Chinese Journal of Agrometeorology ›› 2016, Vol. 37 ›› Issue (05): 545-554.doi: 10.3969/j.issn.1000-6362.2016.05.007

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Changes of Physiological Indices of Jujube Branches under Process of Low Temperature and Freeze Injury

JI Chun-rong,LIU Hai-rong,LUO Ji,YANG Ming-feng,FAN Jin-xia,ZOU Chen   

  1. 1.Institute of Desert Meteorology, China Meteorological Administration, Urumqi 830002, China; 2.Xinjiang Agro-meteorological Observatory, Urumqi 830002; 3.Akesu Meteorological Bureau, Akesu 843000; 4.Wulanwusu Agriculture Meteorology Station, Shihezi 832000; 5.Korla Meteorological Bureau, Korla 841000
  • Received:2016-01-28 Online:2016-10-20 Published:2016-10-12

Abstract:

Two cold-resistant jujube (Zizyphus jujube Mill) varieties (named Junzao and Huizao) were selected to carry out the experiment in middle ten days of January 2014, which were subjected to low temperature stress at five different grades (-18, -21, -24 and -27℃, as well as -10℃ as the reference temperature) for periods of 5h, 12h and 24h simulating experiments(total of 15 treatments). The chlorophyll fluorescence parameters of basic fluorescence(Fo) and photochemical efficiency(Fv/Fm), physiological indices of relative electrical conductivity, lipid peroxidation, protective enzyme activities and osmotic adjustment substances, were measured after recovering 24h from the experiment process at -10℃, to analyze the change of physiological indexes of jujube branches under process of low temperature and freeze injury. The results indicated that, the basic fluorescence (Fo) increased greatly, and the photochemical efficiency of photosystem II (Fv/Fm) decreased greatly as the low temperature dropped. The relative electrical conductivity of branches increased gradually as the low temperature dropped, and increased significantly at -24℃ treatment. The change of relative electrical conductivity was significant at 24h duration of low temperature and freeze injury treatment, and the variation range on Junzao was smaller than it on Huizao. The malondialdehyde(MDA) content, which was the lipid peroxidation product, and superoxide dismutase(SOD) activity, which was the protective enzyme, increased all greatly as the low temperature dropped, and then decreased all slightly at -27℃ treatment after reaching the peak value at -24℃ treatment. The changes of MDA content and SOD activity at 12h duration were all significant among the periods of 5-24h simulating experiments. The variation range of MDA content on Junzao was smaller than it on Huizao, and variation range of SOD activity on Junzao was more active than it on Huizao. The proline and soluble sugar content, which were the osmotic adjustment substances, increased all greatly as the low temperature dropped, and then decreased all slightly after reaching the peak value at -24℃ treatment. The changes of 12h duration were all significant among the periods of 5-24h simulating experiments, and the variation ranges of them on Junzao were higher than that of Huizao. Results showed that the different physiological process were inspired and induced by low temperature, and by applying the dynamic variation of physiological process to reply synthetically the influence of low temperature and freeze injury on jujube tree.

Key words: Jujube tree, Low temperature, Duration time, Physiological character, Influence process