Abstract
To assess the reliability and sensitivity of non-invasive optical methods to detect the early effects of water deficit in the field, we analyzed the time-series of non-invasive measurements obtained in a dry season in a representative collection of wheat genotypes grown in small-plot field trials, in non-irrigated and irrigated variants. Despite a progressive water deficit and significant yield loss, the measurements indicated very minor changes in chlorophyll content or canopy cover. This corresponded well to the insignificant differences in spectral reflectance normalized difference vegetation index (NDVI) values. On the other hand, we identified the significant and rapid response of fast fluorescence kinetics data following the onset of irrigation. Analysis of parameters showed the main effects of drought were associated with changes in the amplitude of the I–P phase of the OJIP transient, indicating changes at the level of photosystem I and beyond. Statistical analyses identified the integrative parameter performance index PItot as the most sensitive parameter, which well-reflects the differences in responses of the genotypes to water deficit. Our results suggest that focusing on photosynthetic functions detected by the rapid chlorophyll fluorescence records can provide more accurate information on the drought stress level, compared to the structural data obtained by absorbance or reflectance measurements.
Highlights
Climate change and related environmental stress factors play an increasingly important role in the performance, vulnerability, and productivity of crop plants on a global scale, with important economic impacts [1,2] and associated effects on food security, along with the expected increase of the world population [3]
The onset of irrigation was immediately reflected in the values of the water band index (WBI; Figure 1B), which has been previously shown to be an indicator of dynamic changes in the water supply in plants [37,38,39]
This indicates that the plants were exposed to a slowly progressing moderate drought stress, which is typically associated with the absence of chlorophyll depletion [40] and, mostly, stomatal limitation of photosynthesis [41]
Summary
Climate change and related environmental stress factors play an increasingly important role in the performance, vulnerability, and productivity of crop plants on a global scale, with important economic impacts [1,2] and associated effects on food security, along with the expected increase of the world population [3]. This has led to increased pressure on researchers to contribute towards increased food production and quality, through development and innovation in relevant fields [4,5]. In addition to simple morphological and growth parameters, a larger contribution of physiological traits and responses measured in field conditions are required [10,11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
