Interspecific Hybridization for Brassica Crop Improvement

Abstract

Interspecific hybridization is widespread in nature, where it can lead to either the production of new species or to the introgression of useful adaptive traits between species. In agricultural systems, there is also great potential to take advantage of this process for targeted crop improvement. In the Brassica genus, several crop species share close relationships: rapeseed (Brassica napus) is an ancestral hybrid between turnip (B. rapa) and cabbage (B. oleracea), and mustard species B. juncea, B. carinata and <i>B. nigra</i> share genomes in common. This close relationship, plus the abundance of wild relatives and minor crop species in the wider Brassiceae tribe which readily hybridize with the Brassica crop species, makes this genus an interesting example of the use of interspecific hybridization for crop improvement. In this review we introduce the Brassica crop species and their wild relatives, barriers to interspecific and intergeneric hybridization and methods to overcome them, summarize previous successful and unsuccessful attempts at the use of interspecific hybridization for crop improvement in Brassica, and provide information about resources available to breeders wishing to take advantage of this method in the Brassica genus.