Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2023, Vol. 32 ›› Issue (6): 85-99.DOI: 10.11686/cyxb2022322

Previous Articles     Next Articles

Effects of three exogenous substances on the physiological and fluorescence characteristics of Stylosanthes guianensis under low-temperature stress

Shi-yang ZHANG1(), Feng-min LIU2(), Jun-tao CUI4, Lei HE1, Yue-yan FENG3, Wei-li ZHANG1,3()   

  1. 1.College of Agriculture and Biology,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China
    2.Management Center of Teaching and Research Base of Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China
    3.Deqing Zhongkai Agricultural Technology Innovation Research Co. ,Ltd. ,Zhaoqing 526642,China
    4.College of Horticulture and Landscape Architecture,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China
  • Received:2022-08-10 Revised:2022-12-05 Online:2023-06-20 Published:2023-04-21
  • Contact: Wei-li ZHANG

Abstract:

The aim of this study was to determine whether spraying Stylosanthes guianensis plants with exogenous substances could improve their performance under low-temperature conditions. Abscisic acid, chitosan, and salicylic acid at different concentrations were sprayed onto 50-day-old S. guianensis plants, and their effects on the physiological indexes and chlorophyll fluorescence characteristics of leaves under low-temperature conditions were determined. The low-temperature treatment was applied to plants in a growth chamber, and consisted of 7 days of cold temperature (8 °C/5 °C days/nights) followed by 2 days of normal temperature (28 °C/25 °C days/nights) for recovery. It was found that spraying S. guianensis plants with exogenous substances at different concentrations significantly increased the photosynthetic pigment content, antioxidant enzyme activity, and soluble protein content of the leaves under low temperature; And significantly decreased the chilling injury index, relative conductivity, and malondialdehyde content. After 2 days of recovery at normal temperature, all indexes were restored to their respective pre-chilling levels. Compared with the control plants, those sprayed with 300 mg·L–1 chitosan, 0.4 mmol·L–1 salicylic acid, or 10 mg·L–1 abscisic acid showed significantly increased values of Fv/Fm, φE0, and PIABS (by 80.88%-122.57%, 119.87%-170.53% and 271.77%-580.49%, respectively) and significantly decreased φD0 (by 26.39%-37.10%). Based on a multivariate evaluation using a membership function analysis, the optimal concentrations of chitosan, abscisic acid, and salicylic acid to improve the low-temperature tolerance of S. guianensis are 300 mg·L–1, 10 mg·L–1, and 0.4 mmol·L–1, respectively. Among the three exogenous substances, chitosan (at 300 mg·L–1) significantly increased the chlorophyll content and the activity of photosystem II, reduced heat dissipation, and was most effective in alleviating low-temperature damage to S. guianensis.

Key words: Stylosanthes guianensis, low temperature stress, chitosan, abscisic acid, salicylic acid, physiological indicators, chlorophyll fluorescence