Hybridization and Selection 



299 



Fig. 188. 



U. S. Dept. of Agriculture 



The same field shown hi Figure 187, planted with seeds from plants that sur- 

 vived the attack of the disease. 



the best plants found in a field and sowing them together the fol- 

 lowing year, the seeds from each of the best plants are kept sepa- 

 rate. These are then planted separately in short rows and a 

 record is kept of the performance of the progeny of each of the 

 selected plants, and the most desirable varieties are speedily 

 isolated. 



Since these trial rows are short, the amount of seed produced is 

 small ; and when a desirable strain or variety is discovered it 

 must be grown in larger plots C increase plots ") until sufficient 

 seed is obtained for distributing or marketing. 



Marquis wheat. As an example of what may be accomplished 

 in plant breeding by individual plant selection attention may be 

 called to Marquis wheat, which is perhaps the most valuable 

 variety of wheat, and perhaps the most valuable variety of a 

 food plant, thus far discovered. In 1903 it was found by 

 Charles Saunders as a single plant derived from a cross made 

 several years previously between two varieties of wheat, known 



