Cultural and symbiotic properties of Rhizobium strains isolated from nodules of Cicer arietinum L

Rhizobium isolates capable of nodulating chick pea (Cicer arietinum L.) roots were compared. Soil inoculation with isolates from Israel and the United States increased both seed yield and size. They were all Gram-negative and of the subpolar rod type, but differed in their growth rate and antigenic properties. After nodule formation bacteria from the different inoculants were reisolated. The resulting colonies were found to have identical growth rates and antigenic properties, but the local strains reverted to the original form after five transfers on agar medium.