Effectiveness of mycorrhizal fungi in the protection of juniper, rose, yew and highbush blueberry against Alternaria alternata

Abstract

After conducting two-year observations in nurseries in the Małopolska province, Poland, the species of shrubs on which symptoms of discoloration and withering of the leaves/needles and shoots, and sometimes of whole plants, occurred most frequently were selected for further study. The species included juniper (Juniperus horizontalis ‘Wiltonii’, rose (Rosa ‘Star Profusion’), yew (Taxus × media ‘Hillii’) and highbush blueberry (Vaccinum corymbosum ‘Patriot’). The predominant fungus isolated from the diseased plants was Alternaria alternata (Fr.) Keissl. A pathogenicity test performed in the laboratory confirmed the pathogenic effects of A. alternata on all of the tested species of shrubs. In 2011-2014, a field experiment was conducted with A. alternata inoculum introduced into the growth substrate. The presence of the pathogen reduced considerably the annual growth of all the shrubs tested. The applied mycorrhizal inocula had an effect on some morphological characteristics of plants, such as height and number of shoots. Moreover, the plants whose roots had been treated with the mycorrhizal inocula and were grown in the substrate inoculated with the pathogen also achieved greater increases in growth in comparison with the plants treated with the pathogen as well as relative to the control. The protective role of mycorrhizal inocula against the damaging effects of the pathogen was evident in all the species of shrubs.

Biological Control of Three Fungal Diseases in Strawberry (Fragaria × ananassa) with Arbuscular Mycorrhizal Fungi

“…It has been reported that AM fungal species applied to strawberries reduced the pathogenicity of R. fragariae [59]. In an experiment with shrubs, it was determined that mycorrhiza application both suppressed the A. alternata pathogen and encouraged the development of plants [60]. In another study, F. mosseae and Trichoderma harzianum were used against the A. alternata in cucumber and a combination of bioagents had a positive synergistic effect on the reduction in disease severity [61].…”

Influence of Grafting on Rootstock Rhizosphere Microbiome Assembly in Rosa sp. ‘Natal Brier’

“…In contrast, grafted plants' taxa enriched in the rhizosphere were assigned to guilds ectomycorrhizal and arbuscular mycorrhizal. In roses, arbuscular mycorrhizal colonization stimulates nutrient and water uptake, biomass accumulation, and tolerance to environmental stress (drought and alkaline irrigation) and disease [66][67][68][69][70][71][72][73]. Among the enriched fungal taxa in grafted plants, some Mortierella, Chaetomium, Humicola, Metarhizium, Schizothecium, and Volutella species have been reported to benefit plant growth or health [74][75][76][77][78][79].…”

Linking Endophytic Fungi to Medicinal Plants Therapeutic Activity. A Case Study on Asteraceae

“…Plant and coexisting microbial signal molecules are required to induce particular pathways of endophyte metabolism leading to a balance of sexual to asexual reproduction and biochemical profile modification as well [17][18][19][20]. Moreover, the secondary metabolites are energy-consuming compounds, so endophytes can increase/decrease their production depending on specific needs, like competition with the other microorganisms or host plant communication and protection [9,[21][22][23]. However, some fungal endophytes were shown to produce the desired compounds without a host plant association.…”