Diseases

Puccinia hordei G.H. Otth. - Leaf Rust of Barley

Systematic position.

Class Basidiomycetes, order Uredinales, family Pucciniaceae, genus Puccinia

Biological group.

Obligate parasite of barley and other species of the genera Hordeum and (rare) Elytrigia and Bromus.

Morphology and biology.

Puccinia hordei G.H. Otth. is a long-cycled rust. It produces five distinct fruiting structures with five different spore forms: spermatia, aeciospores, urediniospores, teliospores, and basidiospores. Teliospores are two-celled, ellipsoidal or long clavate, 16-23 x 35-50 microns in size, and moderately constricted by a septum. Teliospores are mostly located on the underside of barley leaves. They are sexual only, over winter and, upon germination, produce basidia. The basidium, following meiosis, produces four haploid basidiospores. The basidiospores, upon infection of the star-of-Bethlehem (Ornithogalum umbellatum L.), produce haploid mycelium that forms spermagonia (pycnidia) (100-150 microns in diameter) containing haploid spermatia and receptive hyphae. Several other Liliaceae species also support the formation of pycnidia and aecia. Spermatia are unable to infect plants; their function is the fertilization of receptive hyphae of the compatible mating type and the subsequent production of dicaryotic mycelium and spores. This mycelium forms aecia that produce aecidiospores, which infect barley and produce uredia and urediniospores. Aecidiospores are oval to ellipsoidal, 20-26 x 18-24 microns. Uredinia (0.4 x 0.1-0.2 mm) are produced on the upper surface of barley leaves. Urediniospores are 21-30 x 18-22 microns and finely echinulate.

Distribution.

The disease is widely distributed throughout the world. In the former USSR countries it occurs in all areas of barley cultivation.

Ecology.

Causal agent of the Barley Leaf Rust is able to survive in Russia in areas with moderate winter climates as mycelium and urediniospores on winter barley. The Leaf Rust develops rapidly between 15 and 22.C in the presence of free moisture. Incubation period in optimum conditions (15 - 25.C) is 6 to 8 hours. The next generation of urediniospores is formed in 7 to 10 days. Urediniospores are distributed by wind.

Economic significance.

The P. hordei is most important in the Volga Basin, North Caucasus, Central Chernozem Regions, Western and Eastern Siberia, the Far East. An epiphytoty appears 1 or 2 times per 10 years in the Volga Basin, Northern Caucasus and the Central Chernozem Region. The yield losses are estimated at 1.42%.

Reference citations:

Chumakov A.E., Sidorenko E.A. 1972. Rust of cereal crops. In: Chumakov A.E., ed. Distribution of diseases in agricultural crops in the USSR in 1968-1972. Leningrad: VIZR. 42-44 p. (In Russian)
Ishkova T.I., Berestetskaya L.I., Gasich E.L., Levitin M.M., Vlasov D.U. 2000. Diagnostics of the main diseases of cereals. Saint Petersburg: VIZR. 76 p. (In Russian)
Mathre D.E., ed. 1997. Compendium of barley diseases. St. Paul, Minnesota: APS PRESS. 90 p.
Novozhilov K.V., Zakharenko V.A., eds. 2000. Levels and tendencies of variability of species composition and intrapopulation structure, areas of complexes of harmful and useful organisms and forecast of dangerous phytosanitary situations in zones of the country. St. Petersburg: VIZR. 100 p. (In Russian)
Peresypkin V.F. 1969. Agricultural Phytopathology. Moscow: Kolos. 479 p. (In Russian)
Rassadina E.G., Shashkova K.P. 1971. Cereal Rusts in book: Distribution of pests and diseases of agricultural crops in Russian Federation in 1970 and prognosis of their appearance in 1971. Moscow: MSKh SSSR. 96-101 p. (In Russian)
Sanin S.S. 1997. Phytosanitary monitoring: modern state and ways of improvement. In: Zakharenko V.A., Novozhilov K.V., eds. Problems of Optimization of Phytosanitary State in Plant Industry. Proc. of All-Russian Congr. on Plant Prot., St. Petersburg. St. Petersburg: VIZR. 166-175 p. (In Russian)

© Afanasenko O.S.