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【目的】研究盆栽条件下不同形态氮对苹果砧木—平邑甜茶幼苗生长以及对连作土壤微生物的影响,为连作建园时科学施肥、减轻苹果连作障碍提供依据。【方法】试验于2015年露地进行,以平邑甜茶幼苗为试材,以连作土为对照1(CK1)和溴甲烷熏蒸为对照2(CK2),设置施入铵态氮(T1)、硝态氮(T2)和酰胺态氮(T3)3个不同形态氮处理(N 180 mg/L),于2015年8月测定平邑甜茶生物量、光合参数和土壤微生物等相关指标。【结果】铵态氮(T1)和酰胺态氮(T3)处理均能明显提高连作条件下‘平邑甜茶’苹果幼苗的生物量,其中T1处理的株高、地径、鲜重、干重与CK1相比分别提高了35.3%、24.4%、42.0%、57.7%。添加3种形态氮素均可不同程度地提高平邑甜茶幼苗叶片的净光合速率(Pn)、气孔导度(Gs)和根系呼吸速率,其中T1处理的Pn、Gs和根系呼吸速率分别比CK1提高了27.6%、35.6%、43.3%,却并未达到CK2的效果。实时荧光定量PCR结果表明,CK2尖孢镰孢菌的基因拷贝数降低最为明显,比CK1降低了52.6%,T1也有效地降低了尖孢镰孢菌的基因拷贝数,而T2和T3处理尖孢镰孢菌的基因拷贝数与CK1没有显著性差异。T-RFLP结果表明,T1和T3处理的真菌群落结构与CK1有明显差异,T1处理与CK2的真菌群落结构较为相似,T2处理的真菌群落结构与CK1较为相似。【结论】铵态氮处理可更好地提高连作平邑甜茶幼苗的生物量、净光合速率以及根系呼吸速率,降低土壤尖孢镰孢菌的基因拷贝数,明显改变连作土壤的真菌群落结构,可作为减轻苹果连作障碍的措施。
【Objective】 The objective of this study was to investigate the effects of different forms of nitrogen on the growth of apple rootstocks, Malus hupehensis Rehd. Et Wils. And its effect on soil microbes in continuous cropping. 【Method】 The experiment was carried out in the open field in 2015. The experiment was conducted with CK (CK1) and CK2 (CK2) Nitrogen (T2) and amido nitrogen (T3) were applied to nitrogen (N 180 mg / L) treatment. The biomass, photosynthetic parameters and soil microorganisms of P. euphratica were determined in August 2015. 【Result】 The results showed that both ammonium nitrogen (T1) and amide nitrogen (T3) significantly increased the biomass of ’Pingyi Sweet Tea’ apple seedlings under continuous cropping conditions. The plant height, diameter, fresh weight and dry weight Compared with CK1 increased by 35.3%, 24.4%, 42.0%, 57.7%. Adding three kinds of nitrogen could improve the net photosynthetic rate (Pn), stomatal conductance (Gs) and root respiration rate of P. euphratica seedling leaves to varying degrees, in which the Pn, Gs and root respiration rate of T1 were higher than that of CK1 Increased 27.6%, 35.6%, 43.3%, but did not reach CK2 effect. The real-time PCR results showed that the gene copy number of Fusarium oxysporum CK2 decreased most significantly, which was 52.6% lower than that of CK1. T1 also effectively reduced the gene copy number of Fusarium oxysporum, while T2 and T3 The gene copy number of Fusarium was not significantly different from that of CK1. The results of T-RFLP indicated that the fungal community structures of T1 and T3 treatments were significantly different from that of CK1. The fungal community structures of T1 and T3 were similar to those of CK2. The fungal community structure of T2 was similar to that of CK1. 【Conclusion】 The results showed that ammonium nitrogen treatment could improve the biomass, net photosynthetic rate and root respiration rate, lower the gene copy number of Fusarium oxysporum f. Sp., And significantly change the fungal community structure of continuous cropping. Can be used as a measure to alleviate obstacles to continuous cropping of apples.