Perfil metabolômico e introgressão de genes de nanismo em tomateiro a partir de retrocruzamentos visando background do tipo salada

Abstract

The use of dwarf tomato lines for obtaining hybrids is an alternative that can provide additional advantages, being a known strategy for increasing productivity in the mini tomato segment. However, there are still no dwarf lines with salad-type fruits for the use of this technology. Through backcrossing, populations of dwarf tomatoes can be developed, and by characterizing and evaluating the genetic dissimilarity between populations, it is possible to select the most promising ones for obtaining lines. Therefore, this study aimed to obtain populations of saladtype dwarf tomatoes using the backcross method to develop lines and subsequently obtain hybrids. The work was carried out in two stages: first, the dwarf tomato populations obtained after two backcrosses (BC1), (BC2) were characterized, and the presence of metabolites in dwarf tomatoes was evaluated. In the second stage, the potential and genetic dissimilarity of the dwarf populations obtained after the first (BC1), second (BC2), and third (BC3) backcrosses were measured to observe the increments obtained in each backcross and select the best populations for line development. Both experiments were conducted in a greenhouse at the Vegetable Experimental Station of the Federal University of Uberlândia (UFU), Monte Carmelo-MG. The dwarf tomato populations were characterized for agronomic potential, fruit quality, and indirect pest resistance. The data were analyzed using mean tests, multivariate analyses, and selection indices. In the first experiment, it was found that the second backcross was responsible for significant increments in fruit size, and predominantly, the second backcross produced fruits with salad-type characteristics. The dwarf tomato populations UFUDTOM 8#2-3, UFU-DTOM 22#1-17, and UFU-DTOM 4#4-14 from the second backcross proved to be promising for the development of lines and could be therefore be used later to obtain hybrids. In addition acyl sugars in the leaflets of the dwarf line UFU DTOM 1, a higher expression was foundof the metabolites identified as glycine, myo-inositol, acetamide, and dodecanoic acid, promising molecules for new research aiming at resistance to different types of biotic and abiotic stress. In the second experiment, the populations that presented promising results for line development were UFU-DTOM 4#4-11-1 (BC3), UFU-DTOM 21#2-1-1 (BC3), UFU-DTOM 19#1-3-1 (BC3), and UFU-DTOM 4#4-11 (BC2). The predominant selection of salad-type dwarf tomato populations from the third backcross (BC3) demonstrates the importance of performing the third backcross to obtain introgression lines of dwarf tomatoes with salad-type fruit characteristics.