If pursuant to Section 50740 a district election is not held, the board of supervisors of the county in which the district, or the largest part thereof in area, is situated shall at its next regular meeting appoint to the positions of trustees those persons nominated, or if no persons have been nominated for said positions, the board of supervisors shall appoint any qualified person or persons, and such person or persons shall qualify, take office, and serve exactly as if elected at a general district election.