摘要
【目的】微生物菌肥作为一种绿色环保的生物肥料,可以改善土壤质量,促进作物生长。以水稻根际和根表微生物为对象,探究不同微生物菌肥单施和混施对其群落多样性和功能的影响。【方法】采用盆栽试验,设单施沼泽红假单胞菌(Rhodopseudomonas palustris)、单施枯草芽孢杆菌(Bacillus subtilis)及两个菌株混施处理,以清水作对照,共4个处理。在水稻收获期,采集植株10 cm×10 cm×10 cm范围内的根域土壤,从中分出根表和根际土壤,通过16S rDNA高通量测序和PICRUSt功能预测,分析细菌群落的多样性和功能,并测定水稻产量。【结果】沼泽红假单胞菌和枯草芽孢杆菌的单施和混施均显著提高了水稻结实率,单施沼泽红假单胞菌及其与枯草芽孢杆菌混施处理显著增加了水稻产量,且混施的增产效果最明显,水稻产量和结实率分别提高了13.7%和17.2%。短期内3个菌肥处理对收获期的土壤理化性质没有显著影响。与施化肥对照相比,两种功能菌单施或混合施用对水稻根际土壤细菌群落的多样性和功能均没有显著影响,但单施枯草芽孢杆菌和两种功能菌的混施降低了根表土壤细菌群落的物种丰富度(Chao1)和Shannon-Wiener多样性指数,提高了优势菌变形菌门(Proteobacteria)的相对丰度(单施沼泽红假单胞菌,单施枯草芽孢杆菌和两种功能菌混施处理下分别平均增加3%和10%、13%),在属水平上引起了优势菌属的差异变化,如不同程度地增加了Novosphingobium、Flavobacterium和Rhizobium的相对丰度,减少了Anaeromyxobacter、Bradyrhizobium、Pleomorphomonas、Nocardioides、Propionicimonas和Methanobacterium等的相对丰度,改变了根表土壤细菌群落结构,增加了根表土壤细菌的功能基因丰度。根际和根表土壤细菌涉及的新陈代谢、遗传信息处理、环境信息处理、细胞过程等功能的基因丰度与水稻结实率均显著正相关(r=0.60~0.68,P<0.05)。功能基因丰度的增加与优势菌属的变化有关,且根表土壤细菌中优势菌属的变化对整体群落功能的基因丰度影响更大。【结论】施用沼泽红假单胞菌与枯草芽孢杆菌可提高水稻结实率和产量,且混施效果比单施好。与施化肥对照相比,混施和单施微生物菌剂都改变了根表土壤细菌多样性,提高了优势菌及相关功能基因丰度,其中混施与单施枯草芽孢杆菌对土壤细菌群落的影响相似,而与单施沼泽红假单胞菌对土壤细菌群落的影响有一定差异。微生物菌肥可通过影响根域微生物多样性及其功能而间接促进作物生长。
【Objectives】Microbial fertilizer is effective to improve soil fertility and promote crop growth.We studied the effects of single-and co-inoculation of two microbial fertilizers on rice rhizosphere and rhizoplane bacterial diversity and function.【Methods】A rice pot experiment was conducted,and four treatments were set up,i.e.clean water as control,single inoculation of Rhodopseudomonas palustris(R.palustris),single inoculation of Bacillus subtilis(B.subtilis),and co-inoculation of both(Mix).At harvest of rice,soil samples were collected around rice plant of 10 cm×10 cm×10 cm,and rhizoplane and rhizosphere samples were separated from the soil samples,to determine bacterial diversity and function by 16S rDNA high-throughput sequencing and functional prediction.【Results】All the three biofertilizer treatments increased rice yield and the setting rate,of which Mix treatment increased the most by 13.7%and 17.2%,respectively.All the three biofertilizer treatments did not change soil physicochemical properties significantly at harvest stage of rice.Compared with control,the application of the two functional bacteria did not significantly affect the diversity and function of rhizosphere bacterial community,but single-inoculation of B.subtilis and co-inoculation reduced Chao1 richness and Shannon-Wiener index of rhizoplane bacterial community.An increase in the relative abundance of rhizoplane dominant phylum Proteobacteria(average increase of 3%,10%and 13%by single-inoculation of R.palustris,single-inoculation of B.subtilis and co-inoculation of both,respectively)was found.Microbial fertilizer treatments caused variations in the dominant genera,such as increasing the relative abundances of Novosphingo-bium,Flavobacterium and Rhizobium and reducing those of Anaeromyxobacter,Bradyrhizobium,Pleomorpho-monas,Nocardioides,Propionicimonas and Methanobacterium,changed rhizoplane bacterial community structure,and increased their functional gene abundance.The abundance of both rhizosphere and rhizoplane bacterial genes involved in metabolism,genetic information processing,environmental information processing,and cellular processes were positively correlated with panicle seed setting rate(r=0.60-0.68,P<0.05).The increase of functional gene abundance was related to the change of dominant genera,and such change in rhizoplane bacterial community had a greater impact on the bacterial functional gene abundance.【Conclusion】Application of R.palustris improved rice yields significantly,and its co-inoculation with B.subtilis was more effective than single-inoculation.Compared with control,both co-inoculation and single-inoculation changed the rhizoplane bacterial diversity and increased the abundance of dominant bacteria and functional genes.The effect of co-inoculation on bacterial community was similar to single-inoculation of B.subtilis,but different with that of single-inoculation of R.palustris.Microbial fertilizer can indirectly promote crop growth by affecting the diversity of root zone bacterial communities.
作者
张娜
朱艳
肖娴
赵远
ZHANG Na;ZHU Yan;XIAO Xian;ZHAO Yuan(School of Environmental and Safety Engineering,Changzhou University,Changzhou,Jiangsu 213000,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing,Jiangsu 210008,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2022年第1期58-71,共14页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金(42007027)
常州市科技支撑计划(社会发展)(CE20205002)。
关键词
微生物菌肥
水稻
根际细菌
根表细菌
microbial fertilizer
rice
rhizosphere bacteria
rhizoplane bacteria