Mutagenesis Breeding for Drought-Tolerance and Improvement of Oil and Seed Quality in Oilseed Crops: Case of Rapeseed and Sesame

Nowadays, world food security is more and more threatened by the extreme events caused by climate change associated with the increasing population. Particularly, drought is reported to be the most harmful for agricultural production, including oilseed crops. However, some key traits for adaptation to this stress may be lost as a result of the restriction of wild germplasm and natural genetic diversity due to overexploitation and climate change. Hence, mutagenesis breeding has been widely adopted to ensure a sustainable genetic gain in crop adaptation and tolerance to drought as well as other abiotic stresses. In oilseed crops, many efforts have been expended during the last 50 years in mutation breeding, mainly to improve oil and seed quality for feed, food, and industrial applications. Like other crops, major advances in rapeseed and sesame have been achieved in the alteration of seed oil fatty acid composition and modification of some bioactive compounds. However, fewer reports have been published on the improvement of drought tolerance. In this chapter, we will present and discuss the main achievements in drought tolerance and seed and oil quality in rapeseed and sesame through induced mutagenesis breeding. The emphasis will be on the application of random mutagenesis, which is widely accepted, via the use of physical or chemical mutagen agents. New genome editing techniques, such as TALEN, ZFN, and CRISPR-Cas9 targeted mutagenesis, are increasingly applied to edit some genes associated with seed quality and to target specific drought-associated genes.