PURPOSE: To prepare the subject plant enabling the breeding thereof in a form capable of expressing the character controlled with recessive genes and in a short period breeding by culturing the anther of the genus Cucumis plant in a medium.

CONSTITUTION: The anther of the genus Cucumis plant [preferably the tetraspore or microspore of a plant such as Cucumis melo or Cucumis sativa] is cultured in a medium (preferably containing amino acids) to prepare the objective plant.