Dear All: Hybrid vigor, while evident in plants raised from seed, does not last for ever if continued asexual reproduction of a plant is continued over many years. The classic example perhaps is to be found in the strawberry Royal Sovereign, which just failed after many years. At one time it was far ahead of other cultivars, but then lost many of the qualities for which it was renowned. To my knowledge such loss of desired qualities were simply lost due to the continued asexual propagation. Just what happens when such does take place I do not know, but such has been refereed to as Clonal Breakdown. Possibly the desired arrangement and composition of the cells in the plant(s) was changed. John Lonsdale asked how TC fix this. Again a definitive answer, to my knowledge, as not been determined, but it does work. Perhaps this method of propagation is taking advantage of cells that are, for want of a better explanation, stronger and closer to the original cells of the first crosses and better replicas of cells carrying the desired qualities. I should have mentioned the plants of Enchantment did not show any visible signs of virus, to all intents and purposes the plants appeared to be the same, except for size of flowers and bud count. Here it must be stated, those plants used for asexual propagation, were selected in the field, the strongest, those with good flower size and bud count were those selected and these plants showed no color variation in the foliage at all. Selecting those plants that are the most vigorous is an ongoing practice of good growers. When growing many hundreds of Dahlias, I used to tag those tubers for propagation in the field and they were lifted first prior to the lifting of others. John Londsale asks if reduced flower size and count are not classic signs of viral infection, perhaps they are, but are not such accompanied by other signs as well, such as changes in the foliage? Does this mean such changes as clonal breakdown do not exist? When examined in the 60's for virus, using the techniques available at that time, no virus was found. Rodger Whitlock almost choked on his bagel, when he read my comments regarding growers in the Netherlands, if you have found such poor practices s you describe, I hope you have reported such to all authorities who could challenge the practices and do something about it. Is this perhaps a reason why such strict regulations are now in place with importation of plants from overseas and which are decried by so many? Perhaps the USDA are correct! In any profession there are rogues, but firms such as Hoog and Dix, to mention but one, strive to maintain the highest standards in nomenclature and health of the products they sell. To label all growers as being, in effect, dishonest is not only untrue but, in my opinion a libelous statement. such as Dahlias loaded with nematodes. To which grower(s) are you referring? Have you reported them to authorities? If not, why not? As to the selling of wild selected bulbs, I presume you are aware of the rule governing such and these rules are and have been imposed by the authorities in the Netherlands. Alani Davis asked how can one know if it is clonal breakdown and not environmental or pathanogenic? I do not know, but the term clonal breakdown was the term we used, other factors may well have played a part, but let us not blame virus for all such occurrences, especially after tests were made to see if virus was present. But as I mentioned, this was way back in the 60's and more recent procedures might be able to answer this question. The posting of Jim McKenney was interesting. I had not heard the term Clonal Drift before, but obviously this must be the same. jim, as mentioned above, steps were taken to keep the product within the expectations of the consumer. this is why that, during the last years I was with Oregon Bulb Farms, we were relying on 'strains' as such, being seed of crosses between established clones as were the seed parents, had vigor and the variation in height, color, size and number of flowers were between very narrow limits. Black Dragon Strain took the place of the clone Black Dragon, and Golden Splendor Strain took the place of the clone of the same name, etc. Jim, could you explain somatic mutations? How do such differ from other mutations/ Cheers and Happy Thanksgiving to all I hope your turkeys are tasty, and good eating and would there be clonal breakdown in such birds brought about by inbreeding?