Discloses a Brassica plant comprising a mutant allele at a fatty acyl-acly-ACP thioesterase A2 (FATA2) locus, wherein said mutant allele results in the production of a FATA2 polypeptide having reduce thioesterase actuvity relative to a corresponding wild-type FATA polypeptide. Further discloses seeds, production of oil and a method for making a Brassica plant.