CHANGES IN NITROGEN METABOLISM INDICES OF ARACHIS HYPOGEA LEAVES DURING LEAF SENESCENCE

Changes in nitrogen metabolism indices in peanut leaves during leaf senescence were studied in two high-yielding peanut cultivars (cv. Luhua 11 and Fu 8707) from 1996 to 1998 in the campus and an experimental farm of Shandong Agricultural University, Taian, China. The main results were as follows: During the process of leaf growth and senescence, changes in many nitrogen metabolism indices such as nitrate reductase (NR) activity, chlorophyll, soluble protein(Pr) and free amino acid content in leaves, may be simulated with a parabolic function. Total N content decreased gradually, but the activity of proteinase increased linearly. The first parameter of nitrogen metabolism to show a decline was NR activity, the second was chlorophyll content while soluble protein and free amino acid declined last.