284 GENETICS IN RELATION TO AGRICULTURE 
character of G. rubicalyx is conditioned by one or two specific factors. 
This new form (see Fig. 118) was discovered by Gates in 1907, among a 
population of over 100 rubrinervis plants grown from self-fertilized seed 
of rubrinervis. The original rubricalyx plant when self-fertilized produced 
12 plants, 11 rubricalyx and 1 rubrinervis, which would indicate that the 
original rubricalyx plant was heterozygous for one or more factors for 
excessive production of anthocyanin and that rubricalyx is dominant to 
rubrinervis. Gates has raised ten generations of rubrinervis (more than 
Fic. 118.—Flower bud and leaf of A, @nothera rubrinervis; B, G2. rubricalyx. The 
deeper pigmentation of rubricalyr is not confined to the bud and lower side of the leaves, 
but is also present, in the stems. The rosette leaves also show more or less color on the 
midrib in rubricalyz. 
one pedigreed strain) and found it to breed true and he has one strain of 
rubricalyx that has bred true for five years, but as yet there are no data 
on the results of a cross between them where the fF’: progeny were grown 
on a large scale and with controlled seed germination. However, in Fi 
rubricalyx is dominant. Another Ginothera character which is inherited 
in simple Mendelian fashion is the typical feature of brevistylis (Fig. 115). 
Brevistylis is known to breed true when self-fertilized and the results 
of various crosses indicate that the short style is conditioned by a single 
factor, although it is not always completely recessive in Ff). Thus we 
find that, while most of the experimental breeding data on cenotheras 
cannot be interpreted in terms of ordinary Mendelian concepts, neverthe- 
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