Impact of salt stress on the reproductive development of Solanum lycopersicum and its wild halophyte relative Solanum chilense

Salinity is a growing global concern that affects the yield of crop species, including tomato (Solanum lycopersicum). In contrast to S. lycopersicum, its wild relative Solanum chilense was reported to have halophyte properties. We compared salt resistance of both species during reproductive phase and investigated minerals accumulation and sugar metabolism to identify the main causes of the decrease of flower production and fertility. Plants were exposed to NaCl (0, 60, 120 mM) from the seedling stage for 91 days. Inflorescence production decreased in both species under salinity while inflorescences and flowers abortion increased in S. lycopersicum only. Regarding flower fertility, the number of pollen grains per flower decreased in S. chilense. Pollen viability increased with salt in S. chilense. Both species limited the accumulation of Na and Cl in the inflorescences without affecting K concentration. The concentration of Na and K in the inflorescences was lower in S. lycopersicum than in S. chilense under salt stress while the concentration of Cl was higher in the inflorescences of S. lycopersicum. In flowers, Na was mainly located in male floral organs of S. chilense but in non-reproductive floral organs of S. lycopersicum under salinity. Sugar analysis showed that S. lycopersicum and S. chilense did not present the same composition of sugars in the inflorescences and that S. lycopersicum presented more sugars in inflorescences than S. chilense. Overall, our results indicated that both species differed towards strategies of minerals and sugars accumulation in reproductive organs