Johansen A, Jakobsen I, Jensen E S
Plant Biology Section, Environmental Science and Technology Department, Rise National Laboratory, DK-4000 Roskilde, Denmark.
New Phytol. 1992 Oct;122(2):281-288. doi: 10.1111/j.1469-8137.1992.tb04232.x.
Hyphal transport of nitrogen from a N-labelled ammonium source by a VA-mycorrhizal fungus was studied under controlled experimental conditions. Cucumis sativus L. cv. Aminex (F1 hybrid) was grown alone or together with Glomus intraradices Schenck and Smith in containers with a hyphal compartment separated from the rooting medium by a fine nylon mesh. Lateral movement of the applied N towards the roots was minimized by using a nitrification inhibitor (N-serve) and a hyphal buffer compartment. Recovery of N by mycorrhizal and non-mycorrhizal plants was 6 and 0%, respectively, after a labelling period of 23 days. The corresponding figures, without N-serve added, were 4 and 7%. A prolongation of the labelling period by 8 days (N-serve applied) resulted in an increase in the N recovery by mycorrhizal plants to 30% of the applied N. Non-mycorrhizal plants contained only traces of N. The external hyphae depleted the soil in the hyphal compartment efficiently for inorganic N. In contrast, hyphal compartments of control containers still contained considerable amounts of inorganic N. The N assimilated by the external hyphae in one hyphal compartment was not translocated in significant amounts to the external hyphae in another hyphal compartment. The possible implication of this for inter-plant N transfer by VA hyphal connections is discussed.
在可控实验条件下，研究了VA菌根真菌从氮标记铵源中进行菌丝体氮转运的情况。黄瓜品种Aminex（F1杂交种）单独种植或与根内球囊霉（Glomus intraradices Schenck and Smith）一起种植在容器中，容器中有一个菌丝体隔室，通过细尼龙网与生根培养基隔开。通过使用硝化抑制剂（N-serve）和菌丝体缓冲隔室，使施用的氮向根部的横向移动最小化。标记23天后，菌根植物和非菌根植物对氮的回收率分别为6%和0%。不添加N-serve时，相应的数字分别为4%和7%。将标记期延长8天（施用N-serve），使菌根植物的氮回收率提高到施用氮的30%。非菌根植物仅含有微量的氮。外部菌丝体有效地耗尽了菌丝体隔室土壤中的无机氮。相比之下，对照容器的菌丝体隔室仍含有大量无机氮。一个菌丝体隔室中被外部菌丝体吸收的氮没有大量转移到另一个菌丝体隔室中的外部菌丝体。讨论了这对VA菌丝体连接进行植物间氮转移的可能影响。
