Study On Dormancy And Germination Characteristics Of Styrax Obassia Sieb.et Zucc.seeds

The article takes the Styrax obassia Sieb.et Zucc.seeds as the research object.The seeds have a long dormancy stage,so we conduct series of studies on the seeds.On this paper,the cause of seed dormancy of Styrax obassia Sieb.et Zucc.were investigated by permeability of seeds,and the bioassay of extracts from different parts of seeds. In order to reveal the mechanism of seed dormancy and germination, the storage material contents and amylase activity of treated seeds sampled at the process of cold stratification were measured. The main achievements are as followes:1. The thousand-seed weight is 68.388 g,belonging to small seed;Water content of seeds is 8.68%,and seed viability is 85%,indicating greater germination potential2. we know the testa had some difficulty in permeability, which was one of reasons of seed dormancy.There were germination inhibitions in all parts of seeds, and the order of inhibitory effect was: testa < endosperm(embryo). And it proved that the presence of endogenous inhibitor is also a key reason of seed dormancy. It can be seen,it is a kind of comprehensive dormancy caused by testa restrictions and germination inhibitions.3. Cold stratification is an effective way to break seed dormancy.Im In the process of releasing dormancy,the life activities of the seeds had been increasing, the seed storage materials were degradated,conversed and utilized.Soluble sugar content showed a tent of falling after rising first,which had negative correlation with seed germination.Starch and protein content reduced, having negative correlation with seed germination.With the extension of stratification time,the activity of amylase increased constantly,and it had positive correlation with seed germination.All these changes prepared substance and energy for germination of seeds.The study preliminarily reveals the main physiological and biochemical indexes in the process of stratification.And it will provide a reference for the study of StyraxobassiaSieb.et Zucc. about seed dormanc,dormancy reason,breaking dormancy and improving seeding germination rate.