MICROBIOLOGY AND NATURE

Rice seeds harbour a variety of microorganisms, including pathogenic fungi, bacteria and nematodes which are capable of causing damage to rice crop. Newly discovered bacterial species belonging to the genus Pantoea, have been found to exhibit similar symptoms to Xanthomonas oryzae pv. oryzae (Xoo) in rice plants. In Sub-Saharan Africa, there are three species of Pantoea that are particularly identified as the causative agents for bacterial leaf blight, a disease that causes blighting and discoloration of rice grains. For effective implementation of a Pantoea management system, a diagnosis was carried out on rice seeds from 21 African countries. The tests revealed the presence of different Pantoea species in 15 African countries including Pantoea stewartii; Pantoea ananatis; Pantoea deleyi. Following the identification of the isolated microorganisms two Pantoea species were selected for pathogenicity testing in greenhouse using the leaf clipping method on seven elite rice varieties. The pathogenicity tests highlighted the susceptibility of rice variety Gigante to Pantoea stewartii V11SEN1 a strain identified from Senegal and varieties Moroberekan and Azucena to Pantoea ananatis IVV6CI1, a strain isolated from Côte d’Ivoire. From these investigations, it would be important to pay particular attention to these emerging strains of Pantoea in Africa.