摘要
【目的】碳是微生物代谢活动的能量来源,解析碳驱动的微生物磷周转对根系/根际属性以及作物磷吸收的影响,对探索提高磷利用效率的根际调控措施具有重要的指导意义。【方法】以绿叶蔬菜上海青(Brassica chinensis L.,Xiaqing 3)为供试作物进行盆栽试验,供试碳源为葡萄糖。设置添加葡萄糖(+G)和不添加葡萄糖(−G,对照)两个处理,在添加葡萄糖后第7天和第21天,测定土壤微生物量磷与Olsen-P含量、根际酸性磷酸酶活性以及柠檬酸和苹果酸含量、根系形态(生物量、根冠比、根长、根系直径、比根长和根系组织密度)与根际生理(酸性磷酸酶、柠檬酸和苹果酸)指标和作物磷吸收量。【结果】添加葡萄糖后第7天,土壤微生物量磷增加,Olsen-P含量降低;上海青根系生物量和根冠比显著高于对照,另外,与不加葡萄糖处理相比,添加葡萄糖导致上海青总根长降低33%,根系平均直径增加27%,比根长降低46%,根际柠檬酸含量增加106%。从第7天到第21天,添加葡萄糖处理土壤微生物量磷降低,Olsen-P含量增加,上海青根系生长速率显著提高。葡萄糖添加后第21天,添加葡萄糖处理土壤Olsen-P含量高于对照土壤;与不加葡萄糖的处理相比,根际酸性磷酸酶和柠檬酸的分泌降低,上海青根系总根长增加,其相对增加量为31%。添加葡萄糖对第7天和第21天上海青地上部磷吸收没有显著影响。【结论】添加葡萄糖提高了前期(添加葡萄糖后第7天)根际微生物量磷,降低了Olsen-P含量,促进根际柠檬酸的分泌满足作物生长对磷的需求。后期(添加葡萄糖后第21天),微生物量磷的降低促进土壤有效磷含量的增加,刺激根系快速伸长。微生物介导磷周转诱导作物调节根系形态和根际分泌物响应土壤磷环境的变化,维持地上部磷营养。
【Objectives】Carbon(C)underpins microbial metabolism.Thus,it is critical to understand the microbe-root interaction associated with high P use efficiency.This study investigated the influence of C on microbial mediated P availability and its role in modifying root morphological and exudation traits.【Methods】A pot experiment with glucose addition was conducted to investigate the effects of microbial mediated P availability(microbial biomass P and Olsen-P)on root morphological(root biomass,root/shoot ratio,root length,diameter,specific length and tissue density)and exudation traits(acid phosphatase,citrate,and malate)governing P acquisition by Brassica chinensis at day 7 and 21.【Results】At 7 days after addition,glucose increased microbial biomass P while decreasing soil Olsen-P.When roots in glucose and no-glucose soils were compared,root biomass and root/shoot ratio increased,while total root length decreased by 33%.Furthermore,root diameter increased by 37%,while specific root length decreased by 46%.When glucose amended soil was compared to no-glucose soil,the rhizosphere citrate content increased by 106%.Microbial biomass P decreased from the 7th to the 21st day after glucose addition,and soil Olsen-P increased,eliciting higher Olsen-P in glucose soil than no-glucose soil on the 21st day after addition.In parallel with the variation in microbial biomass P and Olsen-P,Brassica chinensis proliferated rapidly,increased root length by 31%,but decreased rhizosphere exudation of acid phosphatase and citrate in the former compared to the no-glucose soil.On days 7 and 21,there was no difference in the shoot P content of Brassica chinensis in the glucose and no-glucose treatments.【Conclusions】Glucose addition increased microbial biomass P but decreased soil Olsen-P content,resulting in strong citrate exudation to meet crop P demand on day 7.However,at day 21,microbial biomass P decreased,increasing soil P availability and stimulating rapid root elongation.To summarize,microbial biomass P turnover and effi
作者
李洪亮
诸海焘
徐四新
蔡树美
付子轼
张德闪
LI Hong-liang;ZHU Hai-tao;XU Si-xin;CAI Shu-mei;FU Zi-shi;ZHANG De-shan(Institute of Ecological Environment Protection Research,Shanghai Academy of Agricultural Sciences/Shanghai Scientific Observing and Experimental Station for Agricultural Environment and Land Conservation,Ministry of Agriculture and Rural Affairs/Shanghai Key Laboratory of Protected Horticultural Technology,Shanghai 201403,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2021年第10期1757-1766,共10页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划项目(2017YFD0200200)
国家自然科学基金青年科学基金项目(31801946)
上海市科技兴农推广项目沪农科推字(2018)第4-14号
上海市科委国内合作项目(20025800500)。
关键词
根系–微生物互作
微生物量磷周转
根系形态特征
根际过程
磷利用效率
root-microbe interaction
microbial biomass P turnover
root morphological traits
rhizosphere process
P use efficiency
