کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4382233 1617804 2014 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Analysis of the occurrence and activity of diazotrophic communities in organic and conventional horticultural soils
ترجمه فارسی عنوان
تجزیه و تحلیل وقوع و فعالیت جوامع دیازوتروپیک در خاک های آلی و معادن متعارف
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
چکیده انگلیسی


• Organic management and season affect diazotrophs structure, abundance and activity.
• Cultivation method controls the effects of management and season on diazotrophs.
• Organic management increases diazotroph abundance and activity, and likely N fixation.
• Greenhouse cultivation can boost the effect of organic management on soil diazotrophs.
• In tandem, DNA and RNA analyses provide a comprehensive analysis of diazotrophs.

Nitrogen (N)-fixing microorganisms are an important soil component as they help replenish the pool of available N. Organic management can influence the N-fixing community; however, diazotroph community structure and activity in horticultural systems and the impacts of specific cultivation methods (i.e., greenhouse and open field) are unclear. Using the nifH gene, a marker gene for the microbial community involved in N fixation, we investigated the occurrence (DNA) and activity (RNA) of the diazotrophic community in organically and conventionally managed soils in a horticultural system over the course of 1 year. Ordination analysis of DGGE profiles revealed organic management affected the community structure in the greenhouse but not the open field; fertilization intensity may explain this divergent response, as indicated by the relevance of total C content to community structure. Quantitative PCR revealed that organic management increased the abundance and activity of diazotrophs. The soluble organic N concentration was higher in organically managed soils and during warmer months, and correlated with diazotroph abundance. Most identified sequences were from known diazotrophs, predominantly β-, γ- and α-proteobacteria. Twenty-four bands resembled Pseudomonas stutzeri and eight resembled Azoarcus sp. Our results show that the cultivation method controls the extent of the effects of season and organic management on diazotrophs, and that greenhouse cultivation can boost the effects of organic management on this community. Organic management intensified the positive effect of seasonal temperature on diazotroph abundance and activity, which may increase biological nitrogen fixation rates. In tandem, soil DNA and RNA analyses provide a comprehensive picture of the community.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Soil Ecology - Volume 79, July 2014, Pages 37–48
نویسندگان
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