| 摘要: |
| 摘要：以“济麦22”为试验材料，采用单因素完全随机试验设计，以小麦开花期充分供水为对照（CK，75%-80%田间持水量），设置轻度（L，60%-65%田间持水量）)、中度（M，40%-45%田间持水量）和重度（S，30%-35%田间持水量）3个水分胁迫水平进行盆栽试验，利用Illumina高通量测序技术分析土壤微生物群落构成和多样性，研究小麦开花期水分胁迫对根际土壤酶活性和微生物群落结构及多样性的影响。结果表明：与CK相比，L处理能显著提高土壤蔗糖酶活性，轻度水分胁迫L处理蔗糖酶和脲酶活性最高，分别为51.62 mg·g-1·d-1和0.85 mg·g-1·d-1，显著高于M和S处理；多样性指数结果表明轻度胁迫L处理下细菌/真菌群落多样性Shannon指数显著高于S处理，但chao1指数、ACE指数和Simpson指数表明L处理与CK无显著性差异；水分胁迫处理细菌优势菌属类诺卡氏菌属（Nocardioides）、地杆菌属（Pedobactor）、马赛菌属（Massilia）和Promicromonospora属相对丰度均高于CK，其中地杆菌属、马赛菌属和Promicromonospora属在L处理下显著或极显著高于CK。L、M和S处理真菌优势属油壶菌属（Olpidium）和链格孢菌属（Alternaria）相对丰度均高于CK，其中油壶菌属在S处理下最高，为16.02%，显著高于其他处理；链格孢菌属在M处理下达到最高，与CK、L和S差异显著性（P＜0.05）。主成分分析表明，L和M处理之间细菌群落组成较为相似，真菌群落组成在CK与L之间更为相似。冗余分析表明，土壤含水量与细菌群落类诺卡氏菌属、马赛菌属、norank_f__Saccharimonadaceae属、Promicromonospora属和地杆菌属均呈负相关；土壤含水量、蔗糖酶、脲酶和碱性磷酸酶活性与真菌被孢霉属（Mortierella）和Acremonium属呈正相关，与赤霉菌数（Gibberella）、油壶菌属、枝孢菌属（Cladosporium）等真菌属呈负相关。轻度水分胁迫（60%-65%田间持水量）可显著提高土壤蔗糖酶活性和根际土壤微生物多样性，并且明显改变了根际土壤微生物群落结构，从而提高作物对干旱的适应性，对小麦关键生育期的土壤水分管理具有良好的调控作用。 |
| 关键词: 冬小麦；水分胁迫; 土壤酶活性；根际微生物群落结构及多样性 |
| DOI： |
| 分类号:S311 |
| 基金项目:“十三五”国家粮食丰产增效科技创新专项(2018YFD0300504) |
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| Response of rhizosphere microbial community structure and diversity to water stress of winter wheat |
|
Wang Guiyan
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|
Hebei Agricultural University
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| Abstract: |
| Abstract: :?"Jimai 22" was used to study the effects of water stress on rhizosphere soil microbial community structure and diversity and enzymatic activity at flowering stage of winter wheat. Four levels of water stress treatments (CK, 75%-80% field water capacity; L, 60%-65% field water capacity; M, 40%-45% field water capacity; S, 30%-35% field water capacity) were designed. Illumina high-throughput sequencing technology was used to analyze the composition and diversity of soil microbial community. The results showed that compared with CK, L treatment significantly increased soil sucrase activity and had the highest sucrase and urease activities, which were 51.62 mg?g-1? d-1 and 0.85 mg?g-1?d-1, respectively, which were significantly higher than that of M and S treatments.?The soil microbial community of diversity index showed that the Shannon index of bacterial/fungal community under L was significantly higher than that of S, but the index of chao1, ACE and Simpson showed no significant difference between L and CK.?Under L, M and S treatments, the relative abundance of dominant bacteria genera Nocardioides, Pedobactor, Massilia and Promicromonospora were all higher than that of CK.?Under L treatment the genera of Earthbacter, Marseillae and Promicromonospora were significantly or extremely significantly higher than that of CK.?The relative abundance of dominant genera of Olpidium and Alternaria under L, M and S treatments was higher than that of CK, and the relative abundance of dominant genera Olpidium and Alternaria under S treatment was the highest (16.02%), which was significantly higher than that of other treatments, and the the relative abundance of Alternaria was highest under M treatment, which was significantly different from CK, L and S (P < 0.05) treatments.?Principal component analysis showed that bacterial community composition was similar between L and M, and fungal community composition was more similar between CK and L.?The results of Redundancy analysis showed that soil water content was negatively correlated with the bacterial communities of Nocardia, Marseillaria, norank_f__Saccharimonadaceae, Promicromonospora and Geobacter.?Soil water content, sucrase, urease and alkaline phosphatase activities were positively correlated with fungi of Mortierella and Acremonium, but negatively correlated with fungi of Gibberella, oleomycete and Cladosporium.?In conclusion, mild water stress (60% - 65% of field capacity) could significantly increase soil invertase activity and rhizosphere soil microbial diversity, and obvious change of soil microbial community structure to improve the adaptability of crops to drought. It was important for winter wheat to regulate growth against soil water stress during the key growth period. |
| Key words: Winter wheat; Water stress; Soil enzymatic activity; Soil microbial community structure and diversity |
