The invention relates to a breeding method of
brassica napus variety capable of being specially adopted as a
green manure. The method comprises that
brassica oleracea type
hybrid brassica campestris is selected as the female parent and is subjected to
interspecific hybridization with white brassica parachinensis to obtain a F1 generation
hybrid species; the F1 generation
hybrid species and the female parent are subjected to
backcrossing to obtain BC1F1 seeds; the seeds are cultivated and are subjected to
selfing to obtain BC1F2 seeds; the
single plant having the
chromosome number close to the brassica campestris female parent is selected to carry out
selfing to obtain BC1F3 seeds; the
single plant having the
chromosome number n of 19 is further selected to carry out
selfing to obtain BC1F4 seeds; and the BC1F4 seeds are subjected to subsequent multi-generation selfing, wherein the short growth period of the
plant is adopted as the main limiting target character during the multi-generational selfing process and the consistent directional
system selection in the line is performed until the brassica napus variety capable of being specially adopted as the
green manure is obtained. With the breeding method of the present invention, the brassica napus variety capable of being specially adopted as the
green manure and with characteristics of short growth period, strong adaptability, high biological yield and low seed production cost can be bred out.