University of California

A study of Tranzschelia pruni-spinosae on Prunus species in California


Clayton O. Smith

Author Affiliations

Clayton O. Smith was Associate in the Experiment Station, Emeritus.

Publication Information

Hilgardia 17(7):251-266. DOI:10.3733/hilg.v17n07p251. March 1947.

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The genus Prunus comprises a heterogeneous collection of plants originating in many different parts of the world. The foliage of these plants is at times attacked by plant rust caused by various species of Tranzschelia.

The plant-rust genus Tranzschelia, as established by Arthur (1)4 in 1906, consisted of a number of macrocyclic and microcyclic species, one of the macrocyclic species being the heteroecious rust of Prunus spp., T. pruni-spinosae (Pers.) Diet., formerly described as Puccinia pruni-spinosae Pers., but now separated from Puccinia because of differences in morphological characters.

This rust of Prunus is world wide in its distribution and probably occurs wherever Prunus species are grown. It is widely distributed in Europe and occurs in Asia (China, India, and Japan), Africa (Egypt and Uganda), Australia, and New Zealand. In South America this rust is found where Prunus is indigenous, in the mountains of Brazil, Colombia, Uruguay, and Venezuela. It is also reported from Mexico and Central America. In the United States it is found in the eastern states and is especially prevalent in the southeastern states and along the Pacific coast.

Other species of Tranzschelia found on the foliage of Prunus spp. and described by Tranzschel and Litvinov (11) should be listed: T. japonica on P. armeniaca var. Ansu and on P. mume; T. microcerasi on P. microcarpa and on six other species of Prunus, all from Central Asia; and T. arthurii on P. serotina, in the United States “(Michigan, leg. C. H. Hicks; Iowa, leg. Holway).”

The present study concerns observations of the rust Tranzschelia prunispinosae, both natural infection and that induced by artificial inoculation, on different species of Prunus in California. The study has extended over a series of years, though many of the artificial inoculations were made during the years 1942 and 1943.

Literature Cited

[1] Arthur J. C. Eine auf die Struktur und Entwicklungsgeschichte begründete Klassifikation der Uredineen. Res. Sci. Cong. Internatl. de Bot. (Vienne). 1906. 1905: 331-48.

[2] Barrett J. T. Observations on prune rust, Puccinia pruni-spinosae Pers., in Southern California. (Abstract) Phytopathology. 1915. 5:293

[3] Cristinzio M. Studio sulla ruggine delle drupacee (Puccinia pruni-spinosae, Pers.). Ricerche, Osservazionie Divulgazioni Fitopat. Campania ed Mezzogiorno [Portici (Napoli)]. 1936. 5: 15-60.

[4] Dunegan John C. The rust of stone fruits. Phytopathology. 1938. 28: 411-27.

[5] Dunegan John C., Smith Clayton O. Germination experiments with uredio- and teliospores of Tranzschelia pruni-spinosae discolor. Phytopathology. 1941. 31:189-91.

[6] Goldsworthy M. C., Smith Ralph E. Studies on a rust of clingstone peaches in California. Phytopathology. 1931. 21: 133-68.

[7] Scott C. Emlen, Stout Gilbert L. Tranzschelia punctata on cultivated anemone in the Santa Clara Valley. California State Dept. Agr. Mo. Bul. 1931. 20: 648-54.

[8] Smith Clayton O. Inoculations of the evergreen species of Prunus (Laurocerasus) with Tranzschelia pruni-spinosae. Phytopathology. 1945. 35: 572-74.

[9] Smith Clayton O., Cochran L. C. Rust on the California native Pruni.. Phytopatholog. 1939. 29:645-46.

[10] Thomas H. Earl, Gilmer Ralph A., Emlen Scott C. Rust of stone fruits. California State Dept. Agr. Mo. Bul. 1939. 28: 322-27.

[11] Tranzschel V. G., Litvinov M. A. [Rust fungi of the genus Prunus.] [In Russian.]. Jour. de Bot. 1939. 24: 247-53.

Smith C. 1947. A study of Tranzschelia pruni-spinosae on Prunus species in California. Hilgardia 17(7):251-266. DOI:10.3733/hilg.v17n07p251
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