Responses of root nodule formation and nitrogen fixation activity to nitrate in a split-root system in peanut (Arachis hypogaea L.)
Responses of root nodule formation and nitrogen fixation activity to nitrate in a split-root system in peanut (Arachis hypogaea L.)
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DOI：
10.1046/j.1439-037x.2001.00505.x
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发表时间：
2001-09-01
影响因子：
3.5
通讯作者：
Yoshioka, M
中科院分区：
文献类型：
--
作者：
Daimon, H;Yoshioka, M
花生是蔬菜轮作体系的重要组成部分，需要大量的无机氮。硝酸盐抑制这些种植系统中花生植株的根瘤形成和固氮。为了阐明这种硝酸盐诱导的抑制作用，设计了一种使用分根系统的实验方法，并在盆栽实验中将抑制水平的硝酸盐（14 mm）施加到一半的根上，持续5或30天。在施硝5天后，每半根的干重、含氮量、根瘤数和根瘤鲜重均不受另一半根施硝的影响。然而，硝酸盐诱导显着降低固氮酶活性的一半。在30 d的施用期内，硝酸盐显著提高了施氮一侧根系的含氮量，并抑制了施氮一侧和另一侧根系的结瘤和根瘤发育。因此，长期施用硝态氮对花生固氮和固氮酶活性的抑制作用可能是系统性的，而短期施用硝态氮对花生固氮的抑制作用可能不是系统性的。
Peanut is an important constituent of crop rotation systems with various vegetable crops, which need large amounts of inorganic nitrogen. Nitrate inhibits nodule formation and nitrogen fixation of the peanut plants in these cropping systems. To elucidate this nitrate-induced inhibition, an experimental method using a split-root system was designed and the inhibitory level of nitrate (14 mm) was applied to half of the roots for 5 or 30 days in pot experiments. In the application of nitrate for 5 days, the dry weight, the nitrogen content, and both the number and the fresh weight of nodules for each half of the roots were unaffected by the nitrate applied to the other half. However, the nitrate induced significantly lower nitrogenase activity in the applied half. In the application for 30 days, nitrate induced a significantly higher nitrogen content in the applied half of the roots, and the inhibitory effect on nodulation and nodule development was observed not only in the applied half but also in the other half. Thus, the inhibitory effect of long-term nitrate application on the nodulation and nitrogenase activity of peanut may be systemic, but that of short-term nitrate application, in which external nitrate may regulate nitrogen fixation, may not be systemic.