Symbiotic and genomic diversity of ‘cowpea’ bradyrhizobia from soils in Botswana and South Africa

摘要: Strain CB756 is usually an effective competitor against indigenous bradyrhizobia for nodulation of peanut in South Africa. Recently, inoculation and cowpea with loamy sand soils Botswana or a sandy clay loam Africa proved unsuccessful, achieving <2% nodule occupancy. A survey ‘cowpea’ from five one showed that many were ability to fix N2 on cowpea. However, 15 isolates Good Hope, all but ineffective peanut, three failing nodulate the latter. Selected significantly more competitive than Leonard jars, four unsuccessful when inoculated at Roodeplaat, When strain two pots containing Roodeplaat soil, 4:1 inoculant soil ratio, their average occupancy was 8% compared 40% peanut. Significant differences not detected either In contrast, Botswana, 40:1 22.4% only 6.8% Hope weakest insignificant Whereas population cowpea, it DNA fingerprinting Gaborone, Francistown contained several different genotypes, whereas those Rasesa Maun homogeneous. The dominance genotypes emphasises value assessing symbiotic capabilities structures populations.