Fungal pathogen accumulation at the expense of plant-beneficial fungi as a consequence of consecutive peanut monoculturing

• Published in: Soil biology & biochemistry Vol. 72; pp. 11 - 18
• Main Authors: Li, Xiao-gang, Ding, Chang-feng, Zhang, Tao-lin, Wang, Xing-xiang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.05.2014; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Arachis hypogaea; Ascomycota; Beneficial soil fungi; Biochemistry and biology; Biological and medical sciences; Bionectria ochroleuca; Chemical, physicochemical, biochemical and biological properties; China; Clonostachys rosea; community structure; crop yield; Cropping systems; ecological function; Fundamental and applied biological sciences. Psychology; Fusarium oxysporum; internal transcribed spacers; Leptosphaerulina; Mortierella; Next generation deep sequencing; pathogens; peanuts; Phoma; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant health; Plant pathogens; sequence analysis; soil; Soil fungal communities; soil fungi; soil sampling; Soil science; Trichoderma; Yield decline; China, People's Rep; China; Cropping systems; Yield decline; Plant pathogens; Beneficial soil fungi; Soil fungal communities; Next generation deep sequencing; Mycosis; Plant pathogen; Mycoflora; Cropping system; Soil fungi; Arachis hypogaea; Infection; Fungi; Soils; Leguminosae; Dicotyledones; Angiospermae; Spermatophyta; Yield; Soil science; Sequencing; Oil plant (vegetal); Groundnut
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2014.01.019

Peanut yield and quality are seriously compromised by consecutive monoculturing in the red soil region of southern China. Soil fungi are, however, also critical to the ecological functioning of soils and plant health and were thus the study subject here. Using 454 pyrosequencing, the entire soil fungal communities of a field where peanut had been consecutively cultured for five years and another field, where peanut had been consecutively cultured for at least 20 years, and a control field with only a single peanut crop after a lay period were compared. Fungal richness, community composition, and relative taxon abundances in soil were compared among the fields and sampling times, the latter corresponding to the pod-bearing and the pod-maturing stages. Eight hundred fungal operational taxonomic units at 97% ITS sequence identity were found among 194,783 sequence reads derived from 18 separate soil samples. Members of the phylum Ascomycota strongly dominated the soil fungal communities and putative pathogens, such as Fusarium oxysporum, Leptosphaerulina australis, Phoma sp., and Bionectria ochroleuca showed higher relative abundances in the fields where peanut was consecutively monocultured, compared to the control field, at the expense of putatively plant-beneficial fungal groups, such as Trichoderma sp., a glomeromycotan fungus, and Mortierella elongata. The results suggest that the accumulations of fungal pathogen loads at the expense of plant-beneficial fungi in the soil appear likely explanations for yield declines as a consequence of consecutive peanut cultivation. •Shifts in soil fungal community composition and structure were assessed by 454 pyrosequencing.•Consecutive peanut monoculturing increased putative fungal pathogens.•Consecutive peanut monoculturing decreased putative beneficial soil fungi.•An ecological imbalance of soil fungi appears to explain yield declines over continuous cropping.