Diversity and habitat distribution of tomato (Solanum lycopersicum) nematoda fauna (Zarafshan valley, Uzbekistan)

Nematodes are the most widespread multicellular organisms found in soil ecosystems. They engage in complex and diverse relationships with plants and other living organisms. Additionally, the composition of nematode communities varies across different climatic conditions. This study was conducted in the Zarafshan Valley of Uzbekistan, where the species and ecological diversity of nematodes have not been thoroughly explored. Our research identified 87 nematode species belonging to seven orders across various biotopes associated with tomato plants in three regions of the Zarafshan Valley. Notably, the majority of these species were found in the rhizosphere soil. For the first time in this region, we classified nematodes into ecological groups based on their trophic characteristics, revealing that the bacterivores group is the most dominant. We calculated ecological indicators for nematodes in different biotopes using the Simpson index (Dˊ), Shannon index (Hˊ), Menhinck index, Margalef index, and Berger-Parker index. The diversity of nematode fauna across these biotopes was analyzed in relation to soil organic matter content, humidity, and pH levels. Our findings further demonstrate that variations in the species and ecological composition of nematodes among biotopes are influenced by multiple factors, particularly their trophic characteristics.