No assignment shall be valid unless it has the approval of the Board of Educational Lands and Funds and has been recorded in the office of the board, and, if the grantee is otherwise legally disqualified, approval by the board, or recording, will not make such assignment valid. Any association, corporate or otherwise, operating on state lands, transferring its interests or capital stock, or more than ten percent thereof, to any association or corporation which is legally disqualified for holding, or which has its full quota of state leases, will render the leases it holds void upon an order of the state board or act of the Legislature. The purpose of sections 72-301 to 72-314 is to prevent for all times, directly and indirectly, the monopolization of natural resources of the State of Nebraska.