ISSN:
1573-5079
Keywords:
chilling
;
Photosystem II
;
quantum efficiency
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Chl fluorescence of mature leaves in low-temperature treated plants was studied under identical measuring conditions in a segregating population of the F3 offspring of a cross between a chilling-tolerant and a chilling-sensitive tomato species. Through recombination of genes involved in photosynthesis, the population revealed a wide, continuous variability of photosynthetic capacity from plants performing much worse to those performing better than the parental lines of the cross. In the parental species, a nearly linear correlation was observed between photochemical chl fluorescence quenching (qP) and O2 evolution over a wide temperature range. Across the F3 generation, still a weak correlation between the two parameters was found at 20 °C, but not at 10 °C, when measured under identical conditions. This indicates that the fraction of open reaction centres could at least in part be adjusted to the photosynthetic capacity of the individual genotype. However, the correlation was so weak, that the previously suggested use of qP as a selection criterion for chilling tolerance of photosynthesis in breeding programs is regarded as doubtful, as long as photosynthesis rates are not measured in addition. Quantum efficiency of Photosystem II (ΦPSII) was strongly dependent on qP both at 20 and at 10 °C measuring temperature and depended on the quantum efficiency of open reaction centres (F′v/F′m) at 20, but not at 10 °C. F′v/F′m, in turn, correlated negatively with the processes of energy dissipation by the mechanisms of non-photochemical quenching (qN), i.e. its fast-relaxing component (qF) and photoinhibitory quenching (qI).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006241729948
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