Glutamine synthetase mutant having glufosinate resistance and application thereof and cultivation method therefor

A glutamine synthetase mutant resistant to glufosinate, wherein the glutamine synthetase mutant has the following mutations when comparing an amino acid sequence of the glutamine synthetase mutant to a reference sequence, wherein

• (1) the glutamine synthetase mutant has a mutation of X1 at an amino acid site corresponding to site 59 of the reference sequence, where X1=G;
• and
• the glutamine synthetase mutant has a mutation of X2 at an amino acid site corresponding to site 296 of the reference sequence, where X2=R,
• the glutamine synthetase mutant has the same length and the same amino acid residues at remaining sites as the reference sequence, and the reference sequence is any one of SEQ ID NOs. 1-3;
• or
• (2) the glutamine synthetase mutant has a mutation of X2 at an amino acid site corresponding to site 296 of the reference sequence, where X2=A, D, E, G, I, K, M, P, Q or R,
• the glutamine synthetase mutant has the same length and the same amino acid residues at remaining sites as the reference sequence, and the reference sequence is SEQ ID NO. 1.