Abstract:
Objective By adding Funneliformis mosseae to the sweet corn field, roles of AM fungi play on the nitrogen (N) utilization and the fungal diversity in rhizosphere soil were studied.
Method Various N applications including no N (N0), 330 kg N·hm−2 (N22), 297 kg N·hm−2 (N19.8), and 264 kg N·hm−2 (N17.6) were used. In addition, at a same level of N, two split-plots with (AM+) or without (AM-) 315 kg·hm−2 of F. mosseae were included for the experimentation. Thus, 8 treatments with 3 replicates each were performed. Rhizosphere soil were sampled for chemical analysis and Illumina Hiseq 2500 sequencing to determine the diversity and community structure of the AM fungi.
Result Among the AM+ treatments, the fresh bud yield of the corn plants increased by 32.6% at N0, 16.7% at N17.6, 8.0% at N19.8, and 0.8% at N22. In comparison to AM-, the N utilization of the plants on the AM+ plots with N17.6, N19.8, and N22 improved by 5.51%, 4.14%, and 6.19%, respectively. From the 1 558 461 valid sequences obtained, 15 771 OTUs were clustered at 97% similarity level to show a result of one class, 4 orders, 5 families, and 5 genera. Among the common genera, Glomus, Claroideoglomus, and Paraglomus, Glomus predominantly presented in the rhizosphere accounting for more than 21.82% of all species with a relative abundance ≥1%. The N22/AM+ treatment yielded higher Chao1 and richness indices than others (P<0.05). The greatest abundance index as well as the lowest Shannon and Simpson indices were found with the N0/AM+ treatment. The addition of F. mosseae significantly increased the correlations between Shannon index, Simpson index and infection rate, spore density, and utilization rates of 4 types of N (NAE, PFP, NRE, and NPE) (P<0.05).
Conclusion The addition of F. mosseae in corn field altered the AM fungal community in the rhizosphere resulting in an increased crop yield. This study confirmed the significant promotional effect of AM fungi on the N utilization efficiency by sweet corn plants, which would effectively reduce the need for N fertilizer in the field.