THE INHERITANCE OF ALIPHATIC GLUCOSINOLATES IN BRASSICA-NAPUS

The inheritance of aliphatic glucosinolates was studied in crosses bet ween synthetic B. napus lines and oilseed rape cultivars. Six unlinked loci are described which determine the aliphatic glucosinolate profil e of B. napus. One locus regulates the presence or absence of propyl g lucosinolates, while another regulates the expression of pentyl glucos inolates. Two loci regulate the removal of the terminal H3CS-group fro m the amino acid derivative to produce alkenyl glucosinolates as oppos ed to methylthioalkyl and methylsulphinylalkyl glucosinolates, regardl ess of the length of the alkyl chain. Likewise, another two loci regul ate the hydroxylation of both butenyl and pentenyl glucosinolates. The functional alleles at one of the hydroxylation loci results in signif icantly more hydroxylation than those at the other locus. The large nu mber of aliphatic glucosinolates which have been described in Brassica thus results from an interaction between genes which regulate side ch ain elongation and genes which modify the structure of the side chain, regardless of its length. The implications of this study for the bios ynthesis of aliphatic glucosinolates, the origin of B. napus and the p otential to manipulate the leaf and seed glucosinolate profile of oils eed rape are discussed.