4种物料对连作烟草根际土壤细菌群落的影响OA

[Objective]The aim of this study was to examine the microecological mechanism of diffe-rent ameliorating materials in alleviating continuous cropping obstacles of flue-cured tobacco,to provide support for the sustainable development of tobacco production.[Method]With 15-year continuous cro-pping tobacco field as the research object,five treatments were set:CK(conventional fertilization,600 kg/hm2 tobacco compound fertilizer+750 kg/hm2 tobacco commercial organic fertilizer),T1(600 kg/hm2 tobacco compound fertilizer+4 500 kg/hm2 Actinomycete organic fertilizer),T2(600 kg/hm2 tobacco com-pound fertilizer+4 500 kg/hm2 Trichoderma organic fertilizer),T3(600 kg/hm2 tobacco compound ferti-lizer+750 kg/hm2 tobacco commercial organic fertilizer+4 500 kg/hm2 biochar)and T4(600 kg/hm2 to-bacco compound fertilizer+750 kg/hm2 tobacco commercial organic fertilizer+900 kg/hm2 potassium ful-vic acid).Each treatment was repeated 3 times,with a total of 15 treatment areas and an area of 106.67 m2.Tobacco plants were selected by five-point sampling method during the vigorous growth stage(60 days after transplanting)and maturity stage(90 days after transplanting),and the rhizosphere soil samples were collected by root shaking method.High-throughput sequencing was used to analyze the characteristics and stability of the rhizosphere soil bacterial population of flue-cured tobacco treated with different materials at the vigorous growth stage and maturity stage.[Result]During the vigorous growth stage of tobacco,com-pared to CK treatment,the Ace index and Chao1 index of tobacco rhizosphere soil bacteria in T1 treatment were significantly increased by 26.69%and 28.80%,respectively(P<0.05).During the tobacco maturity stage,the Ace index,Chao1 index,and Shannon index of tobacco rhizosphere soil bacteria in T1 treatment were significantly higher than those in other treatments,but the Simpson index was the lowest.The bacte-rial population structure in tobacco rhizosphere soil under different treatments was generally similar.Dur-ing tobacco maturity,compared to the CK treatment,the relative abundance of Acidobacteriota in tobacco rhizosphere soil under T1 and T2 treatments increased significantly by 97.13%and 83.59%,respectively,and other treatments also showed significant difference compared with CK.The results of co-occurrence network analysis showed that compared with CK treatment,T1,T2 and T3 treatments had larger and more complex collinear networks,with T1 treatment showing the shortest average path,indicating that T1 treat-ment had the highest information transmission rate and the closest connections between bacterial species in the tobacco rhizosphere soil co-occurrence network.[Conclusion]Actinomycete organic fertilizer(T1)can improve the bacterial community structure in the rhizosphere soil of long-term continuously cropped flue-cured tobacco,increase the richness of the dominant bacterial population,and optimize the cohesion of the bacterial network,which is suitable for microecological soil restoration with continuous cro-pping of flue-cured tobacco.