Generating Novel Tomato Germplasm Using Solanum neorickii

Tomato (Solanum lycopersicum) is the second-largest vegetable crop globally after potato (S. tuberosum), while the narrow genetic base of cultivated tomatoes seriously restricts their improvement. However, the rich genetic diversity harbored in tomato’s wild relatives provides the enormous potential for the genetic enhancement of cultivated tomatoes. Solanum neorickii, a green-fruited wild relative, harbors valuable traits such as high nutritional quality and resistance to biotic and abiotic stresses and exhibits no reproductive barrier with cultivated tomato. This study demonstrates the potential of S. neorickii for improving cultivated tomato by developing interspecific hybrid populations between LA0247 (S. neorickii) and the elite tomato variety Momotaro (S. lycopersicum). A suite of traits, including morphological, chemical, and physiological characteristics, was systematically dissected. The results showed that F1 generation phenotypes predominantly resemble LA0247, while the botanical characteristics in the F2 generation exhibit enriched phenotypic diversity, presenting a range of morphologic phenotypes resembling Momotaro, LA0247, or intermediate types. Compared with the core parent Momotaro, LA0247 had significantly higher nutritional quality traits such as ascorbic acid, soluble solids, firmness, β-carotene, lutein, and sucrose. In both F1 and F2 generations, several families demonstrated superior performance in key quality components, with F2-50 and F2-160 showing overall better quality than Momotaro. Mannitol (C6H14O6) and sodium chloride (NaCl) were used to mimic drought and salt stresses. The results showed that LA0247 seedlings exhibited a stronger response to mannitol and NaCl than Momotaro, and this enhanced stress responsiveness was also consistently observed across different F1 and F2 progenies. These findings highlight that LA0247 (S. neorickii) has great potential to improve fruit quality and abiotic stress tolerances in cultivated tomato. Notably, a set of the valuable novel germplasm resources has been developed in this study, which is of great value for simultaneously enhancing fruit quality and stress tolerance in tomatoes.