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Chinese Journal of Applied Ecology ›› 2021, Vol. 32 ›› Issue (1): 231-240.doi: 10.13287/j.1001-9332.202101.028

• Original Articles • Previous Articles     Next Articles

Effects of high temperature on photosynthetic physiological characteristics of strawberry seedlings in greenhouse and construction of stress level.

XU Chao1, WANG Ming-tian3,4*, YANG Zai-qiang1,2, HAN Wei1, ZHENG Sheng-hua4   

  1. 1Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China;
    2College of Binjiang, Nanjing University of Information Science and Technology, Wuxi 214000, Jiangsu, China;
    3Sichuan Meteorological Observatory, Chengdu 610091, China;
    4Key Laboratory of Agricultural Environment in Southwest Mountain Areas, Ministry of Agriculture and Rural Affairs, Chengdu 610066, China
  • Received:2020-07-13 Accepted:2020-11-19 Online:2021-01-15 Published:2021-07-15
  • Contact: * E-mail: wangmt0514@163.com
  • Supported by:
    National Key R&D Program of China (2019YFD1002202), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX20_0928), the Jiangsu Provincial Natural Science Foundation Youth Fund (BK20180810), the Foundation ofHeavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province (Key Laboratory of Sichuan Province-2018-Key-05) and the Open Project of Key Laboratory of Agricultural Environment in Southwest Mountain Areas, Ministry of Agriculture and Rural Affairs (AESMA-OPP-2019006).

Abstract: Strawberry variety ‘Benihoppe’ was used as the experimental material. The temperature treatments were set at 32 ℃/22 ℃, 35 ℃/25 ℃, 38 ℃/28 ℃ and 41 ℃/31 ℃ (daily maximum temperature/daily minimum temperature), and the stress days lasted for 2, 5, 8 and 11 d, with 28 ℃/18 ℃ as the control. We measured the photosynthetic characteristics, chlorophyll fluorescence characteristics, reactive oxygen species, protective enzyme activity and membrane lipid peroxidation of strawberry under different high temperature treatments. The key indices were extracted by principal component analysis. The high temperature stress index (Z) was defined to divide the high temperature stress grade. The results showed that 1) with the aggravation of high temperature stress and the extension of stress time, chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), light saturation point (LSP), maximum net photosynthetic rate (Pmax), apparent quantum efficiency (AQE) and maximum photochemical efficiency (Fv/Fm) decreased, while light compensation point (LCP) and dark respiration rate (Rd) increased. 2) High temperature hindered the energy transfer of thylakoid in PSⅡ center (ΔWOK>0), and accelerated the reduction rate of PSⅠ terminal electron receptor pool. On the 11th day of the stress, except that under 32 ℃, all other oxygen evolution complexes (OEC) were inactivated. 3) The content of reactive oxygen species (H2O2 Content and O2 production rate) and malondialdehyde (MDA) increased with the stress days under different high temperature treatments. 4) The protective enzyme activities and soluble protein content increased first and then decreased with stress duration. 5) Based on principal component analysis (PCA) and combined with the difficulty of index acquisition, Chl a, Pmax, Fv/Fm and MDA were extracted as the key indices, and Z value was calculated. Five high temperature stress grades were divided which were normal (0<Z≤1), mild (1<Z≤2), moderate (2<Z≤3), severe (3<Z≤4) and extra severe (4<Z). The results would be helpful for the prevention of strawberry high temperature disaster and the optimization of microclimate environment.

Key words: photosynthetic parameters, chlorophyll fluorescence, antioxidant enzymes, reactive oxygen species, principal component analysis, stress index