Identifying salt-tolerant traits in Solanum pimpinellifolium through in vitro screening to enhance crop resilience

Abiotic stresses are considered the primary cause of crop loss worldwide, with salinity being particularly significant. Excessive salt accumulation can impair photosynthetic efficiency, disrupt nutrient assimilation, reduce growth, and lower product quality. In response to these issues, genetic improvement has focused on a limited number of tomato cultivars, significantly reducing their biodiversity. Tomato is a moderately salinity-sensitive crop widely cultivated even with poor-quality irrigation water, making it an ideal candidate for this research.An innovative in vitro screening method was developed using wild tomato seedling accessions grown on plates with sucrose-free agarized medium containing increasing concentrations of sea salt, using marine salinity as a reference. This autotrophic approach allowed us to (i) evaluate biometric and biochemical parameters while closely resembling in vivo plant behaviour, (ii) expand knowledge on biometric traits relevant to adaptation to adverse environmental conditions (salinity), (iii) define innovative phenotyping methodologies to select wild genotypes, and (iv) simultaneously analyse numerous accessions in the confined space of a growth chamber. The results from the in vitro culture screening effectively discriminated the biometric and biochemical parameters involved in salt stress resistance. Notably, the S. pimpinellifolium L. accessions investigated thus far have proven to be more resistant to salinity than traditional cultivars when grown in media enriched with 60% seawater. This study aimed to explore the existing genetic variability in wild tomato species (Solanum pimpinellifolium L.) and highlights their potential as genetic resources for developing more resilient tomato cultivars to meet future agricultural challenges posed by climate change, by enhancing the genetic diversity of contemporary cultivar.