Effects Of Storage Methods On Allelopathic Substances And Seed Germination Rate Of Two Kinds Of Holly Seeds

Ilex chinensis Sims and Ilex rotunda Thunb are excellent garden trees,because their seeds have the characteristics of germination every other year,which increases the difficulty of seed propagation.In order to explore the effects of storage methods on allelopathic substances and seed germination of two ilex sinensis seeds,this study took the seeds of ilex sinensis and Ilex iron as materials to explore the allelopathic effects of seed extracts of different storage methods on the seeds of recipient plants.Moreover,Gas chromatography-ion mobility spectrometry(GC-IMS)was used to determine the change rules of allelopathic materials,and finally,seed germination test was used to verify the existence of allelopathic materials.The main results are as follows:(1)Allelopathic substances were present in the seed extracts of both ilex and Ilex iron.Low concentration of radish seed germination and seedling growth had promotion effect,high concentration had significant inhibition effect,and the higher the concentration the stronger the inhibition effect.The inhibitory effects of the two kinds of Holly seed extracts on radish seed germination and seedling growth were in the order of current seeds>seeds stored at room temperature for one year>seeds stored at 4℃ for one year.The allelopathic effect of Holly seed was stronger than that of iron Holly seed.(2)A total of 52 allelopathic substances were identified by GC-IMS analysis.Among them,37 kinds of Holly seeds were born in the same year,42 kinds were stored at room temperature for one year,52 kinds were stored at 4℃ for one year.There were 42 kinds of iron Holly,44 kinds of iron Holly and 48 kinds of iron Holly.The allelopathic substances in current year seeds of Holly mainly included alcohols(9 kinds),esters(7 kinds),aldehydes(5 kinds),ketones(5 kinds)and hydrocarbons(6 kinds).After one year of storage at room temperature,11 kinds of allelopathic substances were added.The contents of alcohols,ketones and aldehydes increased by 4 kinds and 3 kinds respectively.The content of five esters decreased most significantly.15 new allelopathic substances were added after storage at 4℃ for one year.The content of alcohol increased 11 kinds,aldehydes and ketones 5 kinds;The content of esters decreased most significantly in 5 kinds.The main alleles in the current seed of iron ilex were alcohols(11 kinds),esters(8 kinds),aldehydes(5 kinds)and hydrocarbons(5 kinds).After one year of storage at room temperature,6 kinds of alcohols were added,3 kinds of aldehydes,ketones and hydrocarbons were added.The content of 7 esters decreased most significantly.9 new species after one year of storage at 4 ℃;8 kinds of alcohols,4 kinds of aldehydes,3 kinds of ketones and 3 kinds of hydrocarbons increased in content.There were 6 esters with the most significant reduction in content.(3)During seed storage,the changes of allelopathic substances were as follows:the types and contents of allelopathic substances that can promote seed germination increased,such as alcohols,aldehydes and ketones.A reduction in the number and variety of seeds that inhibit germination,such as esters.(4)The seed germination test showed that the current seeds of the two kinds of Holly could not germinate.The germination rate of the seeds stored at 4℃ for one year was significantly higher than that of the seeds stored at room temperature for one year,and the germination rate of the iron Holly seeds was higher than that of the Holly seeds.In conclusion,low temperature storage has a significant effect on the changes of the types and contents of allelopathic substances in the seeds of Holly and Ilex ferro.The content of allelopathic substances that inhibit seed germination decreases,while the content of allelopathic substances that promote seed germination increases.Low temperature storage has a positive effect on promoting seed germination.