Identification of Two Novel Pathovars of Pantoea stewartii subsp. indologenes Affecting Allium sp. and Millets

subsp. is a causative agent of leafspot of foxtail millet and pearl millet; however, novel strains were recently identified that are pathogenic on onion. We phenotypically and genotypically characterized 17 . subsp. strains from onion and other sources (pearl millet, foxtail millet, guar pulse, verbena, and corn). Based on the host range evaluation, we propose two pathovars: . subsp. pv. pv. nov. and . subsp. pv. pv. nov. . subsp. pv. pv. nov. causes symptoms on spp. (leek, onion, chive, and Japanese bunching onion) and on foxtail millet, pearl millet, and oat. However, . subsp. pv. pv. nov. can only infect the members of family (foxtail millet, pearl millet, and oat). We also propose that the type strain of . subsp. (LMG 2632 ) should be designated as a pathotype strain of . subsp. pv. and recommend that the strain PNA 14-12 be designated as the pathotype strain of . subsp. pv. . The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI), and multilocus sequence analysis study showed that the two pathovars are genotypically closely related. Our study also showed that . subsp. pathovars and . subsp. share high genotypic relatedness and cannot be differentiated by dDDH and ANI values. Although the newly proposed pathovars are not clearly distinguishable by their fatty acid and methyl esterase profiles and substrate use patterns, a fatty acid (unknown with retention time: 10.9525) and a few metabolites (3-methyl glucose, Na butyrate, and fusidic acid) can be potentially used to distinguish them. We also report the distribution of previously known pathogenicity (HiVir, ) and virulence ( ) factors of spp. in the new pathovars. The impact of these new pathovars in the center rot pathosystem of onion is yet to be determined.