Miller R M, Miller S P, Jastrow J D, Rivetta C B
Environmental Research Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
Department of Agronomy, University of Kentucky, N-122 Agricultural Sciences North, Lexington, KY 40506-0091, USA.
New Phytol. 2002 Jul;155(1):149-162. doi: 10.1046/j.1469-8137.2002.00429.x.
• The carbon sink strength of arbuscular mycorrhizal fungi (AMF) was investigated by comparing the growth dynamics of mycorrhizal and nonmycorrhizal Andropogon gerardii plants over a wide range of equivalent tissue phosphorus : nitrogen (P : N) ratios. • Host growth, apparent photosynthesis (A ), net C gain (C ) and P and N uptake were evaluated in sequential harvests of mycorrhizal and nonmycorrhizal A. gerardii plants. Response curves were used to assess the effect of assimilate supply on the mycorrhizal symbiosis in relation to the association of C with N and P. • Mycorrhizal plants had higher C than nonmycorrhizal plants at equivalent shoot P : N ratios even though colonization did not affect plant dry mass. The higher C in mycorrhizal plants was related to both an increase in specific leaf area and enhanced photosynthesis. The additional carbon gain associated with the mycorrhizal condition was not allocated to root biomass. The C in the mycorrhizal plants was positively related to the proportion of active colonization in the roots. • The calculated difference between C values in mycorrhizal and nonmycorrhizal plants, C , appeared to correspond to the sink strength of the AMF and was not an indirect result of enhanced nutrition in mycorrhizal plants.
• 通过比较菌根和非菌根的糙毛须芒草植物在广泛的等效组织磷：氮（P：N）比范围内的生长动态，研究了丛枝菌根真菌（AMF）的碳汇强度。• 在对菌根和非菌根的糙毛须芒草植物进行连续收获时，评估了宿主生长、表观光合作用（A）、净碳增益（C）以及磷和氮的吸收情况。使用响应曲线来评估同化物供应对菌根共生关系的影响，该关系涉及碳与氮和磷的关联。• 在等效的地上部P：N比条件下，菌根植物的碳含量高于非菌根植物，尽管定殖并未影响植物干质量。菌根植物中较高的碳含量与比叶面积的增加和光合作用的增强均有关。与菌根状态相关的额外碳增益并未分配到根生物量中。菌根植物中的碳与根中活跃定殖的比例呈正相关。• 计算得出的菌根植物和非菌根植物碳值之间的差异C，似乎对应于AMF的碳汇强度，而不是菌根植物营养增强的间接结果。
