Abstract: Protoplast fusion for combining and exchanging nuclear and cytoplasm genomes in hybrid progeny provides a new strategy to improve traits controlled by chloroplast or mitochondrial DNA. This paper reviews the methods and mechanisms of obtaining cybrids, advances in transforming cytoplasmic male sterility (CMS), the potential use of these CMS somatic hybrids and the genetic transformation of CMS in sex hybrids. In addition, the application of this strategy to breeding seedless woody fruit trees is discussed.

Key words: Protoplast fusion, Cytoplasmic male sterility (CMS), Cybrids, Seedless breeding