外源硅添加对模拟干旱胁迫下垂穗披碱草苗期根系形态的影响  

Effects of exogenous silicon on root morphology of Elymus nutans seedlings under simulant drought stress

作　　者：杨智 陈仕勇[1] 周青平 汪辉 陈有军 胡健 YANG Zhi;CHEN Shiyong;ZHOU Qingping;WANG Hui;CHEN Youjun;HU Jian(College of Life Science and Technology,Southwest Minzu University,Chengdu 610041,Sichuan,China;Academy of the Qinghai-Tibetan plateau,Southwest Minzu University,Chengdu 610041,Sichuan,China)

机构地区：[1]西南民族大学生命与技术学院,四川成都610041 [2]西南民族大学青藏高原研究院,四川成都610041

出　　处：《草业科学》2019年第5期1371-1378,共8页Pratacultural Science

基　　金：国家重点研发计划课题(2017YFC0504806);西南民族大学研究生创新型项目(CX2018SZ68);国家牧草产业技术体系青藏高原牧草育种岗位(CARS34);青藏高原生态畜牧业协同创新中心开放基金(QZGYXT04)

摘　　要：为了探讨外源硅添加对干旱胁迫下垂穗披碱草(Elymus nutans)苗期根系形态的影响,本研究采用聚乙二醇(PEG-6000)模拟干旱胁迫的方法,分析添加不同浓度硅对干旱胁迫下垂穗披碱草苗期根系总根长、表面积、体积、平均直径、分枝数等形态指标的影响。结果表明:15%PEG模拟干旱胁迫处理7 d后,随着硅浓度的增大幼苗的根系生物量、总根长、表面积、体积、平均直径、分枝数及根尖数呈现上升趋势;处理21 d后随着硅浓度的增大,以上指标先上升后下降,当硅浓度为0.5 mmol·L^(–1)时效果最好。同时,硅添加后的幼苗的根系指标在R1(0～0.5 mm)直径范围显著升高(P <0.05)。这些结果表明,外源硅添加缓解了干旱胁迫对垂穗披碱草幼苗根系的危害,细根分化能力明显加强;添加外源硅可使垂穗披碱草幼苗通过调整根系形态来适应干旱的环境。本研究为垂穗披碱草的抗旱性研究及其生产利用等提供了重要的参考。In order to explore the effect of exogenous silicon(Si)on the root morphology of Elymus nutans seedlings under drought stress,the total root length,root surface area,root volume,average root diameter,and root branch number of seedlings were determined by adding exogenous Si under polyethylene glycol(PEG-6000)simulated drought conditions.The results showed that the total length,root biomass,root surface area,root volume,average root diameter,branch root numbers,and root tip numbers of seedlings were increased with increasing concentrations of exogenous Si when treated with 15% PEG for 7 days.Nevertheless,these indices first increased and then decreased under the condition of 15% PEG for 21 days as the concentration of Si increased,and 0.5 mmol·L^–1 was found to be the best concentration for Si.Meanwhile,the root index of seedlings with the diameter range of R1(0~0.5 mm)increased significantly(P<0.05)with Si addition.These results indicate that Si addition enhanced the ability of fine root differentiation and alleviated the damage due to drought stress to the root system of E.nutans seedlings by adjusting the root morphology of seedlings to adapt to the arid environment.This study provides an important reference for drought resistance research and the production and utilization of E.nutans.

关 键 词：垂穗披碱草 PEG-6000 干旱胁迫 硅添加 根系形态 

分 类 号：S543.9[农业科学—作物学]