To investigate the effects of two rhizosphere plant growth-promoting bacteria on the agronomic traits and nutritional quality of radish, this experiment utilized Kocuria rosea SDB9 and Brevibacterium frigoritolerans SDB5 to irrigate seedlings of the white radish variety ‘Xingyu No. 6’. The agronomic traits and nutritional quality indicators were then measured. The results showed that, compared with the control group (CK), treatment with both bacterial strains altered radish root morphology—specifically, root length was reduced and root diameter increased—with SDB9 exhibiting a more pronounced effect. The yield improvement effect of SDB9 was greater than that of SDB5. SDB5 also enhanced the contents of vitamin C, soluble sugars, soluble proteins, reducing sugars, starch, and cellulose in radish roots to varying degrees, with significant or highly significant increases in vitamin C, soluble sugars, and starch. In contrast, SDB9 significantly increased soluble protein levels but significantly reduced reducing sugars and cellulose, indicating that SDB9 affects the nutritional quality of radish. In conclusion, SDB9 can significantly enhance radish yield but may negatively effect quality, while SDB5 slightly increases yield but improves nutritional quality. Both bacterial strains demonstrate potential value in radish cultivation. |