回交亲本为7902-4和40354。杂种第二代用7902-4进行回交，回交第二代用40354再次回交，之后用改良系谱混合选择法进行选育。

Their F_2 is backcrossed with 7902- 4, and F_2 of this backcross is backcrossed again with 40354, and then selected by using the modified pedigree and bulk selection procedure.

youdao

回交亲本为7902-4和40354。杂种第二代用7902-4进行回交，回交第二代用40354再次回交，之后用改良系谱混合选择法进行选育。

Their F_2 is backcrossed with 7902- 4, and F_2 of this backcross is backcrossed again with 40354, and then selected by using the modified pedigree and bulk selection procedure.

youdao