叶面喷施寡糖对花生根区固氮菌群落结构及产量的影响

Effects of leaf spraying oligosaccharides on the community structure of azotobacter in the rhizosphere and the yield of peanut

研究施用壳寡糖和纤维寡糖对花生根区土壤固氮菌群落结构及产量的影响。通过田间试验,以清水处理作为对照(CK),叶面喷施浓度为50 mg/L的壳寡糖(CSOS)和纤维寡糖(COS),利用高通量测序技术,研究土壤中固氮菌群落结构组成及多样性分布特征,分析2种寡糖对土壤理化性质和花生产量指标的影响。(1)与CK相比,CSOS处理慢生根瘤菌属(Bradyrhizobium)、透明颤菌属(Vitreoscilla)、固氮氢自养单胞菌属(Azohydromonas)、固氮螺菌属(Azospirillum)、假单胞菌属(Pseudomonas)、眉藻属(Calothrix)和弗兰克氏菌属(Frankia),相对丰度显著增加分别为10.99%、45.63%、29.88%、23.24%、181.13%、27.75%和36.61%。COS处理固氮螺菌属(Azospirillum)、中华根瘤菌属(Sinorhizobium)和眉藻属(Calothrix)相对丰度显著增加分别为86.12%、664.41%和277.97%。(2)与CK相比,CSOS处理显著提高土壤中全氮和铵态氮含量,平均增幅分别为15.50%和20.19%。COS处理显著增加土壤中全氮、硝态氮和铵态氮,分别为17.05%、18.68%和27.58%;此外,CSOS和COS处理相较于CK,土壤p H均显著下降,分别下降了0.08和0.06。(3)CSOS和COS处理均显著增加花生产量,分别为19.3%和22.0%。因此,叶面喷施壳寡糖和纤维寡糖,可以调节花生根区土壤不同固氮菌属的相对丰度和影响土壤的理化因子(全氮、硝态氮和铵态氮),最终均显著提高花生产量。

Field experiment was conducted to study the effects of chitosan oligosaccharides and cello-oligosaccharide on the community structure of azotobacter in the rhizosphere and the yield of peanut.The experiment included three treatments on the surface of leaf:clean water(CK),chitosan oligosaccharides 50 mg/L(CSOS)and cello-oligosaccharide 50 mg/L(COS).High throughput sequencing technology was used to analyze the community structure and diversity of azotobacter in the rhizosphere.(1)Compared to CK,the relative abundance of Bradyrhizobium,Vitreoscilla,Azohydromonas,Azospirillum,Pseudomonas,Calothrix and Frankia,significantly increased of CSOS treatment by 10.99%,45.63%,29.88%,23.24%,181.13%,27.75%and 36.61%,respectively.The relative abundance of Azospirillum,Sinorhizobium and Calothrix of COS treatment significantly increased by 86.12%,664.41%and 277.97%,respectively.(2)Compared with CK,the CSOS treatment significantly increased the content of total nitrogen and ammonium nitrogen in the soil with an average increase of 15.50%and 20.19%,respectively.COS treatment significantly increased total nitrogen,nitrate nitrogen and ammonium nitrogen in the soil by 17.05%,18.68%and 27.58%,respectively;In addition,soil pH decreased significantly by 0.08 and 0.06 for both CSOS and COS treatments compared to CK,respectively.(3)Both CSOS and COS treatments significantly increased peanut yield by 19.3%and 22.0%,respectively.Therefore,foliar sprays of chitosan oligosaccharides and cellooligosaccharide regulated the relative abundance of different nitrogen-fixing bacterial genera and affected soil physicochemical factors(total nitrogen,nitrate nitrogen and ammonium nitrogen)in the root zone of peanut,all of which ultimately significantly increased peanut yield.