Sammelreferat. 



Some Recent Work on Avena. 



By M. S. Pease (Cambridge). 



Several papers have lately been published, particularly in America, 

 relating to the breeding of oats. Many of the experiments described have 

 been concerned with variety trials, the sorting out of pure lines, the results 

 of selection, or the effects of biometrical treatment. But in the following 

 resume it is proposed to consider only the relatively few researches dealing 

 with oats from the Mendelian standpoint. These papers are given in the 

 bibliography, which, it should be noted; has been strictly confined to works 

 that are at once recent and relevant. 



Colour. 



The grain of oats is black, grey, red, yellow, or white: experiments 

 agree that there are four colour factors concerned ; Black, which is epistatic 

 to Grey, which in turn is epistatic to Yellow, which is dominant to white 

 (4)1). The Red factor acts as a dominant to Yellow (2), but it is not clear 

 how it fits into the Black -Grey series. Besides these, there are recorded 

 two other colour factors, for which the evidence is less convincing. Capom 

 gives the ca.se for a second independent Black factor (1) and Praser records 

 a case of two independent yellow factors (2). 



Awns. 



Oats show every degree of awning, from the one extreme, in which 

 both florets are strongly awned, to the other, in which neither floret shows 

 any trace of an awn. The cross recorded by Love and Fräser is one between 

 a variety which is weakly awned and one which is completely awnless. The 

 F, was awnless and the F., gave the complete range from one parental type 

 to the other. An F3 analysis showed this to be an overlapping 1:2:1 se- 

 gregation, and further that the degree of awning of the individual F, hetero- 



The numbers in brackets refer to the Bibliography. 



