scholarly journals Growth and Physiological Responses of Adenophora triphylla (Thunb.) A.DC. Plug Seedlings to Day and Night Temperature Regimes

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 173 ◽  
Author(s):  
Ya Liu ◽  
Xiuxia Ren ◽  
Hai Jeong ◽  
Hao Wei ◽  
Byoung Jeong
Keyword(s):  
Temperature Regime ◽  
Starch Content ◽  
Soluble Sugar ◽  
Polyacrylamide Gel Electrophoresis ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Guaiacol Peroxidase ◽  
Night Temperature ◽  
Native Page ◽  
Temperature Regimes

Adenophora triphylla (Thunb.) A.DC., three-leaf lady bell, is an important medicinal plant used against cancers and obesity. It has been well-established that the temperature regime affects plant growth and development in many ways. However, there is no study available correlating the growth of A. triphylla seedlings with different day and night temperature regimes. In order to find an optimal temperature regime, growth and physiology were investigated in A. triphylla plug seedlings grown in environment-controlled chambers at different day and night temperatures: 20/20 °C (day/night) (TA), 25/15 °C (TB), and 20/15 °C (TC). The seedlings in plug trays were grown under a light intensity of 150 μmol·m−2·s−1 PPFD (photosynthetic photon flux density) provided by white LEDs, a 70% relative humidity, and a 16 h (day)/8 h (night) photoperiod for six weeks. The results showed that the stem diameter, number of roots, and biomass were significantly larger for seedlings in TB than those in TA or TC. Moreover, the contents of total flavonoid, total phenol, and soluble sugar in seedlings grown in TB were markedly higher than those in seedlings in the other two treatments. Soluble protein content was the lowest in seedlings in TC, while starch content was the lowest in seedlings grown in TA. Furthermore, seedlings grown in TB showed significantly lower activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase. Native PAGE (polyacrylamide gel electrophoresis) analysis further proved low activities of antioxidant isozymes in TB treatment. Meanwhile, the lowest content of hydrogen peroxide was observed in seedlings grown in TB. In conclusion, the results suggested that the 25/15 °C (day/night) temperature regime is the most suitable for the growth and physiological development of A. triphylla seedlings.

scholarly journals ACCUMULATION AND METABOLISM OF CARBOHYDRATES IN MARIGOLD SEEDLINGS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648d-648
Author(s):  
Jack W. Buxton ◽  
Donna Switzer ◽  
Guoqiang Hou
Keyword(s):  
Light Intensity ◽  
Reducing Sugars ◽  
Starch Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Lower Light ◽  
Lower Light Intensity

Marigold seedlings, 3 weeks old, were grown in natural light growth chambers at 3 day/night temperature regimes, 8°N/16°D, 13°N/20°D and 18°N/24°D, in a factorial combination with ambient and 1000-1500 ppm CO2. Seedlings were harvested at regular intervals during a 24 hr period and were analyzed for soluble sugars (reducing sugars and sucrose) and starch. Neither temperature nor CO2 concentration affected the accumulation of soluble sugars or starch during the day or night. The soluble sugar concentration ranged from 3% of dry weight at sunrise to 6% at mid-day; the concentration changed little during the night. Light intensity was different during replications of the experiment. Increased light intensity appeared to cause a slight increase in the soluble sugars maintained by the seedling during the day. Accumulated starch increased 6% to 8% from sunrise to late afternoon. Preliminary results indicate that light intensity greatly affected the concentration of starch. On the higher light intensity day, starch accumulated to a maximum of 18% of dry weight; whereas on the lower light intensity day the maximum concentration was 10%. During the night following the lower light intensity day, the starch concentration decreased to approximately 3% by the end of the night; following a brighter day the starch content was 13% at the end of the night.

Effects of Temperature on Leaf Expansion in Sunflower

1982 ◽  
Vol 9 (2) ◽  
pp. 209 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh
Keyword(s):  
Field Studies ◽  
Leaf Expansion ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Leaf Position ◽  
Leaf Emergence ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

Environmental Effects on Peppermint (Mentha piperita L.). I. Effect of Daylength, Photon Flux Density, Night Temperature and Day Temperature on the Yield and Composition of Peppermint Oil

1980 ◽  
Vol 7 (6) ◽  
pp. 685 ◽  
Author(s):  
RJ Clark ◽  
RC Menary
Keyword(s):  
Environmental Factors ◽  
Flux Density ◽  
Mentha Piperita ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Peppermint Oil ◽  
Oil Composition ◽  
Night Temperature ◽  
Low Concentrations ◽  
High Concentrations

Long days (16 h light), high photon flux density (1200 �Em-2 s-1.) and high night temperature (20°C) resulted in the highest oil yield. : Daylength, night temperature, day temperature and photon flux density were important interacting factors determining oil composition. The photosynthate model proposed by Burbott and Loomis (Plant Physiol., 1967, <B.42, 20-8) explained the effect of environmental factors with respect to pulegone, menthone and menthofuran. Factors favouring the maintenance of high levels of photosynthate resulted in high concentrations of menthone and low concentrations of pulegone and menthofuran. The photosynthate model does not explain the effect of environmental factors on several other monoterpenes.

Environmental Control of Flowering of Boronia megastigma (Rutaceae) and Hypocalymma angustifolium (Myrtaceae)

1994 ◽  
Vol 42 (2) ◽  
pp. 219 ◽  
Author(s):  
JS Day ◽  
BR Loveys ◽  
D Aspinall
Keyword(s):  
Temperature Regime ◽  
Flower Development ◽  
Vegetative Growth ◽  
Environmental Control ◽  
Night Temperature ◽  
Root Temperature ◽  
Aerial Parts ◽  
Temperature Regimes ◽  
Controlled Flowering

The flowering responses of Boronia megastigma Nees (Rutacae) and Hypocalymma angustifolium Endl. (Myrtaceae) to different photoperiod and temperature regimes were similar despite the fact that these species are from different families. No flowers reached anthesis in a temperature regime of 25°C day/17°C night but flowering of both species occurred in a cool temperatures (17°C day/9°C night). Photoperiod had no effect on flowering at the temperatures tested. Ten weeks of cool temperatures (17°C day/9°C night) were required for a maximum number of flowers to reach anthesis on H. angustifolium plants whereas B. megastigma plants required 15 weeks. Flower development in both species was inhibited by a large difference between day and night temperature (21°C day/5°C night) and promoted if the day/night difference was reversed (9°C day/17°C night). The temperature of the aerial parts of the plant controlled flowering, whereas vegetative growth was controlled by root temperature. Therefore, while a reduction in vegetative growth naturally coincides with the production of flowers, these events are not necessarily linked.

Germination characteristics of Artemisia ordosica (Asteraceae) in relation to ecological restoration in northern China

2005 ◽  
Vol 83 (8) ◽  
pp. 1021-1028 ◽  
Author(s):  
Yuanrun Zheng ◽  
Glyn M Rimmington ◽  
Yong Gao ◽  
Lianhe Jiang ◽  
Xuerong Xing ◽  
...  
Keyword(s):  
Temperature Regime ◽  
Northern China ◽  
Photon Flux ◽  
Artemisia Ordosica ◽  
Ordos Plateau ◽  
Temperature Regimes ◽  
Percent Germination ◽  
Alternating Temperature ◽  
Moisture Conditions ◽  
Semi Arid

Artemisia ordosica Krasch. (Asteraceae) is the dominant psammophytic shrub species on the Ordos Plateau of northern China and is used for revegetation of semi-arid areas. Experiments were conducted to determine the effects of light intensity, constant temperature, alternating temperatures, and water potential on germination to determine why air-dispersed achenes fail to germinate well in the field. Achenes germinated within a wide alternating temperature window, except under the 5:15 °C (night:day) temperature regime in darkness. Final percent germination (FPG) was higher in darkness than in light at alternating temperature regimes, except under the 20:30 °C (night:day) temperature regime. Achenes subjected to a range of constant temperatures in the dark had high FPG over 76.8% except at 30 °C (8%). Photosynthetic photon flux densities (PPFD) of 100 and 400 µmol·m–2·s–1 significantly lowered FPG under a 10:20 °C (night:day) regime, while at 0–25 µmol·m–2·s–1 PPFD, the FPG was over 92%. Few achenes germinated at –1.4 MPa. The most suitable temperature for germination of achenes placed under water stress was 20 °C. The best timing for air dispersal is mid-May, so seeds would become covered with sand at a time when temperature and soil moisture conditions were optimal for germination.Key words: air dispersal, Artemisia ordosica, hydrothermal time, psammophytes, semi-arid regions, temperature.

scholarly journals POINSETTIA GROWTH AND DEVELOPMENT IN RESPONSE TO DAY-NIGHT TEMPERATURE REGIME AND UNICONAZOLE.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1074c-1074
Author(s):  
Richard J. McAvoy
Keyword(s):  
Leaf Area ◽  
Temperature Regime ◽  
Dry Weight ◽  
Plant Canopy ◽  
Night Temperature ◽  
Specific Leaf Weight ◽  
Leaf Weight ◽  
Temperature Regimes ◽  
Potting Medium ◽  
Total Plant

Poinsettias, Euphorbia pulcherrima Willd. cvs Lilo and Diva Starlight, were exposed to either warm day-cool night or cool day-warm night greenhouse temperature regimes. Day time temperatures were imposed between 900 to 1600 HR. Within each temperature regime, poinsettias were grown single stem or pinched and drenched with either 0.04 or 0.08 mg a.i. uniconazole per 1.6 1 pot or grown as untreated controls. Light levels (PAR) and potting medium and plant canopy temperatures were continuously monitored.Over the course of the study, the day-night temperature differential (DIF), in the plant canopy, averaged 4.2C in the warm day regime and -1.4C in the cool day regime. The average daily temperature was lower (16.9C) in the warm day regime than in the cool day regime (18.7C).DIF treatment significantly affected final leaf area, leaf and total plant dry weight, leaf area ratio and specific leaf weight, The DIF treatment by cultivar interaction was significant for final poinsettia leaf area, stem, leaf and total plant dry weight, break number and average break length. Uniconazole significantly affected final plant height, stem and total plant dry weight, break number, average break length and specific leaf weight. Uniconazole by DIF treatment effects were not significant,

scholarly journals A Forced Ventilation Micropropagation System for Photoautotrophic Production of Sweetpotato Plug Plantlets in a Scaled-up Culture Vessel: II. Carbohydrate Status

2001 ◽  
Vol 11 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Sandra B. Wilson ◽  
Jeongwook Heo ◽  
Chieri Kubota ◽  
Toyoki Kozai
Keyword(s):  
Ipomoea Batatas ◽  
Starch Content ◽  
Soluble Sugar ◽  
Ventilation System ◽  
Soluble Sugars ◽  
Leaf Tissue ◽  
Photon Flux ◽  
Culture Vessel ◽  
Forced Ventilation ◽  
Starch Concentration

Sweetpotato [Ipomoea batatas (L.) Lam., `Beniazuma'] plantlets were grown photoautotrophically (without sugar) for 12 days in an improved forced ventilation system designed with air distribution pipes for uniform spatial distributions of carbon dioxide (CO2) concentration. Enriched CO2 conditions and photosynthetic photon flux (PPF) were provided at 1500 μmol·mol-1 and 150 μmol·m-2·s-1, respectively. The forced (F) ventilation treatments were designated high (FH), medium (FM), and low (FL), corresponding to ventilation rates of 23 mL·s-1 (1.40 inch3/s), 17 mL·s-1 (1.04 inch3/s), and 10 mL·s-1 (0.61 inch3/s), respectively, on day 12. The natural (N) ventilation treatment was extremely low (NE) at 0.4 mL·s-1 (0.02 inch3/s), relative to the forced ventilation treatments. Total soluble sugar (TSS) and starch content were determined on day 12. Total soluble sugars (sucrose, glucose, fructose) of FH plantlets were lowest in leaf tissue and highest in stem tissue as compared to other ventilation treatments. Starch concentration was higher in leaf tissue of FH or FM plantlets as compared to that of FL or NE plantlets. Plantlets subjected to FH or FM treatments exhibited significantly higher net photosynthetic rates (NPR) than those of the other treatments; and on day 12, NPR was almost five times higher in the FH or FM treatment than the FL or NE treatments. Carbohydrate concentration of plantlets was also influenced by the position of the plantlets in the vessel. Within the forced ventilation vessels, leaf TSS of FH and FM plantlets was similar regardless of whether plantlets were located near the inlet or outlet of CO2 enriched air. However, under FH or FM conditions, leaf starch concentration was higher in plantlets located closest to the CO2 inlet as compared to the outlet.

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

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 654
Author(s):  
Liu ◽  
Ren ◽  
Jeong
Keyword(s):  
Soluble Sugar ◽  
Seedling Quality ◽  
Astragalus Membranaceus ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Codonopsis Lanceolata ◽  
Noticeable Effect ◽  
Plug Seedling ◽  
The Difference

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

scholarly journals Differential Effects of Low Light Intensity on Broccoli Microgreens Growth and Phytochemicals

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 537
Author(s):  
Meifang Gao ◽  
Rui He ◽  
Rui Shi ◽  
Yiting Zhang ◽  
Shiwei Song ◽  
...  
Keyword(s):  
Light Intensity ◽  
Soluble Sugar ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Carotenoid Content ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Artificial Light ◽  
Plant Factory ◽  
Phytochemical Contents

To produce high-quality broccoli microgreens, suitable light intensity for growth and phytochemical contents of broccoli microgreens in an artificial light plant factory were studied. Broccoli microgreens were irradiated under different photosynthetic photon flux density (PPFD): 30, 50, 70 and 90 μmol·m−2·s−1 with red: green: blue = 1:1:1 light-emitting diodes (LEDs). The broccoli microgreens grown under 50 μmol·m−2·s−1 had the highest fresh weight, dry weight, and moisture content, while the phytochemical contents were the lowest. With increasing light intensity, the chlorophyll content increased, whereas the carotenoid content decreased. The contents of soluble protein, soluble sugar, free amino acid, flavonoid, vitamin C, and glucosinolates except for progoitrin in broccoli microgreens were higher under 70 μmol·m−2·s−1. Overall, 50 μmol·m−2·s−1 was the optimal light intensity for enhancement of growth of broccoli microgreens, while 70 μmol·m−2·s−1 was more feasible for improving the phytochemicals of broccoli microgreens in an artificial light plant factory.

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