Soil Eukaryotic Microorganism Succession as Affected by Continuous Cropping of Peanut - Pathogenic and Beneficial Fungi were Selected

Abstract

Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales , Glomerales , Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales , Cantharellales , Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping.

Application of Serratia marcescensRZ‐21 significantly enhances peanut yield and remediates continuously cropped peanut soil

“…It has also been reported that plant pathogens show complex genetic diversities for their different host ranges, pathogenicity and physiological characters, and S. marcescens has the ability to overcome these diversities, which implies that S. marcescens is an ideal bacterium for ecological remediation. Other studies have shown that the soil microbial community is seriously affected by continuous cropping, and the trend toward an increase in pathogens and simplification of the beneficial microorganism community could be an important factor contributing to the decline in peanut growth and yield . Our results of pathogen quantification were in agreement with this.…”

Dynamic Succession of Soil Bacterial Community during Continuous Cropping of Peanut (Arachis hypogaea L.)

“…It was reported that the rhizobacterial communities were minor affected by plant development [12], [47]. Interestingly, the eukaryotic microorganisms did not show any obvious correlation with peanut development in the earlier study [23]. There needs to be further study into the interaction mechanisms between microbial communities and the growth or development of peanut.…”

“…It was reported that Fusarium genus was major pathogens of plant root rot, and Pseudomonas was major antagonists [40], [41], [42]. Interestingly, contrary to the decrease tendency of Pseudomonales, sequences affiliated with Fusarium showed increasing tendency with continuous cropping of peanut [23], [43]. The succession analyses of soil eukaryotic microorganisms in the earlier study demonstrated that the pathogenic and beneficial fungi were positively selected over time and showed, respectively, increased and simplified tendencies with continuous cropping [23].…”

High-throughput sequencing technology reveals that continuous cropping of American ginseng results in changes in the microbial community in arable soil

“…As mentioned above, phylotype diversity of fungi also increased during continuous cropping of peanut [5]. Benizri et al [27] reported that the bacterial diversity changed in the continuous cropping soil of peaches.…”