Characterization of Hungarian rice cultivars in nitrogen fixing associations with bacteria

Partial nitrogen supply by biologically fixed nitrogen may well be an envir onment friendly and energy-saving improvement in production of cereals. Nit rogen fixing associations of various Hungarian rice cultivars were establis hed with associative diazotrophic bacterium Azospirillum brasilense and end ophytic diazotroph herbaspirillum seropedicae. The cultivars expressed diff erent susceptibility to accept the associations, as manifested in root and shoot growth. Established pattern of colonizing bacteria within the plantle ts well correlated with the host plant responses. Growth promoting effect o f A. brasilense was unambiguous while H. seropedicae elicited inconsequenti al plant reactions. Moreover, immobilized inoculum formula was developed in order to support protection and competitiveness of bacteria in the soil an d provide agrotechnical advantages in the field.