Comparative Analysis of Culturable Microbial Diversity in the Rhizosphere of Hybrid and Traditional Tomato (Solanum lycopersicum L.)

Tomato ( Solanum lycopersicum L.) is one of the most economically important vegetable crops worldwide and supports a diverse rhizosphere microbial community that plays a crucial role in nutrient cycling, soil fertility, plant growth, and disease suppression. Understanding the influence of different tomato varieties on rhizosphere microorganisms is essential for developing sustainable agricultural practices. The present study compared the culturable microbial diversity associated with the rhizospheres of hybrid and traditional tomato varieties using conventional microbiological techniques. Rhizosphere soil samples were collected from healthy plants cultivated under similar environmental conditions. Bacterial and fungal isolates were obtained through serial dilution and culture-based methods, followed by colony characterization, Gram staining, biochemical identification, and microscopic examination. Microbial populations were estimated as colony-forming units (CFU), and representative isolates were identified using standard microbiological procedures. The results revealed that both tomato varieties supported diverse culturable bacterial and fungal communities. However, the traditional tomato rhizosphere consistently exhibited greater microbial abundance and diversity than the hybrid variety. Beneficial bacterial genera, including Bacillus , Pseudomonas , and Azotobacter , together with fungal genera such as Aspergillus , Penicillium , and Rhizopus , were identified among the isolates. Greater variation in colony morphology and higher CFU counts observed in the traditional tomato rhizosphere suggest that plant genotype may influence the composition and abundance of culturable rhizosphere microorganisms. Overall, this study demonstrates the usefulness of conventional microbiological techniques for investigating culturable rhizosphere microorganisms and provides valuable baseline information for understanding plant–microbe interactions. The findings contribute to current knowledge of rhizosphere microbial diversity and may support future research aimed at improving soil health, sustainable crop production, and the development of environmentally friendly agricultural practices.