Physiological fundamentals of the AnM cultivation technique in peanut production: leaf photosynthetic hysteresis is reduced by exposing hypocotyls.

摘要

When photosynthetic photon flux (PPF) is changed from low to high and then from high to low, the photosynthetic rate (P_N) at each PPF level is usually higher during the cycle of changing PPF from high to low than during the cycle from low to high. The difference between the two PPF response curves is defined as photosynthetic hysteresis (H_P). H_P would be smaller if physiological activities are high in a plant. The previous experiments of our research have demonstrated that physiological activities are higher in peanut plants grown with the AnM technique including hypocotyl exposure. In the present experiment, H_P was examined in the peanut crop grown with the AnM technique. Peanut leaf photosynthetic activities were improved by exposing the hypocotyl, one practice of the AnM technique, and film mulching, the combined practice of the modified AnM technique. The improved photosynthetic activities also reflected in less H_P. H_P was consistent with hysteresis of stomatal and mesophyll conductance. Less H_P could be an indicator of higher physiological activities, as improved by the hypocotyl exposing and film mulching in the peanut crop.