Dear John In each plant there are about 25000 different genes Small changes in the DNA of most of them will not be noticed. Let alone changes in the 90% plus amount of DNA that does not code for something. Ben J.M.Zonneveld Institute of Biology,Leiden University, Clusius lab Wassenaarse weg 64, 2333 AL Leiden, The Netherlands Zonneveld@rulbim.Leidenuniv.NL Fax: +31-71-5274999. min temp -10C (15F)