Bin mapping of water stress tolerance‐related, fruit quality, and horticultural traits in tomato introgression lines derived from wild Solanum habrochaites

Abstract

AbstractClimate change is reducing water availability for crop production. Cultivated tomato, Solanum lycopersicum, has a limited genetic base for improvement. A wild tomato, Solanum habrochaites, is water stress tolerant and may serve as a genetic source of abiotic stress‐tolerance traits. A set of 24 introgression lines (ILs) derived from S. habrochaites and processing tomato inbred cultivar E6203 were evaluated in the field in replicated experiments over 3 years for 15 traits, including water stress tolerance‐related, fruit quality, and horticultural traits. A split plot experimental design was employed with reduced and full irrigation treatments as main plots. Subplots consisted of the ILs and control E6203, and trait data were collected on a per‐subplot basis. Statistical data analyses and bin mapping were performed on a per‐trait basis. Trait‐genomic region associations (TGRAs) were detected in ILs when a significant difference between E6203 and an IL was present. A total of 268 TGRAs were detected for all 15 traits. Traits mapped to introgressions in 22 of the 24 ILs and in 11 of 12 tomato chromosomes. ILs contributed both positive and negative allelic effects at TGRAs. TGRA with positive allelic effects from S. habrochaites were identified for soluble solids content, fruit weight, degree of fruit sunburn, canopy cover, and maturity. Our results suggest that S. habrochaites may be a useful resource for breeding improvement of certain fruit quality and horticultural traits in cultivated tomato. Overall, S. habrochaites alleles did not contribute to increased water stress tolerance relative to E6203 at the milder level of water stress used in this study.