不同玉米茎腐病抗性品种根际微生物群落多样性及功能差异OA

[Objective]This study aims to compare and analyze the structure,interaction networks,and functional profiles of the rhizosphere microbial communities in maize varieties with different resistances to stalk rot,to reveal their relationship with resistance to disease.[Method]We selected resistant(JK580,K2322)and susceptible(DK2207)varieties from 90 maize genotypes through field inoculation with the dominant pathogen Fusarium graminearum.Using 16S rRNA and ITS high-throughput sequencing,we then compared the diversity,composition,network structure,and functional potential of the rhizosphere microbiota in these varieties under pathogen stress.[Result]The α-diversity(Shannon and Pielou indexes)of the rhizosphere microbiome in the resistant maize varieties was significantly higher than that in the susceptible varieties.The β-diversity analysis showed that the bacterial and fungal community structures of the resistant varieties were more similar to each other and substantially different from those of the susceptible varieties.Composition and differential-taxa analyses revealed that the resistant varieties hosted a more diverse rhizosphere microbial community and were enriched with more beneficial taxa,such as Xanthomonadaceae,Microscillaceae,Oxalobacteraceae,and the fungal family Cladosporiaceae.In contrast,the susceptible variety DK2207 demonstrated a relatively simplistic community structure,primarily enriched with Pseudomonadaceae.Co-occurrence network analysis revealed that the rhizosphere microbial networks of the resistant varieties had higher robustness and lower vulnerability indices,indicating greater stability and resilience.Functional analysis further revealed that under pathogen stress,the rhizosphere bacteria of the resistant varieties maintained efficient energy acquisition functions,while the susceptible variety showed higher carbon and nitrogen metabolism and was enriched with more pathotrophic fungi.[Conclusion]Significant differences in the rhizosphere microbial community structure and function between resistant and susceptible maize varieties under pathogen stress.High microbial diversity,a greater variety of beneficial taxa and stable community networks may be important ecological mechanisms for enhancing stalk rot resistance in maize.