Analysis on the Transcriptome Group Information of Cymbidium ensifolium Based on the High-throughput Sequencing

In order to obtain the transcriptome group information of Cymbidium ensifolium, the transcriptome sequencing, assembling, annotation and differential gene analysis were carried out by taking the three stages of flower development as the research objects. The results showed that a total of 120.86 Gb clean reads were obtained, and 56 804 Unigenes were assembled, with a mean length of 1 502 bp. Among them, 34 324 Unigenes were annotated, accounting for 60.43% of all Unigenes. 33 908 Unigenes were annotated in the NR database, which had the highest matching degree with Dendrobium nobile. 18 459 Unigenes were annotated to 50 branches in the GO database. A total of 13 145 unigenes were annotated in KEGG and 11 662 unigenes were annotated to 129 KEGG pathways. The cluster analysis of differential genes showed that there were 7 873 differential genes, among which 3 934 showed up-regulated expression and 3 939 showed down-regulated expression. In the KEGG annotation of differential genes, there were more differential genes in the related pathways of flower scent. A total of 19 737 SSR loci were screened by MISA software, among which the number of SSRs with single nucleotide repeats was the highest (13 291), followed by that with dinucleotide repeats (3 374). This study could provide basic data for the gene functional verification and secondary metabolism analysis of Cymbidium ensifolium in the later stage.