INHERITANCE IN NICOTIANA TABACUM. 

 II. ON THE EXISTENCE OF GENETICALLY 

 DISTINCT RED-FLOWERING VARIETIES^ 



DR. R. E. CLAUSEN and DR. T. H. GOODSPEED 

 University of California 



In our studies of inheritance in Nicotiana Tahacum- 

 it lias been demonstrated that the red flower color of 

 macrophylla (U. C. B. G. 22/07) is recessive to the light 

 pink of angustifolia (U. C. B. G. 68/07), and the same 

 relations are exhibited by the red of calychia {Y . C. B. G. 

 110/05) as contrasted with the light ijink of rn-iinrir<i 

 (Maryland, U. C. B. G. 78/05). In both castas \ \w V\ was 

 pink, Fo conformed to the ratio 3 pink: 1 red, and F.. and 

 subsequent generations yielded data consistent with a 

 single factor difference between these two flower colors. 

 It was also shown that when macrophylla was crossed 

 with the white-floweriim- vai-icty alhn (TJ. C. B. G. 30/06), 

 F, was pink, F, eonfci imd i.. the ratio 9 pink: 3 red: 4 

 white, and F.. and suIi-im lucnt ucii. 'rations gave data in 

 agreement with a two-t actor dilTcrence for this charac- 

 ter contrast. 



Allard,'^ however, had presented evidence, at first sight 

 contradictory to ours, to the effect that the carmine flower 



possible by a portion of the .\,l;nii. I nn.i allnttr.l t,. Tnr I )ri,;,n inrnt or 

 2Setchell, W. A., T. H. (MM.l<i,.v,i ami R. K. Clansni, "A Pivliinniaiy 



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