December, 1921. 



SCIENTIFIC AGRICULTURE. 



113 



The Dominant Mendelian Characters in 

 Barley Breeding 



By J. G. CARL FKASEK. 

 Cerealist, Experimental Farm, Ottawa. 



The idea of this article is to present the 

 results of some of the workers in barley 

 breeding, and to tabulate for ready re- 

 ference the dominant Mendelian charactei s 

 of barley, in so far as they have been de- 

 termined. While the dominant characters 

 may be generally known, this article may 

 sum them up, help shed more light on the 

 subject and put them in tabular form. The 

 material for this article has been obtained 

 from published articles from various 

 writers on both sides of the Atlantic (such 

 as R. H. Biffin, Rimpau and others in 

 Europe), from various United States bul- 

 letins and from our own work here, at Ot- 

 tawa. 



In the following findings the deductions 

 of the various workers wil be set forth and 

 where any uncertainty or contradictions 

 occur, both sides of the questions will be 

 put down. 



Black colour in palea dominant over white. 

 Tlie fact that the black colour of the 

 palea w'as dominant over white has been 

 known for some considerable time and had 

 been noted in pre-Mendelian times, in- 

 stances being cited by Rimpau, in which 

 the hybrid from a black and white cross 

 gave a black and white; and white. Tscher- 

 mak more recently investigated the ques- 

 tion and found that hlack and white forms 

 appeared in the ratio 3 to 1 in the Fj. The 

 same results were obtained by Biffin where 

 he crossed the following black and white 

 varieties : 



H. Japanicum x Steudelii 

 H. Vulgare x Steudelii 



H. Nutans x Steudelii 



and several more varieties. In all cases, 

 the result of the cross was a black, as deep 

 in colour as the black parent, and in" the 

 F, the expected break up into black and 

 ichite forms in the ratio 3 to 1 occurred. 

 Some single cultures of the recessive char- 

 acter have been cultivated and not a sin- 

 gle black eared individual has shown up. 

 In one case, such a white form has been 

 used for further crossing work with a ivhite 

 variety without showing even a tint of 

 black in the progeny. Kezer and Bavlock 



repoit the same result in a cross between 

 California (white hulled) and Black 

 Hulled. 



Two-rowed condition dominant over 

 Six-rowed. 



When we come to this character there 

 seem to be some differences of opinion, not 

 so much as to refute the statement that 

 two-rowed is not the dominant character, 

 but more that there is incomplete domin- 

 ance of the two-rowed. This Dr. C. E. 

 Saunders, Dominion Cerealist, found to be 

 the case in a series of crosses which he 

 made at Ottawa. In a number of cases 

 where he crossed a tAvo-rowed on a six- 

 rowed variety, in the F^ generation all 

 kinds of intermediate stages were obtained : 

 from two-rowed to almost perfect six- 

 rowed. In the F3 generation, however, 

 these almost perfect six-rowed acted as 

 true intermediates, throwing off about 25 

 per cent, two-rowed, 50 per cent, like the 

 parents and 25 per cent, six-rowed. 



Other workers in the United States have 

 noted this imperfect dominance with some 

 certain varieties, an instance of which is 

 furnished in a cross between Hanna, a two- 

 rowed, bearded, and California, a six- 

 rowed, bearded variety. In this case, true 

 dominance with respect to beards was not 

 found, but what could be called interme- 

 dium or better still heterozygous. The F^ 

 generation contained six-rowed types like 

 the original California parent but carry- 

 ing only two rows of awns down the cen- 

 tral rows of kernels. 



Hoods dominant over Awns. 



Hooded or trifurcated heads are dom- 

 inant to the awns, and numerous experi- 

 ments have been made by different work- 

 ers wliich have shown unmistakably that 

 this character followed the Mendelian ratio 

 of 3 to 1. Examples of parents carrying 

 one or the other of these characters' are 

 provided by the following crosses.- 

 Hordium trifurcatum x H. nutans 

 H. rigens x H. atrum.' 



Black Hulled x Beardless 



