Phosphorus availability and microbial community in the rhizosphere of intercropped cereal and legume along a P-fertilizer gradient
Phosphorus availability and microbial community in the rhizosphere of intercropped cereal and legume along a P-fertilizer gradient
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DOI：
10.1007/s11104-016-2949-3
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发表时间：
2016-06
期刊：
影响因子：
4.9
通讯作者：
Xiaoyan Tang;S. Placella;F. Dayde;L. Bernard;A. Robin;E. Journet;E. Justes;P. Hinsinger
中科院分区：
文献类型：
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作者：
Xiaoyan Tang;S. Placella;F. Dayde;L. Bernard;A. Robin;E. Journet;E. Justes;P. Hinsinger
根据压力梯度假说，当资源限制作物生长时，地下的积极相互作用（促进作用）应该更加明显。我们的目的是测试这一假设间作硬粒小麦和蚕豆沿着P-fertilization.MethodsA田间试验进行了长期的P-肥料试验与三个速率的P-施肥（无，低，高P）。微生物生物量进行了评估，氯仿熏蒸提取。应用定量PCR方法对相关微生物类群的丰度进行了评价。结果根际土壤中磷的有效性和微生物生物量较非根际土壤显著增加。施磷导致目标细菌门，整个细菌和真菌群落的丰度更高，并抑制硬粒小麦的菌根定殖，但不是蚕豆。微生物量碳只有在施磷处理下才显著增加，说明微生物群落的磷限制作用。间作产生了显着的影响，只有在高P.微生物生物量P增加间作蚕豆根际只有在无P水平，因此是唯一的发现支持应力梯度hypothes. ConclusionsP施肥是主要的驱动程序在这个领域的试验中的微生物群落，磷肥的应用调制的物种特异性的影响在间作。植物的表现没有验证应力梯度假设，积极的植物-植物的相互作用发生，无论水平的P-施肥。
Background and aimsPositive below-ground interactions (facilitation) should be more pronounced when resources limit crop growth, according to the stress-gradient hypothesis. Our aim was to test this hypothesis for intercropped durum wheat and faba bean along a P-fertilizer gradient.MethodsA field experiment was conducted in a long-term P-fertilizer trial with three rates of P-fertilization (No, Low and High P). Microbial biomass was assessed by chloroform fumigation-extraction. Quantitative PCR was applied to evaluate the abundance of relevant microbial groups.ResultsPhosphorus availability and microbial biomass systematically increased in the rhizosphere compared to bulk soil. P-fertilization resulted in higher abundance of targeted bacterial phyla, whole bacterial and fungal communities, and depressed mycorrhizal colonization of durum wheat, but not faba bean. Microbial biomass carbon significantly increased in the rhizosphere only in P-fertilized treatments,pointing to P limitation of microbial communities. Intercropping yielded a significant effect on rhizosphere microbial properties only at High P. Microbial biomass P increased in the rhizosphere of intercropped faba bean only at No P level, and was thus the sole finding supporting the stress-gradient hypothesis.ConclusionsP-fertilization was the main driver of microbial communities in this field trial, and P-fertilizer application modulated the species-specific effect in the intercrop. Plant performance did not validate the stress-gradient hypothesis as positive plant-plant interactions occurred regardless of the level of P-fertilization.