Kathryn Hallada

Kathryn R. Hallada, Kristi E. Ledman, Rebecca D. Curland, and Ruth Dill-Macky

Bacterial leaf streak (BLS) is a disease caused by the bacterial pathogen Xanthomonas translucens, which typically affects wheat, barley and other grasses, including perennial and annual grassy weeds. There are four pathovars (a sub-specific taxonomic grouping based on unique host range) of X. translucens that are known to impact cereal crops. Wild rice, known as Manoomin, is a native annual grass that holds an honored place in Native American culture and is still gathered in the traditional manner. Cultivated wild rice (Zizania palustris L), the domesticated form of this cereal, is commercially grown in paddies. BLS has been reported on cultivated wild rice, yet little is known about which X. translucens pathovars are associated with this host. In this study, two strains of X. translucens, recently isolated from cultivated wild rice in Minnesota, were examined by comparing their in planta host reaction profiles to the reference strains for these four X. translucens pathotypes. In addition, we examined three strains collected from wild rice in Minnesota during the early 1980s, which were previously identified as X. campestris pv. cerealis. Recent molecular phylogenies placed the recent and historical strains from cultivated wild rice in the same clade as X. translucens pv. undulosa. Our results showed that the host reactions of these strains are consistent with the profile of the X. translucens pv. undulosa reference strain. Identifying which pathovars of X. translucens cause BLS in Minnesota’s cultivated wild rice paddies is important when developing disease management strategies, including the identification of host resistance.