Aug. 6, 1917 Studies on Oat Breeding 297 



FIRST GENERATION 



The first generation originated from a cross in which the naked oat 

 was the male parent and the Victor oat the female. Eleven hybrid 

 grains were obtained, seven of which failed to germinate when planted 

 in the garden in 1915. The plants arising from the remaining four 

 grains exhibited, on the whole, uniform characters, there being only a 

 slight quantitative variation of the hull character. This point will be 

 referred to below. Plate 39, C, gives the external appearance of the 

 Fi plants. By comparing this figure with figures A and B of Plate 39, 

 it may be noted that the F^ plants present an intermediate type between 

 the two parents as to shape of head and form of spikelets. The longer 

 head and the more widely spreading branches of the F^ plants markedly 

 contrast with the type of head of the naked oat and resemble rather the 

 Victor parent, though the two types can be easily distinguished from 

 each other. 



With regard to the multiflorous characters, the Fi plants show a 

 prevalence, if not dominance, of this character over the common biflo- 

 rous habit of the Victor oat. This observation agrees with the results 

 obtained by Von Tschermak (9, p. 85; 10, p. 364) in a cross between 

 the multiflorous oat Avena saliva var. chinensis and a common oat with 

 normal flowers. While the habit of the spikelets of the F^ plants is 

 generally multiflorous, their form is different from that of the spikelets 

 of the naked parent. This can be clearly seen by comparing figures B 

 and C of Plate 39. The pedicels of the individual flowers within the 

 spikelets of the F^ plants are shorter than in the case of the naked 

 parent, thus causing a shortening of the multiflorous spikelet. It was 

 stated above in connection with the description of the naked oat that 

 there is a tendency for the pedicels and for the flowers to be reduced in 

 length and number, respectively, from the top of each whorl, and also 

 from the top of the panicle as a whole toward the base. This tendency 

 is still more pronounced in the F^ plants. The longest multiflorous 

 spikelets are grouped on the tips of the upper whorls and lead through 

 gradual transitional forms to the biflorous spikelets present at the base 

 of the whorls and of the panicle. It will be worth while bearing this 

 feature in mind, as it is shown in a still more pronounced form in the 

 intermediate types of Fj plants and is correlated with gradual changes 

 in the nature of the glumes. 



With regard to the inheritance of the hull character — that is, the way 

 in which the flowering glumes inclose the caryopsis — the F^ plants repre- 

 sent an intermediate condition. Both parental forms, as well as the 

 intermediate types of kernel described below, are present on the same 

 panicle (PI. 44, A). These intermediate forms are rather interesting, 

 as they show naked kernels and firmly hulled ones side by side within 



