| 摘要: |
| 为探究制种玉米连作根内微生物、土壤氮素与根腐病发病率间的相关关系，采用大田试验及高通量测序技术，以不同连作年限（5、10、15、20、25年）制种玉米田为研究对象，未种植玉米的地块为对照（CK），调查玉米根腐病发病率，测定玉米根部内生菌与土壤不同形态氮素含量。结果表明，与对照（CK）比较，连作25 年的地块土壤全氮含量显著降低，至0.72 g/kg；铵态氮含量显著升高，至72.97 mg/kg；而硝态氮与水解氮含量呈现先增加后下降趋势。5个连作地块的酸解氮、水解氮和铵态氮含量均显著增加，氨态氮含量显著下降；除连作5年外，其余4个连作地块的氨基酸态氮含量显著增加，全氮、非酸解氮和氨基糖态氮含量显著下降（P＜0.05）。连作显著降低根内微生物多样性与丰富度（P＜0.05）。在属水平，制种玉米根内优势细菌13个属，其中假单胞菌属（Pseudomonas）、根瘤菌属（Rhizobium）、鞘氨醇单胞菌属（Sphingomonas）、地杆菌属（Pedobacter）与泛菌属（Pantoea）丰度最高；优势真菌10个属，其中隔孢伏革属（Peniophora）、曲霉属（Aspergillus）、裂褶菌属（Schizophyllum）与单孢平霉属（Phialemoniopsis）丰度最高。连作对制种玉米根内细菌与真菌属的类型变化无显著影响，但连作改变了根内细菌与真菌属的相对丰度。此外，制种玉米根腐病发病率均显著上升，根腐病发病率与土壤酸解氮、氨基酸态氮、水解氮、铵态氮及硝态氮含量均呈极显著正相关（P＜0.01），与土壤全氮、非酸解氮含量却呈极显著负相关（P＜0.01）；根腐病发病率与镰刀菌属、曲霉属的相对丰度均呈显著正相关（P＜0.05）。综上，制种玉米连作生产中土壤有效态氮，特别是酸解氮和非酸解氮的含量与优势病原菌的相对丰度、根腐病发病率均呈显著正相关（P＜0.05），可用来准确地预测玉米根腐病的发生。 |
| 关键词: 制种玉米 连作 土壤氮 根腐病 酸解氮 |
| DOI：10.11841/j.issn.1007-4333.2024.02.03 |
| 投稿时间：2023-08-22 |
| 基金项目:甘肃省重点研发项目（22YF7NG128）；国家自然科学基金（41867010）；甘肃省玉米种业全产业链关键技术联合攻关与示范项目（21ZD10NF003） |
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| Effects of continuous corn seed production on the soil nitrogen distribution and incidence of root rot |
|
FU Wenjiang1,2, ZHAO Yunchen1*, WANG Wenli1, YAN Zhibin3, WANG Zhijiang1, CHEN Ye1, CHEN Guangquan1
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| (1.College of Agricultural and Ecological Engineering, Hexi University, Zhangye 734000, China;2.College of Resources and Environment, Northwest Agriculture & Forestry University, Yangling 712100, China;3.Gansu Dunhuang Seed Industry Research Institute, Jiuquan 735000, China) |
| Abstract: |
| To explore the relationship between endophyte， soil nitrogen and the incidence of root rot， field experiment was conducted and high-throughout sequencing technology were adopted to investigate five different continuous cropping years fields （5， 10， 15， 20， 25 years）. The plots that seed corn were never been planted was taken as control （CK）. The endophytic bacteria and the content of different form of nitrogen in soil was also determined. Compared with CK， the content of soil total nitrogen decreased significantly to 0.72 g/kg and the contend of ammonium nitrogen increased to 72.97 mg/kg in 25 years continuous cropping plots. The content of nitrate nitrogen and hydrolyzed nitrogen increased first and then decreased. The content of acidolytic nitrogen， hydrolyzed nitrogen and ammonium nitrogen increased significantly， while ammonia nitrogen decreased significantly in the five different continuous cropping plots. With exception of continuous cropping of five years， the content of amino acid nitrogen increased significantly， while the content of total nitrogen， non-acidolytic nitrogen and amino sugar nitrogen decreased significantly （P＜0.05）. At the genus level， there were 13 dominant bacteria genera in the root of maize， among which Pseudomonas， Rhizobium， Sphingomonas， Pedobacter and Pantoea had the highest abundance. There were ten dominant fungi genera， among which Peniophora， Aspergillus， Schizophyllum and Phialemoniopsis had the highest abundance. The continuous cropping had no significant effect on the types of bacteria and fungi rhizobacteria， but the relative abundance was changed in different continuous cropping years. The incidence of root rot of seed corn increased significantly. The incidence of root rot was positively correlated with the contents of soil acidolytic nitrogen， amino acid nitrogen， hydrolyzed nitrogen， ammonium nitrogen and nitrate nitrogen （P＜0.01）， but negatively correlated with content of soil total nitrogen and non-acidolytic nitrogen （P＜0.01）. The incidence of root rot was positively correlated with the relative abundance of Fusarium and Aspergillus （P＜0.05）. In conclusion， the contents of soil available nitrogen， especially acidolytic nitrogen and non-acidolytic nitrogen were significantly correlated with the relative abundance of dominant pathogens and the incidence of root rot in corn seed production （P＜0.05）， which could be used to accurately predict the occurrence of root rot in maize production. |
| Key words: corn seed production continuous cropping soil nitrogen root rot acidolytic nitrogen |
