AECIAL STAGES OF THE LEAF RUSTS OF RYE, PUCCINIA 
DISPERSA ERIKSS. AND HENN. ; AND OF BARLEY, P. 
ANOMALA ROSTR., IN THE UNITED STATES 1 
By E. B. Mains, Associate Botanist , and H. S. Jackson, Chief in Botany , Pur¬ 
due University Agricultural Experiment Station y and Agents , Office of Cereal In¬ 
vestigations , Bureau of Plant Industry , United States Department of Agriculture 
INTRODUCTION 
In 1918, investigations on the leaf rusts of rye, barley, wheat, com, and related 
grasses were begun by this laboratory in cooperation with the Office of Cereal 
Investigations, United States Department of Agriculture. Since it has been 
shown by Stakman (11) 2 and others that, as in northern Europe, Puccinia graminis 
Pers., the stem rust of wheat, oats, barley, rye, and related grasses, can be con¬ 
trolled in the northern United States by eradicating its alternate host, the com¬ 
mon barberry, Berberis vulgaris L., it seemed important to determine the 
aecial hosts of the leaf rusts in this country and the r61e they may perform in 
propagating these rusts. In a previous paper, the writers (5) already have reported 
on the alternate host of the leaf rust of wheat, P. tritidna Erikss., and at this time 
are presenting the results of similar studies on the leaf rusts of rye and barley. 
LEAF RUST OF RYE, PUCCINIA DISPERSA 
DeBary ( 8) established the fact that Anchusa arvensis and A. officinalis are 
aecial hosts of Puccinia dispersa . This relationship was determined by inocu¬ 
lating the leaves of Anchusa w$th the basidiospores of the rust fungus. The 
resulting infection produced aeciospores which, when applied to the leaves of 
rye plants, produced infection and subsequent development of urediniospores. 
When basidiospores of rye leaf rust were sown on Berberis vulgaris L., Rhamnus 
frangula L., R. cathartica L., Ranunculus acris L., Ranunculus bulbosus L., Leon - 
todon taraxacum L. (Taraxacum officinale Weber), and Urtica dioica L., no infection 
resulted. Nielson (9) later obtained infection on rye following inoculation 
with aeciospores from Anchusa officinalis. Plowright (10) also obtained aecia on 
Anchusa arvensis by placing rusted rye straw near that host. Eriksson (4) was 
able t o infect Anchusa arvensis and A. officinalis with Puccinia dispersa on rye, 
but obtained no infection on Myosotis alpestris F. W. Schmidt, Symphytum asperum 
Lepechin (S. asperrimum Donn), and Pulmonaria officinalis L. and only pycnia 
on Nonnea rosea Link. Sowings of aeciospores from Anchusa produced uredinia 
on ryejDut not on the other inoculated grass hosts. Klebahn (6) reports on 
similar experiments in which aecia were obtained on Anchusa. Uredinia also 
were obtained on rye when inoculated with aeciospores from Anchusa. In the 
i Received for publication Apr. 19, 1924—issued November, 1924. Published with the approval of the 
Director as a contribution from the Department of Botany, Purdue University Agricultural Experiment 
Station. Cooperative investigation between the Purdue University Agricultural Experiment Station and 
the Office of Cereal Investigations, Bureau of Plant Industry, U. S. Department of Agriculture. 
* Reference is made by number (italic) to “Literature cited,” p. 1126. 
Journal of Agricultural Research, 
Washington, D. C. 
(1119) 
Vol.XXVIII, No. 11 
June 14,1924 
Key No. G-415 
