Monitoring the physiological activity of plants by menas of EPR spectgroscopy. Mn (II) signal in Pinus nigra Arnold

Differently aged needles from a Pinus nigra Arnold tree growing in a typical urban area have been examined by means of electron paramagnetic resonance (EPR) spectroscopy, and the variation of the observed six-line Mn (II) signal was monitored for 1 year. An inverse trend has been established between the photosynthetic efficiency of the plant and the measured content of Mn (II). The possibility of using EPR spectroscopy in studying ageing and in assessing stress situations in plants is considered