Received for publication 18 May 1984. Journal Paper No. 9867 of the Purdue Univ. Agricultural Experiment Station. We acknowledge the generosity of Charles Youtsey, Citrus Budwood Registration Bureau, Lake Alfred, Fla., who supplied seed of ‘Temple’ tangor and ‘Troyer’ citrange. This research was supported by a grant from the American Seed Trade Assn. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.