Problem with bowtie2, any suggestions?

root@linas-Aspire-E5-571:/home/linas/Desktop/genome# bowtie2 -x rattus_norvegicus --qc-filter -U /home/linas/Desktop/merged/1M.fastq -S 1M_alligned.sam --end-to-end -p 1

Could not open index file rattus_norvegicus.rev.1.bt2
Could not open index file rattus_norvegicus.rev.2.bt2
Segmentation fault (core dumped)
(ERR): bowtie2-align exited with value 139

P.S. I have seen a similar topic on this website, however, have not found a solution.