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Title: KINETIC IMAGING OF CHLOROPHYLL FLUORESCENCE USING MODULATED LIGHT

Author
item NEDBAL, L
item SOUKUPOVA, J
item KAFTAN, D
item MESZAROS, T
item WHITMARSH, CLIFFORD
item TRTILEK, M

Submitted to: Photosynthesis Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Photosynthesis is a major determinant of plant growth and productivity. Determining photosynthetic performance in plants is an important goal in plant research. Instruments that measure chlorophyll fluorescence from leaves provide a non-invasive technique to evaluate photosynthetic performance. There are currently two types of instruments, those that measure fast events and those that image individual leaves or plants. The fast instruments provide a wide range of information on photosynthetic capacity and performance, but cannot image. The imaging instruments can distinguish between different regions of a leaf, between different leaves, and between different plants, but the measurements are slow and provide only a crude estimate of photosynthetic performance. We have developed a new instrument that combines the advantage of the fast measurements with fluorescence imaging. This instrument, which makes it possible to image plant performance in the field under diverse environmental conditions or to screen for photosynthetic mutants, adds a powerful new tool for plant research

Technical Abstract: Kinetic fluorometers that measure chlorophyll fluorescence have become invaluable tools for determining the photosynthetic performance of plants. Most kinetic instruments depend on high frequency, modulated exciting light to measure the rate, efficiency, and regulation of photosynthesis under diverse environmental conditions. Recently imaging instrumentation has been introduced that provides information on photosynthetic variability over the surface of a leaf or between individual plants. Most imaging instruments depend on continuous light or low frequency modulated light for fluorescence excitation, which imposes serious limitations on measurements of the minimum fluorescence and the variable fluorescence. Here we describe a new instrument that combines the advantage of modulated measuring light with two-dimensional imaging of chlorophyll fluorescence. The instrument produces rapid time-resolved images of a single leaf or plant, providing accurate mapping of fluorescence intensities and analysis of non-photochemical quenching. The instrument can record and analyze fluorescence images of leaves in full sunlight under field conditions.