Maritsa Vegetable Crops Research Institute, Agricultural Academy, 4003 Plovdiv, Bulgaria.
Tobacco and Tobacco Products Institute, Agricultural Academy, 4108 Plovdiv, Bulgaria.
Int J Mol Sci. 2023 Jan 6;24(2):1119. doi: 10.3390/ijms24021119.
This study of a legume's rhizosphere in tripartite symbiosis focused on the relationships between the symbionts and less on the overall rhizosphere microbiome. We used an experimental model with different garden pea genotypes inoculated with AM fungi ( and with a mix of AM species) to study their influence on the population levels of main trophic groups of soil microorganisms as well as their structure and functional relationships in the rhizosphere microbial community. The experiments were carried out at two phenological cycles of the plants. Analyzes were performed according to classical methods: microbial population density defined as CUF/g a.d.s. and root colonization rate with AMF (%). We found a proven dominant effect of AMF on the densities of micromycetes and actinomycetes in the direction of reduction, suggesting antagonism, and on ammonifying, phosphate-solubilizing and free-living diazotrophic Azotobacter bacteria in the direction of stimulation, an indicator of mutualistic relationships. We determined that the genotype was decisive for the formation of populations of bacteria immobilizing mineral NH-N and bacteria Rhizobium. We reported significant two-way relationships between trophic groups related associated with soil nitrogen and phosphorus ions availability. The preserved proportions between trophic groups in the microbial communities were indicative of structural and functional stability.
本研究以豆科植物的根际三方共生体为研究对象，重点关注共生体之间的关系，而较少关注整个根际微生物组。我们使用了一个具有不同豌豆基因型的实验模型，这些基因型接种了丛枝菌根真菌（和混合的丛枝菌根真菌物种），以研究它们对主要营养类群土壤微生物种群水平的影响，以及它们在根际微生物群落中的结构和功能关系。实验在植物的两个物候周期进行。分析根据经典方法进行：微生物种群密度定义为 CUF/g a.d.s. 和丛枝菌根真菌（%）的根定植率。我们发现丛枝菌根真菌对真菌和放线菌的密度具有明显的主导作用，表现为降低（表明拮抗作用），对氨化、解磷和自生固氮菌（如 Azotobacter）具有刺激作用（表明共生关系）。我们确定基因型对固定矿质 NH-N 和 Rhizobium 细菌种群的形成起决定性作用。我们报告了与土壤氮和磷离子可用性相关的与营养组相关的重要双向关系。微生物群落中营养组之间的保存比例表明其具有结构和功能稳定性。
