Influence of High Salt on Protein Contents and Lipid Peroxidation and their Interaction with High Photon Flux Density on Isolated Chloroplasts of Mustard

1993 ◽  
Vol 2 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Sanjay K. Mishra ◽  
J. V. V. Dogra ◽  
Gauri S. Singhal
Keyword(s):  
Lipid Peroxidation ◽  
Flux Density ◽  
High Salt ◽  
Photon Flux ◽  
Photon Flux Density ◽  
High Photon Flux ◽  
Isolated Chloroplasts

The Effect of Photoperiod, Temperature and Photon Flux Density on Flowering in Pimelea ciliata

1994 ◽  
Vol 42 (5) ◽  
pp. 575 ◽  
Author(s):  
AT Slater ◽  
PR Franz ◽  
WK Thompson
Keyword(s):  
Flux Density ◽  
Flowering Plant ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Apparent Effect ◽  
Low Light ◽  
Flowering Response ◽  
High Photon Flux

A range of photoperiods were investigated to determine their effect on newer induction in Pimelea ciliata. Temperatures and photon flux densities were also investigated to determine their effect on modifying the response to photoperiod. Pimelea ciliata developed flowers on all plants after exposure to at least 4 weeks of an 8 h photo- and thermoperiod at a high photon flux density. As the time under the 8 h photo- and thermoperiod increased, the total number of flowers produced and the percentage of buds which were floral on each flowering plant increased. Plants gown under a 16 or 10 h photoperiod for up to 8 weeks did not produce any flowers. Under a 12 h photoperiod, only two plants out of 36 flowered, and they produced a low number of flowers. Under the conditions tested, temperature had no apparent effect on the number of plants which flowered or the number of flowers on each flowering plant. However, a vernalisation response may be increasing the rate of flowering. The flowering response was reduced when plants were grown under a low photon flux density. Few plants produced flowers, and the percentage of shoots that were floral was also reduced under low light.

Effects of Detector Nonlinearity on Spectra Measured on Three Commercial FT-IR Spectrometers

1998 ◽  
Vol 52 (4) ◽  
pp. 572-578 ◽  
Author(s):  
Robert L. Richardson ◽  
Husheng Yang ◽  
Peter R. Griffiths
Keyword(s):  
Flux Density ◽  
Signal To Noise Ratio ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Source Image ◽  
Empirical Correction ◽  
High Photon Flux ◽  
Beer's Law ◽  
Ft Ir ◽  
Beer’S Law

The effect of the nonlinear response of mercury-cadmium-telluride (MCT) detectors has been evaluated on three commercial Fourier transform infrared (FT-IR) spectrometers. The greater the photon flux and the photon flux density, and the smaller the area of the detector on which the source image is focused, the greater are the effects of the nonlinearity. The signal-to-noise ratio (SNR) of spectra measured with an MCT detector under conditions of high photon flux and, especially, high photon flux density is significantly less than the SNR calculated by using the manufacturer's D* value. Detector nonlinearity usually leads to negative deviations in Beer's law plots. An empirical correction algorithm has been applied to Beer's law spectra acquired with the use of photoconductive MCT detectors and has been found to work well.

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.

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