颖苞结构对结缕草种子休眠的影响

The Effects of Glumes on Breaking Down Dormancy of Zoysiagrass Seed

自然条件下种子处于休眠状态、发芽率低,限制着结缕草的大规模应用。休眠种子的扫描电镜照片显示颖苞表面致密光滑,颖孔被颖盖所覆盖,造成种子萌发过程水分难以透过。用NaOH或丙酮处理结缕草种子后,颖盖出现脱落,颖孔露出,颖苞表面变得粗糙,吸水实验表明颖苞透性得到显著提高,提前48小时以上达到饱和吸水量;发芽实验证明上述处理能有效打破种子休眠,种子提早2天发芽,发芽速度加快,在14天发芽率即达到90％以上。表明颖苞透性差是结缕草种子休眠的主要原因,改善颖苞透性能有效打破种子休眠。

Zoysiagrass seed are dormant under natural conditions, and germination rate are low during this period. The results of this study indicated that the water uptake speed of glumes treated with 300 ml/L acetone for 20 min, 200 g/kg NaOH for 20 min respectively, were much higher than untreated seeds. Scanning Electro-microscope photos showed that glumes of treated seeds changed in appearance, indicating that the permeating of glumes were improved. Also, germination speed and rate both increased significantly. Germination rate reached 90% after germinating for 14days. This experiment proved that permeating handicap was the main factor for the dormancy of zoysiagrass seeds.