Changes in Bacterial Community Structure and Enriched Functional Bacteria Associated With Turfgrass Monoculture

Area of Science:

• Microbial ecology
• Plant pathology
• Agricultural science

Background:

• Microbial communities can enhance plant health and reduce agricultural inputs.
• Large patch disease, caused by Rhizoctonia solani AG2-2, significantly impacts turfgrass cultivation.
• Understanding rhizosphere bacterial community shifts in long-term monocultures is crucial for developing sustainable turfgrass management.

Purpose of the Study:

• To investigate changes in rhizosphere bacterial community structure in Zoysia japonica monocultures of varying ages (2, 13, and 25 years).
• To identify and evaluate functional bacteria with biocontrol potential against Rhizoctonia solani AG2-2.
• To assess the efficacy of selected bacteria in enhancing turfgrass tolerance to abiotic stresses like drought and temperature.

Main Methods:

• Rhizosphere soil samples were collected from turfgrass monocultures aged 2, 13, and 25 years.
• Bacterial community structure was analyzed.
• Culturable bacteria with biocontrol potential were isolated and identified.
• In vitro and in vivo experiments were conducted to assess disease inhibition and stress tolerance.

Main Results:

• Rhizosphere bacterial communities differed significantly with monoculture duration, with Streptomyces dominant in 2-year fields and Burkholderia enriched in 25-year fields.
• The 13-year monoculture field exhibited higher Rhizoctonia solani AG2-2 population density.
• Streptomyces neyagawaensis J6 and Burkholderia vietnamiensis J10 demonstrated excellent inhibition of large patch disease.
• These bacterial strains also enhanced turfgrass tolerance to drought and temperature stresses.

Conclusions:

• Long-term turfgrass monoculture induces significant shifts in rhizosphere bacterial communities.
• Specific bacterial strains, S. neyagawaensis J6 and B. vietnamiensis J10, show promise as effective biocontrol agents against large patch disease.
• These beneficial bacteria can also improve turfgrass resilience to abiotic stresses, offering a sustainable approach to turfgrass management.