基于高通量测序分析优化施氮对养蟹稻田土壤细菌多样性的影响

Effects of Optimized N Fertilization on Rice Soil Bacterial Diversity of Rice Crab Symbiosis System Analyzed by High-throughput Sequencing Technology

为研究优化施氮对养蟹稻田土壤细菌群落结构和多样性的影响,利用高通量测序技术对不施氮肥(ck0)、常规施氮(ck1)、优化施氮(T1)和优化施氮+PASP-Ca(T2) 4组处理的水稻土壤细菌群落结构及多样性进行了研究分析。结果表明:与常规施氮(ck1)相比,优化施氮+PASP-Ca(T2)可显著提高土壤有效磷和有效钾含量,而优化施氮(T1)可显著提高土壤有效磷含量并有效调节土壤p H。4个处理的12份土壤样品共获得约7. 4万条有效序列,基于≥97%的相似度水平下,通过聚类分析对可操作分类单元(Operational taxonomic unit,OTU)进行归类,ck0、ck1、T1、T2平均分别有4 180. 3,4 417. 7,4 314. 0,4 025. 7个OTU类型,Shannon指数为6. 81~6. 92;4个处理的土壤样品中,在门分类水平上细菌种群组成较为一致,主要包括变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、拟杆菌门(Bacteroidetes)等,主要覆盖了80%以上物种。4个处理土壤样品中,细菌属共有889个,均有分布的种属有721个,其中共有优势菌属分别为厌氧绳菌科(Anaerolineaceae)的一种不可培养属、硫杆菌属(Thiobacillus)、亚硝化单胞菌科(Nitrosomonadaceae)的一种不可培养属、芽单胞菌科(Gemmatimonadaceae)的一种不可培养属等,约占总类群的16%,ck0、ck1、T1与T2的特有属分别有3,1,0,4个。土壤样品中存在20%细菌16S r DNA序列未能归类。T1和ck1相比以及T2与T1相比,主要的优势属相对丰度均发生改变。说明水稻土壤样品中细菌类群具有高度丰富的多样性,通过优化施氮和施用PASP-Ca增效肥料,可提高土壤有效磷和有效钾含量并能改变土壤主要细菌属的相对丰度。

In order to study the effects of nitrogen reduction on soil bacterial community of rice field,high throughput sequencing technology was performed to determine the soil microbial community structure and diversity of ck0,ck1,T1 and T2.Seventy-four thousand effective 16S rDNA V3-V4 sequences were obtained from 12 soil samples of four groups.The results showed that T2 could significantly improve soil available P and available K compared with ck1;T1 could significantly improve available P,adjusting pH to neutral.The 4 groups were assigned to 4180.3,4417.7,4314.0 and 4025.7 OTU types in ck0,ck1,T1 and T2 soil samples based on the similarity level of≥97%,respectively.The Shannon-Wiener index varied between 6.81 and 6.92.The structure of bacterial communities,on the classification level of the phylum,was similar in the 12 samples.The dominant bacterial phyla in the soil were Proteobacteria,Chloroflexi,Acidobacteria and Bacteroidetes,which accounted for more than 80%of all bacteria in paddy soil.There were 889 genera in total in four groups,among which 721 genera existed in each group.The amount of soil bacteria at genus level in T1 increased by 1.2%compared with ck1.The dominant bacteria in the paddy soil were a kind of uncultured bacterium of Anaerolineaceae,Thiobacillus,a kind of uncultured bacterium of Nitrosomonadaceae,a kind of uncultured bacterium of Gemmatimonadaceae.The 4 genera accounted for about 16%of all bacteria in paddy soil.The endemic genera of the 4 treatments were 3,1,0 and 4,respectively.And about 20%proportion of bacterial 16S rDNA sequences were not classified.The relative abundance of the dominant bacteria genera between T1 and ck1 changed,and so did between T2 and T1.The composition and abundance of the bacterial community in paddy soil were significantly rich,and different fertilization treatments could change the relative abundance of the main genera in soil and significantly improved soil available P and available K.