Study On Mechanism Of Seed Dormancy Release And Tissue Rapid Propagation Of Polygonatum Sibircum Red

Polygonatum sibircum Red.is a kind of perennial herb of the genus Polygonatum in Liliaceae family.Under natural conditions,polygonatum seeds have the characteristics of dormancy and low emergence rate,which makes it difficult for artificial cultivation.In this paper,the seeds of P.sibircum Red.were used as experimental materials to establish a tissue rapid propagation system,in which the seeds of Polygonatum luteum were used as explants.The main results are as follows:1.Study on the physiological changes in the process of seed stratification.It was found that the content of soluble sugar and starch decreased continuously during stratification,while the content of soluble protein decreased first and then increased.Through the analysis of SOD,CAT and POD in seeds,the activity of SOD decreased first and then increased with the increase of stratification time.The maximum activity of SOD reached 112.52 u/g.FW at 90 days of stratification,and the activity of CAT and POD increased with the change of temperature stratification The time of the increase gradually.At 120 days of stratification,the seeds of P.sibircum Red.gradually completed morphological post ripening,and the activities of related enzymes increased gradually.The nutrients and GA₃,ABA in the seeds transformed to physiological mature state.120 days of stratification was the best time to break the dormancy of P.sibircum Red.seeds.2.Study on transcriptome during seed dormancy release of P.sibircum Red.The results showed that exogenous GA₃ could effectively break the seed dormancy of P.sibircum Red..;60 074 up-regulated genes and 19 642 down regulated genes were obtained by transcriptome sequencing;116 570 differential genes were annotated by go function to GO items such as metabolic process,biological regulation,cell component synthesis and enzyme catalytic activity.A total of 138 metabolic pathways were found by pathway analysis of 65 038 differentially expressed genes.In the process of dormancy release,DEGs were mainly enriched in carbon metabolism,secondary metabolite biosynthesis and polysaccharide metabolism.Based on the annotation results in KEGG database,15 metabolic pathways related to dormancy release were found.In the process of seed development and dormancy release,a large number of different genes involved in the expression of embryo morphogenesis,polysaccharide decomposition and protein synthesis are involved in the interaction of multiple metabolic pathways,forming a complex regulatory network of dormancy release,among which plant hormone signal transduction is one of the key factors to regulate dormancy release.3.Study on the rapid propagation system of P.sibircum Red.dormant seed tissue.It was found that the best medium for germination induction was MS+2.0mg/L6-BA+0.1mg/L NAA,the best medium for proliferation was MS+1.5mg/L 6-BA+0.5mg/L NAA,the best medium for rooting was 1/2MS+0.1mg/L 6-BA+1.5mg/L NAA,and the best transplanting medium ratio was vermiculite:river sand:nutrient soil:coconut bran=1:1:1:1.