Study On The Physiological And Biochemical Characteristics Of Germination Of Viburnum Sargentii Seeds

Viburnum sargentii is an excellent rare and endangered native tree species in Shandong.Its crown shape,leaf shape,flower position and fruit are very beautiful.The ornamental,medicinal and potential economic value are extremely high.The promotion and application prospect is broad,because Viburnum sargentii seeds have deep dormancy characteristics.Mature seeds can germinate under natural conditions for many years,and the germination rate is low,which greatly limits the promotion of Viburnum sargentii.In this experiment,three kinds of differently treated seeds of Viburnum sargentii were sedimented in sand,and their biological characteristics and physiological and biochemical and endogenous hormone dynamic changes during lamination were measured.At the same time,for the different periods of the stratification,the anatomical structure of Viburnum sargentii seeds was observed to explore the biological characteristics,anatomical structure,physiological and biochemical indexes and the dynamic changes of endogenous hormones during seed germination.The reasons for seed dormancy of Viburnum sargentii were discussed.The results are as follows:1.In the experiment,the seed viability of Viburnum sargentii was over 85%,which had great germination potential,but it did not germinate in the germination experiment,which indicated that there was a deep dormancy phenomenon in the seeds of Viburnum sargentii。2.The results of physiological and biochemical studies on the seed stratification process of Viburnum sargentii showed that the soluble sugar content continued to decrease in the early stage of lamination,and the soluble sugar content increased in the middle stratification.The soluble protein content continued to decrease and larger declined in the later stage of the stratificationing.POD and PPO activities during stratification were single-peak changes,and the two enzyme activities of the seeds of puncture and peeling peaked in the middle of the stratification,and the POD and PPO activities of untreated seeds peaked at 7 months.It indicates that the seed in the early stage of the stratification is in a state of deep dormancy,the metabolic activity is not strong,and the metabolism is strong in the middle and late stages of the stratification,which provides energy for seed germination.The increase of POD activity is beneficial to increase the antioxidant capacity of the seed,and the increase of PPO activity is beneficial to the oxidation of phenolic substances.It has a certain promoting effect on the release of seeds from dormancy.3.With the extension of the stratification time,the endogenous ZT content of the seeds of Viburnum sargentii increased continuously;the IAA content increased in the early stage and the end of the stratification decreased;the ABA content decreased in the early stage of the stratification,and the intermediate stage was basically stable and increased in the later stage.The results showed that the endogenous hormones changed significantly when the seeds broke dormancy,and the ABA as a seed germination inhibitor decreased significantly in the early stage of stratification.The increase of ZT content at the end of stratification antagonized the inhibition of ABA;GA₃ has a significant promoting effect pair the release of seed dormancy.With the increase of GA₃ content,the seed enters the initial stage of germination;the content of IAA increases slightly within the appropriate concentration range,which also promotes the release of seed dormancy.The time of the two peaks of（IAA+GA+ZT）/ABA ratio coincided with physiological activity and anatomical structure.The seeds matured after the first peak appeared,and the seeds germinated when the second peak appeared.4.Stratification for 8 months can effectively improve the germination rate of Viburnum sargentii seeds,and the germination rate of the seeds treated with puncture and peeling can reach more than 90%.