| dc.description.abstract | Polyploidy has substantially contributed to successful plant evolution, and is often connected to a higher resilience to environmental stress. We test the hypothesis that polyploids tolerate
light stress better than diploids. The Ranunculus auricomus complex comprises diploid (2x), tetraploid
(4x), and hexaploid (6x) cytotypes, the former of which occur in shaded habitats and the latter more
in open, sun-exposed habitats in Central Europe. In this study, we experimentally explored the
effects of ploidy and photoperiod extension on the efficiency of photosystem II in the three cytotypes
in climate growth chambers. Quantum yields and various coefficients that can be calculated from
light curve, Kautsky curve, and fluorescent transient OJIP experiments provided support for the
hypothesis that, in comparison to diploids, the improved regulation of excess light by more efficient
photochemical and non-chemical quenching in polyploids might have facilitated the adaptation to
unshaded habitats. We suggest how lower stress levels in reproductive tissues of polyploids might
have favored asexual reproduction. | en_US |
