Isolation and identification of indigenous Azospirillum species in Golestan province soils

agar agar-agar aislamiento asia sudoccidental asie du sud-ouest azospirillum azospirillum brasilense azote cobertura de suelos couverture du sol galactane galactanos galactans geographical distribution hortalizas identification indigenous organisms iran islamic republic isolation isolation techniques isolement land cover legume mucilage mucilages mucilagos nitrogen no metales nonmetals papa plant vegetative organs pomme de terre potatoes racine rendement rendimiento roots separating separation soil sol southwestern asia spirillaceae suelo technique de l'isolement triticum triticum aestivum vegetables yields