The roots check details were then rinsed twice with SDW. The sterilized ginseng roots were dipped in bacterial suspensions (106 CFU/mL and 108 CFU/mL) for
40 min and dried for 1 h on a clean bench . The roots were transplanted into artificially infested soil in plastic pots with concentrations of 5% oatmeal-culture fungal inoculum and incubated at 25°C. Root rot symptoms were examined visually 10 d following inoculation. Two concentrations of Bacillus broth cultures (106 CFU/mL and 108 CFU/mL) were used as treatment. Ginseng root discs were treated with 20 μL of the bacterial suspensions and were placed on moistened filter paper inside petri dishes and incubated at 25°C. There were three replicates of root discs for each treatment, and the experiment was performed twice. To measure cell population changes, the whole root discs treated and inoculated were ground in a blender and suspended in 10 mL SDW. KRX-0401 supplier The solution was then diluted with SDW, spread
on BHI agar, and incubated at 28°C. After incubation of 20 h, the number of colonies formed on the agar plates was counted with the naked eye for the total bacterial population on the root discs. These were examined daily up to 7 d after incubation . To prepare the samples for scanning electron microscopy (SEM), the bacterial isolates grown in BHI broth for 2 d were mixed with the Fusarium isolate and incubated on PDA at 25°C. One d after incubation, mycelial discs were fixed with modified Karnovsky’s fixative [2% paraformaldehyde and 2% glutaraldehyde in 0.05M sodium cacodylate buffer (pH 7.2)] for 12 h at 4°C . The fixed specimens were washed with 0.05M sodium cacodylate buffer three times for 10 min each. These were postfixed in 1% OsO4 at 4°C for 2 h, and briefly washed with distilled water. The specimens were then dehydrated in an ethanol series of 30%, 50%, 70%,
80%, and Inositol monophosphatase 1 90% for 10 min each, and in 100% ethanol three times for 10 min each . Using hexamethyldisilazane (Electron Microscopy Sciences, Hatfield, PA, USA), specimens were dried and coated with gold using a sputter coater (MSC-101, JEOL). The specimens were observed under a field emission SEM (Auriga, Zeiss, Berlin, Germany) at an acceleration voltage of 5.0 kV. The fungal isolate C4-1 obtained from the rotten cactus stem had all the same mycological characteristics of Fusarium species and formed multicellular falcate macroconidia. Morphological characteristics of the fungal isolate were as follows: extensive and cotton-like mycelia with a colony color of pale orange or yellowish brown on PDA; macroconidia produced from polyphialides on CLA, slightly curved, frequently 3–5 septate, with a curved and tapering apical cell and a foot-shaped basal cell, measuring 37.9 ± 4.3 μm × 4.2 ± 0.5 μm; mesoconidia, which were fusoid, 1–5 septate, measuring 20.2 ± 4.3 μm × 3.7 ± 0.7 μm; intercalary chlamydospores; and absent microconidia ( Table 1, Fig. 1), indicating that they are matched well with the F.