Net CO2 exchange rate of in vitro plum cultures during growth evolution at different photosynthetic photon flux density

2005 ◽  
Vol 105 (2) ◽  
pp. 197-211 ◽  
Author(s):  
S. Morini ◽  
M. Melai
Keyword(s):  
Exchange Rate ◽  
Photosynthetic Photon Flux Density ◽  
Co2 Exchange ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Co2 Exchange Rate ◽  
Growth Evolution ◽  
Net Co2 Exchange Rate

scholarly journals Microtuberization of Potato (Solanum tuberosum) under Saline Stress

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873B-873
Author(s):  
Y. Zhang ◽  
D. Donnelly
Keyword(s):  
Flux Density ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Saline Stress ◽  
Photosynthetic Photon Flux ◽  
Nodal Cuttings ◽  
Microtuber Induction ◽  
Night Period

In vitro bioassays for screening and selection of salinity (NaCl)-tolerant potato have primarily focused on nodal cuttings. However, the relative tolerance of the microtuberization stage to salinized medium may be more relevant. A two-step microtuberization protocol was used in which in vitro layering was followed by microtuber induction in salinized media. `Norland', `Russet Burbank', and `Superior' shoots were layered in liquid Murashige and Skoog (1962) basal salt medium with 20 g sucrose/liter and incubated for 4 weeks at 25C with 50 μmol–m–2·s–1 photosynthetic photon flux density and 16-h day/8-h night period. Medium was replaced with liquid medium containing 80 g sucrose/liter and NaCl at 0, 80, or 160 mM. Cultures were incubated for 4 weeks at 15C with 50 μmol–m–2–s–1 photosynthetic photon flux density and 8-h day/16-h night period. Relative salinity tolerance of cultivars differed during the microtuberization stage. Low salinity (80 mM) stimulated, but high salinity (160 mM) depressed, microtuber yields compared with controls.

scholarly journals Estimation of Global and Diffuse Photosynthetic Photon Flux Density under Various Sky Conditions Using Ground-Based Whole-Sky Images

2019 ◽  
Vol 11 (8) ◽  
pp. 932
Author(s):  
Megumi Yamashita ◽  
Mitsunori Yoshimura
Keyword(s):  
Flux Density ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Diffuse Component ◽  
Photosynthetic Photon Flux ◽  
Physiological Processes ◽  
Sky Conditions ◽  
Mean Square Errors ◽  
Relative Root

A knowledge of photosynthetic photon flux density (PPFD: μmol m−2 s−1) is crucial for understanding plant physiological processes in photosynthesis. The diffuse component of the global PPFD on a short timescale is required for the accurate modeling of photosynthesis. However, because the PPFD is difficult to determine, it is generally estimated from incident solar radiation (SR: W m−2), which is routinely observed worldwide. To estimate the PPFD from the SR, photosynthetically active radiation (PAR: W m−2) is separated from the SR using the PAR fraction (PF; PAR/SR: unitless), and the PAR is then converted into the PPFD using the quanta-to-energy ratio (Q/E: μmol J−1). In this procedure, PF and Q/E are considered constant values; however, it was reported recently that PF and Q/E vary under different sky conditions. Moreover, the diffuse ratio (DR) is needed to distinguish the diffuse component in the global PAR, and it is known that the DR varies depending on sky conditions. Ground-based whole-sky images can be used for sky-condition monitoring, instead of human-eye interpretation. This study developed a methodology for estimating the global and diffuse PPFD using whole-sky images. Sky-condition factors were derived through whole-sky image processing, and the effects of these factors on the PF, the Q/E of global and diffuse PAR, and the DR were examined. We estimated the global and diffuse PPFD with instantaneous values using the sky-condition factors under various sky conditions, based on which the detailed effects of the sky-condition factors on PF, Q/E, and DR were clarified. The results of the PPFD estimations had small bias errors of approximately +0.3% and +3.8% and relative root mean square errors of approximately 27% and 20% for the global and diffuse PPFD, respectively.

scholarly journals Different LED Light Wavelengths and Photosynthetic Photon Flux Density Effect on Colletotrichum acutatum Growth

Plants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 143
Author(s):  
Neringa Rasiukevičiūtė ◽  
Aušra Brazaitytė ◽  
Viktorija Vaštakaitė-Kairienė ◽  
Alma Valiuškaitė
Keyword(s):  
Flux Density ◽  
Photosynthetic Photon Flux Density ◽  
Growth Characteristics ◽  
Colletotrichum Acutatum ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Light Emitting ◽  
Led Light ◽  
Fungus Growth

The study aimed to evaluate the effect of different photon flux density (PFD) and light-emitting diodes (LED) wavelengths on strawberry Colletotrichum acutatum growth characteristics. The C. acutatum growth characteristics under the blue 450 nm (B), green 530 nm (G), red 660 nm (R), far-red 735 nm (FR), and white 5700 K (W) LEDs at PFD 50, 100 and 200 μmol m−2 s−1 were evaluated. The effect on C. acutatum mycelial growth evaluated by daily measuring until five days after inoculation (DAI). The presence of conidia and size (width and length) evaluated after 5 DAI. The results showed that the highest inhibition of fungus growth was achieved after 1 DAI under B and G at 50 μmol m−2 s−1 PFD. Additionally, after 1–4 DAI under B at 200 μmol m−2 s−1 PFD. The lowest conidia width was under FR at 50 μmol m−2 s−1 PFD and length under FR at 100 μmol m−2 s−1 PFD. Various LED light wavelengths influenced differences in C. acutatum colonies color. In conclusion, different photosynthetic photon flux densities and wavelengths influence C. acutatum growth characteristics. The changes in C. acutatum morphological and phenotypical characteristics could be related to its ability to spread and infect plant tissues. This study’s findings could potentially help to manage C. acutatum by LEDs in controlled environment conditions.

scholarly journals Biofertlizer Lumbrical improves the growth and ex vitro acclimatization of micropropagated pear plants

2021 ◽  
Vol 22 (1) ◽  
pp. 17-30
Author(s):  
Nataliya Dimitrova ◽  
Lilyana Nacheva ◽  
Małgorzata Berova ◽  
Danuta Kulpa
Keyword(s):  
Woody Species ◽  
Photosynthetic Photon Flux Density ◽  
Stem Length ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Ex Vitro ◽  
Fluorescent Lamps ◽  
Planting Material ◽  
Number Of Leaves

In vitro micropropagation of plants is highly useful for obtaining large quantities of planting material with valuable economic qualities. However, plantlets grow in vitro in a specific environment and the adaptation after the transfer to ex vitro conditions is difficult. Therefore, the acclimatization is a key step, which mostly determines the success of micropropagation. The aim of this investigation was to study the effect of the biofertlizer Lumbrical on ex vitro acclimatization of micropropagated pear rootstock OHF 333 (Pyrus communis L.). Micropropagated and rooted plantlets were potted in peat and perlite (2:1) mixture with or without Lumbrical. They were grown in a growth chamber at a temperature of 22±2 °C and photoperiod of 16/8 hours supplied by cool-white fluorescent lamps (150 µmol m-2 s-1 Photosynthetic Photon Flux Density, PPFD). The plants were covered with transparent foil to maintain the high humidity, and ten days later, the humidity was gradually decreased. Biometric parameters, anatomic-morphological analyses, net photosynthetic rate and chlorophyll a fluorescence (JIP test) were measured 21 days after transplanting the plants to ex vitro conditions. The obtained results showed that the plants, acclimatized ex vitro in the substrate with Lumbrical, presented better growth (stem length, number of leaves, leaf area and fresh mass) and photosynthetic characteristics as compared to the control plants. This biostimulator could also be used to improve acclimatization in other woody species

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