Broadley, M.R., Hammond, J.P., King, G.J., Astley, D., Bowen, H.C., Meacham, M.C., Mead, A., Pink, D.A., Teakle, G.R., Hayden, R.M., Spracklen, W.P. and White, P.J. (2008) Shoot calcium and magnesium concentrations differ between subtaxa, are highly heritable, and associate with potentially pleiotropic loci in Brassica oleracea. Plant Physiology, 146, 1707-1720.