Abstract
Sinojackia xylocarpa is a rare endemic genus in China, and is endangered in their wild habitats. For endangered rare species, sexual propagation is significant for their protection of genetic diversity and restoration of wild population. Especially for S. xylocarpa, the artificially cultivated population is expanded by vegetative propagation, which could lead to a lack of diversity. The fruits of S. xylocarpa require stratification to germinate, during which the hard pericarp becomes soft, and endophytes and soil microorganisms are considered to be involved in the process. Amplicon sequencing was used to analyze the changes in microbial community structure and the role of microorganisms in pericarp degradation. Analyses of pericarp from fresh and stratified fruits of different stages revealed that the abundance of endophytic bacteria in pericarp presented an overall increasing trend as the stratification processing; endophytic bacteria in stratified pericarp can produce beta-glucosidase to participate in the degradation of the pericarp. Soil fungal diversity analyses of different stages showed that the highest levels of the two samples of fungi function clustering is saprophytic in nutritional type; guild model also indicated that wooden saprophytic fungi abundance increased obviously; further the effect of degrading pericarp of four strains isolated from stratified pericarp are confirmed. Results above indicate that soil fungi are involved in the degradation. Breaking seed dormancy with microorganisms has the potential to be applied to endangered plants that face difficulties in germination, especially in their natural habitats.