FIG 1.

Phenotypic characteristics of strain BY2G20. (A) The morphological characteristics of the colony. (B and C) Growth curves of strain BY2G20 on different concentrations of NaCl (B) and different pH values (C). (D) Single colonies of strain BY2G20 were inoculated in LB liquid medium for 12 h at 37°C and then cultured in fresh LB liquid medium with different concentrations of NaCl and different pH values. The morphological characteristics of a single cell. The newly cultivated strain BY2G20 was placed on LB solid plate and incubated for 1 day at 37°C. (E) IAA secretion detection. A single colony of strain BY2G20 was inoculated in Landy liquid medium and then cultured for 4 days at 25°C. Salkowski solution was then added to detect IAA. A 50-mg/L IAA solution was used as the positive control. Landy medium without inoculation of strain BY2G20 was the negative control. The red color indicates the existence of IAA. (F) Strain BY2G20 inhibits the growth of R. solanacearum. Single colonies of strain BY2G20 and R. solanacearum were inoculated in LB liquid medium for 12 h at 37°C. R. solanacearum was then mixed with LB solid medium and plated with oxford cups. The culture supernatant of strain BY2G20 was inoculated into the holes of the oxford cups and then cultured for 24 h at 37°C.