Effects of Drought Stress on the Chlorophyll Fluorescence Parameters of Winter Sowing Potato Leaves at Squaring Stage

Purpose To understand the effects of drought stress on the chlorophyll fluorescence parameters at the squaring stage of winter potatoes.

Method Hezuo88, Lishu6, Xuanshu2 and Hui-2 planted in Yunnan Province were used as the experimental materials. The chlorophyll fluorescence parameters of every potato varieties were determined in winter sowing at squaring stage under drought stress and contrast treatment and the fuzzy membership function value of all chlorophyll fluorescence indexes change range were analyzed.

Result Chlorophyll a, chlorophyll b, chlorophyll a/b, the electron transport rate (ETR), efficiency of open centers of PSⅡ (F_v′/F_m′), photochemical quenching coefficient (qP), the maximum fluorescence (F_m), variable fluorescence (F_v) and maximal photochemical efficiency of PSⅡ (F_v/F_m) of four potato varieties under drought stress at squaring stage in winter sowing were lower than contrast treatment (CK), but the initial fluorescence (F₀) and non-photochemical quenching coefficient (qN) were increased. The F_v′/F_m′ from the tested four potato varieties under drought stress condition was lower than that under no drought stress condition. Drought resistance rank of four potato cultivars was Hui-2>Xuanshu2>Hezuo88>Lishu6.

Conclusion The effects of drought stress at squaring stage on chlorophyll fluorescence parameters of potato in winter sowing were different from the varieties.