The observations made in this study need to be expanded to a larger sample of burley and flue-cured germ plasm. At the present time the yb1 and yb2 alleles are being introduced into additional flue-cured varieties. Subsequent studies of segregating populations from flue-cured × burley crosses are needed to elucidate the genetic mechanism of alkalinity number of water soluble ash. The object of such studies would be to provide additional knowledge of the genetics of the tobacco plant. The authors do not suggest that flue-cured or burley tobacco would necessarily be benefited by a shift in alkalinity number of water soluble ash away from the norm for the respective types.

(Full article published with kind permission from "Tobacco International")