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Journal of Desert Research ›› 2023, Vol. 43 ›› Issue (2): 243-254.DOI: 10.7522/j.issn.1000-694X.2022.00083

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The response mechanism of early seed regeneration process of Caragana korshinskii bushes with different plantation ages in sandy-hilly region of northwest Shanxi Province

Yu Zhang1(), Qianqian Gou1,2(), Min Gao1, Yan Zhang1, Wentin Guo1, Guohua Wang1,2,3   

  1. 1.College of Geographic Sciences,Shanxi Normal University,Taiyuan 030031,China
    2.Linze Inland River Basin Research Station /, Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    3.Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
  • Received:2022-03-21 Revised:2022-05-20 Online:2023-03-20 Published:2023-04-12
  • Contact: Qianqian Gou

Abstract:

Soil desiccation is the key limiting factor for seed germination, survival and growth of regenerated seedlings, and seed regeneration in artificial bushes in sandy areas. In this study, we selected Caragana korshinskii of different planting ages (7,13,19,51 years) as research subjects, and analyzed the effects of severe, moderate and light drought stress on seed germination, seedling growth, physiology and photosynthetic characteristics of C. korshinskii through controlling of soil water in pot culture. The results showed that the seed emergence rate of C.korshinskii significantly decreased with the increased drought stress. The seed emergence rate of C. korshinskii at 13 years was higher than other years, followed by 19 years, and the lowest kept at 51 years. The plant heigh, leaf numbers and total biomass of seedlings decreased significantly with increased of drought severity, and the plant traits were higher at 13 years compared with other ages. The root-shoot ratio of seedlings increased in each age. With increased of drought severity, the soluble sugar content of C. korshinskii seedlings in different ages increased, and the content at 13 years was the highest, which was 30.19 mg·g-1. The content of free proline also increased, and the content of 19 years was the highest,which was 2 683.73 μg·g-1. MDA content in seedlings of all ages increased gradually under drought stress, and reached a maximum value under severe drought stress, the content about MDA had the largest increase in 51 years. Under drought stress, chlorophyll a, b and chlorophyll content of C. korshinskii seedlings in different ages firstly decreased, then increased, and finally decreased again, and the most decreased occurred at 51 years. The plant traits of C. korshinskii seedlings were influenced by different degree of drought stress, but the seedlings at 13 years and 19 years could adjust the osmotically regulated substance to reduce damage and to maintain normal physiological metabolism and seedling growth. However, the lower osmotic regulation ability with the highest MDA content of 51 years, which caused serious damage to the cell membrane, resulting in a significant increase in mortality. According to the membership functions showed that the drought tolerance of C. korshinskii seedlings of different ages was 13 years>19 years>7 years>51 years.

Key words: drought stress, Caragana korshinskii seedlings, physiological characteristics, growth traits, natural regeneration

CLC Number: