Interspecific Hybridization of Prunus

Abstract

Interspecific hybridization is a technique commonly used by plant breeders to transfer genes from one species to another. Interspecific hybrids are usually obtained with greater difficulty than intraspecific hybrids because genetic barriers to hybridization usually increase with an increase in genetic unrelatedness (6, 11, 18, 41). Breeders resort to interspecific hybridization only when the characters are absent or inadequately expressed at the intraspecific level. Stone-fruit breeders have made much use of interspecific hybridization in the improvement of Prunus cultivars and rootstocks (3, 5, 6, 8, 12, 14, 15, 18, 19, 28, 34, 36, 37, 41, 42, 43) particularly in the subgenus Prunophora (plums), because plum species tend to intercross more freely than do members of other subgenera (41, 42). This paper will review the problems that have been encountered in making interspecific Prunus hybrids and the techniques that have been used to overcome them. In addition, techniques are presented that have been employed successfully with other interspecific hybridizations which may have application for Prunus .