THE INHERITANCE OF 

 FLOWER COLOUR IN PISUM 



BY HANS TEDIN 



SVAL(')F 



1. INTRODUCTION. 



MY first pea-crosses were obtained the same year I was entrusted 

 with the management of the breeding of peas and vetches at 

 the Swedish Seed Association at Svalöf, that is, in 1892. They were 

 carried out with hardly any special purpose, more for my own enjoy- 

 ment, even if not entirely without a slight hope that they might give 

 some practical results. The numerous pea-crosses made later on in 

 that decennium included several between different pure strains with 

 white flowers and such with rose-coloured flowers (standard more or 

 less reddish to white, wings light or dark rose)^. These crosses gave 

 without exception a Fi with purple flowers, and F2 yielded purple, rose, 

 and white flowers. The numerical relations were not determined, but 

 it was noted, as is to be seen of my annotations from that time, that 

 in an average always the purple-coloured flowers were in a decided 

 majority in proportion to each of the other two. The different pure 

 strains with rose flowers were also crossed with each other, but how- 

 ever they were combined they never gave purple or white flowered 

 individuals, neither in Fi nor in the following generations. 



In 1901 one of the rediscoverers of the »Mendelian laws», Pro- 

 fessor E. TscHERMAK from Vienna, visited Svalöf. On that occasion I 

 gave him 10 different pure strains of Pisum arvense and 9 different 



^ Already at that time a very large number of pure strains of peas were 

 grown at Svalöf including such with white flowers as well as such with purple 

 flowers (standard more or less light purple, wings dark purple). All these pure 

 strains were selected by the pedigreemethod from native or foreign mixed sorts 

 or found as intermixtures in other kinds of corn etc. I also had five different 

 pure strains with rose flowers (See Hans Teijin och Hugo Witt: Botanisk-kemisk 

 undersökning av 42 nästan uteslutande nya ärtformer, uppdragna vid Sveriges Utsf. 

 pa Svalöf. — Sveriges Utsf:s Tidskrift 1899, pages 121—160). The 42 strains descri- 

 bed in this paper were but a little collection of those selected which were cultivated 

 or stored in the collection of the Seed-Ass. 



