Crambe

Abstract

Compared with other Brassica crops, such as rapeseed (Brassica napus), B. rapa, B. oleracea, or B. juncea, the genus Crambe L. is still under development as an agricultural crop and is not widely grown. In some species, utilization as an herbaceous or root vegetable is known since several centuries. Thus Crambe maritima, known as sea-kale, is a traditional vegetable in its growing regions in northern parts of Central Europe. Further species, e.g., C. cordifolia and C. tataria, are in their natural habitat (central Asia) also of minor importance for food and feed, particularly in times of famine. Nevertheless, the genus Crambe demands attention in an essay about wild relatives of oilseeds and their role in plant genome elucidation and improvement. On the one hand, as a monophyletic genus whose species form a well defined polyploid series from 2n = 30 to 2n = 150, it is of great phylogenetic interest. On the other hand, some species started an agricultural career when their ability as alternative oil crops to rapeseed was recovered in the 1930s in Russia. Since the 1950s, when its extraordinary seed oil quality had been described, one species, namely Crambe abyssinica, became of growing interest as a renewable source of oil for industrial use. It lacks genetic variation for important agronomic traits; however, attempts were made to optimize the seed oil composition via interspecific crosses and traditional breeding, mutagenesis and genetic transformation, etc. Crambe species may also serve as a useful source of genes for Brassica crop improvement via somatic hybridization and embryo rescue.