Hello John and PBSers: I remember when I did my Masters on propagation of Hippeastrums and noticed that mature bulbs from in vitro propagation of Apple Blossum appeared different than the original mother bulb. Maybe this is related to clonal breakdown discussion. James Frelichowski USDA-ARS, College Station, Texas John Bryan <firstname.lastname@example.org> wrote: Way back in the 60's, the lily hybrid Enchantment, introduced by Jan de Graaff's Oregon Bulb Farms, began to loose the size of flowers and the bud count. Many acres of this hybrid had been grown for a great number of years. It was decided to propagate, by tissue culture, a new stock. Enchantment was, the first lily to receive a Patent, being grow widely for cut flower production as well as a garden plant and we exported many thousands to the Netherlands. It is to be noted that the plants did not show signs of virus, just the flower size and count diminished. This was thought to be a clonal breakdown, not an unusual occurrence and I think this was a correct diagnosis. The result of the tissue culture was the new stock, so propagated, regained the flower size and bud count of previous years. Thus it is not only virus that causes such problems, but clonal breakdown is another factor of a decline of a variety/culivar. I suppose Enchantment is still being grown but has been superseded by newer hybrids, but the bloodline of this great Asiatic lilly can still be seen in progeny, for example the black tips of the buds etc. This might be of interest, the point being decline of a plant is not always due to a virus, but continued propagation by vegetative means can also cause problems. Cheers, John E. Bryan _______________________________________________ pbs mailing list email@example.com http://www.pacificbulbsociety.org/list.php --------------------------------- Everyone is raving about the all-new Yahoo! Mail beta.