Photosynthetic properties of maize hybrids under different environmental conditions probed by the chlorophyll a fluorescence


Temperatures and light intensities that deviate from optimum often affect maize (Zea mays L.) production in
temperate regions. Objectives of the current study were (i) to investigate the effects of extreme temperatures
and low light conditions on photosynthesis in maize hybrids, (ii) to test whether maize hybrids show distinctive
reactions when subjected to different stresses, and (iii) to investigate informativeness of different fluorescence
parameters in different stress conditions. Plants of five maize hybrids were subjected to: cold (Co), low light (LL),
heat (H), and severe heat (SH) treatments and field (F) conditions along with control (C), and chlorophyll a fluorescence
(ChlF) was measured. ChlF transients were shown to respond to different treatments by changing the
appearance of OJIP band, mostly at steps J and I, while the appearance of the K step was confirmed as a good
indicator of temperature stress. PC analysis revealed grouping of parameters with PCs according to their informativeness.
Parameter ψEo, was shown to be in most defined by the F treatment, probably due to higher light
intensity compared to C. Variables regarding electron transport and dissipation showed specific reactions to H
and SH treatments. Co and LL conditions caused specific changes in in parameters VJ and VI. Further research on
usability of ChlF in maize breeding is needed, as it represents the data-rich, easy to measure method, providing
the biological framework for explanation of reactions to different stresses.


stress assessment, maize hybrids, ChlF, PIABS, PC analysis

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013