[Changes of photosynthesis parameters and chlorophyll fluorescence around sprout tumble of Pinellia ternata under high temperature stress].

OBJECTIVE

To study the change of photosynthesis and chlorophyll fluorescence characteristics of Pinellia ternata around sprout tumble.

METHOD

Tubers of P. ternata were cultured firstly at (25 +/- 1) degrees C for certain days, and then they were coerced under 37 degrees C stress in the same artificial climate boxes. The chlorophyll contents, photosynthesis and chlorophyll fluorescence during different stages of high temperature stress were measured.

RESULT AND CONCLUSION

After under high temperature stress, the chlorophyll contents, the ratio of chlorophyll a/b, photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum fluorescence (Fm), quantum yield of PS II (phi (PS II)), intrinsic photochemical efficiency of PS II (Fv/Fm) and the chlorophyll photochemical quenching (qP) decreased, but the intercellular CO2 concentration (Ci), minimal fluorescence (F0), the chlorophyll nonphotochemical quenching (NPQ) increased.