Genetic stability in rhizobia in the field

摘要: Genetic instability within strains of rhizobia maintained on laboratory media is well recognized, although rarely has the mutation been characterized. Variability a strain introduced into field very difficult to recognise due poor understanding naturally-occurring populations rhizobia. We have examined Rhizobium leguminosarum bv. trifolii from both cultures and found significant variation in symbiotic effectiveness both. In Australia, only introduction Bradyrhizobium japonicum CB1809 (=USDA136b). Symbiotic tests reisolates obtained by plant entrapment indicate little or no change up nine years after introduction. The RFLP pattern, using RSα probe (Hahn Hennecke, 1987a) was unchanged but marked differences serological characters were observed.