枳椇种子休眠原因及解除方法

A study on the seed dormancy mechanism and ways of dormancy breaking in Hovenia acerba Lindl.

从枳椇种子的种皮结构和透性、离体胚萌发等方面开展种子休眠原因的研究，同时采取低温层积、浓硫酸处理、机械处理等方法研究枳椇种子休眠解除技术。结果表明：枳椇种子种皮结构致密，透水性差是抑制种子萌发的主要原因，种子休眠类型为物理休眠（ PY）。低温层积75 d枳椇种子的发芽率达到72％，层积90 d种子发芽率达到76％，且发芽速度更快；浓硫酸处理5～25 min，种子发芽率在76％～81％，各处理种子的发芽率没有差异，但浓硫酸处理30 min对种子明显产生伤害，发芽率仅为64％；切除部分种皮的种子在置床后4 d开始萌发，发芽速度与层积90 d的发芽速度一致，置床16 d后萌发结束，发芽率为80％；擦伤种子表面的种子置床后6 d开始萌发，发芽率为73％。

In this paper, we studied seed dormant reasons of Hovenia acerba Lindl. based on the observations on the structure and permeability of seed coat and the seed embryo growth. In order to find out an effective way to overcome seed dormancy, the seeds were treated by cold stratification at 3-5 ℃, acid scarification, and mechanical scarification. The results showed that the low seed coat permeability was the main reasons of seed dormancy, and which was a type of phys-ical dormancy （ PY） . 72% seeds germinated when exposure to cold stratification at 3-5℃ for 75 days, and 76% seeds germinated when exposure to cold stratification for 90 days and germinated more quickly. Soaking with sulfuric acid for 5 to 25 minutes promoted seed germination rate to 76%-81%. There were no obvious differences in germination rate among these ways of breaking the dormancy. However,there was a significant seed damage when exposure to acid scarification o-ver 30 minutes, because the seed germination rate was only 64%. The seed started to sprout at the 4th day after parts of seed coat were removed, the germination rate reached to over 80%, this germination speed was the same as that of trea-ting with cold stratification for 90 days. On the other hand, when the surface of seeds bruised, the seeds started to sprout on the 6th day and the germination rate was 73%.