Toward Drought Tolerance in Tomato: Selection of F2BC1 Plants Obtained from Crosses Between Wild and Commercial Genotypes

Abstract

The tomato plant (Solanum lycopersicum L.) demands more water than other vegetables. However, water availability has become a limiting factor worldwide due to climate change. Thus, it is essential to explore the genetic variability of species to develop genotypes with satisfactory yields under low water availability. In this context, the objective of this study was to identify water-deficit-tolerant plants within the genetic variability of tomatoes and to select drought-tolerant genotypes from the second generation of the first backcross (F₂BC₁). For this, seven wild accessions, three S. lycopersicum var. cerasiforme accessions, and six commercial cultivars were tested. Moreover, intra- and interspecific crosses were performed and from the crosses S. lycopersicum × S. pennellii, two F₂BC₁ populations were obtained. Three experiments were conducted where the genotypes were subjected to water deficit and physiological and growth parameters. The commercial tomatoes were the most susceptible to water deficit. Among the tested cerasiform varieties, the RVC 66 accession was the least affected by the reduced water supply. The LA 716 accession (S. pennellii) had the highest tolerance to water deficit, followed by ‘LA 1401’ (S. galapagense) and ‘LA 1967’ (S. chilense). The LA 716 accession was the most promising to introgress drought tolerance-related genes in the commercial tomatoes compared to the intraspecific crosses. In addition, crossing between ‘LA 716’ and the commercial tomatoes ‘Clara’ and ‘Redenção’ allowed the development and selection of drought-tolerant F₂BC₁ genotypes.