P-332 - Exploring close-rotation microbiome dysbiosis in legume

Legumes are a nutrient-rich food crop and an important part of crop rotation cycles. However, a major problem for increasing legume production is the decline in yield caused by close rotation. In a previous study, pea was found to have a significantly higher rhizosphere effect compared to wheat and oats. Thus, the soil microbial community is a key factor that should be considered to maximise productivity. In our study, the effect of soil microbiome on yield was investigated by re-planting pea seeds (Pisum Sativum cv. hakuna) using the same soil throughout three harvests. Rhizobium spp. and Pseudomonas spp. isolated from the rhizosphere were subjected to high-throughput phenotyping assays. The results suggested the selection of specific phenotypes during the close rotation. A phylogenetic tree was constructed based on the rpoB gene, revealing population clustering observed over successive harvests. Furthermore, analysis of microbial communities using 16S rRNA amplicon sequencing showed fluctuations in bacterial populations across the three harvests, while nutrient availability remained stable. Also, a SynCom experiment has been conducted to observe the effect of bacterial inoculation from different harvests. Understanding this dynamic interactions within soil microbiota could be a promising strategy for better crop productivity.