First report of Puccinia kuehnii, causal agent of orange rust of sugarcane, in Guatemala.
In September 2007 at Masagua, Escuintla Department, Guatemala, uredial lesion that appeared different from those of brown rust were observed on a sugarcane cultivar (CP 72-2086) considered resistant to brown rust caused by Puccinia melanocephala. Observed morphological features were consistent with Puccinia kuehnii and appeared similar to orange rust samples obtained from Florida in July. DNA sequences matched sequences of P. kuehnii in GenBank and were distinct from known sequences of P. melanocephala available in GenBank. Orange rust was previously reported in Florida, but this is thought to be the second report of its occurrence in the Western Hemisphere, and the first report of P. kuehnii as orange rust pathogen of sugarcane in Guatemala.