Abstract: With top-opened chamber system, this paper studied the responses of endogenous hormones abscisic acid (ABA), indoleacetic acid (IAA), zeatin riboside (ZR) and gibberellins (GA₃) in gingko leaves to elevated atmospheric CO₂ concentration (ambient+350 μmol·mol^-1, EC). The results showed that EC could decrease the ABA content. After treated with EC for 120 days, the ABA content could be decreased by 63.0%, in comparing with the control. EC could also decrease the contents of IAA and ZR, and the decrement could reach significant with the extension of the treatment. The IAA content was 2 times higher after 100 days treatment, and ZR content was 2.5 times higher after 80 days treatment than those of CK. Under EC, the peak of GA₃ appeared earlier. The (IAA+GA₃+ZR)/ABA ratio decreased gradually with the growth of gingko, and was obviously higher than the control at later stage (after 40-60 days treatment), indicating that elevated atmospheric CO₂ concentration could promote the growth and development of gingko.

Key words: cotton functional leaf, hyperspectral parameter, soil electrical conductivity, monitoring and simulation