Studies on fungal communities and functional guilds shift in tea continuous cropping soils by high-throughput sequencing

Abstract

Purpose: Although soil fungal communities are considered important in tea orchard ecosystems, experimental research on their responses to the long-term continuous ratooning cultivation of tea plants are limited. Methods: In this study, Illumina high-throughput sequencing technology was employed to investigate soil fungal communities in tea orchards with continuous cropping histories of 0, 1, 10, and 20 years. Results: Results indicated that the predominant phyla were Ascomycota and Basidiomycota in all tea soil samples. Plant pathogen fungi Alternaria was the most predominant genus in the 10- and 20-year soils and significantly higher than that in the 0- and 1-year soils. FUNGuild revealed that the symbiotrophs in the 1-year soil (8.00%) was markedly higher than those in the 0-, 10-, and 20-year soils (1.43%~2.47%). The saprotrophs in the 20-year soils was approximately two-fold higher than those identified in the 0-, 1-, and 10-year soils. The pathotroph-saprotroph-symbiotroph fungi were higher in the 10- and 20-year soils in comparison to the 0- and 1-year soils as expected. Diversity analysis showed that the indices of Shannon and Simpson in the 1-year soils were higher than those in other treatments. Redundancy analysis suggested that fungal community structure and function were evidently interrelated to pH and exchangeable aluminum in the soils, respectively. Conclusion: In summary, the long-term continuous ratooning cultivation of tea plants changed the fungal communities in the rhizosphere, enriched saprotrophs and plant pathogens (Alternaria spp.), and reduced beneficial fungi (symbiotrophs). Results of this work can be used to explore reasonable management measures, such as microbial fertilizer application, and eventually relieve the long-term monoculture problems of tea plants.