Impact of Rhizospheric and Phyllospheric Mycobiota on Plant Health of Tomato

Tomato (Solanum lycopersicum) is a significant crop produced globally but suffers from numerous biotic and abiotic stresses when cultivated in fields. Among all the biological stresses, fungal diseases cause a sharp decline in yield and quality but may remain non-pathogenic and symptomless under certain fungal species throughout the plant's entire life cycle. This work aimed to isolate and purify the mycobiota from various parts of the tomato plant—stem, root, fruit, leaf, and rhizospheric soil—to determine the fungal communities present. Morphological and molecular identification established the presence of various fungal species, including Aspergillus fumigatus, Acremoniumspp., Pythiumspp., Geotrichum candidum, Aspergillus parasiticus, Aspergillus carbonarius, Aspergillus terricola, Aspergillus flavus, Aspergillus oryzae, and Alternaria alternata. The density and distribution of these fungi varied among different plant parts and soil, with A. fumigatusshowing the highest frequency (80%) among all isolates. Fungal diversity analysis revealed notable differences in species richness and evenness across plant parts. The rhizospheric soil showed the highest fungal diversity (Shannon index = 2.31), followed by roots (2.05), while the leaf and fruit tissues exhibited lower diversity indices. The Simpson's index values also confirmed greater dominance and lower evenness in aboveground plant parts, indicating a more selective fungal colonization. A heat map was constructed to visually compare diversity metrics across plant parts. Moreover, the effect of microbiomes on tomato plant health, especially on chlorophyll content in the field, was also examined. The results indicate that tomato plant mycobiota play a positive role in plant health based on their interaction. Further studies need to be conducted to investigate the specific possible positive impact of individual fungal species and their interactive effect on plant health of tomato crops.