STUDIES ON OAT BREEDING. I3I 



Thus, the Swedish Experiment Station at Svalof used these 

 morphological characters in its breeding work as a basis for 

 isolating different types, distinguished from each other by dif- 

 ferent qualitative features. The importance of the morphologi- 

 cal external features of the plants, however, must not be over- 

 estimated and too much relied upon when undertaking a selec- 

 tion of desirable plants out of commercial varieties. The best 

 looking plant in such a population does not always possess the 

 best physiological qualities. The environment plays an im- 

 portant part and often misleads the breeder. It is not until we 

 undertake a thorough examination of the progeny of a selected 

 plant that we learn its true merits. Nevertheless morphological 

 characters may be a valuable guide in breeding work. 



As pointed out in the introduction of this paper, every indi- 

 vidual in the progeny of a self- fertilized plant will have the 

 same germinal constitution as every other individual, unless 

 spontaneous germinal changes should occur. Experiments have 

 shown that such changes are relatively infrequent. It has fur- 

 ther been shown that certain pure lines can be isolated from 

 some commercial varieties which are far superior to the parent 

 variety in one or more characteristics. It is now of importance 

 to determine whether these physiological characters are related 

 to definite morphological changes in the plant or whether they 

 have occurred independently of changes in these morphological 

 features. 



The data given in the following paragraphs are the results 

 of an attempt to find definite morphological characters which 

 might serve to distinguish these pure lines. No attempt has 

 been made to determine the definite correlation between these 

 characters. The question of correlation in oats has been studied 

 by many writers. Tschermak 15 and others have determined the 

 relation between many morphological and physiological char- 

 acters. Waldron 16 and especially Love and Leighty" and 



"Tschermak, E. v. Fruwirth's Handbuch der. landwirtschaftlichen 

 Pflanzenzuchtung. 2 Auf. Bd. 4, 1910. 



18 Waldron, L. R. A suggestion regarding heavy and light seed grain. 

 Amer. Nat., Vol. 44, pp. 48-56, 1910. 



17 Love, H. H. and Leighty, C. E. Variation and Correlation of Oats 

 (Avena sativa). Part I. Studies showing the effect of seasonal 

 changes on biometrical constants. Cornell Exper. Stat. Memoir No. 3, 

 pp. 1-70, 1914. 



