超干及老化处理对紫花苜蓿种子活力和生理变化的影响

摘要

Medicago sativa L. cv. Longdong was used as test material, and silica gel was used to study the effect of ultra-drying on vigor and physiological activity of normally stored and aged alfalfa seeds. The results indicated that seeds with moisture content at 5.72％ performed best among all the tested indices, the germination rate, germination potential and vigor index were increased by 28.91％, 30.02％ and 66.06％ than the control (un-ultradried seeds that stored at room temperature), while the above indices of aged seeds were increased by 26.31％, 23. 19％ and 67.09％ than the control (un-ultradried but accelerating aged seeds), respectively; for normally stored seeds, soluble sugar content and APX activity were increased by 22.85 ％ and 76.21％ than the control, whereas MDA content was only 50. 15％ of the control and relative TTC reduction quantity was 95％ of the control; for accelerating aged seeds, soluble sugar content and APX activity were increased by 39％ and 115.27％ than the control, whereas MDA content was only 52.32 ％ and relative TTC reduction quantity was 93.05 ％ of the control, indicating that ultra-drying treatment of alfalfa seeds with moisture content at 5.72％ helps to maintain seeds vigor, which plays a positive effect on long-term preservation and utilization of alfalfa seeds.%以陇东紫花苜蓿为研究对象,采用室温硅胶干燥法对种子进行不同时间的超干处理,测定室温贮藏与高温老化处理后不同含水量种子的活力及生理变化.结果表明:5.72%含水量的超干处理综合表现最优,该处理下室温贮藏种子的发芽率、发芽势和活力指数分别较对应CK(室温贮藏的未超干种子)高28.91%、30.02%和66.06%,可溶性糖含量、APX活性高22.85%、76.21%,而MDA含量仅为CK的50.15%,TTC相对减少量为CK的95%;老化种子的发芽率、发芽势和活力指数较对应CK(老化处理未超干种子)高26.31%、23.19%和67.09%,可溶性糖含量、APX活性分别高39%、115.27%,MDA含量仅为CK的52.32%,TTC相对减少量为CK的93.05%.说明5.72%种子含水量的超干处理可使苜蓿种子活力保持在较高状态,对苜蓿种子的长期保存和利用有积极作用.