VIEW ARTICLE

Etiology

Xanthomonas campestris pv. translucens on Triticale and Other Small Grains. Barry M. Cunfer, Department of Plant Pathology, Georgia Station, University of Georgia, Experiment 30212; Barbara L. Scolari, Department of Plant Pathology, Georgia Station, University of Georgia, Experiment 30212. Phytopathology 72:683-686. Accepted for publication 18 September 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-683.

Bacterial blight symptoms on triticale are elongated translucent, water-soaked lesions similar to those observed on other small grains. Physiological characters of Xanthomonas campestris pv. translucens (syn. X. translucens) from triticale are identical to those of strains from other hosts. Strains from triticale were equally virulent to triticale, wheat, and rye; much less virulent to barley; and nonpathogenic to oats, timothy, and Bromus spp. Strains from barley were restricted in host range, being pathogenic primarily to barley. Strains Xt-202 and Xt-211, isolated from triticale at two locations in Mexico, produced a host response nearly identical to that caused by two strains from Georgia and Alabama on 35 triticale lines. The results indicated that indigenous strains of X. campestris pv. translucens from wheat and rye can infect triticale when it is introduced into a new region. The greater severity of bacterial blight observed among triticales in the field compared to that on wheat and rye is most likely due to high susceptibility of triticale rather than changes in virulence in X. campestris pv. translucens. Both hypodermic injection and spray inoculation of seedlings of different small grain lines caused a similar host response. The chlorotic-fleck resistant reaction was easily detected by the spray-inoculation method. Triticale lines UP 7th ITSN #20, UPT 72142, S-69 (M2A-BgC), and Siskiyou were resistant to four to more of six X. campestris pv. translucens strains from the various geographic areas.