Studies On Dormancy And Germination Mechanism Of Celtis Koraiensis Nakai Seeds

In this study,the dormancy cause of Celtis koraiensis were discussed,by measuring the morphological characteristics,testa permeability,embryo excision test together with the bioassay of extracts from different parts of seeds.The seeds also treated by soaking with hormone solutions and stratification in cold temperature to find out the method for breaking seed dormancy.To further reveal the seed dormancy mechanism,the hormone contents,nutriments content and enzymes activities were also determined.The results were as follows:1.Water permeability of testa was poor and its mechanical hinder also was hard,which was one of reasons of seed dormancy.2.All extraction phases are gained in seed coat and embryo by using systematical solvent separation method.The seed coat and embryo all contains germination inhibitors substances,they had significant inhibitory effect on germination rate and root seedling height of the cabbage seed.The higher the concentration,the more significant inhibitory effect.The germination of seed embryo was not dormant itself.3.The seeds treated with 400mg/L and 600mg/L GA3 for 2 days combined with cold stratification had higher germination.4.In the process of stratification of Celtis koraiensis seeds,the dynamic changes of starch,crude fat and souble protein showed decreasing trend,but the contents of souble sugar declined with the period of stratification.The nutriments content in the seeds treated with GA3 for 2d showed the highest utilization.5.The tendency of hormones revealed different character.The content of GA and ZR increased as the time of stratification prolongs.At the same time,the content of IAA and ABA declined.The ratio of GA/ABA and ZR/ABA gradually increased,the ratio of IAA/ABA has no significantly changes.