Exploration of soil fungi in the tomato rhizosphere in Batu and Malang, East Java Province, Indonesia

Abstract Soil fungi are important indicators of the biological components of soil fertility, which are significantly influenced by the presence of microorganisms. Currently, the soil fertility of agricultural land is experiencing a drastic decline, largely due to overuse of chemical fertilizers and unsustainable farming practices. This underscores the need for research on soil microbial communities, especially in agricultural systems. The purpose of this study is to investigate the presence of soil fungi in the rhizosphere of tomato plants ( Solanum lycopersicum ). The rhizosphere, a narrow area of soil affected by root exudates, is home to diverse populations of microorganisms that are vital for plant productivity and health. Fungi play a significant role in disease suppression, nutrient cycling, and the overall dynamics of soil ecosystems, yet their diversity in relation to crops like tomatoes remains underexplored. Research in this area is critical for sustainable agriculture, particularly in the face of challenges such as soil degradation and reduced crop yields. The aim of this study is to fill existing research gaps by characterizing the fungal diversity in the tomato rhizosphere and identifying potentially beneficial or harmful taxa. Soil samples were collected from tomato-growing regions, and the methods employed included isolation and purification of soil fungi, as well as macroscopic and microscopic identification. The study identified eleven fungal isolates belonging to seven genera: Acremonium, Aureobasidium, Cephalosporium, Chrysosporium, Mucor, Penicillium, and Rhizopus. The diversity of soil fungi in the tomato rhizosphere was categorized as moderate, with a balanced distribution of individuals across species, no single dominant species, and a high degree of uniformity. This work not only highlights the ecological significance of soil fungi in agricultural systems but also contributes to the growing body of knowledge on fungal diversity in tomato roots. Future research will focus on understanding the functional roles of these fungal species, particularly their potential applications in sustainable crop management practices, and how they might influence soil health and productivity.