All agreements or contracts with the members of the System pursuant to any of the provisions of this chapter shall be deemed solely obligations of the System and the full faith and credit of the State and of its departments, institutions and political subdivisions is not, and shall not be, pledged or obligated beyond the amounts which may be hereafter annually appropriated in the annual general appropriations act of the State, and other periodic appropriations for the purpose of this chapter. In case of termination of the System, or in the event of discontinuance of contributions thereunder, the rights of all members of the System to benefits accrued to the date of such termination or discontinuance of contributions, to the extent then funded, are nonforfeitable.