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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 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]

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]

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 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]

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]

Heat stress significantly accelerates senescence process during reproductive phase in rice, but the effects of heat stress are not yet well simulated by most of the existing crop models. Three-year experiments under different temperature levels and temperature durations at anthesis and 12 days after anthesis were carried out in phytotron using two japonica cultivars. Significant positive correlations were observed between the shortened grain growing days from anthesis to maturity (GD AM ) and heat degree-days (HDD). The impact of post-anthesis heat stress on rice phenology was quantified by adding thermal effectiveness of heat stress to the original RiceGrow model. Performance of the improved model was tested with phenological data from different cultivars under post-anthesis heat stress of phytotron environments and field conditions. Validation results showed that root mean square error (RMSE), mean bias error (MBE) and variance of the distribution of differences ( S d 2 ) for the prediction of GD AM , decreased from 4.60 d, 2.65 d and 7.80 in the original model to 1.58 d, −0.16 d and 2.40 in the improved model, respectively, under post-anthesis heat stress conditions. The determination coefficient ( R 2 ) and index of agreement (IA) between simulated and observed GD AM , increased from 68.5% and 0.71 in the original model to 93.5% and 0.92 in the improved model under post-anthesis heat stress conditions, respectively. Overall, the improved model gave better predictions of GD AM in different rice cultivars under different post-anthesis heat stress environments. Our study highlights the necessity of accurately simulating the heat stress effects on phenological processes in rice to forecast crop production for ensuring food security under climate change reliably. [ABSTRACT FROM AUTHOR]

This paper describes how, from the early twentieth century, and especially in the early Cold War era, the plant physiologists considered their discipline ideally suited among all the plant sciences to study and explain biological functions and processes, and ranked their discipline among the dominant forms of the biological sciences. At their apex in the late-1960s, the plant physiologists laid claim to having discovered nothing less than the “basic laws of physiology.” This paper unwraps that claim, showing that it emerged from the construction of monumental big science laboratories known as phytotrons that gave control over the growing environment. Control meant that plant physiologists claimed to be able to produce a standard phenotype valid for experimental biology. Invoking the standards of the physical sciences, the plant physiologists heralded basic biological science from the phytotronic produced phenotype. In the context of the Cold War era, the ability to pursue basic science represented the highest pinnacle of standing within the scientific community. More broadly, I suggest that by recovering the history of an underappreciated discipline, plant physiology, and by establishing the centrality of the story of the plant sciences in the history of biology can historians understand the massive changes wrought to biology by the conceptual emergence of the molecular understanding of life, the dominance of the discipline of molecular biology, and the rise of biotechnology in the 1980s. [ABSTRACT FROM AUTHOR]

Allocation of recent photoassimilates of juvenile beech and spruce in response to twice-ambient ozone (2 × O 3 ) and plant competition (i.e. intra vs. inter-specific) was examined in a phytotron study. To this end, we employed continuous 13 CO 2 / 12 CO 2 labeling during late summer and pursued tracer kinetics in CO 2 released from stems. In beech, allocation of recent photoassimilates to stems was significantly lowered under 2 × O 3 and increased in spruce when grown in mixed culture. As total tree biomass was not yet affected by the treatments, C allocation reflected incipient tree responses providing the mechanistic basis for biomass partitioning as observed in longer experiments. Compartmental modeling characterized functional properties of substrate pools supplying respiratory C demand. Respiration of spruce appeared to be exclusively supplied by recent photoassimilates. In beech, older C, putatively located in stem parenchyma cells, was a major source of respiratory substrate, reflecting the fundamental anatomical disparity between angiosperm beech and gymnosperm spruce. [ABSTRACT FROM AUTHOR]

Highlights: Structural analyses of plant remains from the greenhouses have been made.Prediction models for higher heating value based on the structural analysis have been made.Ten prediction models of higher heat value have been validated. [Copyright &y& Elsevier]

Highlights: [•] We examine the development of the FOL-caused disease in lettuce in phytotrons. [•] Microbial count, enzymatic assays, and PCR-DGGE were performed. [•] High temperatures can cause a modification in the development of disease. [•] The total bacterial abundance was reduced at elevated CO2 concentration. [•] The microbial enzyme activity was not affected by the elevated CO2. [ABSTRACT FROM AUTHOR]

Abstract: Although grassland species are usually classified as grazing increasers or decreasers, the response mechanisms to herbivore action in these two groups have yet to be clarified. One such action is dung deposition. The present study tested the hypothesis that increaser species perform more efficiently than decreasers during germination and/or establishment in the presence of dung leachates. A phytotron experiment was conducted on fourteen Mediterranean grassland species from five families, with an equal number of increaser and decreaser species chosen for each family to control for phylogeny. Seeds were germinated and grown in different concentrations of cattle dung leachate. We monitored germination percentages, median germination time and root length, measured five days after germination. To analyse the response and identify potential thresholds, we fitted piecewise mixed models using family/species as nested random factors. Differences in germination parameters between the two groups peaked in favour of increasers under intermediate leachate concentrations. Root growth was also negatively affected by leachates in decreaser species and promoted in increasers. Livestock dung deposition can increase the germination and colonising performance of increasers over decreasers, and may therefore be one of the mechanisms that explain the different species composition of grazed and ungrazed environments. [Copyright &y& Elsevier]

Abstract: The present study aimed at breeding new rice germplasms with similar genome but significantly differed in heat tolerance during the grain filling stage. A total of 791 BC1F8 backcross recombinant lines, derived from the cross of Xieqingzao B / N22 // Xieqingzao B, were used as materials. Each rice line was separated evenly into two groups, and the heat tolerance of all rice lines were evaluated at natural high temperature in fields. The rice lines with heat tolerant index higher than 90% or lower than 40% were selected to compare the phenotypic characters and further identify heat tolerance at the early milky stage in a phytotron. Rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were analyzed by 887 simple sequence repeat markers that were evenly distributed on the 12 rice chromosomes. In the result, 12 (6 pairs) rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were obtained. Molecular marker analysis indicated that the genomic polymorphism between 703T and 704S was the smallest in the 6 pairs of rice lines, with only 16 polymorphic sites, including 22 different alleles. The application of these two backcross introgression rice lines for future study on the mechanisms of heat tolerance in rice at the milky stage will be theoretically beneficial in reducing the interference caused by genetic differences from experimental materials. [Copyright &y& Elsevier]

Abstract: It was previously shown that nitrogen fertilization immediately after commencement of SD exposure enhanced the floral induction effect of SD in June-bearing strawberries (). In order to optimize the timing of such fertilization under field conditions, seasonal timing of floral initiation in the strawberry cultivars ‘Frida’, ‘Polka’, ‘Korona’ and Florence’ was studied in the field at five contrasting latitudinal and altitudinal geographic locations in Norway and, for comparison, under controlled environment conditions with 12h photoperiod and temperatures ranging from 9 to 18°C. Serial collections and dissections of crowns from the various locations revealed that floral initiation was successively delayed with increasing latitude and altitude of the location, and with decreasing temperature under controlled environment conditions. Both in the field and in the phytotron, floral initiation was earliest in ‘Frida’ closely followed by ‘Polka’ and in due course by ‘Korona’ and finally ‘Florence’ which was particularly slow to respond. Floral initiation in the phytotron was progressively advanced with increasing temperature and was optimal at 15–18°C. Flowering time in the field was mainly determined by thermal relations in the spring and early summer, and accordingly, it was strongly delayed with increasing latitude and altitude of the location. In addition, late floral initiation in autumn also delayed flowering in the spring. Based on these observations, optimal timing of autumn fertilization for the various locations and cultivars are suggested. [Copyright &y& Elsevier]

Abstract: The production and quality of belowground roots and plant are likely to be affected by the increase in atmospheric CO2 level with subsequent changes in their decomposition rates in soil. However, the quality of residues has received very little attention, particularly in rice and wheat residues. The present experiment was laid out to study the decomposition of residues of rice (R) and wheat (W) grown in a Typic Haplustept soil under ambient (A) and elevated (E) CO2 conditions maintained in a phytotron. The decomposition of RA and WA was carried out in ambient atmospheric CO2 conditions, while that of RE and WE was done in elevated CO2 condition. Ambient CO2 grown rice and wheat residues were found to decompose at a faster rate compared to the corresponding elevated CO2 grown residues. The amount of residues left over after 150 days of decomposition was comparatively higher in the elevated CO2 grown residues indicating their slow rate of decomposition. However, ambient and elevated CO2 grown wheat residues did not differ significantly with respect to the amount remaining at later stages of decomposition. The RA and RE decomposed to 81% and 77% of their initial amount after 150 days of decomposition, while WA and WE decomposed to 73% and 71% of their initial amounts, while the C loss from RA, RE, WA and WE were 83%, 79%, 76% and 73%, respectively. Ambient atmospheric CO2 grown residues exhibiting narrow C:N ratios decomposed to a faster rate than the elevated CO2 grown residues. Overall, total organic carbon (TOC) content was significantly higher in WA treated soil than in WE treated soil. Net N mineralization (Nmin), microbial biomass carbon (MBC) and Nmin:MBC were greater in soil amended with ambient CO2 grown residues than in elevated CO2 grown residues. Rice residues as compared to wheat residues decomposed at a faster rate thereby releasing higher amount of N in soil. In near future the residues produced under higher concentration of atmospheric CO2 need to be handled carefully as these are decomposed with difficulty due to wide C:N ratios. This has direct implications on N cycling in soil and therefore N fertilization needs to be modified when crop residues are incorporated in soil for optimum crop production. Though lower decomposability of elevated CO2 grown residues might cause more C sequestration in soil, N limitation might adversely affect the plant C sequestration in future. [Copyright &y& Elsevier]

Abstract: Fruit development was investigated in the field in over-winter off-season (bloomed in late November) and on-season (bloomed in mid April) longans (Dimocarpus longan Lour. cv. Chuliang) in 2004–2005 and 2007–2008 crops, and in potted trees grown in phytotrons set at cold (15/10°C, day/night, simulating winter) or warm temperatures (28/23°C, day/night) in 2008. Development of fruit in both on-season and off-season longans could be divided into two stages based on the pattern of fresh weight increase. Stage I was characterized by the slow fruit growth, and Stage II by rapid fruit growth with aril expansion. Off-season longan had a longer period of fruit development than on-season longan, chiefly due to a longer Stage I. The development of off-season fruit, especially in Stage I, was exposed to low and abruptly fluctuating temperatures. In contrast, the temperatures during on-season fruit growth were warmer and less fluctuating. Off-season fruit were smaller with a significantly higher fruit drop. Intensive fruit drop did not occur during cold period until temperature had risen. Fruit cracking in off-season longan was severe (27.6%) in 2004–2005 with a dry and cold winter, but negligible in 2007–2008 with a wet and cold winter. In phytotron experiment, trees exposed to the cold temperature regime during early fruit development produced significantly smaller fruit compared to those exposed to the warm temperature regime (6.2g vs 7.3g), while there was no significant difference in fruit drop rate and cracking incidence. The results suggested temperatures lower than 15°C were stressful for the growth of young fruit and reduced the growth potential and thus fruit size. Severe fruit drop in over-winter off-season longan might be associated with stressful cold plus abrupt temperature fluctuations, while severe fruit cracking in over-winter off-season longan might be related to cold and dry weather in the winter. [Copyright &y& Elsevier]

Recent evidence from novel phytotron and free-air ozone (O3) fumigation experiments in Europe and America on forest tree species is highlighted in relation to previous chamber studies. Differences in O3 sensitivity between pioneer and climax species are examined and viewed for trees growing at the harsh alpine timberline ecotone. As O3 apparently counteracts positive effects of elevated CO2 and mitigates productivity increases, response is governed by genotype, competitors, and ontogeny rather than species per se. Complexity in O3 responsiveness increased under the influence of pathogens and herbivores. The new evidence does not conflict in principle with previous findings that, however, pointed to a low ecological significance. This new knowledge on trees'' O3 responsiveness beyond the juvenile stage in plantations and forests nevertheless implies limited predictability due to complexity in biotic and abiotic interactions. Unravelling underlying mechanisms is mandatory for assessing O3 risks as an important component of climate change scenarios. [Copyright &y& Elsevier]

Abstract: The aim of this experiment was to investigate effects of temperature and photoperiod on growth characteristics, chemical composition and indigestible fibre (IaNDF) in timothy harvested at three defined maturity stages. Two cultivars of timothy, Engmo (69oN) and Grindstad (59oN) were grown in a controlled environment using a phytotron, and were exposed to two different temperature regimes (21/15°C and 15/9°C, 12h/12h) and photoperiods (18 and 24h). Plants were harvested at beginning of heading (BH), full heading (FH) and anthesis (AN). Leaves and stems were separated prior to chemical analyses and ruminal in situ incubation for 288h was used to determine indigestible aNDF (IaNDF) content. Plants grown at low temperature used almost twice the number of days to reach AN, compared to the highest temperature regime. This explained the lower leaf:stem ratio (LSR), higher aNDF content and lower crude protein (CP) content in low temperature plants. The effect of temperature was often dependent on maturity stage. However, the content of IaNDF and lignin(sa) was only affected by maturity stage at harvest. The content of IaNDF and lignin increased by 70% and 35% respectively from BH to AN. The lack of response in IaNDF and lignin(sa) content and dry matter digestibility to temperature was probably caused by a combination of direct and indirect temperature effects. Photoperiod affected growth characteristics, but had minor effects on chemical composition and IaNDF. Due to the lower LSR, Engmo had higher IaNDF and lignin(sa) content than Grindstad. This study showed a high positive correlation (0.93) between IaNDF and lignin(sa). Interactions between temperature and maturity stage affect the growth and nutritive characteristics of timothy. However, only maturity stage affected IaNDF and lignin(sa) content. [Copyright &y& Elsevier]

Abstract: To demonstrate the existence of light thresholds in plant growth and to examine the effects of elevated CO2 on the shade tolerance of a tree species an experiment consisting of a completely randomized design for a total of 96 yellow birch (Betula alleghaniensis Britton) seedlings was conducted with 3 light levels (2.9% 7.7% 26.1% of full sunlight) × 2CO2 levels (350 and 700±10 ppm) with 4 replications in a phytotron. The study proved that thresholds exist and they vary in different plant organs. In ambient CO2 the thresholds were 13.3% 18.7% 15.0% 15.2% and 15.6% of full sunlight for stem leaf root total plant biomass and the averaged value respectively. In 700 ppm CO2 the corresponding thresholds were 16.7% 21.3% 18.1% 21.7% and 19.5% for stem leaf root total plant biomass and the averaged value respectively. The lowest threshold in the stem is an indicator of the minimal light intensity for regular growth for seedlings of this species. Below this threshold light-stressful growth occurs. The result of a paired t-test indicated that the thresholds in elevated CO2 were significantly higher than in ambient CO2. This suggests that yellow birch will lose its moderate shade tolerance evolutionally becoming a shade-intolerant species and that it may become more difficult to naturally regenerate in the future. [Copyright &y& Elsevier]

Abstract: The effects of storage regime (laboratory and soil storage) and fire cues (heat and charate) on seed viability and germination were investigated in the nut-fruited Restionaceae species, Cannomois virgata (Rottb.) Steud. Soil-stored seeds were cycled through a series of alternating temperature and moisture regimes in a phytotron, while laboratory-stored seeds were kept at comparatively constant temperatures and low humidity. Seed deterioration in soil-stored seed was not significantly different to laboratory-stored seed. A marked improvement in germination of soil-stored seed was observed on exposure to charate from a fire. [Copyright &y& Elsevier]

Abstract: The effects of seed pretreatment by magnetic field (MF) on the impacts of ultraviolet-B (UV-B) radiation were tested using cucumber (Cucumis sativus) seedlings in phytotron. Soaked cucumber seeds were placed in MF of various strengths (0, 0.2 and 0.45T). After germination the seeds were sowed in homogeneous garden soil and grown, then cucumber seedlings were exposed to 0 (as control) and 3.5kJm−2 UV-B irradiation, respectively. Some effects of UV-B radiation and MF-pretreatment as well as their combination were investigated. MF-pretreatment increased seed germination rate, seedling growth and development, although also increased lipid oxidation and ascorbic acid contents. On the other hand, our results provided evidence that seed MF-pretreatment increased the sensitivity of cucumber seedlings to UV-B radiation. The seedling growth and development were significantly decreased by the combination of UV-B irradiation and MF-pretreatment. This combination also increased oxidative pressure and decreased actual quantum yield of PS II. Leaf UV-B absorbing compound was increased by MF-pretreatment or UV-B irradiation, whereas their combination significantly decreased it. These results suggested that the harmful effects of combination were partially due to the inhibition of secondary metabolism. [Copyright &y& Elsevier]

Frost is one of the principal limiting factors for agricultural production in the high Andean region. One of the most important grain crops in that region, quinoa (Chenopodium quinoa Willd.), is generally less affected by frost than most other crop species, but little is known about its specific mechanisms for frost resistance. This study was undertaken to help understand quinoa’s response to various intensities and durations of frost under different levels of relative humidity (RH). The effect of frost on seed yield and plant death rate was studied, and content of soluble sugars, proteins, and free proline, was analyzed, in order to develop criteria for the selection of cultivars with improved resistance to frost. On the basis of greenhouse and phytotron experiments, it was concluded that at the two-leaf stage, cultivars from the altiplano of Peru, 3800 m above sea level, tolerated -8 °C for 4 h, whereas a cultivar from the Andean valleys tolerated the same temperature for only 2 h. At -4 °C, plant death rate increased from 25% at high relative humidity to 56% at low RH After a frost treatment of -4 °C applied at the two-leaf stage, final seed yield was reduced by 9% compared to control plants not exposed to frost. For the same treatment applied at the 12-leaf and flowering stages, yield reductions were 51 and 66%, respectively, indicating that frost for 2 h or more during anthesis caused significant damage to the plants. In general, an increased level of soluble sugars implied a greater tolerance to frost, resulting in higher yields. [Copyright &y& Elsevier]

The effect of high temperatures (35 and 45 °C) on microflora of the root zone of radish plants grown in phytotron was evaluated by the response of microorganisms from 9 indicator groups. Phytotron air temperature elevated to 35 °C for 20 hours caused no significant changes in qualitative and quantitative composition of the root microflora in experimental plants. By the end of the experiment, the species diversity of microflora had changed. The amount of phytopathogenic microorganisms decreased which can be interpreted as more stable co-existence of microflora with plants. The numbers of microbes from other indicator groups was in dynamic equilibrium. The plants'' condition did not deteriorate either. Exposure to the temperature of 45 °C for 7 hours have been found to change the numbers and species diversity in the radish root zone microflora. The microorganisms were observed to increase their total numbers at the expense of certain indicator groups. Bacteria increased spore forms at the stage of spores. Colon bacillus bacteria of increased their numbers by the end of experiment by an order. By the end of experiment the roots of experiment plants had microscopic fungi from Mucor, Aspergillus, Trichoderma, Cladosporium genera. The observed changes in the microbial complex seem to be associated with the changes of root emissions and general deterioration of the plants'' condition. It is suggested that the response of the microorganisms can be indicative of the condition of plants under investigation. [Copyright &y& Elsevier]

Nowhere is the problem of understanding the complex linkages between organisms and their environments more apparent than in the science of plants. Today, efforts by scientists to predict and manage the biological consequences of shifting global and regional climates depend on understanding how organisms respond morphologically, physiologically, and behaviorally to changes in their environments. Investigating organismal “adaptability” (or “plasticity”) is rarely straightforward, prompting controversy and discourse among and between ecologists and agricultural scientists. Concepts like agro-climatic adaptation, phenotypic plasticity, and genotype–environment interaction (GxE) are key to those debates, and their complex histories have imbued them with assumptions and meanings that are consequential but often opaque. This special section explores the diverse ways in which organismal adaptability has been conceptualized and investigated in the second half of the 20th century, and the multifarious political, economic, environmental, and intellectual contexts in which those conceptions have emerged and evolved. The papers in this section bring together perspectives from the histories of agriculture, population ecology, evolutionary theory, and plant physiology, cutting across Asian, North American, and British contexts. As a whole, this section highlights not only the diversity of meanings of “adaptability” and “plasticity,” but also the complex linkages between those meanings, the scientific practices and technologies in which they are embedded, and the ends toward which those practices and technologies are employed. [ABSTRACT FROM AUTHOR]

Climate change is likely to decrease crop yields worldwide. Developing climate resilient cultivars is one way to combat this production scarcity, however, little is known of crop response to future climate conditions and in particular the variability within crops. In Scandinavia, barley is widely cultivated, but yields have stagnated since the start of this century. In this study we cultivated 138 spring barley accessions in a climate phytotron under four treatments mimicking forecasted levels of temperature, carbon dioxide concentration ([CO 2 ]) and ozone ([O 3 ]) at the end of the 21 st century 1 . The ambient control had 19/12 °C (day/night) and [CO 2 ] at 385 ppm. Three single-factor treatments had elevated temperature +5 °C day/night, [CO 2 ] at 700 ppm or [O 3 ] at 120 ppb, and in a two-factor treatment the combination of elevated temperature and [CO 2 ] was applied. Treatment effects were assessed on grain yield, grain protein concentration, grain protein harvested, number of grains, number of ears, aboveground vegetative biomass and harvest index. In addition, stability of the production was calculated over the applied treatments for the assessed parameters. In the climate scenario of elevated temperature and [CO 2 ] the grain yield of barley decreased 29% and harvested grain protein declined 22%. Vast variation was identified among the individual barley accessions, which should be exploited by plant breeders in the development of climate resilient cultivars. A genome-wide association study (GWAS) of recorded phenotypes and 3967 SNP-markers identified 60 marker-trait associations (-log p >2.95) 2 . Markers were found associated with grain yield under all three single factor treatments temperature, [CO 2 ] and [O 3 ], as well as with stability over treatments. To our knowledge, this is the first study that evaluates numerous barley accessions under future climate conditions and identifies candidate markers for abiotic stress tolerance - markers that could be used in the development of cultivars to secure future primary production. [ABSTRACT FROM AUTHOR]

Mature beech trees (Fagus sylvatica) grown at two different altitudes in the Bavarian forest were compared with young beech trees grown at nearby field sites or in phytotrons for their macroscopic and physiological responses to different ozone (O3) exposures. Cumulative O3 exposure expressed as the sum of hourly mean concentrations above the canopy ranged between 100 and 150 mu l l-1 h, with the vertical O3 profiles at the higher altitude site being enhanced by 30%. O3 profiles at all sites were reduced by up to 20% with increasing depth within and beneath the canopy. The leaf discoloration that developed in the absence of premature leaf loss was similar in the sun foliage of mature and young trees (including plant grown in the phytotron). Injury became apparentat low O3 exposures, expressed as accumulated hourly means over a threshold of 40 nl l-1 (AOT40 <3.5 mu l l-1 h) at the lower site in both the mature trees and the young beech at the field site, but only occurred when AOT40 values reached 7 mu l l-1 h at the upper site, and 6 mu l l-1 h in the phytotrons. However, the association between injury and O3 exposure was improved when cumulative ozone uptake to sun leaves was the ozone index, used with values of about 3 mmol m-2 resulting in visible injury in both mature and young beech growingin phytotrons. Under high ozone exposure levels of inositol were lowered, whilst concentrations of lignin-like materials were enhanced inmature beech. Similar responses were observed in young beech grown in phytotrons. As the sun foliage was affected by only a small and variable extent each year, the seasonal O3 impact at high altitude did not appear to pose an acute risk to mature beech trees. [ABSTRACT FROM AUTHOR]