Abstract: With lower-and higher heat-resistant varieties of eggplant (Solanum melongena L.) HeibeiⅠand Heibei Ⅱ as test materials, and by using Plant Efficiency Analyzer (PEA) from Hansatech, this paper measured the fast chlorophyll a fluorescence transient and its parameters. The results showed that PS Ⅱ construction became more sensitive to heat stress when ambient temperature was higher than 40 ℃. The F_o went up slowly, and F_v/F_m and ΔF/F_m′came down dramatically. Heibei Ⅱ had a longer semi-attenuation temperature of F_v/F_m (T₅₀) and ΔF/F_m′(t₅₀) than Heibei Ⅰ. Under strong heat stress (5 min at 48 ℃ or 20-30 min at 44 ℃), the K-step in relation to the inactivation of oxygen-evolving complex appeared in fluorescence rise at about 700 μs, and the regular O-J-I-P transient was transformed to O-K-J-I-P one. The K-phase of HeibeiⅠand Heibei Ⅱappeared when the treatment time was up to 20 and 30 minutes at 44 ℃, respectively. In comparing with 35 ℃heat treatment, the DI_o/RC in the parameters of Strasser′s specific energy fluxes model was increased by a great extent under 48 ℃ or more heat stress, reflecting a strong safeguard of energy dissipation to PS Ⅱ. When the temperature of heat stress increased from 35 ℃ to 52 ℃, the F_vi/F_v of PS Ⅱ silent reaction centers of HeibeiⅠand Heibei Ⅱ increased remarkably.

Key words: SO₂, Spatial temporal distribution, Passive sampling, Acid rain, Hangzhou