Evaluation of cold stress of young industrial chicory (Cichorium intybus L.) plants by chlorophyll a fluorescence imaging. I. Light induction curve

Abstract

Industrial chicory, Cichorium intybus L., is cultivated for the production of inulin. Most varieties of industrial chicory exhibit rather poor early growth, which limits further yield improvements in their European cultivation area. The poor early growth could be due to suboptimum adaptation of the gene pool to growth at low temperatures, sometimes in combination with high light intensities, which is typical of early-spring mornings. We have used chlorophyll (Chl) a fluorescence to evaluate the response of young plants of the cultivar 'Hera' to low temperatures and high light intensities. Plants were grown at three temperatures: 16°C (reference), 8°C (intermediate), and 4°C (cold stress). Lightresponse measurements were carried out at different light intensities in combination with different measurement temperatures. Parameters that quantify the photosystem II (PSII) operating efficiency (including PSII maximum efficiency and PSII efficiency factor) and nonphotochemical quenching (NPQ) are important to evaluate the stress in terms of severity, the photosynthetics processes affected, and acclimation to lower growth temperatures. The results clearly demonstrate that in young industrial chicory plants the photosynthetic system adapts to lower growth temperatures. However, to fully understand the plant response to the stresses studied and to evaluate the long-term effect of the stress applied on the growth dynamics, the subsequent dark relaxation dynamics should also be investigated.

Evaluation of cold stress of young industrial chicory (Cichorium intybus L.) by chlorophyll a fluorescence imaging. II. Dark relaxation kinetics

“…Our results clearly show that both MT and ML have a large impact on the Kautsky curve itself (Devacht et al 2011;part I) and the relaxation kinetics (this paper). This should be kept in mind when defining a procedure to estimate plant responses derived from Chl fluorescence measurements, but even more when comparing Chl fluorescence data obtained in growth chambers and those obtained under field conditions, where the light environment and temperature change continuously and at different temporal scales.…”

“…In the first part of this study (Devacht et al 2011), where the light-adapted state of the Kautsky curve was evaluated, we found that parameters such as the PSII operating efficiency (including PSII maximum efficiency and PSII efficiency factor) and NPQ are important to evaluate the effect of stress in terms of severity, processes that are affected, and acclimation to low GT. Analysis of the light-induction curves clearly demonstrated that young industrial chicory plants can adapt to low GT.…”

“…---A more detailed description of the crop and its reaction to low temperatures can be found in Part I (Devacht et al 2011). In Part I we described the response of young industrial chicory plants to cold stress at the level of the light induction curve.…”

Changes in thermic limits and acclimation assessment for an alpine plant by chlorophyll fluorescence analysis: F_v/F_mvs. R_fd

“…On the contrary, it is recognized that thylakoid membranes are the primary site of freezing damage in plant cells, thus affecting photosynthesis and CO2 fixation (Hincha et al 1996, Devacht et al 2011. Low temperatures always tend to inhibit electron transport via increased membrane viscosity through alterations in the biophysical properties of thylakoid lipids.…”

Sensing Technologies for Precision Phenotyping in Vegetable Crops: Current Status and Future Challenges

“…Cold stress tolerance evaluations by means of CFI were reported in chicory (Cichorium intybus L.) [108,109]. In these studies, measurement of the induction and relaxation kinetics of the chlorophyll fluorescence in plants cultivated at different combinations of light intensities and temperatures were made through an imaging fluorescence system (CFImager, Technologica Ltd., Colchester, UK).…”