The fast fluorescence kinetics; a sensitive tool for early detection of water stress in sugarcane : ASSCT peer reviewed paper
Date
2016Metadata
Show full item recordAbstract
Water stress is a major constraint for sugarcane production in many regions of the
world, including Australia. Sensitive and non-destructive early measurement of the crop
response to water stress would be of great value for producers, advisors, and
researchers. Chlorophyll-a (Chla) fluorescence is well established as a tool for
measurement of photosynthetic efficiency. Changes in the kinetics of Chla fluorescence
can provide valuable insight into the structure and function of the photosynthetic
apparatus and chloroplast membrane integrity. The parameter Fv/Fm is often used to
describe the effect of stress on the quantum yield of photosystem two (PSII). In this
study the polyphasic OJIP fluorescence transient was used to evaluate the response of
the sugarcane photosynthetic electron transport system. Chlorophyll fluorescence was
measured on three leaves in the canopy of KQ228A over a five-day water stress period,
and the response analysed using the OJIP-test. The results show that several of the
parameters that can be derived from the OJIP test are more sensitive and a better
reflection of water stress than the Fv/Fm ratio. Evidently PSII is much more sensitive to
water stress than photosystem one (PSI). In late stages of stress there are signs of a loss
in membrane integrity and a disruption of water splitting in PSII.