Breeding Methods

Abstract

Oleiferous rapes are interesting breeding material since they have a complete range of breeding systems ranging from complete range of cross-pollination to self-pollination. A strong intergenomic interaction, also accounting for the evolution of mating systems in Brassica genus, affects the mode of pollination and therefore accounts for the choice of breeding methods in a particular rapeseed species. Seed and oil yield and early maturity have been the primary objectives of breeding in the Indian subcontinent, while quality received greater attention in the European countries, and accordingly the breeding methods also differed. However, more recently, major breeding efforts have been shifted toward the development of "double-zero" or "double-low" cultivars throughout the globe, and the desirable genes within as well as outside the genus are being tapped for the purpose, aided by conventional and biotechnological breeding methods. For this, both interspecific and intergeneric hybridizations have a great potential for creating new variability. Induced mutagenesis has also been fruitful to create variability for earliness, compact plant type, and yellow seed color. Conventional breeding methods have received due attention by rapeseed breeders throughout the globe and a large number of varieties have been bred utilizing these methods. Lately, artificial synthesis of amphidiploids and development of herbicide tolerant cultivars has also gained momentum. The present chapter focuses on various breeding methods and issues in rapeseed related to breeding for various biotic and abiotic stresses and herbicide tolerance, male-sterility and fertility restoration, development of hybrids, synthetics and composites, quality aspects, and creation of new variability through hybridization and mutagenesis. © 2007 Elsevier Inc. All rights reserved.