Except as provided in section 55-136, the Nebraska National Guard shall consist of the regularly enlisted personnel between the ages of seventeen and sixty years organized, armed, and equipped as hereinafter provided, of warrant officers between the ages of eighteen and sixty-two years, and of commissioned officers between the ages of eighteen and sixty-four years. The number of officers and enlisted personnel of the National Guard shall be determined from time to time and organized so as to at least meet the minimum requirements of the National Guard organizations allotted to this state. No discrimination shall be made in the enlistment of an individual, advancement in grade, or appointment of officers on account of race, color, creed, or sex.