Soil microbiota impact on Boletus edulis mycelium in chestnut orchards of different ages

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment ecosystems & environment, 2023-05, Vol.185, p.104790, Article 104790
• Main Authors: Santolamazza-Carbone, Serena, Iglesias-Bernabé, Laura, Sinde-Stompel, Esteban, Gallego, Pedro Pablo
• Format: Article
• Language: English
• Subjects: Bacterial community; Boletus edulis; Castanea × coudercii; DNA metabarcoding; Fungal community; qPCR
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2022.104790

Biotic factors (host plant age and soil microbiota) influencing Boletus edulis mycelium frequency and concentration have been investigated. The study was carried out in September, October and November 2018 and 2020, using six orchards of chestnut hybrid Castanea × coudercii of 40-, 10- and 3-years-old. Taxonomical identity of bacterial and fungal species was ascertained by DNA metabarcoding. Mycelium frequency and concentration of B. edulis were studied through quantitative PCR (qPCR) of soil samples. It was hypothesized that mature plants (40-years-old) have a greater soil microbiota associated at the rhizosphere, in comparison with young plants (10- and 3-years-old). This situation may reverberate on B. edulis mycelium that should be more abundant in 40-years-old orchards, also thanks to the higher number of beneficial interactions whit soil microbiota. It was found that host plant age significantly altered bacterial and fungal assemblages in both years. Bacterial fraction was dominated by the phylum Proteobacteria, Acidobacteria and Actinobacteria and showed a higher species richness and diversity in orchards of 10- and 3-years-old. Fungal phylum such as Basidiomycota was more abundant in 40- and 10-years-old orchards, whereas Ascomycota and Mortierellomycota were more abundant in the 10- and 3-years-old orchards. Mycelium frequency of B. edulis in soil samples was higher in 2020 (97 %) than in 2018 (19 %), although without differences between plant age and sampling month in each year. Boletus edulis mycelium concentration was higher in 2020 than in 2018, and in September 2020, whereas plant age did not have any effect. Of 173 bacterial taxa considered, the 12 %, 54 % and 82 % of the significant correlations with B. edulis mycelium concentration were found in 40-, 10- and 3-years-old orchards, respectively. On the other hand, of 180 fungal taxa, the 12 %, 24 % and 42 % of the significant correlations occurred in 40-, 10- and 3-years-old orchards, respectively. This investigation represents the first report about the role of soil microbiota on the ecology of B. edulis in Castanea agro-ecosystem. •Richness and diversity of soil bacterial and fungal species changed depending on plant age in chestnut orchards•Boletus edulis mycelium frequency significantly changed depending on the year, whereas mycelium concentration did change by the month•Younger orchards had a larger bacterial community and a higher richness of ascomycetes, which increased the correlatio