UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 

 BOTANY 



Vol. 5, No. 4, pp. 189-198 



Issued March 21, 1913 



ON THE PARTIAL STERILITY 



OF NICOTIANA HYBRIDS MADE WITH 



iV. SYLVESTBIS AS A PARENT 



LIBRARY 



NEW YOi^K 

 BOTANICAL 



BY 



THOMAS HAEPEE GOODSPEED 



In 1910 Professor W. A. Setchell. in connection with other 

 similar experiments, all of which have been made possible by 

 a grant under the Adams Fund, made a number of cross pollina- 

 tions back and forth between Nicotiana Tahacum var. macrophylla 

 purpurea (U. C. B. G. 25/06) (Setchell, p. 10) and N. sylvestris 

 (U. C. B. G. 107/01) (Setchell, p. 29) which species form a part 

 of a considerable Nicotiana collection in the University of Cali- 

 fornia Botanical Garden. The F^ hybrid plants produced from 

 the seed obtained as a result of these crosses were grown in 

 1911 and exhibited a striking increase in size (habit) and size 

 of flower as compared with the parent plants (cf. East and 

 Hayes, 1912). There seemed to be a possibility, also, that these 

 hybrids might be only partially sterile, though as noted below 

 no ' ' pure ' ' seed was formed under bag. On account of the inter- 

 esting appearance of the 1910 hybrids in general and in particu- 

 lar with this suspected partial sterility in mind, all the N. Tah- 

 acttm-varieties available, i.e., grown from pure seed in the pure 

 line for a number of years, and one F^ Iwbrid made between two 

 such N. Tahacum-yarieties, were in 1911 crossed back and forth 

 with N. sylvestris. In the following list are given the hybrids 

 produced from the seed of the 1910 and 1911 crosses with the 

 hybrid numbers prefixed in each case. 



