Table 3.
Examples highlighting the variation in sensitivity of plant pathogens to biological control agents or plant extracts described as having a simple mode of action.
| Modes of action of BCA | BCA/plant extract | Plant pathogen | Number of isolates | Main results | Reference |
|---|---|---|---|---|---|
| Antibiosis | Agrobacterium rhizogenes | Agrobacterium tumefaciens | 65 | Biotype 3 are resistant to the antibiotic agrocin 84. | VAN Zyl et al. (1986) |
| B. subtilis, Serratia plymuthica, P. putida, Streptomyces setonii | Rhizoctonia solani | 8 | Diverse levels of sensitivity (dual culture assay in vitro). | Faltin et al. (2004) | |
| Bacillus mojavensis | Fusarium verticillioides | 3 | Diversity in percent of lesion reduction in maize. | Bacon and Hinton (2011) | |
| 4 endophytes of elm + 2 Trichoderma strains | Ophiostoma novo-ulmi | 6 | In vitro growth inhibition less marked in some strains of O. novo-ulmi. | Diaz et al. (2013) | |
| 15 fungal endophyte species | Gremmeniella abietina | 4 | Diverse levels of sensitivity (dual culture assay in vitro). | Santamaria et al. (2007) | |
| 20 strains of Streptomyces spp. | Streptomyces scabies | 15 | Diverse levels of sensitivity; 1 isolate resistant to 16 BCA strains. | Otto-Hanson et al. (2013) | |
| 3 strains of Streptomyces spp. | Botrytis cinerea | 41 | In vitro growth inhibition less marked in some strains of B. cinerea. | Boukaew et al. (2015) | |
| Aqueous extract of Cuscuta pedicellata L. | Xanthomonas campestris | different pathovars | In vitro variation in susceptibility among pathovars of X. campestris. | Ali et al. (2013) | |
| Hyperparasitism | Cryphonectria hypovirus 1 (CHV-1) | Cryphonectria parasitica | 6 8 | Difference in tolerance; small magnitude of tolerance. | Peever et al. (2000), Bryner and Rigling (2012) |
| 5 bacteriophages | Erwinia amylovora | 52 | 23 strains exhibit resistance to at least one phage. | Schnabel and Jones (2001) | |
| Acremonium strictum | Helminthosporium solani | 4 | Diverse levels of sensitivity. | Rivera-Varas et al. (2007) | |
| Coniothyrium minitans | Sclerotinia sclerotiorum S. trifoliorum | 34 9 | Considerable variation in the rate and extend of infection by Coniothyrium. | Turner and Tribe (1976) | |
| Coniothyrium minitans | Sclerotinia sclerotiorum | 3 | 1 strains less susceptible to infection. | Huang et al. (2011) |