104(1)_str11

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 104, No. 1 (2017), p. 79–84
DOI  10.13080/z-a.2017.104.011

Effect of potassium bicarbonate on photosynthetic parameters of Setaria viridis under drought conditions

Natalija BURBULIS, Rimanta VAINORIENĖ, Aušra BLINSTRUBIENĖ, Vaida JONYTIENĖ, Vytautas LIAKAS

Abstract

The current study set out to investigate the effects of drought stress and potassium bicarbonate (KHCO₃) on green foxtail (Setaria viridis (L.) Beauv.) photosystem II (PSII) photochemistry under a moderate and severe drought. The plants at phenological stage 13 (according to BBCH scale) were divided into three groups and sprayed with water or with 10, 20 and 30 mg l^-1 KHCO₃. The plants of the first group (well-watered) were hand-watered every second day. The plants of the second (moderately stressed) and third (severely stressed) groups were used for drought stress treatment by withholding water. The results indicated that drought conditions resulted in a decrease in maximum quantum yield and effective quantum yield most likely due to the expected photoinhibition of photosystem II. Decreased gas exchange parameters revealed that the reduction in photosynthesis of green foxtail under drought stress was caused by the stomatal factors. A significant increase in the maximum quantum yield, effective quantum yield and gas exchange parameters in KHCO₃ treated plants showed that KHCO₃ protects photosystem II of green foxtail from drought, and may have potential benefit for other C₄ plants.

Key words: drought stress, green foxtail, KHCO₃, photosystem II.

Full text: 104_1_str11.pdf