Leaf senescence and the metabolism of active oxygen in peannt

The leaf senescence and the metabolism of active oxygen in peanut were studied with two high-yielding peanut cultivars (cv. Luhua No.11 and Fu 8707) in the campus and experiment farm of Shandong Agricultural University. The results showed that changes of many physiobiological characters such as activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in leaves, may be simulated with a parabolic function, Y=A+Bx+Cx 2. Content of malondialdehyde (MDA), production of active oxygen (O 2 · ) and permeability of plasma membrane in leaves changed to increase after leaf unfolding during leaf senescence. These tendencies of change could be described by an exponential function of Y=Ae Bx . The leaf senescence could be divided into slow senescence phase (the leaf age was from 25~30 to 55~60 days after unfolding) and rapid senescence phase (the leaf age was from 55~60 days after unfolding to falling off). The leaf senescence of Fu8707 was earlier than that of Luhua No.11.