| 引用本文: | 池曌男,李为萍,张家鹏,等.水分亏缺对膜下滴灌向日葵根际微环境的影响[J].灌溉排水学报,2023,42(12):53-62. |
| CHI Zhaonan,LI Weiping,ZHANG Jiapeng,et al.水分亏缺对膜下滴灌向日葵根际微环境的影响[J].灌溉排水学报,2023,42(12):53-62. |
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| 摘要: |
| 【目的】探究水分亏缺对向日葵根际土壤微生物多样性、群落结构及代谢功能的影响。【方法】基于膜下滴灌田间试验，在向日葵播种前灌溉畦灌压盐水900 m3/hm2，生育期内实施膜下滴灌处理。以当地向日葵膜下滴灌灌水水平W1（现蕾期灌水450 m3/hm2，生殖生长期灌水450 m3/hm2）为对照，设置现蕾期轻、重度水分亏缺处理：W2（现蕾期灌水300 m3/hm2，生殖生长期灌水450 m3/hm2）、W3（现蕾期灌水150 m3/hm2，生殖生长期灌水450 m3/hm2），生殖生长期轻、重度水分亏缺处理：W4（现蕾期灌水450 m3/hm2，生殖生长期灌水225 m3/hm2）、W5（现蕾期灌水450 m3/hm2，生殖生长期不灌水）。采用Illumina高通量测序技术分析根际土壤微生物群落结构、功能及多样性，并分析土壤理化性质与微生物群落结构及功能对水分亏缺的响应。【结果】与W1处理相比，W2、W3处理显著提高了现蕾期根际土壤电导率（EC）、铵态氮（NH4+-N）量和温度（T），降低了成熟期根际土壤含水率（SWC）、EC和pH值。W2处理提高了成熟期根际土壤细菌、真菌的丰富度指数（Chao1）、均匀度指数（Pielou）和多样性指数（Shannon）。在4个水分亏缺处理中，W2处理下的变形菌门相对丰度相比W1处理显著降低了7.66%，W3处理下的绿弯菌门、子囊菌门相对丰度较W1处理分别提高了32.19%、5.25%。W4、W5处理提高了放线菌门、酸杆菌门、被孢霉门的相对丰度。细菌群落与土壤理化性质之间的相关性高于真菌群落，细菌群落与NH4+-N量、硝态氮（NO3--N）量呈正相关，与SWC、pH值呈负相关。生物合成是根际土壤细菌和真菌的优势代谢功能。SWC是影响细菌优势代谢功能的主要因子，EC、NH4+-N、NO3--N量对细菌优势代谢功能具有积极影响。【结论】现蕾期水分亏缺相比生殖生长期水分亏缺更有利于改善根际土壤微环境，现蕾期轻度水分亏缺提高了根际土壤微生物群落结构、多样性及代谢功能，是适宜向日葵根际微生物生长的水分处理。 |
| 关键词: 膜下滴灌；水分亏缺；微生物群落结构；代谢功能；高通量测序技术 |
| DOI：10.13522/j.cnki.ggps.2023476 |
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| Effect of Water Deficiency on the Rhizosphere Microenvironment of Sunflower under Film Drip Irrigation |
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CHI Zhaonan, LI Weiping, ZHANG Jiapeng, ZHAO Sha, WU Yixuan, WANG Jiashuang
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College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
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| Abstract: |
| 【Objective】This field experiment of drip irrigation under sunflower film was carried out in the Hailiutu Science and Technology Park of Inner Mongolia Agricultural University, in order to explore the effects of water deficit on the microbial diversity, community structure and metabolic function of sunflower rhizosphere soil.【Method】Sunflower was irrigated with 900 m3/hm2 of saline before planting, and drip irrigation under film was used throughout the growth period. The control treatment, W1(450 m3/hm2 in the squaring stage and 450 m3/hm2 during the reproductive growth stage), involved sunflowers under mulch drip irrigation with a water deficit. Two water deficit treatments were implemented during the squaring stage: W2 (300 m3/hm2 irrigation during the squaring stage, 450 m3/hm2 irrigation during the reproductive growth stage), W3 (150 m3/hm2 irrigation during the squaring stage, 450 m3/hm2 irrigation during the reproductive growth stage).During the reproductive growth period, mild and severe water deficits were treated using two strategies: W4 (450 m3/hm2 irrigation during the squaring stage, and 225 m3/hm2 irrigation during the reproductive growth period), and W5(450 m3/hm2 irrigation during squaring stage, with no irrigation during the reproductive growth period).The Illumina high-throughput sequencing technology was utilized to analyze the structure, function, and diversity of the soil microbial community in the rhizosphere. Additionally, the study examined the impact of water deficit on soil physicochemical properties, as well as on the structure and function of the microbial community.【Result】At the squaring stage, W2 and W3 treatments significantly increased the electrical conductivity (EC), ammonium nitrogen (NH4+-N) content, and temperature (T) of rhizosphere soil compared to W1.Moreover, this water deficit also decreased the soil water content (SWC), EC and pH value of the mature rhizosphere soil. At the mature stage, W2 treatment boosted the richness index(Chao1), evenness index(Pielou), and diversity index(Shannon) of rhizosphere soil bacteria and fungi. In the four water deficit treatments, the relative abundance of Proteobacteria under W2 treatment was significantly reduced by 7.66% compared with W1. The relative abundance of Chloroflexi and Ascomycota increased significantly by 32.19% and 5.25%, respectively, under W3 treatment compared to W1. The application of W4 and W5 treatments led to an increase in the relative abundance of Actinomycetes, Acidobacterium, and Mortierella. The correlation between bacterial community and soil physicochemical properties was stronger than that of the fungal community. Bacteria showed a positive correlation with EC, ammonium nitrogen, and nitrate nitrogen in the rhizosphere soil. On the other hand, bacteria had a negative correlation with soil moisture content (SWC) and pH value. Biosynthesis is the dominant metabolic function of bacteria and fungi in rhizosphere soils. The main factor affecting dominant metabolic function of bacteria is SWC. In addition, EC, ammonium nitrogen, and nitrate nitrogen will have a positive impact on dominant metabolic function of bacteria.【Conclusion】In summary, The water deficit at the squaring stage improved the physicochemical properties of rhizosphere soil compared with the water deficit in the reproductive growth stage. Additionally, the mild water deficit at the squaring stage improved the structure, diversity, and metabolic function of the rhizosphere soil microbial community, thereby making it a suitable water treatment for the growth of rhizosphere microorganisms. |
| Key words: drip irrigation under film; water deficiency; microbial community; metabolic function; high-throughput sequencing |
