The Research Of Breaking Dormancy And Germination Mechanism Of P.tatarinowii Seeds

P.statarinowii,as the only tree species of Ulmusm,Ulmus,It is a special product of China.It is a endangered III-class protection plant in China.Because of its rich economic,ornamental,cultural and other values,it has been heavily cut down in recent years,resulting in a scarcity of the number of plants.At present,the main cultivation method of P.statarinowii is seeding propagation,and its production is difficult due to its long dormant period.Therefore,it can only plant the seeds in the second yearwith low germination rate,so only the comprehensive analysis of the most fast break seed dormancy of P.statarinowii method,find out the optimal way of germination,the seed of P.statarinowii can be speed up the production,improved the efficiency of breeding,reduced unnecessary losses and improved the germination rate.In this paper,the seeds of P.statarinowii in Taishan area were used as experimental materials,it mainly discusses the mechanism of seed germination and how to promote the rapid germination of sandalwood seeds from the aspects of breaking the dormancy of seeds and the environment of seed germination.Mainly on the low-temperature wet storage,low temperature,dry storage at room temperature,room temperature dry wet storage reservoir of 4kinds of storage methods on breaking seed dormancy of P.statarinowii,analysis process of breaking dormancy P.statarinowii seeds from physiological and biochemical aspects,different germination environmental factors?moisture,temperature,illumination,growth regulator?to promote P.statarinowii seeds germination,also discussed the effect of seed coating method in breeding of P.statarinowii seeds.The main results are as follows:?1?reason for dormancy P.statarinowii seeds is physiological dormancy?PD?,It needs a certain amount of storage and ripening to break the dormancy.The safe water content of P.statarinowii seeds is high,and the dry storage method is not suitable for the seeds,compared with dry storage method and room temperature storage method,low temperature wet storage method is the best method for seed storage.Although the germination rate of low temperature wet storage for 90 days reached the maximum under the experimental conditions,the germination rate of 60 days and 90 days was not much different.In practical application,the seed stored in low temperature sand for 2-3 months could meet the requirements of production.?2?after a certain time of biochemical low-temperature wet storage P.statarinowii seeds in physiological studies showed that:soluble sugar in storage time showed upward trend after the first drop,the storage time of 60d-90d when the content of soluble sugar in the seed is remarkably improved,large molecules begin to decompose,the seeds break dormancy to provide energy for themselves,and the internal metabolism of seeds is stronger,soluble protein continuously decomposed into free amino acids,but the difference of soluble protein content of 90d¹20d was not significant showthat the metabolic activity of seeds was inhibited and inhibit seed germination indirectly.In the process of storage,the content of Pro increased continuously,and the growth rate of Pro content in the early stage was faster than that of the later Pro.The content of MDA increased and then decreased along with the prolongation of storage time.Combined with Pro analysis,it could be concluded that when the seeds were around 90d,most of the seeds began to break dormancy and began to have strong vigor in the stage of imbibition and germination.Through the analysis of SOD and POD inside the seeds,The antioxidant capacity of seeds during seed storage is getting stronger and stronger,POD began to increase sharply in 90d,may be the seed peroxide in the accumulation cause the antioxidant system began to disorder,the seeds also began to deterioration,thus more and more is not conducive to seed germination.Through the analysis of the above physiological indexes,it is the most suitable for the seed germination of P.statarinowii when the low temperature is stored at about 90d.?3?P.statarinowii seeds do not like light.Less light per day can promote the germination of P.statarinowii seeds.?4?too low temperature?below 15?degree?or too high?above 30?degrees?is not conducive to seed germination of P.statarinowii.Variable temperature and stratification can effectively promote seed germination,but constant temperature 25?are more suitable for seed germination.?5?the germination rate of P.statarinowii seeds increased with the increase of moisture content.The optimum soil moisture content of the seeds was about 60%.When the soil moisture content was too high,the germination rate would decrease.?6?The effect of GA₃ and NAA was beneficial to the germination of P.statarinowii seeds,and the effect of CTKwas not significant.P.statarinowii seeds treated with the concentration of400 mg/L^-1,GA3 and 30 mg/L^-1,NAAare more suitable for P.statarinowii seeds germination.