小麦百农矮抗58幼苗对Na_(2)SO_(4)胁迫响应及阈值鉴定

Response and Tolerance Threshold of Bainong Aikang-58 Wheat Seedlings toward Na_(2)SO_(4) Stress

【目的】百农矮抗58是我国小麦的主栽品种之一,探讨百农矮抗58幼苗对Na_(2)SO_(4)胁迫响应机制,并界定其对Na_(2)SO_(4)胁迫耐受阈值,进而为进一步深入研究提供基础数据,也为农业生产实践提供科学依据与理论指导。【方法】通过水培试验,设置不同浓度(0、20、40、60、80、100 mmol·L−1)Na_(2)SO_(4)胁迫处理,通过测定株高、鲜重、生物量、各种抗氧化酶活性、质膜透性、丙二醛(MDA)含量及渗透调节物质含量,研究Na_(2)SO_(4)胁迫对小麦幼苗生长与生理的影响。【结果】随着Na_(2)SO_(4)浓度的升高,小麦幼苗的株高、鲜重及生物量均下降,小麦幼苗的各种抗氧化酶活性会随着Na_(2)SO_(4)浓度的升高而不断升高,当超过一定阈值后会下降,MDA含量和质膜透性会随着Na_(2)SO_(4)浓度的升高而升高,最大值分别为对照的3.20倍和4.94倍;小麦幼苗叶片的叶绿素含量随着Na_(2)SO_(4)浓度的升高而下降;小麦体内的可溶性糖含量随着Na_(2)SO_(4)浓度的升高呈先上升后下降的变化趋势,在80 mmol·L^(−1)时可溶性糖含量最高;脯氨酸含量则随着Na_(2)SO_(4)浓度的升高而升高,最大值为对照的8.51倍。【结论】根据试验结果界定小麦百农矮抗58耐Na_(2)SO_(4)胁迫阈值为80~100 mmol·L^(−1)。

【Objective】Bainong Aikang-58 is one of the major wheat cultivars in China.To investigate the response mechanism of Bainon Aikang-58 seedling to Na_(2)SO_(4)stress was discussed and to define its tolerance threshold to Na_(2)SO_(4)stress was determined so as to provide basic data support for further research and scientific basis and and theoretical guidance for agricultural production practice.【Method】Effects of Na_(2)SO_(4)stress at 0,20,40,60,80,and 100 mmol·L−1 on the growth and physiology of the wheat seedlings were studied in a hydroponic experimentation.【Result】As the Na_(2)SO_(4)concentration in the medium increased,the plant height,fresh weight,and biomass of the seedlings decreased.The activity of each antioxidant enzyme in wheat seedlings would continuously increase with the increase of Na_(2)SO_(4)concentration,and would decrease after exceeding a certain threshold.The membrane permeability and content of MDA in the synplasmic membrane increase with increasing of Na_(2)SO_(4)concentration to maximize 3.2 and 4.94 times of the control.The chlorophyll content in the leaves were decreased with the increase of Na_(2)SO_(4)concentration.The soluble sugar content in wheat increased first and then decreased with the increase of Na_(2)SO_(4)concentration.The soluble sugar concentration was the highest at 80 mmol·L^(−1)Whereas,the proline content kept increasing to reach a maximum that was 8.51 times of control.【Conclusion】The tolerance threshold of Bainong Aikang-58 wheat seedling toward Na_(2)SO_(4)stress was determined to be 80−100 mmol·L^(−1).