CRISPR/Cas9(clustered regularly interspaced short palindromic repeats/CRISRP‑associated
nuclease 9)is a new type of genome⁃directed editing technology after ZFNs(zinc finger nucleases)and
TALENs(transcription activator like effector nucleases).Compared with the previous two generations of
technology,it has the characteristics of simplicity and high efficiency.CRISPR/Cas9 is not only a basic
research tool,but also has become one of currently useful molecular breeding tools,and important
progress has been made in crop genetic improvement. The structure,classification,action mechanism of
the CRISPR/Cas9 system and its application progress in crop quality improvement,yield enhancement,
resistance breeding and male sterile material selection were reviewed,its existing problems were
discussed,and its application prospects were prospected.