Fig. 1.
Growth curve of Bacillus subtilis CTXW 7-6-2 and its antifungal activity against Rhizoctonia solani.
A) CTXW 7-6-2 growth curve;
B) a: colony morphology of the control group, b: colony morphology after confrontation with the bacteria, c: sterile fermentation broth treatment group without high-temperature treatment, d: high-temperature sterile fermented broth treatment group; e: crude lipopeptide treatment group, f: volatile compounds treatment group.
The red box indicates the back of the colony.
Table I
Antifungal activity of Bacillus subtilis CTXW 7-6-2 against Rhizoctonia solani.
| Classes | Control (cm) | Treatment (cm) | Inhibition ratio (%) |
|---|---|---|---|
| Antagonistic bacteria confront pathogenic fungi | 7.11 ± 0.13 | 0.43 ± 0.03 | 94.02 ± 0.41a |
| Sterile fermentation broth without high-temperature treatment | 3.23 ± 0.06 | 54.63 ± 0.89c | |
| High-temperature processing of sterile fermentation broth | 3.49 ± 0.14 | 50.88 ± 1.92c | |
| 100 mg/l crude lipopeptide | 5.28 ± 0.01 | 0.23 ± 0.21 | 74.88 ± 4.03b |
| Volatile compounds | 6.66 ± 0.26 | 0.23 ± 0.12 | 96.62 ± 1.77a |
Fig. 2.
Hypha morphology and cell ultrastructure of Rhizoctonia solani after treatment with Bacillus subtilis CTXW 7-6-2. A) Scanning electron microscopy observation of mycelium morphology; B) Ultrastructure of hyphal cells observed using transmission electron microscopy. The arrows in the figure indicate cell wall (cw), plasma membrane (pm), and mitochondria (m). a: the control hyphae, b: mycelia of the treated group
Fig. 3.
Effects of A) nutrient broth medium and B) CTXW 7-6-2 fermentation broth on seedling growth of Yunyan no. 87.
Table II
Effects of CTXW 7-6-2 fermentation on the growth of tobacco seedlings.
| Treat | CTXW 7-6-2 | Nutrient broth |
|---|---|---|
| Leaf length (cm) | 7.59 ± 0.29a | 4.44 ± 0.28b |
| Leaf width (cm) | 5.41 ± 0.31a | 3.25 ± 0.23b |
| Leaf number (piece) | 4.67 ±0.33a | 4.00 ± 0.00a |
| Whole plant fresh weight (g) | 2.01± 0.13a | 0.60 ± 0.0064b |
| Root number | 26.33 ± 0.88a | 24.33 ± 0.88a |
| Root length (cm) | 6.31 ± 0.37b | 10.41 ± 0.85a |
| Dry weight of root (g) | 0.17 ± 0.0025a | 0.091 ± 0.0041b |
Fig. 4.
Expression of genes involved in tobacco disease course induced by Bacillus subtilis CTXW 7-6-2.