Among the most widely cultivated vegetable crops, worldwide, tomatoes (Solanum lycopersicum) and peppers (Capsicum annuum) are both diverse in form, flavor and utility, and they contribute vitamins necessary to human health such as provitamin A carotenoids, vitamin C and folate (vitamin B9). Accordingly, the investigation and the discovery of new genetic variation that influences fruit nutritional quality and plant vigor underlies the ability of these crops to address human needs. Chapter 1 of this dissertation entails a review, originally published in 2021, that examines the roles of the various phytohormones that orchestrate soft fruit development, maturation and ripening. Tomato and strawberry are chiefly discussed as respective models for climacteric and non-climacteric ripening behavior, and recent advances across a diversity of other fruit crops are also discussed. Chapter 2 concerns the functional analysis of the candidate carotenoid accumulation regulators, ORANGE and ORANGE-Like. Both proteins are DnaJE1 molecular chaperones with established roles mediating pathway flux in melons, sweet potatoes and orange cauliflower, but they remain uncharacterized in tomato. Single and double mutants bearing knockout alleles of one or both genes were generated through CRISPR/Cas9-mediated editing and phenotyped for growth attributes as seedlings, and subsequently for flower color, fruit color and ripening behavior. Chapter 3 explores quantitative traits mediating plant vigor and fruit ease-of-harvest in pepper, specifically node height, stem diameter and basal branching. A biparental population, derived from a cross between an elite cayenne variety and an architecture ideotype, was grown during two field seasons (2024, 2025) and used to map major-effect QTLs accounting for over 30% of observed variation. Genomic prediction (GS) models were also used to perform selections and assess whether genomics-assisted selection could be an effective complement to phenotypic selection for plant morphological breeding. Within the Appendix, I describe my progress on continuing projects. These include my efforts to characterize folate profiles in a commercial panel of elite peppers, where biological folate variation is undescribed, using a dual approach pairing LC-MS/MS and a microbiological assay. This is an experiment that I plan to publish after my graduation, in addition to the projects undertaken for Chapters 2 and 3.