化肥减量配施紫色光养细菌对花生的增产作用和土壤细菌群落的影响

Yield increasing effect of purple photosynthetic bacteria on peanut yield and its effect on soil bacterial community with reduced chemical fertilizer

微生物肥料在现代农业生产中具有很大应用潜力,可在提高作物产量的同时减少化肥使用,从而创造环境友好型农业生产体系.通过田间长期试验对分离的一株紫色非硫细菌Rhodopseudomonas palustris ISP-1的5年花生增产效果进行研究,并探讨浇灌菌液(R1)和叶面喷施(R2)两种追肥方式对花生产量、花生仁品质和土壤细菌群落的影响.经过5年的连续施用,R1和R2处理分别使花生产量平均增加12.5%和17.9%,追肥时喷施菌液在植株的叶面比直接浇灌在植株根部增产效果更好.R1和R2处理显著促进了花生植株的生长,提高了花生仁中的蛋白质含量.在施肥第5年花生收获期,R1和R2处理土壤中的残留养分与对照处理相比无显著差异.R2处理显著改善了土壤pH并增加了细菌生物多样性,但R1和R2处理对细菌的丰富度和群落结构均没有显著影响,仅Verrucomicrobia门细菌丰度显著增加.细菌基因功能预测分析发现R1和R2处理的土壤细菌群落中参与磷吸收和转运的基因总相对丰度显著降低,而无机磷溶解和有机磷矿化的基因分别增加了2.71%和3.20%.偏最小二乘路径建模(PLS-PM)分析表明,施用R.palustris ISP-1菌液对花生产量和花生仁养分含量有显著的直接影响,而施用菌液导致的土壤细菌多样性增加、部分细菌群落结构以及细菌磷代谢功能的变化对花生增产的作用相对较小.本研究表明施用R.palustris ISP-1可以促进花生植株生长,提高花生仁蛋白含量,并在长时序年的田间试验过程中维持较高的花生产量,展示了紫色光养细菌作为生物肥料的应用潜力.(图6表3参44)

Microbial inoculation is a promising strategy in modern agricultural production.This can increase crop yield and reduce chemical fertilizer use,thereby creating an environmentally friendly agricultural production system.In this study,through a long-term field experiment,the five-year effect of Rhodopseudomonas palustris ISP-1 on peanut yield was studied;the effects of topdressing methods including irrigation bacterial suspension(R1)and foliar spraying(R2)on peanut yield,peanut kernel quality,and soil bacterial community structure were discussed.The R1 and R2 treatments increased the five-year average peanut yields by 12.5%and 17.9%,respectively.Therefore,when topdressing with a suspension containing the R.palustris ISP-1 cells,foliar fertilization is better than direct irrigation.Both R1 and R2 significantly promoted the growth of peanut plants and increased the protein content of peanut kernels.In the fifth year of the peanut harvest,the residual nutrients in the soil of R1 and R2 were not significantly different from those of the control.R2 significantly increased soil pH and bacterial community diversity;however,R1 and R2 had no significant effect on the richness and community structure of the soil bacterial community.Only the abundance of bacterial phyla in Verrucomicrobia increased significantly.According to the PICRUSt prediction,bacterial inoculums significantly reduced the total relative abundance of genes involved in phosphorus uptake and transport in the soil bacterial communities of R1 and R2,whereas the genes associated with inorganic phosphorus solubilization and organic phosphorus mineralization increased by 2.71%and 3.20%,respectively.PLS-PM analysis demonstrated that the application of R.palustris ISP-1 had a significant direct impact on peanut yield and nutrient content of peanut kernels,while the increase in soil bacterial diversity,fine-tuning of bacterial community structure,and changes in the phosphorus metabolism function of soil bacteria caused by the application of R.palustris ISP-1 had relatively less effect on peanut yield.In conclusion,the application of R.palustris ISP-1 can promote peanut plant growth,improve the protein content of peanut kernels,and maintain high peanut yield during a five-year field experiment,showing the application potential of purple photosynthetic bacteria as biofertilizers.