Biological control of Dothistroma needle blight on pine with Aneurinibacillus migulanus

Abstract

The ability of two strains of the antibiotic-producing bacillus Aneurinibacillus migulanus to control Dothistroma septosporum infection of pine was tested in artificial inoculation experiments on 2-year-old Pinus contorta plants. Disease severity (% needles with conidiomata) on control plants was 5.8 AE 1.7%, compared with 6.2 AE 2.0% on plants treated with A. migulanus NCTC 7096. In contrast, treatment with A. migulanus Nagano reduced Dothistroma needle blight (DNB) severity to 1.1 AE 0.4%. The conidial density and percentage germination of D. septosporum on needles were also greatly reduced on seedlings treated with A. migulanus Nagano compared with the A. migulanus NCTC 7096 and control treatments. The results suggest that A. migulanus Nagano has potential as a biological control agent for use against DNB in forest nurseries.

Increased Biological Activity of Aneurinibacillus migulanus Strains Correlates with the Production of New Gramicidin Secondary Metabolites

“…Our results confirmed previous findings suggesting that A. migulanus Nagano has potential as a BCA against plant diseases (Edwards and Seddon, 2001; Schmitt and Seddon, 2005; Chandel et al, 2010; Alenezi et al, 2016a). These results indicated clearly that selection of an appropriate strain of A. migulanus for use as a BCA is crucial in obtaining successful disease management.…”

“…Biofilm formation has also been proposed as a mean of providing efficient attachment of bacteria to plant surfaces (Yaron and Römling, 2014). Moreover, Nagano showed strong attachment to pine needles whereas NCTC 7096 showed only a weak attachment ability (Alenezi et al, 2016a). Nagano was able to persist after infection with Dothistroma septosporum .…”

“…Bacillus brevis ; Brevibacillus brevis ) controls plant disease development through production of the cyclic peptide GS (Edwards and Seddon, 2001; Belbahri et al, 2015). A. migulanus strain Nagano shows considerable potential as a biocontrol agent (Edwards and Seddon, 2001; Schmitt and Seddon, 2005; Chandel et al, 2010; Alenezi et al, 2016a). Apart from the direct antibiosis effect, A. migulanus Nagano GS biosurfactant activity increases the rate of evaporation from the plant surface, reducing periods of surface wetness and thereby indirectly inhibiting spore germination (Seddon et al, 1997, 2000).…”

Growth and fruition of a pathology research community: the Dothistroma story

“…Storage of fungal cultures from such studies is extremely important; in this issue, Fraser et al (2016c) outline a thorough study of six storage methods and make recommendations about the best methods to retain culture viability in the long term. Continuing the same theme, Alenezi et al (2016) describe a potential biocontrol bacterium that acted in a strain-specific manner to reduce DNB symptoms on Pinus contorta artificially inoculated with D. septosporum. With a focus on environmental effects, the review by Woods et al (2016) assesses the relationship between DNB, weather factors and climate, to gain a clearer picture of possible underlying causes of the recent increase in disease range and severity.…”

A worldwide perspective on the management and control of Dothistroma needle blight

“…Some Trichoderma and Bacillus species were shown to kill D. septosporum or inhibit its growth in vitro (McDougal et al 2011), indicating potential as biocontrol agents for DNB. A strain of the bacterium Aneurinibacillus migulanus reduced DNB severity from 6% to 1% and also lowered conidial abundance and germination when artificially inoculated into 2-year-old P. contorta trees (Alenezi et al 2016). Ridout and Newcombe (2015) carried out inoculations on P. ponderosa in Idaho, USA, with six fungi that naturally occur on hosts infected by Dothistroma spp.…”