Abstract:

In order to provide a theoretical basis for desiccation tolerance and the storage of switchgrass (Panicum virgatum L.) seeds, we investigated the effect of ultra-dry treatment on the vigor of switchgrass seeds and seedling growth. The moisture content of switchgrass seeds was reduced to 7%, 5%, 4%, 3%, 2% and 1% from 9% (control), respectively, with silica gel, and the vigor were detected when the seeds were re-moistened. And the leaf area, root length, seedling length, root/shoot ratio, fresh weight, dry weight and relative electrical conductivity were detected after the seed had germinated in 14 days. In the process of reducing the moisture content of switchgrass seeds from 9% to 2%, the seed vigor was kept relative high. When the moisture was reduced to 1%, seed vigor decreased significantly. However, there was no significant difference between seed vigor and relative electrical conductivity. The seedling growth of the ultra-dry seeds was normal. Switchgrass seed was an orthodox seed and its low-limit of safe moisture content was 2%. Ultra-dry treatment didn't damage the integrity of the cell membrane and the seedling growth.

Key words: Switchgrass, Ultra-dry treatment, Seed vigor, Desiccation tolerance, Seedling growth

摘要：

研究超干处理对柳枝稷（Panicum virgatum L.）种子活力及幼苗生长特性的影响，为柳枝稷种子耐干性及贮藏提供理论基础。采用硅胶干燥法将柳枝稷种子含水量由9%分别降至7%，5%，3%，2%，1%，测定不同含水量条件下种子的活力以及种子萌发后第14 d幼苗的叶面积、根长、苗长、根冠比、鲜重、干重及相对电导率等指标的影响。柳枝稷种子含水量由对照9%降到2%的过程中，种子仍保持较高活力。含水量降至1%种子活力显著下降，但种子的相对电导率与种子活力没有显著相关性。超干处理后幼苗生长正常。柳枝稷种子属于正常型种子，其贮藏的安全水分下限为2%。超干处理并没有破坏柳枝稷种子细胞膜的完整性，也未对幼苗的生长造成损伤。

关键词: 柳枝稷, 超干处理, 种子活力, 耐干性, 幼苗生长