scholarly journals Dynamics of Bacterial and Viral Communities in Paddy Soil with Irrigation and Urea Application

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 347 ◽  
Author(s):  
Yuting Li ◽  
Hao Sun ◽  
Weichao Yang ◽  
Guanxiong Chen ◽  
Hui Xu
Keyword(s):  
Bacterial Abundance ◽  
Nitrogen Addition ◽  
Nitrogen Fixing ◽  
Short Term ◽  
Nitrogen Fixing Bacteria ◽  
Ecological Processes ◽  
N Accumulation ◽  
Natural Systems ◽  
Viral Communities ◽  
Abundance And Diversity

Viruses are ubiquitous in natural systems. By influencing bacterial abundance (BA) and community structure through lysis-lysogenic conversion, viruses are involved in various ecological processes. In agricultural management, nitrogen addition and irrigation should be considered as important factors that can modify soil viral dynamics but have been ignored. In our study, short-term dynamics of autochthonous soil viral and bacterial abundance and diversity after irrigation and urea application were examined in a long-term experimental paddy field. Urea addition delayed the emergence of peak viral abundance for three days, suggesting that viruses are sensitive to N addition. Under short-term eutrophic conditions through urea application, viruses undertake a lysogenic-biased strategy. Moreover, nitrogen-fixing bacteria were most likely specifically lysed in urea-treated soil, which suggests that soil viruses block N accumulation by killing nitrogen-fixing bacteria. To the best of our knowledge, this study is the first to investigate dynamic changes in autochthonous viruses in paddy fields.

scholarly journals Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1291 ◽  
Author(s):  
Anna K. Simonsen ◽  
Shery Han ◽  
Phil Rekret ◽  
Christine S. Rentschler ◽  
Katy D. Heath ◽  
...  
Keyword(s):  
Fertilizer Application ◽  
Phenotypic Traits ◽  
Field Soil ◽  
Nitrogen Fixing ◽  
Growth Responses ◽  
Short Term ◽  
Soil Microbial Diversity ◽  
Nitrogen Fixing Bacteria ◽  
Free Living ◽  
Evolutionary Trajectory

Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia), a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community, either directly though changes in the soil chemistry or indirectly through altered host legume feedbacks, and is potentially a strong selective agent acting on natural rhizobia populations.

Towards evolutionary agroecology

2018 ◽  
Vol 6 (14) ◽  
pp. 51 ◽  
Author(s):  
Kristin L. Mercer
Keyword(s):  
Social Dynamics ◽  
Agricultural Systems ◽  
Short Term ◽  
Ecological Processes ◽  
Genetic Analyses ◽  
Holistic Perspective ◽  
Evolutionary Study ◽  
Quantitative Genetic ◽  
Field Evolution

Agroecology derives much of its strength from interactions between disciplines that produce a holistic perspective on agricultural systems and issues.  Although ongoing integration of social dynamics into agroecology has strengthened the field, evolution and genetics have not been embraced to the same degree, despite the fact that they have been are discussed in some common agroecology texts.  I argue that the field of agroecology could extend its reach and depth by embracing the evolutionary study of agroecosystems.  Areas of evolutionary inquiry with relevance to agriculture focus on long or short term processes, encompass a range of scales, incorporate molecular or quantitative genetic analyses, and explore ecological processes to differing degrees.

scholarly journals Cowpea symbiotic efficiency, pH and aluminum tolerance in nitrogen-fixing bacteria

2014 ◽  
Vol 71 (3) ◽  
pp. 171-180 ◽  
Author(s):  
Bruno Lima Soares ◽  
Paulo Avelar Ademar Ferreira ◽  
Silvia Maria de Oliveira-Longatti ◽  
Leandro Marciano Marra ◽  
Marcia Rufini ◽  
...  
Keyword(s):  
Aluminum Tolerance ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Symbiotic Efficiency
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