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This study addresses the growing need for phytoncide studies, driven by the demand to design indoor forest healing programs, including virtual reality experiences, for patients unable to visit actual forests. Previous studies have struggled to establish consistent phytoncide emission patterns in outdoor forest environments owing to varying microclimates and abiotic factors. In addition, the traditional gas chromatography–mass spectroscopy (GC-MS) method presents field measurement challenges, whereas the selected ion flow tube (SIFT)-MS method offers improved efficiency. This study concentrated on a controlled phytotron environment and compared the GC-MS and SIFT-MS findings, revealing similar emission trends with slightly higher SIFT-MS concentrations. Daily phytoncide emissions fluctuated with light intensity and abiotic stressors. Both methods consistently detected pinenes, primarily emitted by Pinus strobus L. seedlings, in the phytotron. Statistical analysis confirmed the compatibility between GC-MS and SIFT-MS results, supporting the use of SIFT-MS for forest phytoncide assessment. In the second phase, the phytoncide emissions were assessed indoors, outdoors, and in the phytotron, highlighting the superiority of the phytotron under controlled conditions. Despite certain limitations, this study underscores the value of phytotron-based measurements for indoor forest healing programs and the potential adoption of SIFT-MS in future field-based phytoncide research. [ABSTRACT FROM AUTHOR]

The study of indoor plant lighting is noted to be an interdisciplinary research area. Thus, there is a need to integrate various technical sciences and practical methods in growing plants under artificial conditions. Nowadays, it is reasonable to treat energy-ecological efficiency of indoor plant lighting as a complex scientific direction that takes into account substance flow forming the energy and environmental indicators of an artificial agroecosystem. (Research purpose) To develop an experimental laboratory phytotron intended for research on the energy-ecology efficiency of indoor plant lighting, and to conduct its biological testing. (Materials and methods) From the standpoint of the logical-semantic approach, the term "energy-ecological efficiency" was interpreted as a conjunction of its components - energy efficiency and environmental compatibility. The paper outlines the theoretical fundamentals of the energy-ecological efficiency approach to indoor plant lighting, which determine the experimental research features. The requirements for the techniques of conducting experiments are formulated. The phytotron design and its operation principles are described. Biological testing was carried out on Blagovest F1 tomato plants (Lycopersicum Esculentum Mill.) in the seedling phase of plant development. The plant response to changes in the lighting factors was determined: photoperiod (normal and extended), spectrum (a blue-enhanced spectrum and a control one), and irradiance level (low, medium, and high). (Results and discussion) Under the varied lighting conditions, energy-ecology efficiency varied from 0.075 grams per mole (with the control spectrum, an extended photoperiod and high irradiance) to 0.138 grams per mole (with the blue-enhanced spectrum, a normal photoperiod and medium irradiance). (Conclusions) An experimental laboratory phytotron was developed to study the energy-ecology efficiency of indoor plant lighting. The ability to control irradiance was achieved depending on the mass of plants. The phytotron unit provides easy access to plants, it is compact, ergonomic and has improved functional capacity.

Negative air ion (NAI) is an important index for measuring air quality and has been widely recognized to be influenced by photosynthesis processes. However, vegetation type and light intensity are also known to impact NAI, contributing to significant uncertainties in the relationship between light and NAI. In this paper, we selected Pinus bungeana, Platycladus orientalis and Buxus sinica as research subjects and obtained their NAI, light intensity, and meteorological data through synchronous observation under the relatively stable condition of the phytotron. We analyzed the change characteristics of NAI and the difference of NAI production ability in needle and broadleaf vegetation under different light intensities. Finally, we determined the relationship and underlying mechanism governing light intensity and NAI using diverse tree species. The results showed that the influence of light on NAI was significant. In the environment without vegetation, the influence of different light intensities on NAI was not significant, and the mean NAI concentration was 310 ions·cm-3. Conversely, in the presence of vegetation, NAI showed a "single-peak" trend with increasing light intensity. The NAI concentration of the three tree species was significantly higher than under different light intensities when vegetation was not present. The NAI promoting ability of P. bungeana was the highest (675 ions·cm-3), followed by P. orientalis (478 ions·cm-3) and B. sinica (430 ions·cm-3), which increased by 117.5%, 53.9% and 38.6% compared to the environment without vegetation. The NAI growth rate was significantly different between needle and broadleaf vegetation based on the specific tridimensional green biomass. Additionally, the NAI growth rates of P. bungeana and P. orientalis were 647 and 295 ions·cm-3·m-3, respectively, which were 3.06 and 1.39 times that of B. sinica (211 ions·cm-3·m-3). The piecewise equation fitting effect of NAI and light intensity was better for different tree species, the determination coefficients (R2) of P. bungeana, P. orientalis and B. sinica were 0.926, 0.916 and 0.880, and the root mean square errors (RMSE) were 7.157, 6.008 and 5.389 ion·cm-3, respectively. Altogether, our study provides a theoretical basis as well as technical support for the construction of healthy vegetation stands, the selection of preferred tree species, and the optimization of vegetation models, and promotes air quality and the provision of ecosystem functions and services. [ABSTRACT FROM AUTHOR]

Maize has come a long way from the tropics to the temperate zone. In the beginning, the spreading of maize was prevented by its sensitivity to cold. Improved cold tolerance at germination is one of the most important conditions for early sowing. The advantage of cold tolerant hybrids is that they can be sown earlier, allowing longer growing seasons and higher yields, due to the fact that the most sensitive period in terms of water requirements, flowering, takes place earlier, i.e. before the onset of summer drought and heat. In Martonvásár, continuous research is carried out to improve the cold tolerance of maize. In the present experiment, the cold tolerance of 30 genetically different maize inbred lines was investigated in a Phytotron climate chamber (PGV-36). The aim of our research is to identify cold tolerant lines that can be used as parental components to produce proper cold tolerant hybrids and/or as sources of starting materials for new cold tolerant inbred lines. After observing and evaluating changes in phenological traits under cold-test, the results of the cold-tolerance traits of interest have been used to highlight several inbred lines that could be good starting materials for further research on genetic selection for cold tolerance. [ABSTRACT FROM AUTHOR]

The most recent platform for protected horticultural crop production, with the shortest history to date, is located entirely indoors, lacking even the benefit of free, natural sunlight. Although this may not sound offhand like a good idea for commercial specialty-crop production, the concept of indoor controlled-environment plant growth started originally for the benefit of researchers—to systematically investigate effects of specific environmental factors on plant growth and development in isolation from environmental factors varying in uncontrolled ways that would confound or change experimental findings. In addition to its value for basic and applied research, it soon was discovered that providing nonlimiting plant-growth environments greatly enhanced crop yield and enabled manipulation of plant development in ways that were never previously possible. As supporting technology for indoor crop production has improved in capability and efficiency, energy requirements have declined substantially for growing crops through entire production cycles in completely controlled environments, and this combination has spawned a new sector of the controlled-environment crop-production industry. This article chronicles the evolution of events, enabling technologies, and entrepreneurial efforts that have brought local, year-round indoor crop production to the forefront of public visibility and the threshold of profitability for a growing number of specialty crops in locations with seasonal climates.

The production of compost from biodegradable municipal waste is important not only for reducing the amount of landfilled waste. The compost produced with the right technology can replenish the missing organic matter in the soil and improve its properties. This paper deals with the evaluation of the phytotoxicity of composts from garden and kitchen biodegradable wastes. Their effect on plant germination and overall plant condition under laboratory conditions was investigated. The samples of compost from the industrial composting plant of the city of Nitra and compost from the electric composter GG02 were used for this test. The tested composts were mixed with the reference substrate in different concentrations and applied to two plant species -- Lettuce (Lactuca sativa) and Barley (Hordeum vulgare). After 21 days, the number of germinated plants (i.e. germination rate), the length of the aerial part of the plants, the weight of fresh biomass and also its weight after drying were evaluated. The highest lettuce germination rate was obtained with 25% of the compost from the industrial composting plant. Barley achieved the best germination rate at up to 50% concentration of this compost. However, the highest biomass weight was obtained for the barley in the reference sample, i.e. without the addition of compost. In contrast, the application of compost from the industrial composting plant on lettuce, regardless of its concentration, had a clear stimulating effect, in all the parameters studied. The compost from the electric composter at concentrations of 25 and 50% had an inhibitory effect on all tested parameters of both plants. [ABSTRACT FROM AUTHOR]

Cuticle is the first layer protecting plants against external biotic and abiotic factors and is responsive to climatic factors as well as determined by genetic adaptations. In this study, the chemical composition of bilberry fruit cuticular wax was investigated through a latitudinal gradient from Latvia (56°N 24°E) through Finland (65°N 25°E) to northern Norway (69°N 18°E) in two seasons 2018 and 2019. Changes in the major cuticular wax compounds, including triterpenoids, fatty acids, alkanes, aldehydes, ketones, and primary alcohols, were detected by GC-MS analysis. Generally, a decreasing trend in the proportion of triterpenoids from southern to northern latitudes, accompanied with an increase in proportion of fatty acids, aldehydes, and alkanes, in bilberry fruit cuticular wax was observed. A correlation analysis between climatic factors with proportion of wax compounds indicated that temperature was the main factor affecting the cuticular wax composition in bilberries. A controlled phytotron experiment with southern and northern bilberry ecotypes confirmed the major effect of temperature on bilberry fruit cuticular wax load and composition. Elevated temperature increased wax load most in berries of northern ecotypes. The level of triterpenoids was higher, while levels of fatty acids and alkanes were lower, in wax of bilberry fruits ripened at 18°C compared to 12°C in both northern and southern ecotypes. Based on our results, it can be postulated that the predicted increase in temperature due to climate change leads to alterations in fruit cuticular wax load and composition. In northern ecotypes, the alterations were especially evident. [ABSTRACT FROM AUTHOR]

It is important to use light that has a positive effect on plants. For plant growers, achieving the lowest possible cost of shrub production is crucial. We investigated the influence of light (white and violet LEDs as well as fluorescent white and red light) on the rooting and growth of blueberry cuttings (V. corymbosum L.) 'Aurora' and 'Huron'. Blueberry cuttings (4 cm tall) were planted into boxes with peat, which were placed in a phytotron at 22 °C and illuminated for 16 hours a day. The plants died under the red fluorescent light source and, therefore, we discontinued its use. The other three light sources had a positive effect on plant growth and development. The light source had little effect on the content of macroelements in the leaves. Plants grown under white fluorescent and white LED light did not significantly differ in the height (22.0-25.8 cm), proline (4.67-7.23 μmol g-1), and polyphenol content (4987-5212 mg 100 g-1). In both cultivars, the violet LED light reduced plant growth and increased the content of polyphenols (6,448 mg 100 g-1) and proline (8.11-9.06 μmol g-1) in the leaves, which may indicate abiotic stress. During the rooting of highbush blueberry cuttings, it is advisable to use white LED light. It has a positive economic impact on crop production due to low electricity consumption and it benefits the environment by eliminating mercury. The plant quality is similar to that of fluorescent white light.

It is important to use light that has a positive effect on plants. For plant growers, achieving the lowest possible cost of shrub production is crucial. We investigated the influence of light (white and violet LEDs as well as fluorescent white and red light) on the rooting and growth of blueberry cuttings (V. corymbosum L.) 'Aurora' and 'Huron'. Blueberry cuttings (4 cm tall) were planted into boxes with peat, which were placed in a phytotron at 22°C and illuminated for 16 hours a day. The plants died under the red fluorescent light source and, therefore, we discontinued its use. The other three light sources had a positive effect on plant growth and development. The light source had little effect on the content of macroelements in the leaves. Plants grown under white fluorescent and white LED light did not significantly differ in the height (22.0-25.8 cm), proline (4.67-7.23 µmol g-1), and polyphenol content (4987-5212 mg 100 g-1). In both cultivars, the violet LED light reduced plant growth and increased the content of polyphenols (6,448 mg 100 g-1) and proline (8.11-9.06 µmol g-1) in the leaves, which may indicate abiotic stress. During the rooting of highbush blueberry cuttings, it is advisable to use white LED light. It has a positive economic impact on crop production due to low electricity consumption and it benefits the environment by eliminating mercury. The plant quality is similar to that of fluorescent white light. [ABSTRACT FROM AUTHOR]

Following high summer temperatures in Taiwan, erratic fruit production and yellowed cladode have been observed in red-fleshed ‘Da Hong’ pitaya (Hylocereus polyrhizus). However, the specific environmental influences that result in the yield loss and cladode damage are unknown. The aim of this study was to evaluate how high temperature affects fruit production and cladode yellowing of ‘Da Hong’ pitaya under controlled conditions. One-year-old field-grown potted plants with moderately yellow-colored cladodes were placed in the phytotron at either 40/30 °C ± 1 °C [day/night, high-temperature treatment (HT)] or 30/20 °C ± 1 °C [day/night, control (CK)] during the natural long-day reproductive period. Floral bud development duration, flower opening behavior, fruit set and development, as well as fruit characteristics and seed setting (which was expressed as the estimated number of seeds), and the weight per fruit at harvest were investigated. In addition, the percentage of dry matter and color change (regreening) of cladodes were examined. We found that floral bud development was completed 8 days earlier than the control, but the time of blooming was 2 to 3 hours later within a day; and fruit set, fruit size, seed weight, and peel color were strongly suppressed in HT-treated plants compared with the control. Furthermore, both the estimated seed number and seed weight were positively correlated with fruit weight, suggesting that reduced seed setting and weight arising from incomplete fertilization in the HT plants may have resulted in fruit drop and smaller fruit. Although the color on the sunny (sun-exposed) side of the cladode remained yellow, the percentage of dry matter in the HT cladodes was not significantly different from the control, indicating that the yellow-colored cladodes did not reduce their carbon supply potential. The results indicate that HT during bloom led to poorer fruit set and lower fruit weight, presumably due to lower seed setting/weight per fruit arising from incomplete fertilization. The HT treatment also caused less regreening of cladodes, but this did not seem to impact fruit production. Further study is required to ascertain whether disrupted stamens or pistils resulting from HT treatment lead to incomplete fertilization.

The data provided in this article were obtained from fresh and dry samples of green Basilic (Ocimum Basillicum L.), red Basilic (Ocimum basilicum 'purpurascens'), green Mizuna (Brassica rapa var. niposinica), and red Mizuna (Brassica rapa var. pipposinica) microgreens grown in climatic chamber (phytotron) on jute mats for 15 days. Phytonutrients contents including chlorophylls, pheophytins, carotenoids pigments, total antioxidant capacity, total phenolic content, ascorbic acid, as well as organic acids contents varied between all cultivars. Spectrometry, electrophoresis, coulometric, and liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS) were the principal employed methods. Data of antioxidants and phytonutrients contents contribute to the understanding of the benefits of microgreens as a newly emerging product. Data of pigments content compares the difference of accumulation of chlorophylls, pheophytins, and carotenoids between red and green cultivars of the studied microgreens, and the variability of their concentrations along with the contents of organic acids provide insights to plants physiology during the differentiation phase.

This article presents comparative data regarding the effect of foliar application of silicon dioxide and organosilicon compounds on soilless-grown Oak leaf lettuce (Lactuca sativa var. crispa). Data were derived from dry and fresh samples. Total nitrogen, total antioxidants capacity, total phenolic content, ascorbic acid, total pigments concentrations and growth parameters varied in response to the concentrations of the used preparations (silicon dioxide and organosilicon compounds). Capillary zone electrophoresis, spectrophotometry and coulometric analyzer were the principal involved methods. Data of total phenolic content, antioxidants capacity and ascorbic acid concentrations can provide physiological health benefits as functional foods along with an insight to plant stress physiology. Chlorophyll a and b concentrations, nitrogen content, dry matter content, plant height and fresh weights contribute to the understanding of physiological and biometric plants growth parameters.

The aim of our study was to analyze the development of Septoria leaf spot in sunflower seedlings artificially infected with the mycelium suspension of the pathogen in the phytotron and to determine the degree of damage caused by this disease in the lines of different origins. The materials for the experiment were self-pollinating sunflower lines ZL22A, ZL58A, ZL78A (all of Zaporizhzhya breeding the Institute of Oilseeds Crops of NAAS) and line HAR7 (originating from the USA). The research was conducted in the phytotron facility at the Department of Genetics and Plant Resources of Zaporizhia National University. The seeds of selected sunflower samples were sown into the soil in the specially prepared pots containing drainage and a mixture of chernozem and sand in equal proportions to a depth of 3 cm in two rows of 10 seeds each, with a distance between seeds of 0.5-1 cm. The plants grew and developed on a photoperiod of 16/8 hours (day / night) at a temperature of 23-25oC and a relative humidity of 65%. All samples were watered when needed and received equal amounts of water. Sunflower plants were inoculated in accordance with generally accepted methods of phytopathology. Next, the infected plants were placed in a humid chamber. The plants were infected with the inoculum of a 30-day old mycelium culture of the fungus Septoria helianthi, grown by cultivating the pathogen on a solid nutrient medium. The isolation of pathogen in pure culture as well as preparation of inoculum for infection were carried out using methods which were generally accepted in phytopathology and mycology, supplemented by author's own methodology. The degree of damage to the plants was assessed by visual examination of all leaves, using a 5-point scale, modified for our studies. The affected lines were determined by the percentage of plants with a certain degree of damage. The results of this research showed that sunflower lines sustained varying degrees of damage and, accordingly, varying degrees of resistance to Septoria. The least affected was line HAR7, with 70% of the plants in this line having damaged leaves. The most damaged of those were cotyledons and the first pair of true leaves, whereas just 11.7% of plants had the second pair of true leaves damaged. Completely unaffected plants made up 29.5% of this line. Line ZL22A was affected by 75%. Almost all plants in this line had damaged cotyledons and the first pair of leaves, with 70%. Besides, there were 5% of plants that had all their leaves affected. The number of unaffected plants was 25%. It should be noted that the ZL22A line was close in degree of damage to that of the HAR7 line and showed relative susceptibility to Septoria under phytotron conditions. ZL58A and ZL78A lines were the most affected by Septoria, with 100%. In the ZL58A line, there were 56.2% of plants with damaged cotyledons and the first pair of true leaves, and 43.8% of plants whose second pair of true leaves showed the symptoms of the disease. The plants of the ZL78A line with lesions on the cotyledons and the first pair of true leaves made up 60%, whereas the number of plants with the symptoms of Septoria leaf spot on the second pair amounted to 40%. In general, these two lines were characterized by the same degree of damage and can be considered susceptible to Septoria leaf blight. The disease progression on the HAR7 line is 38.2%, on the ZL22A line is 40%, on the ZL78A line is 60%, on the ZL58A line is 60,9%. The findings show that sunflower plant lines that were artificially infected with an aqueous suspension of fungal mycelium containing Septoria leaf spot pathogen in the conditions of phytotron developed the disease rather rapidly and exhibited varying degrees of damage. The proposed method provides a reliable infection of sunflower samples with the pathogen S. helianthi, a rapid assessment of the intensity of damage to sunflower lines by septoria. [ABSTRACT FROM AUTHOR]

This paper studies the new repositories of specimens and knowledge that emerged from Sweden's first "phytotron," a modern climate laboratory for plant research established in Stockholm in the 1960s. Different aspects and scales of technoscientific plant and crop growth came together under one roof: inhouse trials on the timing and spacing of trees and crops, postwar domestic policies to modernize a largely rural country, and Swedish forest geneticists' expertise in international efforts to improve forest stand and productivity globally. I argue that a scalar analysis of scientific forestry can help identify and assess the historical contingencies and contexts that formed the interventions in planetary order invoked by the Anthropocene. [ABSTRACT FROM AUTHOR]

Climatic chamber are enclosures where the ambient conditions, i.e. the temperature and humidity, are finely controlled. This one can play multiple roles such as the cultivation of plants (phytotron), the breeding of insects or habitat for exotic animals. The availability on the market of a wide variety of equipment makes it difficult to share settings and operating recipes. In this paper, we propose a versatile and automated modular climatic enclosure system that can be adapted according to the use cases and available material. In this paper, we use IoT device virtual representation, data validation by means AI algorithm, the semantic description of material, and ontology locally deployed from the cloud allowing to automate the local installation with container technology. [ABSTRACT FROM AUTHOR]

Abstract Background Reduction in rice yield caused by high temperature-induced spikelet sterility has been a serious concern in rice production. To date, several screening methods have been used, although their reproducibility is sometimes poor due to artifacts mainly caused by varietal differences in heading dates and panicle heights (i.e., the distance from the lamps). Methods We have developed a novel assay system for heat-induced spikelet sterility by using artificial rice paddies in phytotrons to conduct a highly reproducible assay throughout a year. Plants restricted to the main culm were treated under a series of heat conditions, and height uniformity of each plant was ensured by using height-adjustable pots. Results Results suggested that a 3-day heat treatment of 35 °C-day/29 °C-night cycles was the most suitable condition. Under the treatment, two distinct groups were identified among nine heat tolerant cultivars, with no varietal difference in panicle temperature, indicating that the system is capable of eliminating the varietal difference in panicle temperature. Conclusions It is concluded that the assay system would be a powerful tool for selecting heat tolerant varieties, as well as the analysis of genetic factors from various cultivars, eliminating potential artifacts.

Heat stress around anthesis is considered to have an increasing impact on wheat yield under the ongoing climate change. However, the effect of high temperatures and their duration on formation of individual yield parameters is still little understood. Within this study, the effect of high temperatures applied during anthesis for 3 and 7 days on yield formation parameters was analysed. The study was conducted in growth chambers under four temperature regimes (daily temperature maxima 26, 32, 35 and 38°C). In the periods preceding and following heat stress regimes the plants were cultivated under ambient weather conditions. The number of grains per spike was reduced under temperatures ≥ 35°C in cv. Bohemia and ≥ 38°C in cv. Tobak. This resulted in a similar response of spike productivity. Thousand grain weight showed no response to temperature regime in cv. Tobak, whereas in cv. Bohemia, a peak response to temperature with maximum at 35°C was observed. The duration of heat stress had only little effect on most yield formation parameters.

The study aimed to assess response of juvenile progeny of seven forest tree species, Pinus sylvestris, Picea abies, Betula pendula, Alnus glutinosa, Populus tremula, Quercus robur and Fraxinus excelsior, and their populations to different combinations of climate change-related multiple stressors, simulated in a phytotron under elevated CO2 concentration: (1) heat + elevated humidity (HW); (2) heat + frost + drought (HFD); (3) heat + elevated humidity + increased UV-B radiation doses + elevated ozone concentration (HWUO); and (4) heat + frost + drought + increased UV-B radiation doses + elevated ozone concentration (HFDUO). Effects of the complex treatments, species and species-by-treatment interaction were highly significant in most of the growth, physiological and biochemical traits studied, indicating general and species-specific responses to the applied treatments. For deciduous trees, height increment was much higher under HW treatment than in ambient conditions (control) indicating a positive effect of elevated temperature and better water and CO2 availability. HFD treatment caused reduction of height increment in comparison to HW treatment in most species except for Q. robur and F. excelsior which benefited from lower humidity. Treatments HWUO and HFDUO have caused substantial damages to leaves in fast growing deciduous P. tremula, A. glutinosa and B. pendula, and resulted in their lower height increment than in HW treatment, although it was the same or even higher than that in the control. Rates of photosynthesis in most of the tree species were greatest in HFD treatment. A lower photosynthetic rate (compared to control) was observed in B. pendula, P. tremula and F. excelsior in HW treatment, and in most species—in HWUO treatment. Compared to control, intrinsic water use efficiency in all treatments was significantly lower in P. tremula, A. glutinosa and F. excelsior and higher in conifers P. sylvestris and P. abies. Significant population-by-treatment interactions found for most traits showed variation in response of populations, implying that this reflects adaptive potential of each tree species. The observed responses may not always be considered as adaptive as deteriorating growth of some populations or species may lead to loss of their competitiveness thus compromising regeneration and natural successions. [ABSTRACT FROM AUTHOR]

Abstract Agricultural monitoring is required to enhance crop production, control plant stress, and predict pests and crop infection. Apart from monitoring the external influences, the state of the plant itself must be tracked. However, the modern methods for plant analysis are expensive and require plants processing often in a destructive way. Optical spectroscopy can be used for the non-invasive monitoring requiring no consumables, and little to none sample preparation. In this context, we found that the red beet growth can be monitored by Raman spectroscopy. Our analysis shows that, as plants age, the rate of betalain content increases. This increase makes betalain dominate the whole Raman spectra over other plant components. The dominance of betalain facilitates its use as a molecular marker for plant growth. This finding has implications in the understanding of plant physiology, particularly important for greenhouse growth and the optimization of external conditions such as artificial illumination. Graphical Abstract Unlabelled Image Highlights • Raman spectroscopy enables the composition determination of red beet. • The spectra of the leaves and stems show the presence of carotenoids and betalain. • The pigment betalain content in red beet increases with the plant growth. • For the first time, betalain is proposed as a molecular marker for red beet senescence. [ABSTRACT FROM AUTHOR]

Increases in carbon dioxide (CO2) and temperature are expected to induce complex effects on plant pathogens. The results of studies on the effects of climate change on a number of pathosystems, such as the downy and powdery mildew of grapevines, and on several pathogens of vegetable crops, such as rocket, basil, beet and zucchini, have been analysed in this review. In the reviewed works, plants were grown in controlled environment facilities (phytotrons) under six different simulated climatic conditions: a standard CO2 concentration (400-450 ppm) with a standard (ranging from 18 to 22/24 °C) and elevated temperature (5 °C higher than standard), and elevated CO2 (800-850 ppm) under a standard and elevated temperature. When the CO2 level and the temperature were increased, an increase was observed of powdery mildew on zucchini, Alternaria leaf spot on rocket salad, black spot and downy mildew on basil, Allophoma tropica on lettuce and Phoma leaf spot on garden beet. Variable effects were instead observed when individual climate parameters were taken into consideration. The effects of changed environmental values on some physiological parameters on the production of mycotoxins as well as on disease management were also considered on selected pathosystems. CO2 concentration and temperature proved to influence disease severity and mycotoxin production in different ways. As far as the application of biocontrol agents is concerned, the efficacy of Ampelomyces quisqualis against zucchini powdery mildew was found to be improved under higher temperature and CO2 conditions. The results obtained with different host/pathogen combinations will allow to develop adaptation strategies for disease management and to provide the seed industry with useful information in order to develop new cultivars that will be more adapted/adaptable to the changing conditions. The usefulness and limitations of studies carried out under controlled environment conditions are critically discussed. [ABSTRACT FROM AUTHOR]

Abstract: A novel plant epigenetic regulatory system is reported. This is a change in product spectra of genes determining a productivity trait caused by a change in a limiting factor of the environment. Based on this discovery, the Theory of Ecogenetic Organization of Plant Quantitative Traits (TEGOPQT) was elaborated over the period from 1984 to 2014. The Theory gave rise to 24 prognostic corollaries and 10 know-hows. They are able to increase sharply the effectiveness of plant breeding aimed at higher yields. The prerequisite of this success is a creation of a priority breeding phytotron in the Russian Federation. The paper lists the necessary biophysical instruments and other devices that are needed to equip the growth chambers of the phytotron. [ABSTRACT FROM AUTHOR]

Seed-setting rate of rice ( Oryza sativa L.) significantly decreases under high temperatures during the reproductive period largely due to heat-induced spikelet sterility. The effects depend largely on the timing and severity of heat stress, but the variation in the sensitivity of seed-setting rate in response to heat stress at different growth stages is not yet well simulated by most of the present crop models. To investigate the quantitative relationships between seed-setting rates of rice and various exposures of heat stress, we conducted four-year phytotron experiments with four different temperature regimes (the target maximum/minimum temperatures, 32 °C/22 °C, 35 °C/25 °C, 38 °C/28 °C and 41 °C/31 °C in 2011 and 2012; 32 °C/22 °C, 36 °C/26 °C, 40 °C/30 °C and 44 °C/34 °C in 2014 and 2015) with factorial combinations of durations (2, 4 and 6 days in 2014 and 2015; 3, 5 and 7 days in 2011; 3, 6 and 9 days in 2012) and the timings (0, 6 or 12 days after flowering), using three japonica cultivars. The duration and intensity of heat stress were quantified by the heat degree-days (HDD), defined as the temperature sum above a critical temperature value, which varied from 35 to 36 °C, depending on the cultivars. The observed seed-setting rates were well expressed as a logistic function of HDD, but the temperature sensitivity parameter varied with the timing of heat stress and the spikelet positions on the panicle. The variation in timing of flowering was apparent among upper, middle and lower parts of the panicles: 1 and 3-day delay of flowering for the spikelets on the middle and lower parts of the panicles, respectively, compared with upper ones. We therefore developed a simulation model that reflects the changes in the sensitivity of seed-setting rate to HDD to estimate the effects of heat stress with different intensities or durations at any time from flowering onward. The model with the stage-dependent parameters improved substantially the root mean square error (RMSE) and mean bias error (MBE) of seed-setting % from 20.1 and 6.0 to 7.6 and 0.2, respectively, compared to that with the stage-independent parameters. The proposed model needs to be tested under field conditions, but will be an important basis for accurate prediction of seed-setting rates in rice, which is critical for reliable estimates of crop production under climate change. [ABSTRACT FROM AUTHOR]

The aim of the investigation was to assess and compare the environmental limits for growth cessation and floral initiation in a range of new and established biennial-fruiting red raspberry ( Rubus idaeus L.) cultivars of diverse origin under phytotron and field conditions. The results confirmed that growth cessation and floral initiation in biennial-fruiting red raspberry are jointly controlled by the interaction of low temperature and short days (SD). When transferred from non-inductive high temperature and long day (LD) conditions to naturally decreasing autumn daylengths at varying phytotron temperatures on 18 August, growth immediately levelled off and ceased completely within 2 weeks in all cultivars at 9 °C. Serial dissections of lateral buds revealed that floral initiation simultaneously took place. At 15 °C on the other hand, the plants continued growing and remained vegetative until around 15 September when the daylength had decreased to approximately 13 h. The change to 9 °C resulted in an immediate but short-lasting floral induction response that did not bring about initiation in buds situated near the base of the canes, as was the case at 15 °C. At 18 °C, marginal floral induction took place only in the cultivars ‘Glen Ample’, ‘Balder’ and ‘Vene’, even at photoperiods down to 10 h, whereas at 21 °C, all cultivars grew vegetatively regardless of daylength conditions. However, exceptions were some plants of ‘Vene’ and ‘Anitra’ that initiated terminal flowers at 18 and 21 °C and flowered directly without chilling (so-called tip flowering). Although some cultivars of Northern origin ceased growing and initiated floral primordia somewhat earlier (at longer photoperiods) than those of more southerly origin, the differences were relatively minor and not consistent (no latitudinal cline). Results obtained in the field under decreasing autumn temperature and daylength conditions agreed closely with the results in the phytotron. We therefore conclude that results obtained with raspberry in properly controlled daylight phytotron experiments are generally applicable to field conditions. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Vegetable growers in Arctic areas must increasingly rely on market strategies based on regional origin and product quality. Swede roots (rutabaga) were grown in a phytotron to investigate the effect of high latitude light conditions on sensory quality and some health and sensory‐related compounds. Experimental treatments included modifications of 24 h natural day length (69° 39' N) by moving plants at daily intervals to dark chambers with either no light, fluorescent growth light and/or low intensity photoperiod extension. RESULTS: Shortening the photosynthetic light period to 12 h produced smaller roots than 15.7 h and 18 h, with highest scores for bitter and sulfur taste, and lowest scores for sweetness, acidic taste and fibrousness. The photoperiod in combination with the photosynthetic light period also had an influence on glucosinolate (GLS) contents, with lowest concentrations in 24 h natural light and highest in 12 h natural light. Concentrations of vitamin C, glucose, fructose and sucrose were not significantly influenced by any of the treatments. CONCLUSION: High latitude light conditions, with long photosynthetic light periods and 24 h photoperiod, can enhance sweet/less bitter taste and reduce GLS contents in swede roots, compared to growth under short day conditions. This influence of light conditions on eating quality may benefit marketing of regional products from high latitudes. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The phenylpropenoid glycosides rosavin, rosarin, rosin summarised as ‘total rosavins’ are quality indicators of Rhodiola rosea L. Here we report the systematic quantification of these glycosides and the aglycon cinnamyl alcohol in various provenances cultivated homogenously at 1580 m altitude. (I) We examined rhizomes versus roots in cultivation year 9 (20 provenances). Extracts (70% ethanol) contained 0.5–4.3 mg/mL (rhizomes) and 0.4–2.5 mg/mL (roots) total rosavins. The rosavin/cinnamyl alcohol ratio (average rhizomes 8.1:1, roots 6.2:1), was more influenced by plant origin than plant part. We additionally analysed salidroside including its aglycon tyrosol. The rosavins/salidroside ratios (including aglycons) of 6.4:1 (rhizome) and 5.5:1 (root) indicated authentic R. rosea independent of plant part and origin. (II) Rhizomes extracts (8 provenances) from various dates during years 6 and 7 contained 0.4–4.8 mg/mL total rosavins corresponding to 0.2–3.0% in the dry drug. Age (decreasing trend) and provenance impact were superposed by seasonal variation with a phenylpropenoid peak in spring. Rosavin/cinnamyl alcohol ratios in North European plants were 3–8:1, for Alpine/Pyrenean plants 9–14:1. (III) Compared to our previous dataset from cultivation in South England, on average, there was no major difference between phenylpropenoid values from cultivation at 65 m and 1580 m apart from moderately more cinnamyl alcohol at higher altitude. As per provenance, absolute values were site dependent but phenylpropenoid glycoside/aglycon ratios consistent. In conclusion, this is the first systematic investigation for a high altitude cultivation of R. rosea demonstrating the major extent plant part, season and age influence absolute phenylpropenoid values. In contrary, relative phenolic compound profiles are mostly origin-determined, independent of cultivation conditions and site, and could be used for authentication in quality control. [ABSTRACT FROM AUTHOR]

Climate changes, particularly increases in temperature and CO2,are seriously challenging agriculture, and are one of the main factors that should be considered in the emergence of new diseases and their potential spread. Six trials were carried out to evaluate the effects of increased temperature and CO2 on the severity of leaf spot of lettuce, caused by Allophoma tropica (syn. Phoma tropica), a pathogen that was first observed on lettuce in northern Italy in 2011. Temperature, CO2 and their interactions were significant factors (P

Climate change has brought more low temperature events and posed an increasing risk to the global wheat production. In order to evaluate the effects of low temperature at jointing and booting stages on wheat grain yield and its components, two years of environment-controlled phytotron experiments were carried out with two wheat cultivars under different low temperature levels and durations. Low temperature level and its interaction with low temperature duration had negative effects on the observed grain yield in two cultivars. Moreover, wheat yield was more sensitive to low temperature at booting than at jointing stages. Compared with the control treatment (T min /T max /T mean of 6 °C/16 °C/11 °C, T1), 4.6%–56.4% and 3.1%–44.6% decreases of grain yield per plant (YPP) were observed under low temperature at jointing in Yangmai16 (spring wheat) and Xumai30 (semi-winter wheat), and 13.9%–85.2% and 3.2%–85.9% decreases under low temperature at booting in Yangmai16 and Xumai30, respectively. The spike number per plant (SNPP) and grain number per spike (GNPS) were more sensitive to low temperature at jointing and booting stages than 1000-grain weight (TGW). Furthermore, significant negative linear relationships were observed between the accumulated cold degree days (ACDD) and YPP, SNPP, GNPS and TGW in both cultivars. The contribution of GNPS to the variation of YPP was greater than SNPP and TGW at the mild low temperature level (T min /T max /T mean of −2 °C/8 °C/3 °C, T3) in both cultivars. However, at the extreme low temperature level (T min /T max /T mean of −6 °C/4 °C/−1 °C, T5), the major variation of YPP was caused by SNPP of Yangmai16 and GNPS of Xumai30. In general, the decreased YPP under low temperature condition was mainly from the decreased grain number per plant (GNPP = SNPP × GNPS) in both cultivars and treatment stages, thus maintaining a high GNPP is very important for compensating the yield losses caused by low temperature at jointing and booting stages. [ABSTRACT FROM AUTHOR]

This experiment was carried out under controlled conditions in phytotron chambers of artificial climate - KNER 2 and KNER 4, on two soil types - Luvisols and Vertisols. The Spinach plants (Spinacia oleracea) were grown at air temperature of 18°C, illuminance of 9000 lx and 18000 lx, duration of the day 9 hours and rising rates of nitrogen fertilization. The aim of the study was establishing the influence of the factors soil type, nitrogen fertilization and light on the growth characteristics of spinach. From the factors studied (soil type, fertilization and illuminance) the strongest impact (between 41.2 and 60.6%) on the development of the plants (number of leaves, height and biomass) was that of fertilization. The response of the test plants to the illuminance was not in one direction. The number of leaves in both soils and the leaf mass on Vertisols were greater at illuminance 18000 lx. With the increase of the nitrogen fertilization rates, the content of chlorophylls, total sugars, nitrates and nutrients (N, P, K) in plants were rising. [ABSTRACT FROM AUTHOR]

Climate changes, particularly increases in temperature and CO2, are seriously challenging agriculture, and are one of the main factors that should be considered in the emergence of new diseases and their potential spread. Six trials were carried out to evaluate the effects of increased temperature and CO2 on the severity of leaf spot of lettuce, caused by Allophoma tropica (syn. Phoma tropica), a pathogen that was first observed on lettuce in northern Italy in 2011. Temperature, CO2 and their interactions were significant factors (P<0.0001) influencing incidence and severity of leaf spot on lettuce. Temperatures between 22 and 26°C were the most favourable to the pathogen, and increased disease incidence and severity. Reductions in disease incidence and severity were observed at lower (18-22°C) and higher (26-30°C) temperatures. Concentrations of CO2 ranging from 800 to 850 ppm increased disease incidence and severity at all the temperature ranges tested, and these effects were greatest at 22-26°C. Analysis of these results could be useful for mid-term agricultural planning at a regional scale, so that crops and their varieties can be adapted to anticipated future climate trends. [ABSTRACT FROM AUTHOR]

This study was undertaken by simulating the effects of increasing the temperature and CO values on the incidence and severity of F. equiseti on wild rocket ( Diplotaxis tenuifolia) and radish ( Raphanus sativus), under phytotron conditions. Two sets of 3 trials were carried out in which eight different temperature and CO combinations were tested:1) 400-450 ppm CO, 18-22 °C; 2) 800-850 ppm CO, 18-22 °C; 3) 400-450 ppm CO, 22-26 °C, 4) 800-850 ppm CO, 22-26 °C, 5) 400-450 ppm CO, 26-30 °C; 6) 800-850 ppm CO, 26-30 °C; 7) 400-450 ppm CO, 14-18 °C; 8) 800-850 ppm CO, 14-18 °C. The temperature and CO levels were significant factors of influence on disease incidence (DI) and severity (DS) in all the trials, and their combination significantly influenced the DI and DS of F. equiseti leaf spot on both hosts. Disease incidence and severity increased on wild rocket at 850 ppm of CO in comparison to 450 ppm, in each tested temperature range. The highest CO value on radish, for all the tested temperature regimes, caused an increase in DI and DS, which resulted statistically significant at the highest tested temperature range. The results obtained in this study add more concern to the possible negative effects of the spread of F. equiseti on vegetables in Italy as well as in other areas suffering from increased temperatures as a consequence of climate changes. [ABSTRACT FROM AUTHOR]

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Anthocyanins are secondary metabolites that contribute to red, blue, and purple colors in plants and are affected by light, but the effects of low light on the physiological responses of purple pak-choi plant leaves are still unclear. In this study, purple pak-choi seedlings were exposed to low light by shading with white gauze and black shading in a phytotron. The responses in terms of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, anthocyanin biosynthetic enzyme activity, and the relative chlorophyll and anthocyanin content of leaves were measured. The results showed that chlorophyll b, intracellular CO2 content, stomatal conductance and antioxidant activities of guaiacol peroxidase, catalase and superoxide dismutase transiently increased in the shade treatments at 5 d. The malondialdehyde content also increased under low light stress, which damages plant cells. With the extension of shading time (at 15 d), the relative chlorophyll a, anthocyanin and soluble protein contents, net photosynthetic rate, transpiration rate, stomata conductance, antioxidant enzyme activities, and activities of four anthocyanin biosynthetic enzymes decreased significantly. Thus, at the early stage of low light treatment, the chlorophyll b content increased to improve photosynthesis. When the low light treatment was extended, antioxidant enzyme activity and the activity of anthocyanin biosynthesis enzymes were inhibited, causing the purple pak-choi seedlings to fade from purple to green. This study provides valuable information for further deciphering genetic mechanisms and improving agronomic traits in purple pak-choi under optimal light requirements. [ABSTRACT FROM AUTHOR]

The behavior of Myrothecium verrucaria, artificially inoculated on spinach, was studied under seven different temperature conditions (from 5 to 35 °C) and under eight different combinations of temperature and CO concentration (14-30 °C and 775-870 or 1550-1650 mg/m). The isolate used for this study was growing well on spinach, and the mycotoxins verrucarin A and roridin E were produced under all tested temperature and CO conditions. The maximum levels of verrucarin A (18.59 ng/g) and roridin E (49.62 ng/g) were found at a temperature of 26-30 °C and a CO level of 1550-1650 mg/m. Rises in temperature as well as in temperature and CO concentrations had a significant effect by increasing Myrothecium leaf spots on spinach. The biosynthesis of verrucarin A was significantly increased at the highest temperature (35 °C), while roridin E was influenced by the CO concentration. These results show that a positive correlation between climate condition and macrocyclic trichothecene production is possible. However, because of the ability of M. verrucaria to produce mycotoxins, an increase in temperature could induce the spread of M. verrucaria in temperate regions; this pathogen may gain importance in the future. [ABSTRACT FROM AUTHOR]

The greenhouse is a modern agriculture technology that is widely used to provide a favorable microclimate for vegetable growth when an open field is inappropriate for cultivation. Field tests were conducted to test diurnal variations of temperature, relative humidity, and solar radiation and to analyze the microclimate characteristics in naturally ventilated single-sloped greenhouses of different sizes. The results showed that indoor air temperature and humidity under natural ventilation varied from 28.9 °C to 25.8 °C and 96% to 84%, which illustrates that ventilated greenhouses are able to create a favorable self-maintained, energy-balanced environment for vegetable growth. Moreover, it was found that a greater height and shorter span facilitates heat preservation and energy saving in single-sloped greenhouses. In addition, the relationship between the incident solar radiation and indoor air temperature was determined. This study provides a reference for further research to reduce energy consumption and achieve a favorable greenhouse microclimate, leading to higher product quality, improved yield and shorter cultivation time in single-sloped greenhouses. [ABSTRACT FROM AUTHOR]