Xu Chao, Wang Ming-Tian, Yang Zai-Qiang, Han Wei, Zheng Sheng-Hua
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Sichuan Meteorological Observatory, Chengdu 610091, China.
Ying Yong Sheng Tai Xue Bao. 2021 Jan;32(1):231-240. doi: 10.13287/j.1001-9332.202101.028.
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 () 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 (), apparent quantum efficiency (AQE) and maximum photochemical efficiency (/) decreased, while light compensation point (LCP) and dark respiration rate () increased. 2) High temperature hindered the energy transfer of thylakoid in PSⅡ center (Δ＞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 (HO Content and O 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, , / and MDA were extracted as the key indices, and value was calculated. Five high temperature stress grades were divided which were normal (0<≤1), mild (1<≤2), moderate (2<≤3), severe (3<≤4) and extra severe (4<). The results would be helpful for the prevention of strawberry high temperature disaster and the optimization of microclimate environment.
以草莓品种‘红颜’为试验材料。温度处理设置为32℃/22℃、35℃/25℃、38℃/28℃和41℃/31℃（日最高温度/日最低温度），胁迫天数分别为2、5、8和11天，以28℃/18℃作为对照。测定了不同高温处理下草莓的光合特性、叶绿素荧光特性、活性氧、保护酶活性和膜脂过氧化。通过主成分分析提取关键指标。定义高温胁迫指数（）划分高温胁迫等级。结果表明：1）随着高温胁迫的加剧和胁迫时间的延长，叶绿素a（Chl a）、叶绿素b（Chl b）、类胡萝卜素（Car）、光饱和点（LSP）、最大净光合速率（）、表观量子效率（AQE）和最大光化学效率（/）降低，而光补偿点（LCP）和暗呼吸速率（）升高。2）高温阻碍了PSⅡ中心类囊体的能量传递（Δ＞0），加速了PSⅠ末端电子受体库的还原速率。在胁迫第11天，除32℃处理外，其他放氧复合体（OEC）均失活。3）不同高温处理下，活性氧（HO含量和O产生速率）和丙二醛（MDA）含量随胁迫天数增加。4）保护酶活性和可溶性蛋白含量随胁迫时间先升高后降低。5）基于主成分分析（PCA）并结合指标获取的难易程度，提取Chl a、、/和MDA作为关键指标，并计算值。划分了五个高温胁迫等级，分别为正常（0＜≤1）、轻度（1＜≤2）、中度（2＜≤3）、重度（3＜≤4）和极重度（4＜）。研究结果有助于草莓高温灾害的预防和微气候环境的优化。
