Effect of Simultaneously Intercropping with Host and Non-host Plants by Arbuscular Mycorrhizal Fungi on Root Colonization and Growth of Root-split Trifoliate Orange Seedlings
A greenhouse experiment was conducted to examine the combined effect of intercropping bahiagrass (Paspalum notatum Fltigge.)and radish (Raphanus sativus L.)on root colonization by arbuscular mycorrhizal fungi (AMF) and growth of trifoliate orange (Poncirus trifoliata Raf. ). The roots of 3-month-old trifoliate orange seedlings were split into two parts and planted in the two central compartments separated by an acrylic board. Bahiagrass and radish were or were not planted into the compartments immediately lateral to the two split-root compartments. Gigaspora margarita was inoculated into the two outermost compartments. Each compartment was separated by a nylon mesh sheet, which allowed the passage of fungal hyphae but not plant roots. Hoaglands liquid fertilizer with low phosphorus (N: 16.8, P:1.24, K: 18. 72mg/box) was applied to plants. When trifoliate orange seedlings were intercropped with bahiagrass, the AMF root colonization rate, hyphal density and spore number in the soil were higher than in those intercropped with radish or without plants. P and K in trifoliate orange shoots were significantly increased by intercropping with bahiagrass. Total N content in the seedlings was decreased by intercropping with either sod plant. Interestingly, in boxes in which both sides were intercropped with bahiagrass, the root colonization rate on one side of the trifoliate orange was about 80％ , but the rate on the other side was 1.9％. Thus, high root colonization rate on one side resulted in strong suppression of the colonization on the other side. Root P content of trifoliate orange with low root colonization, however, was higher than that with high colonization. High root P content has been well known to inhibit infection of roots by AMF. Our results show that this AMF symbiotic effect of root-split trifoliate orange is mediated by the P status of roots. Thus, we hypothesize that trifoliate orange has an autoregulation system in relation to AMF infection to construct good symbiotic associations.
Arbuscular mycorrhizal symbiosis Autoregulation Bahiagrass Hyphal network Radish Sod culture
D. Yu A. F. Cruz S. Horii S. Ochiai A. Matsumura T. Ishii
Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Ja Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, ap
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
768-773
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）