First Report of Bacterial Leaf Streak of Corn Caused by Xanthomonas vasicola pv. vasculorum in Oklahoma

Following reports of a new bacterial disease of corn (Zea mays) caused by Xanthomonas vasicola in the nearby states of Colorado, Kansas, and Nebraska (Korus et al. 2017), irrigated corn fields in Caddo, Garvin, Kingfisher, and Texas Counties of Oklahoma were surveyed for symptoms of bacterial leaf streak in August 2016. Symptoms consisting of elongated necrotic lesions mostly confined within leaf veins, with irregular yellow to orange colored margins, were observed in several fields in Texas Co., although disease severity was low (less than 5%). Bacterial streaming was observed from excised leaf sections and yellow mucoid bacterial colonies were present on nutrient agar cultures obtained by streaking aqueous bacterial suspensions from lesion sections. Isolates were purified, grown on nutrient agar for 3 d, and DNA was extracted using a quick method. The quick method consisted of heating an aqueous bacterial suspension (one colony picked with sterile toothpick in 100 μl) for 15 min at 100°C and retaining s...