390 GENETICS IN RELATION TO AGRICULTURE 
in a new generation, they were made from the plants most typical and constant 
for the pattern concerned. When a bud variation appeared, if the conditions 
were favorable, the parts possessing it were allowed to develop until there were 
several branches from which cuttings could be taken simultaneously. In such 
cases the selection of branches for the new type was a simple matter, as it 
depended on the taking of branches sharply distinct from the main part of 
the plant. . . . When further cuttings were made for a new generation to 
perpetuate the type they were made from plants most uniform and constant 
(determined from the records) for the pattern in question. Usually but three 
cuttings were taken from a plant and these were taken from branches most uni- 
form and clearly conforming to the type.” 
The relative numbers of ‘‘constant” plants and of plants showing 
either clear-cut bud mutations or ‘‘fluctuations”’ are of considerable 
interest in connection with this matter of maintaining strains. These 
proportions are given in the tabulated summary of the main clones that 
were derived from one of the two original plants Table LV. Clones 11 
Taste LV.—GENERAL SUMMARY OF CLONES DeERIVED FROM PLANT No. 1 
Total Per cent. F 
Clone | numberof | constant | fplants | pud'variations | frequency 
ul 211 132 62 49 1: 860 
12 192 87 45 21 1: 1,830 
13 138 75 4 4 1:6,900 
14 155 80 51 18 1: 1,720 
117 91 54 59 31 1: 590 
111 34 29 85 4 1:1,700 
and 12 were derived from two branches that had the same color pattern, 
yet it seems that they possessed ‘‘quite different potentialities for con- 
stancy and for bud variations. Even more marked differences than these 
developed among the various subclones. A study of pedigrees shows that 
in all patterns and in all main clones there were certain lines of progeny 
much more constant than many others. These could not be detected by 
any other than a pedigree method.” These facts have a definite bearing 
on the maintenance of vegetatively propagated varieties or strains. If 
similar diversity as regards degree of variability exists in other cultivated 
plants, as it undoubtedly does, careful bud selection must be of prime 
importance in keeping varieties true to type or at least in preventing 
deterioration through the accumulation of undesirable bud mutations. 
In Coleus at least it is certain that bud selection is effective and necessary 
in maintaining strains true to type. If it is equally potent in its effect 
on other vegetatively propagated plants, bud selection should be given 
far more attention by nurserymen than it has generally received. 
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