Effects of Low Temperature Stress on Physiological Characters and Yield of Two Wheat Varieties at Jointing Stage

ZHANG Lei; LI Guoling; ZHANG Jianzhou; ZHANG Deqi

doi:10.15933/j.cnki.1004-3268.2017.11.003

Abstract：In order to explore the effects of low temperature stress on physiological characters and yield of different wheat varieties at jointing stage,we took two wheat varieties named Zhoumai 18 and Zhongmai 1 as materials,and treated them in an artificial phytotron under low temperature (0 ℃) stress.The gas exchange parameters,chlorophyll fluorescence parameters,biochemical indexes and yield characters were determined after 24 h and 48 h.The results showed that two wheat varieties had different tolerance to low temperature,and the tolerance of Zhongmai 1 was better than Zhoumai 18.After low temperature stress,the inhibition degree of gas exchange characters,maximum photochemical efficiency(Fv/Fm) and photochemical quenching(qP),chlorophyll content in Zhongmai 1 was lower than that in Zhoumai 18;the increased degree of non-photochemical quenching (NPQ),the content of proline and soluble protein in Zhongmai 1 was higher than that in Zhoumai 18.The net photosynthetic rate of Zhongmai 1 and Zhoumai 18 decreased by 36.47％ and 30.91％ after low temperature stress for 24 h,and decreased by 57.00％ and 49.18％ after 48 h.The tendency of superoxide dismutase,peroxidase and catalase activities rose first and fell later,the increase degree of Zhongmai 1 was higher than that of Zhoumai 18,while it showed the opposite tendency for the inhibition degree.The yield per plant decreased significantly,Zhoumai 18 and Zhongmai 1 decreased by 31.00％ and 19.09％ after low temperature stress for 24 h,and decreased by 56.85％ and 46.59％ after 48 h.The effective heads per plant and grains per head were seriously reduced by low temperature.Collectively,Zhongmai 1 can accumulate more proline and soluble protein,and maintain higher antioxidant enzyme activities than Zhoumai 18 under low temperature stress,which can relieve the damage to the leaves,keep in higher level of photosynthetic efficiency and get higher yield.This is the reason for its good tolerance to low temperature.