华北平原春玉米多熟种植模式对土壤真菌群落的影响

Effects of multiple cropping systems based on spring maize on soil fungal communities in the North China Plain

  • 摘要: 为探究华北平原春玉米多熟种植模式对土壤质量的影响, 基于田间定位试验, 利用DNA Illumina高通量测序方法从土壤微生物的角度对6种种植模式0~20 cm耕层土壤真菌群落多样性进行了研究。结果表明: 1)与春玉米单作(MM, 对照)相比, 5种多熟种植模式黑麦-春玉米(MR)、冬小麦-夏玉米(MW)、菠菜-春玉米(MSp)轮作模式及马铃薯/春玉米(MPo)、豌豆/春玉米(MP)套作模式均能够显著提高土壤真菌群落多样性(P<0.05), Shannon指数分别较MM提高12.18%、12.17%、10.37%、11.69%及8.44%, 各模式间土壤真菌丰富度无显著性差异。2)各种植模式中, 土壤子囊菌门(Ascomycota)、被孢霉门(Mortierellomycota)、担子菌门(Basidiomycota)、壶菌门(Chytridiomycota)、隐菌门(Rozellomycota)是优势种群, 其中子囊菌门相对丰度达80%以上。3)多熟种植模式有利于增加有益真菌, MR、MW及MSp中被孢霉属(Mortierella)及绿僵菌属(Metarhizium)等潜在有益菌相对富集, MSp中绿僵菌属尤为丰富; 而有作物致病风险的拟棘壳孢属(Pyrenochaetopsis)在各种植模式中相对丰度表现为: MM>MW>MP>MR>MSp>MPo。4) FUNGuild功能预测结果表明, 种植模式改变了土壤真菌营养型的占比: MM处理主要为腐生型(26.09%)、病理型(22.48%)及病理-腐生-共生过渡型(26.39%), MW处理主要为腐生型(29.99%), 其他多熟模式中腐生型(21.11%~27.88%)及病理型(23.74%~30.40%)均占较大比例。5)相关分析表明, 土壤田间持水量、有机质含量及容重是影响土壤真菌群落结构的主要环境因子。综上, 与春玉米单作相比, 春玉米轮、套作其他作物能够显著提高土壤真菌群落的多样性。其中黑麦-春玉米、菠菜-春玉米及冬小麦-夏玉米轮作模式在提高土壤真菌多样性, 富集有益微生物群落均有良好表现。此外, 春玉米-黑麦、菠菜-春玉米轮作模式在一定程度上能降低潜在致病菌丰度。因此, 从土壤微生物角度, 综合节水与保地的需求, 春玉米与黑麦或菠菜轮作的模式或是更合适的模式。

     

    Abstract: To explore the impact of multiple spring maize cropping systems on soil quality in the North China Plain, we used DNA Illumina high-throughput sequencing to study fungal community diversity in the 0–20 cm topsoil layer of six cropping systems based on field experiments. The results showed that: 1) Compared with spring maize monocropping (MM, control), the multiple cropping systems double-cropping systems of winter wheat-summer maize (MW), spinach-spring maize (MSp), rye-spring maize (MR), and relay intercropping systems of pea/spring maize (MP), and potato/spring maize (MPo) increased the diversity of soil fungal communities (P<0.05), and the Shannon index by 12.18%, 12.17%, 10.37%, 11.69%, and 8.44%, respectively, compared with MM. However, there was no significant difference among all cropping systems for the soil fungal richness index. 2) The dominant phyla in these cropping systems were Ascomycota, Mortierellomycota, Basidiomycota, Chytridiomycota, and Rozellomycota; in particular, the relative abundance of Ascomycota was more than 80%. 3) Multiple cropping systems increased the number of beneficial fungi. The potentially beneficial communities at the genus level, such as Mortierella and Metarhizium, were relatively enriched in MR, MW, and MSp; and Metarhizium was particularly abundant in MSp. Pyrenochaetopsis was often considered to increase the disease risk in crops, and the order of relative abundance in the six cropping systems was as follows: MM>MW>MP>MR>MSp>MPo. 4) The FUNGuild function prediction results showed that the cropping systems changed the proportion of soil fungal nutrition types. The sprotroph (26.09%), pathotroph (22.48%), and pathotroph-sprotroph-symbiotroph (26.39%) were the main types in the MM; the sprotroph (29.99%) was the main type in the MW; and the sprotroph (21.11%−27.88%) and pathotrophs (23.74%−30.40%) accounted for a larger proportion in the remaining multiple cropping systems. 5) Correlation analysis showed that soil field water-holding capacity, soil organic matter, and bulk density were the main environmental factors affecting soil fungal community structure in this experiment. In summary, compared with spring maize monocropping, rotating or intercropping spring maize with other crops could significantly increase the diversity of soil fungal communities. Among the multiple systems, the rotation patterns of rye-spring maize, spinach-spring maize and winter wheat-summer maize had good performance in improving soil fungal diversity and enriching beneficial microbiota. In addition, the rotation systems of rye-spring maize and spinach-spring maize reduced the abundance of potentially pathogenic fungi to a certain extent. Therefore, combining the demands of water and land conservation, spring maize rotated with rye or spinach may be a better choice from the perspective of soil microorganisms in the North China Plain.

     

/

返回文章
返回