Pasteuria spp occurrence and population fluctuation in Minas Gerais State, Brazil Ocorrencia e flutuacao populacional de Pasteuria spp em Minas Gerais
Souza, J.T.odoro de.; Souza, R.M.gela de.; Campos, V.P.ulo.
Nematologia Brasileira. Dezembro; 202: 41-51
Pasteuria spp. was found in 29.69% of the samples collected from 128 sites on nematodes feeding in 28 plant species of Minas Gerais State, Brazil. Four nematodes genera i.e.: Helicotylenchus, Meloidogyne, Pratylenchus and Tylenchus, out of fifteen found in all samples, had Pasteuria spp. endospores on the cuticle, then they were considered Pasteuria hosts. The bacteria infested 14.61%, 8.66%, 7.30% and 4.21% of Helicotylenchus dihystera, Meloidogyne javanica, Pratylenchus brachyurus, and Tylenchus sp. extracted from soil, respectively. The mean number of Pasteuria spp. endospores on the cuticle of each specimen and endospore diameters as well, were greater on Meloidogyne javanica than on others plant parasitic nematodes. However, endospore diameters had great variation among infested species of plant parasitic nematodes. In 40 samples was observed greater percentage of Meloidogyne javanica, Helicotylenchus dihystera and Pratylenchus brachyurus infested by Pasteuria spp. in summer than in other seasons. But it was not always correlated to higher nematode host population in the soil at the same season. Tylenchus sp., on the other hand, was least infested by Pasteuria in the summer. Natural infestation of plant parasitic nematodes by Pasteuria spp. varied from 0 to 6.93%.