中国农业科学 ›› 2019, Vol. 52 ›› Issue (22): 4027-4038.doi: 10.3864/j.issn.0578-1752.2019.22.008

• 种质资源 • 上一篇    下一篇

谷子萌发期耐盐种质筛选及其保护酶系统对盐胁迫的响应

秦岭,张艳亭,陈二影,杨延兵,黎飞飞,管延安()   

  1. 山东省农业科学院作物研究所/山东省特色作物工程实验室,济南 250100
  • 收稿日期:2019-06-05 接受日期:2019-07-08 出版日期:2019-11-16 发布日期:2019-11-16
  • 通讯作者: 管延安
  • 作者简介:秦岭,0531-66659029;E-mail:qinling1021@163.com
  • 基金资助:
    现代农业产业技术体系建设专项(CARS-06-13. 5-A19);山东省农业科学院农业科技创新工程(CXGC2018D02);山东省杂粮创新团队项目(SDAIT-15-03)

Screening for Germplasms Tolerant to Salt at Germination Stage and Response of Protective Enzymes to Salt Stress in Foxtail Millet

QIN Ling,ZHANG YanTing,CHEN ErYing,YANG YanBing,LI FeiFei,GUAN YanAn()   

  1. Crop Research Institute, Shandong Academy of Agricultural Sciences/Featured Crops Engineering Laboratory of Shandong Province, Jinan 250100
  • Received:2019-06-05 Accepted:2019-07-08 Online:2019-11-16 Published:2019-11-16
  • Contact: YanAn GUAN

摘要:

【目的】确定谷子萌发期耐盐评价指标,筛选萌发期耐盐种质,并探讨不同基因型谷子苗期盐胁迫对保护酶系统的影响,为谷子大规模耐盐性鉴定、耐盐机理的研究提供鉴定方法和优异资源。【方法】 以不同生态区的54份谷子种质为试验材料,用1.5%NaCl溶液进行盐胁迫,蒸馏水为对照,采用培养皿发芽法在人工气候培养箱内进行谷子萌发期耐盐性鉴定;测定谷子相对发芽势、相对发芽率、相对胚芽长、相对胚根长、相对胚芽比以及发芽率、盐害率等指标;通过对指标值的相关性分析、主成分分析和聚类分析,筛选谷子萌发耐盐评价指标。采用筛选出的3个不同耐盐性谷子品种,以0.5%NaCl溶液进行苗期盐胁迫,测定盐土盆栽条件下苗期叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性。分析盐胁迫下3个基因型间生理响应机理的差异。【结果】 在1.5%NaCl溶液胁迫下,谷子的相对发芽势与相对发芽率(r=0.51,P<0.01)、相对胚芽长之间呈显著正相关(r=0.54,P<0.01);相对胚芽长与相对胚根长呈显著正相关(r=0.64,P<0.01);发芽率盐害率与相对发芽势(r=-0.37,P<0.01)、相对胚芽长(r=-0.51,P<0.01)呈显著负相关。通过主成分分析将萌发期盐胁迫处理的6个单项指标转换成3个彼此独立的综合指标;通过隶属函数分析,得到不同品种萌发期耐盐性综合评价值(D值),并通过聚类分析,将54份谷子品种分成高度盐敏感品种、盐敏感品种、中度耐盐品种、耐盐品种以及高度耐盐品种5个不同类型。其中,高度耐盐品种有4个,分别是华北夏谷区的济谷16、矮88,西北春谷区的陇谷3号和延谷13。苗期盐土盆栽试验表明,盐胁迫条件下谷子叶片SOD、POD、CAT酶活性呈现先上升后下降的趋势。耐盐性强品种济谷16的SOD、POD、CAT酶活性上升幅度显著大于耐盐性弱的品种鲁谷1号。【结论】 54份谷子种质材料在耐盐性上存在显著差异,利用隶属函数法综合分析萌发期各指标,全面地评价谷子种质资源萌发期的耐盐性。不同基因型谷子品种叶片保护酶系统对NaCl胁迫响应能力的差异,可能是由于谷子耐盐能力不同造成的。

关键词: 谷子, 盐胁迫, 萌发期, 综合评价, 保护酶

Abstract:

【Objective】The purpose of this study was to select germplasms tolerant to salt at germination stage, to establish an evaluation criterion for salt tolerance, and to investigate the effect of salt stress on protective enzyme system of different genotypes of foxtail millet at seedling stage. The results could propose an identification method and excellent genetic resources for research on salt-tolerant mechanisms of foxtail millet.【Method】54 foxtail millet varieties from different eco-regions were applied as experimental materials. Salt stress was implemented by adding 1.5% NaCl solution, and distilled water was used as the control. A petri dish based germination method was used to assess the salt tolerance of foxtail millet varieties in artificial climate incubator. Six salt-tolerant indexes were investigated in each treatment, including relative germination potential, relative germination rate, relative coleoptile length, relative radical root length, relative radical root / coleoptiles, and relative salt damage rate. A comprehensive analysis of the salt tolerance of different varieties was conducted via correlation analysis, principal component analysis and clustering analysis. Furthermore, pot experiment was conducted to cultivate selected varieties with different salt tolerance under both salt stress and normal conditions, and superoxide dismutase (SOD) activity, peroxidase (POD) activity, and catalase (CAT) activity in shoot were analyzed. And then the differences of physiological responses between those genotypes under salt stress were analyzed.【Result】Under salt stress of 1.5% NaCl , a significant positive correlation was detected between relative germination potential and relative germination(r=0.51, P<0.01) and relative coleoptile length (r=0.54, P<0.01). There was a significant positive correlation between relative coleoptile length and relative radical root length (r=0.64, P<0.01), while the relative salt damage rate showed a significant negative correlation with relative germination rate (r=-0.37, P<0.01) and relative coleoptile length (r=-0.51, P<0.01). Principal component analysis transformed the six single indexes in the salt-stressed germination stage of foxtail millet to three independent comprehensive indexes. Subordinate function analysis was conducted to obtain the comprehensive assessment value (D-value) of salt tolerance of different varieties at germination stage. 54 foxtail millet varieties were classified into five salt tolerant types based on clustering analysis, including extremely salt sensitive, salt sensitive, moderate salt tolerance, salt tolerance and high salt tolerance. The varieties with high salt tolerance were Yangu 13, Longgu 3 from spring sowing region of northwest China, and Jigu 16, Ai88 from summer sowing region of north China. The activities of SOD, POD, and CAT were increased and then decreased under salt stress condition. SOD, POD, and CAT in shoot increased in response to salt stress, and the activity of those enzymes in Jigu 16 was significantly higher than that in Lugu 1.【Conclusion】Remarkable variations in salt tolerance were detected among the 54 genotypes of foxtail millet. The systematical and clear results can be obtained by membership function analysis, and the salt tolerance of foxtail millet can be evaluated objectively and comprehensively. The leaf protective enzymes are important for the adaptability of foxtail millet to salt stress in seedling stage.

Key words: foxtail millet (Setaria italica L.), salt-stress, germination stage, comprehensive evaluation, protective enzymes