library_construction_protocol: RSV were inoculated on rice seedlings after 14 days of germination, and the inoculation process lasted for 3 days Using 500 ng total RNA or enriched small RNA200ng, the 3' splices and 5' splices were connected respectively and then reverse-transcribed using RT primer as primer, using the small RNAs attached to the 5' and 3' splices as templates, cDNA was synthesized under the action of reverse transcriptase. Universal Primer and PCR Primer were used as primers of the two strands respectively, and the first strand of reverse transcriptional cDNA was used as a template to amplify and enrich the fragments. Finally, the glue was cut to recover the small RNA fragments.