Arbuscular mycorrhizas and their role in plant growth, nitrogen interception and soil gas efflux in an organic production system
Arbuscular mycorrhizas and their role in plant growth, nitrogen interception and soil gas efflux in an organic production system
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DOI：
10.1007/s11104-011-1021-6
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发表时间：
2012-04-01
期刊：
影响因子：
4.9
通讯作者：
Jackson, L. E.
中科院分区：
文献类型：
--
作者：
Cavagnaro, T. R.;Barrios-Masias, F. H.;Jackson, L. E.
背景与目的根和菌根不仅在植物养分获取中起重要作用，而且在生态系统养分循环中起重要作用。方法采用田间试验方法，研究丛枝菌根（AM）在番茄植株生长和养分获取中的作用。番茄菌根缺陷突变体的研究以rmc及其菌根野生型祖菌76R作为AM形成的对照。通过在离76R和rmc基因型番茄不同距离的土壤表层或游离土壤中注入N-15标记的硝态氮溶液，研究了根系和AM在土壤氮循环中的作用。研究了菌根和非菌根根系相对于无根土壤对土壤温室气体（CO2、14+15N2O和(N2O)-N-15）排放的影响。结果AM的形成显著促进了植物的生长和养分获取，包括截留新施用的NO3-。与无根处理相比，根处理在标记后23 h引起土壤(N2O)-N-15排放量的小幅但显著减少，而丛枝菌根真菌（AMF）对N2O排放的影响很小。相比之下，含有菌根根系的地块土壤二氧化碳排放量更高，根系生物量也更大。综上所述，根系和AMF在植物养分获取和生态系统氮循环中发挥着重要作用。
Background and aims Roots and mycorrhizas play an important role in not only plant nutrient acquisition, but also ecosystem nutrient cycling.Methods A field experiment was undertaken in which the role of arbuscular mycorrhizas (AM) in the growth and nutrient acquisition of tomato plants was investigated. A mycorrhiza defective mutant of tomato (Solanum lycopersicum L.) (named rmc) and its mycorrhizal wild type progenitor (named 76R) were used to control for the formation of AM. The role of roots and AM in soil N cycling was studied by injecting a N-15-labelled nitrate solution into surface soil at different distances from the 76R and rmc genotypes of tomato, or in plant free soil. The impacts of mycorrhizal and non-mycorrhizal root systems on soil greenhouse gas (CO2 and 14+15N2O and (N2O)-N-15) emissions, relative to root free soils, were also studied.Results The formation of AM significantly enhanced plant growth and nutrient acquisition, including interception of recently applied NO3-. Whereas roots caused a small but significant decrease in (N2O)-N-15 emissions from soils at 23 h after labeling, compared to the root-free treatment, arbuscular mycorrhizal fungi (AMF) had little effect on N2O emissions. In contrast soil CO2 emissions were higher in plots containing mycorrhizal root systems, where root biomass was also greater.Conclusions Taken together, these data indicate that roots and AMF have an important role to play in plant nutrient acquisition and ecosystem N cycling.