1018 
Journal of Agricultural Research 
Vol. XXVIII, No. 10 
connection with cytological work indicates that the 7 additional chromosomes 
possessed by the vulgare group determine in some way the characteristic prop¬ 
erties of that group. Thus it would be expected that segregates of such partially 
sterile hybrids would resemble the vulgare wheat if the segregates possess 21 
chromosomes, while the 14 chromosome segregates would resemble the emmer 
group. The association of certain characters with chromosome number in F 2 
would explain why certain characters are usually associated and why desirable 
characters of the two groups of species can not readily be combined. 
Since there is considerable difference in the degree of sterility of certain species 
crosses it might be expected that the segregates from comparatively sterile 
crosses would tend to resemble more closely the parental form, while with in¬ 
creased fertility certain segregates might be obtained which would combine 
certain of the desirable properties of the two parental species. It may also be 
possible to determine the location of certain genetic factors in these hybrids. 
If, for instance, certain characters are determined by factors in the 14 primary 
chromosomes which pair in the species crosses, then these characters would be 
expected to segregate more or less normally. On the other hand, characters 
borne by the 7 additional chromosomes of the vulgare wheat would be expected 
to behave in a nonMendelian manner, due to the random distribution of a single 
set of chromosomes and more or less sterility of gametes and segregates with an 
intermediate chromosome number. Thus it should be possible to determine 
whether certain genetic factors are in the 14 primary chromosomes or are in the 
additional chromosomes of the vulgare species. A study has been made of the 
sterility, genetics, and cytology of a number of such species crosses with these 
objects in view. 
MATERIAL AND METHODS 
The parents used in this investigation include three species in the emmer 
group and two species in the vulgare group, as follows: 
Variety 
Agronomic variety 
EMMER GROUP 
Triticum polonicum L. 
villosum K6rn 
Polish. 
T. turgidum L. 
pseudo-cervinum 
Alaska. 
T. Durum Desf. 
Korn. 
hordeiforme Korn. 
Kubanka. 
VULGARE GROUP 
T. vulgare Vill. 
lutescens Korn. 
Marquis. 
T. vulgare Vill. 
albxdum K6rn. 
Amby. 
Washington Hybrid 143. 
T. compactum Host. 
humboldtii Korn. 
In describing and referring to the varieties the agronomic name will be used. 
Spikes of the different varieties are shown in Plate 1. Following is a brief 
description of the varieties used. Alaska is a spring wheat, with branched spike, 
black awns 3 to 12 cm. long, kernels white and usually starchy. Polish is a spring 
wheat with black awns 4 to 10 cm. long, glumes and kernels very long, awns usually 
deciduous, kernels white, and very hard. Kubanka is a spring wheat with 
glumes and awns yellowish, awns from 6 to 15 cm. long, kernels white and very 
hard. These three varieties all belong to the emmer group and all have more 
or less pithy straw and sharply keeled glumes. 
