Seasonal diversity of root endophytic fungi and bacteria associated with sainfoin ( <i>Onobrychis viciifolia</i> ) in South Africa

Abstract Background : Sainfoin ( Onobrychis viciifolia ) is a beneficial forage legume adapted to a wide range of climatic conditions. It has the potential to be a useful forage crop due to its high digestibility and palatability, anthelmintic properties, and abundance of nectar and pollen for honey production. Here, we report the first attempts to study the diversity of endophytic fungi and bacteria associated with sainfoin in South African agricultural lands during both dry and wet seasons. Methods : This was achieved by isolating, cultivating, purifying, and performing molecular characterisation of fungi and bacteria from the roots of sainfoin obtained from an established agricultural field. Results : During the dry season, 15 fungal isolates and 10 bacterial isolates were obtained from sainfoin roots, representing nine fungal genera and four bacterial genera, respectively. In the wet season 28 fungal isolates and 24 bacterial isolates were characterised, representing 12 fungal genera and 12 bacterial genera. Fungal and bacterial isolates were molecularly identified, and their potential antagonistic and plant growth-promoting effects were interpreted based on relevant studies and experimental observations. Conclusion : Our findings indicate that sainfoin roots in South Africa interact with a diverse group of endophytes, with seasonal variation greatly influencing their diversity. Notably both the diversity and isolation rate were higher during the wet season.