MINIATURE GROWTH CHAMBERS FOR THE STUDY OF ENVIRONMENTAL CONDITIONS IN VITRO

1990 ◽  
Vol 70 (3) ◽  
pp. 825-836 ◽  
Author(s):  
FRÉDÉRICK LAFORGE ◽  
YVES DESJARDINS ◽  
MICHAEL E. D. GRAHAM ◽  
ANDRÉ GOSSELIN

Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting in vitro culture, provide an accurate and inexpensive method to perform multifactorial experiments under these conditions. Temperature control was achieved by an electronic device combined with a heating cable and a heat exchanger (water to air). Two-dimensional temperature variations in the chamber were within 1 °C of the set point temperature. Nine chambers were placed under photosynthetic photon flux (PPF) of 80, 125 and 250 μmol m−2 s−1 and CO2 concentrations of 330, 1650 and 3000 μL L−1. Gas concentrations in both the chambers and the test tubes with in vitro cultures were monitored and fresh weight accumulation of raspberry (Rubus idaeus), strawberry (Fragaria × ananassa) and asparagus (Asparagus officinalis) cultures were recorded during a growth experiment. Carbon dioxide accumulation in the culture tubes during the night and subsequent depletion during the day indicated CO2 fixation enhancement with CO2 enrichment, which was more pronounced after 4 wk of growth. Fresh weight accumulated significantly under high CO2 enrichment. Temperatures during the day were slightly higher in the test tubes (1 ± 0.3 °C) than in the chamber.Key words: Light intensity, temperature, carbon dioxide, tissue culture

2012 ◽  
Vol 39 (No. 2) ◽  
pp. 67-73 ◽  
Author(s):  
Ž. Karaklajić-Stajić ◽  
I.S. Glišić ◽  
Dj. Ružić ◽  
T. Vujović ◽  
M. Pešaković

Raspberry (Rubus idaeus L.) cultivar Willamette has long been the most commonly grown raspberry cultivar in Serbia, which is owing to high adaptability of the cultivar to respective agro-environmental conditions. Massive dieback of full bearing plantings is a major problem in raspberry growing hence quality planting material is a must when establishing new raspberry plantings. The study was conducted under protected conditions (in screenhouse) on plants obtained by micropropagation in vitro. In order to achieve optimal vegetative potential, plants were grown for two consecutive years (2004–2005) on two substrates (Steckmedium and Seedling) using three foliar fertilizers (Wuxal, Murtonik and Ferticare). The study revealed optimal vegetative growth in plants studied, excess manganese (150.60-214.52 mg/g), optimum iron content (94.00-123.50 mg/g), and zinc (28.60-31.00 mg/g) and copper (3.10-4.00 mg/g) deficiencies, based on the referent values of microelements content. The assessment of nutritional status of plants by the DOP index suggested significant differences in microelements imbalance when different foliar fertilizers and substrates are applied.


1990 ◽  
Vol 115 (3) ◽  
pp. 364-368 ◽  
Author(s):  
Yves Desjardins ◽  
André Gosselin ◽  
Michel Lamarre

Asparagus (Asparagus officinalis L.) transplants and in vitro-cultured clones were grown and acclimatized under two photosynthetic photon flux (PPF) conditions (ambient and ambient + 80 μmol·s-1·m-2) and three atmospheric CO2 concentrations (330, 900, and 1500 ppm). Short- and long-term effects were measured in the greenhouse and after two seasons of growth in the field, respectively. In the greenhouse, CO2 enrichment (CE) and supplemental lighting (SL) increased root and fern dry weight by 196% and 336%, respectively, for transplants and by 335% and 229%, respectively, for clones. For these characteristics, a significant interaction was observed between SL and CE with tissue-cultured plantlets. In the absence of SL, CE did not significantly increase root or shoot dry weight. No interaction was observed between CE and SL for transplants, although these factors significantly improved growth. It was possible to reduce the nursery period by as much as 3 weeks with CE and SL and still obtain a plant size comparable to that of the control at the end of the experiment. Long-term effects of SL were observed after two seasons of growth in the field. Supplemental lighting improved survival of transplants and was particularly beneficial to in vitro plants. Clones grown under SL were of similar size as transplants after 2 years in the field.


2012 ◽  
Vol 36 (6) ◽  
pp. 624-630 ◽  
Author(s):  
Ariel Villalobo ◽  
Justo González ◽  
Ramón Santos ◽  
Romelio Rodríguez

Pineapple producing countries lack good quality propagation material to expand cultivars into new areas. Previously, research protocols may increase the offer of high quality plantlets and speed the introduction of new pineapple cultivars. The present work is to evaluate the morpho-physiological changes in plantlets of pineapple [Ananas comosus (L.) Merr. 'MD-2'] during the acclimatization phase. Plantlets were acclimatized under 80% relative humidity, 25.5 °C temperature and photosynthetic photon flux of 400-500 µmol m-2 s-1 as average for 45 d under natural photoperiods. All measurements (plant length, number of leaves and roots, fresh weight, width and length of leaf 'D', net photosynthesis and total transpiration rate) were carried out at the end of in vitro rooting phase coincident with 0 d of acclimatization and at 15, 30 and 45 d thereafter. Photosynthetic activity of in vitro plantlets did not increase during the first 30 d of the acclimatization phase. After 30 d, photosynthetic activity ranged from 5.72 to 9.36 µmol CO2 m-2 s-1 while total transpiration ranged from 6.0 to 1.42 mmol H2O m-2 s-1. During the first 30 days there were no significant differences in number of leaves, length or width of the longest ('D') leaf (cm) or plant length (cm). However, after 45 days plant fresh weight (g), length and width of the 'D' leaf (cm) and root number all increased significantly, while transpiration (mmol H2O m-2 s-1) declined. There were small but significant decreases in chlorophyll a and b (µg g-1 mf.). Increased photosynthetic activity after 30 d shows that the increase in light intensity and the reduction of relative humidity during acclimatization did not constitute inhibitory factors.


2001 ◽  
Vol 126 (5) ◽  
pp. 531-536 ◽  
Author(s):  
Elise A. Konow ◽  
Yin-Tung Wang

Presently, there are no standards for producing Phalaenopsis Blume (the moth orchids) as a flowering, potted crop. Determining optimal irradiance for in vitro and greenhouse production will help optimize growth and flowering. Four-month-old, aseptically propagated Phalaenopsis Atien Kaala seedlings with 1.0 cm leaf spread were transferred to a sterile agar medium in November 1995. They were placed under 10, 20, 40, or 80 μmol·m-2·s-1 photosynthetic photon flux (PPF) from cool-white fluorescent lamps. In June 1996, plants grown under 40 or 80 μmol·m-2·s-1 in vitro PPF had 38% greater fresh weight (FW), wider leaves, and more roots than those under the two lower PPF levels. Plants from each in vitro PPF were then transplanted and grown ex vitro in a greenhouse (GH) under high, medium, or low PPF, representing 12.0%, 5.4%, or 2.6% of full sunlight, respectively. Full sunlight at this location was 2300 and 1700 μmol·m-2·s-1 in August 1996 and January 1997, respectively. In November 1996 and June 1997, plants that had received 40 μmol·m-2·s-1 in vitro PPF and then grown under the high or medium GH PPF had the greatest FWs. Overall, plants under the high, medium, or low GH PPF had average FWs of 61, 36, or 17 g, respectively, in June 1997. By mid-September 1997, plants had increasingly larger leaves and higher concentrations of malic acid, sucrose, and starch as GH PPF increased. Leaf glucose and fructose concentrations remained constant as GH PPF increased; however, sucrose level doubled and malic acid concentration increased by nearly 50% from the low to high GH PPF. Each doubling in GH PPF more than doubled plant FW. Plants grown under the high, medium, or low GH PPF had 98%, 77%, or 2% flowering, respectively, in Spring 1998. Anthesis occurred 2 weeks earlier under the high GH PPF. Plants grown under the high GH PPF had twice as many flowers and larger flowers than those grown under the medium PPF.


2016 ◽  
Vol 96 (5) ◽  
pp. 908-918 ◽  
Author(s):  
Saeid H. Mobini ◽  
Monika Lulsdorf ◽  
Thomas D. Warkentin ◽  
Albert Vandenberg

Artificial light in growth chambers typically has a higher red to far-red (R:FR) ratio compared with natural light. This higher ratio may delay flowering and reduce plant height in some long-day plants. Modification of light spectral quality to lower than the critical threshold of R:FR for a given plant species can have important implications with respect to plant structural and physiological traits. The objective of this study was to accelerate lentil (Lens culinaris) flower induction in growth chambers re-fitted with T5 fluorescent bulbs, using supplemental FR bulbs to re-balance the R:FR ratio. Lentil cultivars CDC Greenland and CDC Maxim were grown under three light sources differing in R:FR, namely light emitting diodes (LED; R:FR = 3.09), T5 fluorescent bulbs (R:FR = 5.6), and T5 supplemented with near far-red bulbs (R:FR = 3.1). All three light sources provided 500 µmol m−2 s−1 of photosynthetic photon flux (PPF). Lentil floral induction was significantly affected by the R:FR ratio. Plants grown under R:FR ratios of 3.1 or less flowered 10–11 d earlier than plants grown under an R:FR ratio of 5.6. Both cultivars had the same response to R:FR ratio in terms of days to flowering and flowering rate.


HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1312-1314 ◽  
Author(s):  
Chieri Kubota ◽  
Toyoki Kozai

Growth and net photosynthetic rate of potato (Solanum tuberosum L.) `Benimaru' plantlet in vitro were studied under a conventional photomixotrophic condition [with 20 g sucrose/liter in the medium and under 70 μmol·m-2·s-1 photosynthetic photon flux (PPF)] with minimal ventilation (MV) and under photoautotrophic conditions (without sugar in the medium and under 190 μmol·m-2·s-l PPF) with enhanced natural ventilation using an air diffusive filter (DV) or with forced ventilation (FV). Fresh weight of the plantlets cultured in the FV and DV treatments was 2.4 times that of the plantlets cultured in the MV treatment. Net photosynthetic rate and dry weight per plantlet were the highest in FV followed by DV. For photoautotrophic micropropagation, FV was superior to DV.


2020 ◽  
Author(s):  
Lucas S. Ryan ◽  
Jeni Gerberich ◽  
Uroob Haris ◽  
ralph mason ◽  
Alexander Lippert

<p>Regulation of physiological pH is integral for proper whole-body and cellular function, and disruptions in pH homeostasis can be both a cause and effect of disease. In light of this, many methods have been developed to monitor pH in cells and animals. In this study, we report a chemiluminescence resonance energy transfer (CRET) probe Ratio-pHCL-1, comprised of an acrylamide 1,2-dioxetane chemiluminescent scaffold with an appended pH-sensitive carbofluorescein fluorophore. The probe provides an accurate measurement of pH between 6.8-8.4, making it viable tool for measuring pH in biological systems. Further, its ratiometric output is independent of confounding variables. Quantification of pH can be accomplished both using common fluorimetry and advanced optical imaging methods. Using an IVIS Spectrum, pH can be quantified through tissue with Ratio-pHCL-1, which has been shown in vitro and precisely calibrated in sacrificed mouse models. Initial studies showed that intraperitoneal injections of Ratio-pHCL-1 into sacrificed mice produce a photon flux of more than 10^10 photons per second, and showed a significant difference in ratio of emission intensities between pH 6.0, 7.0, and 8.0.</p> <b></b><i></i><u></u><sub></sub><sup></sup><br>


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