Influence of Bacillus spp. on strawberry gray-mold causing agent and host plant resistance to disease

Abstract

The influence of Siberian strains of bacteria Bacillus spp. on the strawberry gray mold causative agent and plant resistance to the disease in three seasons differing in growing conditions has been studied. Bacterial strains B. subtilis, B. amyloliquefaciens, and B. licheniformis suppress the development of the phyto pathogenic fungus B. cinerea in vitro and in vivo. In addition to the antifungal action, bacterial strains show a positive effect on the growth and development of strawberry plants, indicating multifunctional properties of Siberian strains Bacillus spp.

Bacillus subtilis BS-2 and Peppermint Oil as Biocontrol Agents Against Botrytis cinerea

“…(95.3 %) due to the synthesis of surfactin [26]. Shternshis et al [2] tested strains of Bacillus under laboratory conditions and found they suppressed the growth of the phytopathogenic fungus B. cinerea in the range of 70 % (for B. licheniformis) to 100% (for B. subtilis, B. amyloliquefaciens). The inhibitory effect depended on the concentration of the tested bacterial suspension and was achieved at the highest concentration (10 6 CFU/ cm 3 ).…”

“…Grey mould, caused by the fungus B. cinerea, is one of the most significant agricultural phytopathogens that can infect plants throughout all stages of their growth. For example, in cold and damp weather conditions it can affect strawberry plants, attacking the flowers, leaves, and mature fruit [1,2]. B. cinerea produces large amounts of conidia that are widespread in the air and can be readily transported by wind over long distances.…”

“…For this reason, B. cinerea may cause serious pre-and post-harvest diseases and can be one of the most difficult plant diseases to prevent or control [4][5][6]. Control of grey mould disease is usually carried out by the application of chemical fungicides, which are generally not effective and lead to contamination of the environment, accumulation of toxic residues in fruits, and can cause toxic effects on human health [2,7,8]. Several studies have shown that the best alternatives with the potential to control Botrytis cinerea include filamentous fungi (Trichoderma sp., Gliocladium sp.…”

“…), and certain essential oils [9][10][11]. Several mechanisms have been indicated as responsible for their antagonistic activity, including: mycoparasitism [9], secretion of bioactive compounds (trichozianins A1 and B1 from T. harzianum, gliotoxin from G. virens, pyrolnitrin from P. cepacia, and flagelin-like protein from B. subtilis) [9,12], competition for space and nutrients, promotion of plant growth (the growth of plant seedlings, increased the biomass seedlings) [2,13] and induction of systemic resistance (ISR) [14]. These microorganisms can cause inhibition of mycelium growth, morphological changes of mycelium, weakness or inhibition of spore germination, and inhibition of hyphal elongation [2,4,11].…”

“…inhibiting the growth of mycelium and spore germination by membrane disruption, inhibiting the action of enzymes and/or causing their complete inactivation. Thus, biological methods of protection against Botrytis sp., such as using microorganisms or their metabolites and plant extracts or essential oils, offer an effective alternative or complement to the use of conventional disease control methods [2,3,9,14].…”