Desktop Plant Stress Guide

撰稿人: 日期:2018-6-11 点击次数:175

This guide is intended as a starting point for research. Results may sometimes vary by species, plant type, or special interest.
 
Results were compiled from world wide published research, independent of fluorometer brand name. While chlorophyll fluorescence is sensitive to most types of plant stress, in some cases, this is not true. In those cases, quality special fluorescence assays are listed, or other quality alternative solutions are suggested.
 
The best tests for different types of stress are listed on the following pages. Tests are listed in order, with the best tests listed first. For more information contact
Opti-Sciences at: 603-883-4400, or www.optisci.com
 

Measuring protocols
Fv/Fm, Y(II), and ETR are all very robust tests that have been shown to correlate well with carbon fixation under most conditions. However, they do have some limitations in plant stress measurement. Some types of plant stress do not affect PSII especially in early phases. To compensate for these limitations, inventive researchers have found ways to solve some of these issues, by developing unique working assays. These improvements are listed under specific stress categories.
 
The strengths and limitations of each protocol are provided in a summary on the next pages. For information on measuring specific types of stress, go to the appropriate area in the table of contents.
 
Fv/Fm – Dark adapted test - a measurement ratio that represents the maximum potential quantum efficiency of Photosystem II if all capable reaction centers
were open. 0.79 to 0.83 (Maxwell K., Johnson G. N. 2000), (Kitajima and Butler,1975) is a range of the average approximate optimal value for most plant species with lowered values indicating plant stress. Fv/Fm has a photochemical component and a non-photochemical component (Baker 2004). Compare samples with a similar light history because it can take between 40 minutes and 60 hours for chronic photoinhibition to relax after several hours of bright sunlight. (Lichtenthaler 2004). Fv/Fm is a fast test that usually takes less than two seconds, but requires proper dark adaptation. This test was developed by
Kitajima and Butler (1975)
 
Fv/Fm is a normalized parameter that tests whether or not plant stress affects PSII in a dark adapted state. Fv/Fm is the most used chlorophyll fluorescence measuring parameter in the world. “The majority of fluorescence measurements are now made using modulated fluorometers with the leaf poised in a known state.” (Baker 2004)
 
Limitations of Fv/Fm
 
1.        Not sensitive to early or moderate water stress. (Bukhov & Carpentier 2004) (Zivcak 2008)
2.        Not sensitive to early or moderate water stress in C4 plants (da Silva J. A. & Arrabaca M.C. 2008)
3.        Fv/Fm is not sensitive to nitrogen stress until very low levels are reached. (Baker 2004)
4.        Fv/Fm is not sensitive to sulfur stress until starvation levels are reached. (Baker 2004)
5.        Not sensitive to heat stress below 45oC centigrade in Oak. (Haldiman P, & Feller U. 2004)
6.        Not sensitive to DCMU herbicide stress. (Nedbal & Whitmarsh 2004)
7.        Fv/Fm is sensitive to some types of herbicide stress types, and not others. (Nedbal & Whitmarsh 2004)
8.        Not sensitive to nickel stress. (Joshi & Mohanty2004)
9.        Not sensitive to zinc stress. (Joshi & Mohanty2004)
10.     Not sensitive to NaCl stress in rice, but it is sensitive to NaCl stress in sorghum and chickpea. Result here seem vary from plant to plant. It seems to work with some C3 plants, and some C4 plants, but not other C3 plants and other C4 plants. See NaCl stress listed under chemical stress, in this guide, for more detailed information. (Moradi & Ismail 2007) (Netondo 2004)
(Eyidogan 2007), (Moradi & Ismail 2007), (Netondo 2004) (Eyidogan 2007)

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