南京林业大学学报(自然科学版) ›› 2019, Vol. 43 ›› Issue (6): 193-200.doi: 10.3969/j.issn.1000-2006.201808026

• 研究简报 • 上一篇    下一篇

银杏种子脱水敏感性的研究

冯景1,2(), 沈永宝1,3,4,*(), 史锋厚1,3,4   

  1. 1.南京林业大学,南方现代林业协同创新中心,江苏 南京 210037
    2.南京林业大学风景园林学院,江苏 南京 210037
    3.国家林业和草原局南方林木种子检验中心,江苏 南京 210037
    4.南京林业大学林学院,江苏 南京 210037
  • 收稿日期:2018-08-13 修回日期:2019-08-02 出版日期:2019-11-30 发布日期:2019-11-30
  • 通讯作者: 沈永宝
  • 基金资助:
    江苏高校优势学科建设工程资助项目(PAPD)

Study on desiccation sensitivity ofGinkgo biloba seeds

FENG Jing1,2(), SHEN Yongbao1,3,4,*(), SHI Fenghou1,3,4   

  1. 1. Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
    2. College of Landscape Architecture, Nanjing Forestry University, Nanjing 210037, China
    3. Southern Tree Seed Inspection Center, National Forestry Administration, Nanjing 210037, China
    4. College of Forestry, Nanjing Forestry University, Nanjing 210037, China
  • Received:2018-08-13 Revised:2019-08-02 Online:2019-11-30 Published:2019-11-30
  • Contact: SHEN Yongbao

摘要:

【目的】研究银杏种子脱水敏感性及相关的生理生化变化,为银杏种子贮藏、种质资源的保存及苗木生产提供理论依据。【方法】银杏种子于25 ℃、湿度(25±2)%条件下脱水67 d,种子含水量每下降5%左右时随机取样测定相关生理生化指标。【结果】当种子含水量降至45.1%时,发芽率并未有明显变化,然而,当种子含水量降至40.1%时,发芽率从开始的92%下降至50%;相关性分析表明种子含水量与发芽率之间存在极显著的正相关(r=0.910)。银杏种子脱水过程中,其相对电导率不断上升。此外,SOD活性变化与POD活性的变化基本相似,均呈现出先下降,后升高至最大值,再下降的趋势,只是其POD活性的上升比SOD早,说明POD的反应比SOD更为敏感。种子含水量与硫代巴比妥酸反应产物(TBARS)含量(r=-0.619)、相对电导率(r=-0.745)之间存在极显著的负相关关系。【结论】银杏种子对脱水高度敏感,表现出顽拗型种子特点。严重脱水降低了银杏种子抗氧化酶活性,并加剧了膜脂过氧化作用,导致种子活力下降乃至完全丧失。

关键词: 银杏, 脱水敏感性, 种子发芽率, 顽拗性种子, 膜脂过氧化

Abstract:

【Objective】 The aim of this work was to examine the superoxide dismutase (SOD) and peroxidase (POD) activity and germinability of Ginkgo biloba seeds in response to desiccation, to provide technical guidance for the preservation and storage of its germplasm resources. 【Method】 Seeds were placed in a drying room [(25±2)% relative humidity, 25 ℃)] for 67 days. Samples were randomly taken for germination testing and enzyme activity determination after each ±5% decrease in moisture content. 【Result】The germination percentage remained constant when the seed moisture content decreased from 48.0% (fresh seeds) to 45.1%. However, when the moisture content reached 40.1%, the germination percentage decreased from 92% to 50%. A significant positive correlation was observed between the moisture content and seed germination percentage (r = 0.910). The electrical conductivity was significantly higher during the initial desiccation period (48.0%-45.1%). Furthermore, both SOD and POD activity first reduced, and then increased to peak values before declining again. POD activity rose earlier than SOD activity, indicating that the POD reaction was more desiccation-sensitive than the SOD reaction. Significant negative correlations were observed between the moisture content and thiobarbituric acid-reactive substance content (r =-0.619) and electrical conductivity (r =-0.745). 【Conclusion】Our collective results suggest that G. biloba seeds are highly sensitive to desiccation. Excessive desiccation could reduce the antioxidant enzyme activity of G. biloba seeds and intensify membrane lipid peroxidation, which would cause a consequent reduction—or even a complete loss—of seed germinability.

Key words: Ginkgo biloba, desiccation sensitivity, seed germination percentage, recalcitrant seed, lipid peroxidation

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