[Chlorophyll fluorescence transient kinetics of ginkgo leaves during expansion]

To provide the theoretical basis for cultivating ginkgo (Ginkgo biloba).

Changes of chlorophyll fluorescence transient kinetics in chloroplasts of 10-year-old seeded ginkgo leaves during expansion were studied in the field under natural environmental conditions.

W(k) peaked between 12: 00 - 15: 00, phiE(o) and psi(o) declined gradually between 8: 00 - 12: 00. ABS/ RC,TR(o)/RC and DI(o)/RC increased, while RC/CS decreased at noon. PI(abs) and F(v)/F(m) declined and reached its lowest value at 13:00, then increased, and the levels at 19:00 could restore to the levels at 7: 00.

The donor and acceptor sides of PS II are temporarily inhibited. The reaction centers of PS II are damaged, leading to the light energy transfer efficiency of PS II decrease and excess excitation energy increase at noon. The damage of reaction centers of PS II and inhibition of photosynthetic primary reaction are reversible inactivation not irreversible damaged.