CHAPTER VII 



CLASSIFICATION AND INHERITANCE OF SMALL GRAINS 

 OTHER THAN WHEAT 



In the cases of barley and oats quite usable classifications have 

 been proposed. The general adoption of such classification 

 schemes is desirable for often great confusion results from the 

 incorrect use of varietal names. Classification schemes can 

 not be given in detail in a plant breeding text. It seems sufficient 

 here to point out the genetic relationship between wild and 

 cultivated species and to give the major so-called species groups 

 for the various crops. The more important botanical and 

 agronomic characters which are commonly used in varietal 

 classification have also been mentioned. As crossing must 

 frequently be resorted to as a means of improving small grains, 

 the student should have a working knowledge of the known facts 

 of inheritance with respect to particular characters. 



CLASSIFICATION AND INHERITANCE IN OATS 



A workable classification of cultivated American oat varie- 

 ties and the basic wild species has been made by Etheridge 

 (1917). The following outline of species groups is taken from 

 his publication; 



A. Kernel loose within the surrounding hull; lemma and glumes alike in 



texture. '.Avena nuda. 



A A. Kernel firmly clasped by the hull; lemma and glumes different in 

 texture. 



B. Upper grains persistent to their rachillas Avena sterilis. 



BB. Upper grains easily separating from their rachillas. 

 C. Lemma bearing as teeth or awn points. 



D. Lemma with four teeth or awn points. 



Avena abyssinica. 

 DD. Lemma with two teeth or awn points. 



E. Lemma elongate, lanceolate, with distinct awn 



points Avena strigosa. 



EE. Lemma short, abrupt, blunt, rather toothed than 



awn-pointed . . ; Avena brevis. 



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