UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



BOTANY 



Vol. 5, No. 8, pp. 249-272, plate 35 Issued July 21, 1915 



PARTHENOGENESIS, PARTHENOCARPY AND 

 PHENOSPERMY IN NICOTIAN A 



WBW y, 

 BY •OT/^r^•f ■ , 



THOMAS HARPEE GOODSPEED 



• aKOC;.'- 



Following the publication in 1909 of an article by Mrs. K. H 

 Thomas on "Parthenogenesis in Nicotiana,'' the validity of her re- 

 sults — the production of parthenogenetic seed without difficulty in 

 species and hybrids of Nicotiana — has been called in question by 

 a number of investigators who have either made an exhaustive investi- 

 gation of the subject as a special problem or have included a con- 

 sideration of it as a preface to their general breeding experiments 

 (cf. Wellington, 1913, Howard, 1913, Hayes and Beinhart, 1914). 

 So far as I know, how^ever, no one has attempted to investigate the 

 behavior of the strains of tobacco which Mrs. Thomas actually em- 

 ployed in the experiments which she described. The present com- 

 munication details experiments performed on a variety of Nicotiana 

 Tahacum, the seed of which was obtained from Mrs. Thomas. From 

 over 800 castrations and mutilations of buds on the plants raised 

 from this imported seed, a little normally matured and viable seed 

 was obtained. In over 100 cases, involving almost 200 flowers, such 

 treated buds yielded full capsules of seed which was practically normal . 

 in appearance but which consisted, in almost all cases, of empty 

 seed-coats only. This latter situation introduces the possibility that 

 after one or two years additional cultivation in our soil and climate, 

 the undoubted parthenocarpy of the first year, which was accompanied 

 by the production of much "abortive" seed, may be increased to, and 

 accompanied by, a more general parthenogenesis than was found this 

 past year. 



