Evaluation of the Symbiotic Properties of Rhizobium fredii in European Soils

A novel symbiovar (aegeanense) of the genus Ensifer nodulates Vigna unguiculata

“…that are common microsymbionts of cowpea, could be attributed either to the absence of bradyrhizobia from the sampling sites or to the out‐competition of bradyrhizobia from E. fredii strains under alkaline soil conditions. The latter is in agreement with a previous study that showed the high competitiveness of E. fredii HH103 against B. japonicum USDA110 for nodulating soybeans in alkaline soils …”

“…The latter is in agreement with a previous study that showed the high competitiveness of E. fredii HH103 against B. japonicum USDA110 for nodulating soybeans in alkaline soils. 58 Multi-locus sequence analysis (MLSA) is widely used in bacterial species definition providing a high resolution of phylogenetic relatedness at the inter-and intra-specific level. 59 -61 The chosen housekeeping genes were among the best-performing genes for differentiation and description novel species within Ensifer.…”

Symbiotic properties and first analyses of the genomic sequence of the fast growing model strain Sinorhizobium fredii HH103 nodulating soybean

“…The fast-growing soybean rhizobia strains isolated by Keyser et al (1982) are able to form nitrogen-fixing nodules on Asiatic soybean (G. max) cultivars, such as cultivars Peking or Jing Dou 19, but fail to nodulate or are very poorly effective, with modern cultivars from North America, such as cultivar Williams (Buendía-Clavería and Ruiz-Sainz, 1985;Buendía-Clavería et al, 1994;Keyser et al, 1982). Thus, these rhizobial strains exhibit marked soybean cultivar specificity.…”

“…However, field experiments carried out in Andalusia (Spain) showed that seed yields of soybean plants inoculated with some S. fredii strains are as high as those obtained with B. japonicum strain USDA110 or with high levels of nitrogen fertilization, indicating that some S. fredii strains could be valid soybean inoculants (Buendía-Clavería et al, 1994;Rodríguez-Navarro et al, 2003). These studies, however, were carried out in alkaline soils (pH 8.0) that, as with all European soils, are devoid of indigenous soybean microsymbionts.…”

Soybean Cultivation and BBF in China

“…Considering the extensive soybean-cropping areas in China, China's different types of soils and its climatic diversity, there are surprisingly few reports on the indigenous soybean-rhizobia populations, their symbiotic nitrogen-fixation capacity, and their competitive ability to nodulate soybeans (Dowdle and Bohlool, 1985;1987;Chen et al, 1988;Buendía-Clavería et al, 1994;Li et al, 1996;Li Fu-Di, 1996;Jiang et al, 1996). All these facts are of relevance to the ultimate goal of producing rhizobial inoculants to increase soybean productivity SOYBEAN AND BNF IN CHINA under field conditions.…”