102 



BREEDING CROP PLANTS 



mediates by inspection. No other strains except the parental 

 forms and various grades of intermediates were obtained. 



These facts indicate that a classification made on the basis 

 of sterility for the species groups is reliable. 



Simple Mendelian Characters. So far as studied there are 

 several barley characters which can be grouped according to 

 their inheritance and which give simple Mendelian ratios. These 

 are summarized in Table XVI. 



TABLE XVI. BARLEY 



CHARACTERS WHICH SHOW SIMPLE MENDELIAN 

 INHERITANCE 



A study of inheritance in barley was made at the Minnesota 

 Station in cooperation with the Office of Cereal Investigations, 

 United States Department of Agriculture. A cross of Virginia 

 Hooded, a six-rowed, hulled, hooded, colorless barley, with Jet, 

 a two-rowed, naked, awned, black-glumed barley was studied. 

 In this cross there was apparently only one factor difference be- 

 tween two-rowed and six-rowed and the intermediate forms were 

 classed as two-rowed, although they could be differentiated from 

 true two-rowed forms by the presence of awns on the lateral 

 florets. The results showed that these four factor pairs were 

 independently inherited and gave a close approximation to ex- 

 pectation. Crosses differing by four independently inherited, 

 sharply differentiated factor pairs have not been frequently 

 presented, therefore the results are of some interest. They are 

 as follows : 



