Diversity of rhizosphere bacteria associated with different soybean cultivars in two soil conditions

Aiming at learning the effects of soil conditions and cultivar on the bacterial diversity in the rhizosphere of soybean (Glycine max(L.) Merr.), bacterial communities associated with four soybean cultivars grown in two soils were revealed by terminal-restriction fragment length polymorphism (T-RFLP) combined with sequencing analysis of a 16S rDNA clone library. Lower bacteria diversity was found in soil A which has higher salinity and nutrient contents, while the highest bacterial diversity was found in the rhizosphere of cv. Jidou 12 in both soils. These results revealed that both the soil conditions and soybean cultivar affected the community composition of rhizosphere bacteria, but the effect of soil conditions was greater than that of soybean cultivar as demonstrated by the principal component analysis. It also revealed that the abundant rhizosphere bacteria may also the main symbiotic or non-symbiotic nodule endophytes.