Identification and pathogenicity of Pythium species associated with poor growth of tomato plants in the Australian processing tomato industry

Early Detection of Fusarium oxysporum Infection in Processing Tomatoes (Solanum lycopersicum) and Pathogen–Soil Interactions Using a Low-Cost Portable Electronic Nose and Machine Learning Modeling

“…Fusarium oxysporum strain UMT01, isolated from diseased plants collected from processing tomato fields in early 2022, was used in this study. Tomato seedlings rated susceptible to F. oxysporum [1,2] were raised in individual seedling cells in seed raising mix (Plugger 111, Australian Growing Solutions Pty Ltd, Tyabb, VIC, Australia) for three to four weeks until reaching the two-leaf stage. They were gently removed from the seedling cells, and soil particles were thoroughly washed off the root system.…”

“…The Australian Processing Tomato Industry (APTI) has been affected by yield decline over recent years, which is partly attributed to the increase in disease incidence and severity caused by a novel Fusarium oxysporum that causes collar and root rot. F. oxysporum is a slow-growing species compared to many Pythium species that co-existed with it in processing tomatoes, and it often causes severe damage in the middle to late stages of the host plants [1][2][3]. Affected plants usually had poor root development and could not reach full growth and production potential.…”

“…Affected plants usually had poor root development and could not reach full growth and production potential. In more severe cases, approximately 10-15% of the processing tomato plants were infected [1,2]. The APTI depends on field surveys to assess the disease incidence based on symptomology.…”

“…The APTI depends on field surveys to assess the disease incidence based on symptomology. For general isolation and identification of putative soilborne pathogens that have been widely applied, diseased plants are sent to professional laboratories to confirm pathogen identification through culturing and DNA sequences [1][2][3]. Although various pathogens of processing tomatoes have been successfully 2 of 18 isolated and identified through this general approach, disease detection occurs after plants have been infected and are exhibiting clear disease symptoms, which is considered too late and ineffective.…”

“…This study aimed to provide a system for the rapid and effective early detection of Fusarium oxysporum in processing tomatoes in a controlled environment. Since the previous identification and detection of F. oxysporum have relied on molecular technologies, as previously mentioned, applying an e-nose coupled with ML models has never been implemented before [1][2][3]. Output data from an e-nose was used as inputs to construct more accurate supervised ML classification and regression models to classify tomato plants and soil samples into different levels of pathogen infection and to predict plant physiological parameters using a logistic regression model.…”