外源硅调控葡萄生理特性对低温胁迫的响应

本研究以大田葡萄品种‘梅鹿辄’为试材,采用大田喷施硅酸钾与室内低温处理相结合的方法,测定不同温度下葡萄叶片生理指标的变化,研究外源硅酸钾调控葡萄生理特性对低温胁迫的响应,探讨其提高葡萄抗寒性可能的作用机制。结果表明:低温胁迫下葡萄Inv活性被抑制,而其它指标则升高;喷施硅酸钾可显著降低低温胁迫下葡萄叶片的MDA含量,且当硅酸钾浓度为0.75%时对低温的损伤缓解作用最大;而脯氨酸、可溶性蛋白和可溶性糖含量、Inv、SPS活性及SS净活性均随硅酸钾浓度的升高而显著提高,但是可溶性蛋白含量在硅酸钾浓度为0.50%时最大,其它指标均在浓度为0.75%时最大;通过葡萄叶片各抗寒指标的隶属度值与综合评价指标看出,始花期0.75%的硅酸钾处理后葡萄抗寒性最强。综合分析,喷施硅酸钾可提高低温胁迫下葡萄叶片渗透调节物质含量,加快蔗糖转运及代谢速率,缓解活性氧累积,增强其耐寒性。

Exogenous Silicon Regulated the Physiological Characteristics of Grapes Responses to Low Temperature Stress

To study the response of physiological characteristics of grape to low-temperature stress by spraying potassium silicate,and to explore the possible mechanism of improving the cold-resistance of grape.The grape variety Vitis vinifera’Merlot’was used as the experimental material.The results showed that,under low temperature stress,grape leaf Inv activity was inhibited,while other indexes were increased to some extent.Spraying exogenous silicon significantly reduced the MDA content of grape leaves under low temperature stress.When the concentration of exogenous silicon was 0.75%,the MDA content is the lowest.Proline,soluble protein and soluble sugar content,Inv,SPS activity and SS net activity all increased significantly with the increase of exogenous silicon concentration,the soluble protein content reached its maximum when the concentration of exogenous silicon was 0.5%,and other physiological index reach maximum when the concentration of exogenous silicon is 0.75%.The subordinate function value and comprehensive evaluation index of each cold resistance index of grape leaves showed that the grape with 0.75%potassium silicate at the beginning of flowering had the strongest cold resistance.Comprehensive analysis showed that spraying exogenous silicon could increase content of osmotic adjustment substance,accelerate sucrose transport and metabolic rate,alleviate active oxygen accumulation and enhance cold tolerance of grape leaves under low temperature stress.