Evaluation of Dwarf Tomato Germplasm for Dual-Purpose Use: Breeding and Rootstock Potential

Tomato plant (Solanum lycopersicum L.) productivity is threatened by biotic and abiotic stresses, exacerbated by climate change. The use of rootstocks is an effective strategy to enhance tomato resilience. Interest in characterizing dwarf tomato germplasm has increased, though its potential as a rootstock remains unexplored. The objective was to validate the use of dwarf tomato germplasm for: (1) characterizing dwarf tomato genotypes for morphoagronomic traits relevant to hybrid development and (2) evaluating their potential as rootstocks. Two greenhouse experiments were conducted. Experiment I assessed a recurrent parent (normal-architecture tomato), a donor parent (dwarf tomato), and twelve dwarf tomato lines. Morphoagronomic traits of fruits, shoots, and roots were evaluated, allowing the selection of the best dwarf tomato candidate for rootstock use. Experiment II was performed after grafting onto the selected dwarf tomato rootstock (UFU MC TOM1) from Experiment I. Commercial hybrids (Xanthus, Luan, Vivacy, and Bento) were used as grafting material, resulting in four graft combinations: Vivacy/UFU MC TOM1, Xanthus/UFU MC TOM1, Luan/UFU MC TOM1, and Bento/UFU MC TOM1. Both experiments followed a randomized block design in a greenhouse. Data were analyzed using univariate and multivariate approaches. The evaluated dwarf tomato germplasm exhibited relevant morphoagronomic traits, standing out as a promising source for hybrid development. The use of dwarf tomato genotypes as rootstocks proved viable, as grafting significantly increased root volume, overcoming potential limitations associated with the dwarf plant’s root system. These findings highlight the potential of dwarf tomatoes for both breeding programs and grafted seedling production, contributing to crop sustainability and efficiency.