TABLE 3.
Screening tests for biocontrol activity against F. graminearum in vitro and in planta (germination blotter and soil substrate assays).
| Treatment |
Dual culture assay |
Germination blotter assay |
Soil substrate assay |
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| Mean of growth inhibition (%) | FRR protection (%) per plant | FFR protection (%) per treatment | Infected shoot dried weight (mg) per plant | FFR protection (%) per treatment | Infected shoot dried weight (mg) per plant | |
| Water control | – | – | – | 10.69 ± 3.15 | – | 75.14 ± 16.47 |
| DEF06 | 66.66 ± 6.41 | 12.14 ± 23.38 | 17.61 | 17.71 ± 4.49∗ | nt | nt |
| DEF07 | 74.07 ± 3.70∧ | 38.20 ± 21.41*∧ | 24.24∧ | 16.35 ± 4.78∗ | 61.28∗ | 57.30 ± 11.65∗ |
| DEF08 | 60.49 ± 4.27 | 15.20 ± 15.12 | –45.45∗∗ | 10.81 ± 4.70 | –1.12 | 64.47 ± 13.80 |
| DEF09 | 59.26 ± 3.70∧ | 42.66 ± 15.21*∧ | 80.86*∧ | 13.89 ± 3.63 | 46.38∗ | 59.07 ± 12.01∗ |
| DEF13 | 32.1 ± 10.69∧ | 7.87 ± 19.35∧ | 20.45∧ | 11.88 ± 4.90 | nt | nt |
| DEF14 | 49.38 ± 2.14∧ | 6.57 ± 19.96∧ | 41.18*∧ | 11.66 ± 5.84 | nt | nt |
| DEF15 | 37.25 ± 3.92∧ | 18.59 ± 22.84∧ | 62.41*∧ | 11.29 ± 2.42 | nt | nt |
| DEF16 | 56.79 ± 4.28∧ | 38.45 ± 27.18*∧ | 43.61*∧ | 9.61 ± 2.23 | nt | nt |
| DEF17 | 39.50 ± 5.66 | −7.22 ± 13.51 | 28.57∗ | 10.57 ± 2.54 | nt | nt |
| DEF18 | 61.73 ± 2.14 | 18.48 ± 24.57 | 15.97 | 7.49 ± 3.01 | nt | nt |
| DEF19 | 76.54 ± 2.14∧ | 46.74 ± 17.43*∧ | 25.93∧ | 11.08 ± 2.51 | 39.55 | 63.19 ± 12.93 |
| DEF20 | 77.78 ± 0∧ | 27.26 ± 24.45*∧ | 41.23∧ | 11.23 ± 2.02 | 10.64 | 59.58 ± 12.42 |
| DEF21 | 45.68 ± 9.32 | 35.22 ± 25.73∗ | 12.55 | 11.86 ± 2.08 | nt | nt |
| DEF31 | 41.98 ± 19 | 29.14 ± 20.43∗ | –14.81 | 10.98 ± 1.64 | nt | nt |
| DEF33 | 55.56 ± 0 | 7.67 ± 21.09 | 17.36 | 11.29 ± 1.84 | nt | nt |
| DEF39 | 64.20 ± 2.14∧ | 39.77 ± 15.00*∧ | 43.75*∧ | 13.40 ± 3.13 | –24.47 | 44.55 ± 13.36∗ |
| DEF40 | 43.21 ± 2.14 | 24.13 ± 23.23 | 38.82 | 8.61 ± 1.53 | nt | nt |
| DEF41 | 60.49 ± 4.27∧ | 35.96 ± 18.90*∧ | 54.17*∧ | 10.19 ± 2.47 | nt | nt |
| DEF46 | 39.50 ± 8.55 | 21.07 ± 25.69 | 45.00 | 8.90 ± 2.33 | nt | nt |
| DEF47 | 54.32 ± 4.28∧ | 24.79 ± 23.31∧ | 87.50*∧ | 9.81 ± 2.63 | –7.23 | 54.93 ± 14.24∗ |
| DEF48 | 70.37 ± 3.70∧ | 32.28 ± 27.81*∧ | 55.88*∧ | 10.69 ± 1.77 | 29.04 | 61.37 ± 11.00 |
Underlined strains were not originally isolated as endophytes. ∧Experimental data obtained from Colombo et al. (2019). nt Not tested. FRR Fusarium root rot. FFR Fusarium foot rot. The average of mycelium growth inhibitions recorded in dual culture assay against F. graminearum strain Fg8/1 is reported. In planta results of germination blotter assay or using soil are displayed as FRR protection (∗P < 0.05 is considered significant) and FFR protection (Fisher’s test analysis: ∗P < 0.01 treatment considered significantly able to maintain the seedling asymptomatic, ∗∗P < 0.01 treatment considered significantly able to increase disease severity). The average of infected shoot weight (mg) for each treatment assessed after 10 or 20 days after seed bacterization or transplant is also reported.