Research on the types of stands that affect tendril production in agroforestry systems is needed. This study aimed to determine anatomical adaptation of ketak at various types of stands and relative light intensity in agroforestry systems. The research method used a randomized block design. There were 2 treatments i.e. the stand type (natural stands, coffee stands, gliricidia stands, and mahogany stands) and Relative Light Intensity (RLI). Each stand consists of 3 blocks with 30 replication plants, making it a total of 90 plants per stand type. We used natural seedling as understory and combined with forestry plants. Number of leaves, plant height, plant number, plant length, tendrils diameter and growth percentage of ketak, and RLI were measured or calculated in each stand type. Variance analysis was used to determine the effect of stand type. Multiple linear regression was used to determine the relationship between stand types or RLI and number of leaves, plant height, plant number, plant length, and tendrils diameter. This study showed that (1). The growth percentage of ketak in natural stand, coffee stand, gliricidia stand, and mahogany stand respectively 62.22%, 97.77%, 75.56%, and 74.44% (2). The stand type with significant differences were found in the total number of leaves (F = 17.441; p = 0.000); plant height (F = 24.065; p = 0.000) and tendril diameter (F = 7.747; p = 0.000), but not in the total number and lengthof tendrils. (3). There were significant differences in stand type and RLI on total number of leaf, plant height, and tendril diameter of ketak plants with value of total number of leaf (F= 15,92, p = 0,00, and R square = 0,08); value of plant height (F = 34,63, p = 0,00, dan R square = 0,0005); and value of tendril diameter (F = 5,62, p = 0,00, dan R square = 0,0034). While in the total number of tendrils and tendrils length of ketak plants were not significant. The conclusion were (1) The highest growth percentage of ketak in Coffee stand is 97.77%. (2) Coffee stand had the highest influence on the total number of leaves, plant height and tendrils diameter. 3. The stand type and RLI only had a relationship with total number of leaf, plant height, and tendril diameter of ketak plants but not with total number of tendrils and tendrils length.

Manipulating the Difference between the Day and Night Temperatures Can Enhance the Quality of Astragalus membranaceus and Codonopsis lanceolata Plug Seedlings

Astragalus membranaceus Bunge and Codonopsis lanceolata Benth. et Hook. f. are two famous medical species in Korea, China, and Japan, mainly used for treating diseases including cancer, obesity, and inflammation. Manipulation of the difference between the day and night temperatures (DIF) is an efficient horticultural practice to regulate the growth and development of vegetables in a glasshouse. However, little research has focused on how the DIF influences the plug seedling quality of medicinal plants. In this study, uniform plug seedlings were cultivated in three environmentally controlled chambers under an average daily temperature of 20 °C with negative (−10 °C), zero, or positive (+10 °C) DIFs, and the same relative humidity (75%), photoperiod (12 h), and light intensity (150 μmol·m−2·s−1 photosynthetic photon flux density with white LEDs). The results showed that the DIF had a noticeable effect on the growth, development, and morphology of A. membranaceus and C. lanceolata plug seedlings. The positive DIF (+10 °C) significantly increased the biomass (shoot, root, and leaf), stem diameter, and Dickson’s quality index, indicating an enhanced plug seedling quality. Moreover, the contents of primary and secondary metabolites, including soluble sugar, starch, total phenols and flavonoids, were higher with higher DIFs, where the maximum values were found at 0 °C or +10 °C DIF. Furthermore, the increases in the chlorophyll content and stomatal conductance were obtained in a positive DIF, indicating that a positive DIF was favorable to photosynthesis. An analysis of the gene expression showed that a positive DIF (+10 °C) up-regulated the expression of photosynthetic genes, including GBSS, RBCL, and FDX. In conclusion, the results of this study recommend a positive DIF (+10 °C) for enhancing the quality of A. membranaceus and C. lanceolata plug seedlings.

Night Temperature Affects the Growth, Metabolism, and Photosynthetic Gene Expression in Astragalus membranaceus and Codonopsis lanceolata Plug Seedlings.

Astragalus membranaceus and Codonopsis lanceolata are two important medical herbs used in traditional Oriental medicine for preventing cancer, obesity, and inflammation. Night temperature is an important factor that influences the plug seedling quality. However, little research has focused on how the night temperature affects the growth and development of plug seedlings of these two medicinal species. In this study, uniform plug seedlings were cultivated in three environmentally controlled chambers for four weeks under three sets of day/night temperatures (25/10 °C, 25/15 °C, or 25/20 °C), the same relative humidity (75%), photoperiod (12 h), and light intensity (150 μmol·m−2·s−1 PPFD) provided by white LEDs. The results showed that night temperature had a marked influence on the growth and development of both species. The night temperature of 15 °C notably enhanced the quality of plug seedlings evidenced by the increased shoot, root, and leaf dry weights, stem diameter, and Dickson’s quality index. Moreover, a night temperature of 15 °C also stimulated and increased contents of primary and secondary metabolites, including soluble sugar, starch, total phenols and flavonoids. Furthermore, the 15 °C night temperature increased the chlorophyll content and stomatal conductance and decreased the hydrogen peroxide content. Analysis of the gene expression showed that granule-bound starch synthase (GBSS), ribulose bisphosphate carboxylase large chain (RBCL), and ferredoxin (FDX) were up-regulated when the night temperature was 15 °C. Taken together, the results suggested that 15 °C is the optimal night temperature for the growth and development of plug seedlings of A. membranaceus and C. lanceolata.