“HAIRY NECK” WHEAT SEGREGATES FROM 
WHEAT-RYE HYBRIDS 1 
By Clyde E. Leighty, Agronomist in Charge of Eastern Wheat Investigations , 
and J. W. Taylor, Assistant Agronomist, Office of Cereal Investigations, Bureau 
of Plant Industry, United States Department of Agriculture 
Pollen from rye was successfully used to fertilize wheat flowers as early as 
1875 by Wilson (14 ) 2 in Scotland. Subsequently many plant breeders, both 
in Europe and America, have made this cross and produced Fi plants. The 
natural wheat-rye hybrid has been observed frequently in wheat plats, particu¬ 
larly at the Arlington Experiment Farm of the United States Department of Agri¬ 
culture, Rosslyn, Va. ( 8) (see PI. 1), and at Saratov, Russia (9). However, 
despite the many Fi plants produced as the result of these artificial or natural 
cross-pollinations, few studies on the inheritance of specific morphological 
characters for other than the Fi generation have been made and very few fixed 
segregates having any resemblance to rye have been reported. The plants 
described in this paper are believed, therefore, to be of peculiar interest in that 
they are like wheat, except for a single undoubted rye character, and in some 
cases have produced progeny all of which were like themselves. 
SELF-STERILITY IN WHEAT-RYE HYBRIDS 
The cross between wheat and rye is intergeneric and the Fi hybrid is either en¬ 
tirely sterile or only slightly fertile. As shown by Leighty (8), several experi¬ 
menters have reported a small percentage of fertility in this generation. One 
natural hybrid found by Leighty had a fertility of 5 per cent, which is apparently 
unusually high.. When the Fi shows fertility* and no precautions have been 
taken to prevent natural backcrossing, there is always the probability that the 
seeds present are due to the effect of wind-borne pollen of wheat or rye. The 
writers have no evidence that viable pollen is ever formed by the Fi plants, and, 
furthermore, they have never observed opening of the anther sacs. Jesenko 
(4) found the Fi wheat-rye hybrid self-sterile but slightly fertile with wheat 
pollen and very rarely so with pollen of rye. Investigations by the writers 
indicate that fertility in the Fi nearly always is due to backcrossing with wheat 
pollen. 
At Arlington Experiment Farm, during the crop seasons of 1922 and 1923, 
over 8,000 flowers of natural Fi wheat-rye hybrids growing in the wheat plats 
were bagged with glassine bags before blooming and approximately 16,000 flowers 
were unprotected. The results, given in Table I, indicate that the Fi was 
self-sterile, but slightly fertile when open-pollinated. Therefore, unless the 
pollination of the Fi wheat-rye hybrid is controlled the source of pollen will be 
in doubt and inheritance can not be determined with accuracy. 
i Received for publication April 1, 1924. 
» Reference is made by number (italic) to “Literature cited,” p. 575-576. 
Journal of Agricultural Research, 
Washington, D. C. 
( 567 ) 
Vol. XXVIII, No. 6 
May 10, 1924 
Key No. G-400 
