The rapid developments of molecular biological and molecular genetic techniques provide plant-growers with an instrument for target-oriented modifications of the plant genome and obtaining a large number of samples with different characteristics. Under these conditions a major problem for successful breeding work arises – a quick and efficient selection of promising samples with the needed useful properties. Hansatech Instruments Ltd (Kings Lynn, UK) developed a new tool - mPEA (multifunctional Plant Efficiency Analyzer) allowing for fast and very informative sub-millisecond time resolution analysis (in vivo and in situ) of the functional status of the photosynthetic apparatus in plants. It is based on a simultaneous signal 16-bit resolution registration of the kinetic characteristics of prompt chlorophyll fluorescence emission, delayed chlorophyll fluorescence and modulated light scattering and reflection of the actinic incident light at 820 nm. Leaves from bean plants at different physiological states (control and decapitated after the appearance of the first trifoliate leaf) have been analyzed. The prompt fluorescence signal provides information about electron transport fluxes through Photosystem II and Photosystem I. The modulated reflection signal at 820 nm provides information about the activity of the donor and acceptor side of Photosystem I. The delayed fluorescence signals provide information about the oxygen evolving complex and the acceptor side of Photosystem II presenting structural information as rate constants, related to the whole photosynthetic apparatus.