Use of Chlorophyll a Fluorescence Imaging for Photochemical Stress Assessment in Maize (Zea mays L.) Leaf under Hot Air Condition

Abstract

The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity (F m ) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield (F v /F m ) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity (Fm) and Maximum fluorescence value (F p ) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (Φ PSII). Thus, NPQ and ΦPSII were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.

Changes of Several Metabolic Parameters of Soya Inoculated With Phytopathogens at Application Nanochelates

“…We determined another indicator parameter that is closely correlated with net CO 2 assimilationthe chlorophyll fluorescence decrease ratio -R Fd (Lichtenthaler et al, 2007). The R Fd parameter used in any investigation for evaluation different effects on the rate of photosynthesis: salt-induced changes in the photosynthetic apparatus (Stefanov et al, 2022), for an evaluation of hot air stressed on photosynthetic apparatus of maize (Park et al, 2016), for assessed in low and high temperatures resistance in a seasonal study of the acclimation of Pterocephalus lasiospermus (Perera-Castro et al, 2018), effect high-light stress on photosynthetic apparatus (Lichtenthaler & Burkart, 1999), in monitoring of salinity, temperature, and drought stress in grafted watermelon (Shin et al, 2021), for assessors of waterlogging stress on the photosynthetic apparatus of mulberry leaves (Rao et al, 2021) and other. It is worth noting that, in investigation of Perera-Castro et al (2018) under influenced the lethal temperatures (LT50) on Pterocephalus lasiospermus, R Fd resulted to be a more sensitive indicator parameter for low and high temperature treatments, since thermic resistance estimated with R Fd parameter was never higher than those estimated with F v /F m was shown (Perera-Castro et al, 2018).…”