Previous View
APSnet Home
Plant Disease Home

Disease Note.

Glomerella cingulata Associated with Leaf and Shoot Blight of Hybrid Poplar. G. Newcombe, Washington State University, Puyallup 98371-4998. J. M. Staley, and G. A. Chastagner. Washington State University, Puyallup 98371-4998. Plant Dis. 75:1286. Accepted for publication 6 August 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-1286C.

Blighted leaves of hybrid poplar (Populus trichocarpa Torr. & A. Gray × P. deltoides J. Bartram ex Marsh.) in plantations in western Oregon, Washington, and British Columbia were sometimes found to be infected with both Pollaccia elegans Servazzi (anamorph of Venturia populina (Vuill.) L. Fabricius in Hollrung) and Colletotrichum gioeosporioides (Penz.) Penz. & Sacco in Penz. (anamorph of Glomerella cingulata (Stoneman) Spauld. & H. Schrenk). Perithecia of G. cingulata and, less commonly, acervuli of C. gloeosporioides were observed together with pseudothecia of V. populina on blighted shoots during winter and spring. Surface-sterilized, detached poplar leaves on filter paper soaked with gibberellic acid solution (100 µg/g) were inoculated with ascospores of G. cingulata or conidia of C. gloeosporioides. In both cases, lesions developed within 24 hr that gave rise first to acervuli, then to perithecia. Uninoculated control leaves remained green for 3 wk or more and eventually died without yielding C. gloeosporioides. Lesions developed on leaf blades, petioles, and young stems of rooted hybrid poplar plants that had been sprayed with a conidial suspension of a single-ascospore isolate of G. cingulata and incubated 36 hr in a dew chamber (controls remained diseasefree). Stem lesions did not, however, develop the shepherd's crooks that occur after inoculation with V. populina. C. gloeosporioides, but not G. cingulata, has been reported previously on Populus (I). Cultures and voucher specimens of G. cingulata and C. gloeosporioides were deposited in the herbarium of Washington State University (herb. WSP).

Reference: (1) G. C. Marks et al. For. Sci. Il:204, 1965.