干旱胁迫下外源钙对桂西北喀斯特地区青冈栎种子萌发的影响  

Effects of exogenous calcium on seed germination of Cyclobalanopsis glauca in Karst area of Northwestern Guangxi under draught stress

作　　者：邓平[1,2] 吴敏 赵英[1] 赵仕花[1] 邓雯[1] 张风远 韦银霞 DENG Ping;WU Min;ZHAO Ying;ZHAO Shihua;DENG Wen;ZHANG Fengyuan;WEI Yinxia(Key Laboratory Breeding Base for the Protection and Utilization of Rare Economic Species in Southeastern Guangxi,Yulin Normal University,Yulin,Guangxi 537000,China;College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;College of Forestry,Guangxi University,Nanning,Guangxi 530004,China)

机构地区：[1]玉林师范学院桂东南珍稀经济物种保护利用重点实验室培育基地,广西玉林537000 [2]西北农林科技大学林学院,陕西杨凌712100 [3]广西大学林学院,广西南宁530004

出　　处：《西北农林科技大学学报（自然科学版）》2020年第2期69-79,共11页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(31560124,31800205);广西自然科学基金项目(2015GXNSFBA13913);广西高校科学技术研究项目(KY2015YB246,2017KY0539);大学生创新创业训练计划项目(20170606128,20170606246)

摘　　要：【目的】研究喀斯特地区土壤中交换性钙离子对干旱胁迫条件下青冈栎种子萌发特性以及有机渗透调节物质、抗氧化酶活性的影响,探明青冈栎种子在干旱胁迫条件下萌发所需的最佳外源钙浓度,为在喀斯特地区进行青冈栎的推广造林、植被恢复与重建提供理论参考。【方法】以大小相近、饱满的青冈栎种子为供试对象,采用双因素设计试验,即干旱胁迫和添加CaCl22个因素,其中干旱胁迫共设6个水平,环境水势分别为0,-0.1,-0.3,-0.6,-0.9,-1.2 MPa,对应PEG-6000质量浓度分别为0,50,125,200,250和300 g/L;添加CaCl2共设4个水平,对应CaCl 2浓度分别为0,10,20,30 mmol/L,进行完全组合设计,共设24个处理,测定不同处理青冈栎种子萌发参数(萌发率、萌发势、萌发指数和活性指数),丙二醛(MDA)和有机渗透调节物质(可溶性糖、可溶性蛋白、游离脯氨酸)含量以及抗氧化酶(SOD、POD、CAT、APX)活性,用隶属函数法对不同处理青冈栎种子的耐旱性进行综合评价。【结果】(1)外源CaCl2、干旱胁迫及其交互作用对青冈栎种子各萌发参数均有极显著影响。在环境水势为-0.3 MPa、CaCl2浓度为10 mmol/L组合处理下,各萌发参数值均达到最大;在环境水势为-1.2 MPa、CaCl2浓度为30 mmol/L组合处理下,种子停止萌发。(2)外源CaCl2、干旱胁迫及其交互作用对青冈栎种子萌发生理生化参数及抗氧化酶活性均有显著影响。同一外源CaCl 2下,MDA含量随干旱胁迫的加剧而显著增加;在同一环境水势下,随着CaCl 2浓度的增加,MDA含量呈先下降后上升的趋势。当环境水势为0 MPa时,随着CaCl2浓度的增大,有机渗透调节物质含量总体呈增加趋势;当环境水势为-0.1^-1.2 MPa时,在同一环境水势下,随CaCl2浓度的增大,有机渗透调节物质含量均呈先增加后减少的趋势。当环境水势为0 MPa时,与无钙组相比,CaCl2处理组的SOD活性无明显变化,而POD、CAT、APX活�【Objective】The effects of exchangeable calcium ions in soils of Karst area on seed germination characteristics,organic osmotic adjustment substances and antioxidant enzyme activities of Cyclobalanopsis glauca under drought stress were studied,and the optimal exogenous Ca^2+ concentration for germination of Cyclobalanopsis glauca seeds was investigated.The research would provide reference for the promotion of afforestation,vegetation restoration and reconstruction in Karst areas.【Method】The Cyclobalanopsis glauca seeds with similar size and fullness were selected for two-factor experiment including drought stress and addition of CaCl2.Six environmental water potentials(0,-0.1,-0.3,-0.6,-0.9 and-1.2 MPa)were simulated using different concentrations of polyethylene glycol(PEG)-6000(0,50,125,200,250 and 300 g/L),and exogenous calcium with four different concentrations(0,10,20 and 30 mmol/L CaCl2)was installed to simulate calcium-rich soil environment.A total of 24 treatments were conducted to determine germination characteristics(germination rate,germination potential,germination index and vigor index),contents of malondialdehyde(MDA)and organic osmotic adjustment substances(free proline,soluble sugar and soluble protein)and activities of antioxidant enzymes(superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),and ascorbate peroxidase(APX)).Subordinate function analysis was also carried out for comprehensive evaluation of drought tolerance of Cyclobalanopsis glauca seeds in different treatments.【Result】(1)Exogenous CaCl2,drought stress and their interactions had significant effects on germination parameters of Cyclobalanopsis glauca seeds.All the germination parameters reached maximum when environmental water potential was-0.3 MPa and CaCl2 concentration was 10 mmol/L.Seeds stopped germination when the environmental water potential was-1.2 MPa and CaCl2 concentration was 30 mmol/L.(2)Exogenous CaCl2,drought stress and their interactions had significant effects on physiology and biochemistry parameters

关 键 词：青冈栎 种子萌发 干旱胁迫 外源钙 喀斯特地区 

分 类 号：S792.18[农业科学—林木遗传育种]