Study On Seed Dormancy And Germination Of Hovenia Acerba Lindl.

The article takes the Hovenia acerba Lindl. Seeds as the research object. The seeds have along dormancy stage, so we studied the seed biological characteristics, Seed Viability of Hoveniaacerba Lindl by TTC Method, seed dormancy mechanism, and the methods to break seeddormancy. The results were showed as follows:1. TTC method was a proper method for the seed viability test of Hovenia acerba Lindl.Before seeds were stained in0.25%TTC solution at30℃for4h or0.75%TTC solution at30℃for2h, they should be soaked at25℃for24h, and removed the seed coat After cutting partsof seed tissues away from the radical.2. The germination percentages reach to80%when seeds with isolated embryos. Thegermination percentages reach to85%and82%respectively when endopleura, endopleura andepisperm were removed. whereas4%of intact seeds germinated. These results indicated that theseed coat were responsible for seed dormancy. The SEM of the seed indicated that the outmostcell walls of the seed coat were thick and keratinized, which may be impermeable. And coats ofthe Hovenia acerba Lindl seeds were found to have pool water permeability. On the basis of thisresearch, seed dormancy type of Hovenia acerba Lindl. was physical (PY).3. The seed dormancy could effectively overcome by cold stratification, acid scarification andmachines.72%of seeds germinated when exposure to cold stratification at3-5℃for75days. Aswhile,76.00%of seeds germinated when exposure to cold stratification for90days andgerminated quicker. Soaking with sulphuric acid for5to25minutes promoted seed germinationwhich germination percentages reach to76-81%. There were no obvious differences ingermination rate among these processing. However，there was significant damage when exposureto acid scarification reach to30minutes, and the seed germination rate was only64%. The seedstarted to sprout on the4th day and ended on the16th day when parts of seed coat were removed,and the germination percentages reached to over80%, which as same as the speed of germinationof Soaking with cold stratification for90days. On the other hand, when the surface bruised, Theseeds started to sprout on the6th day and had73%germination rate. In addition, it was foundthat seeds treated by NaOH can not help to release seed dormancy.