Traditional breeding

Abstract

This chapter describes traditional strategies used by breeding programs around the world, and how they have resulted in improved citrus varieties. The first part examines scion breeding objectives and the advantages/disadvantages of important techniques including somatic mutants, nucellar selection, diploid and polyploid hybridization, and mutation breeding. Seedlessness remains an enormous challenge for breeders and the available methods are discussed within the context of having to simultaneously maintain or improve a host of other critical traits. The second part describes the main steps leading to the release of improved rootstocks. The importance of hybridization with citrus relatives to introgress useful genes both in scions and rootstocks breeding programs is also emphasized. New diseases and increasing consumer expectations present additional challenges for breeding programs and more efficient phenotyping and molecular markers are required.