Agronomic potential of BC1F2 dwarf round tomato populations

Abstract

The use of dwarf lines to obtain mini-tomato hybrids has provided agronomic and economic benefits. In Brazil, round tomatoes predominate over other varieties. The benefits of using a dwarf parent in round tomato hybrids has yet to be explored, making it important to develop dwarf round tomato lines. Backcrossing is the most suitable method to develop these lines. Evaluation and selection of the dwarf populations can improve the development of such lines. Thus, the aim of this study was to select BC1F2 populations of dwarf round tomatoes with agronomic potential and high-quality fruit. The study was conducted at the Vegetable Experimental Station of the Federal University of Uberlândia (UFU). A randomized block design was used, with 15 treatments and three replicates. The genetic material analyzed consisted of 12 BC1F2 dwarf tomato populations, plus both parents (recurrent and donor) and a commercial hybrid. The characteristics assessed were: average fruit weight (g), total soluble solids (ºBrix), number of locules (locules per fruit-1), fruit shape, pulp thickness (cm), longitudinal (cm) and transverse fruit diameter (cm), internode length (cm) and plant height (cm). The data were submitted to mean testing, multivariate analyses and a selection index. In general, average fruit weight in the dwarf populations increased significantly after the first backcross, with some fruits exhibiting a similar shape to round tomatoes. Selection of the populations UFU-DTOM7, UFU-DTOM10, UFU-DTOM5, UFU-DTOM9, and UFU-DTOM3 resulted in an estimated 6% increase in the number of locules, transverse diameter, TD/LD ratio and average fruit weight. The BC1F2 dwarf populations UFU-DTOM7 and UFU-DTOM10 were the most promising for develop inbred lines with round fruits. Despite the considerable progress achieved in this study, we suggest a second backcross, in order to obtain lines and, posteriorly, hybrids with round fruits and compact plants.

Selection of F2RC1 saladette-type dwarf tomato plant populations for fruit quality and whitefly resistance

“…Such lines can be obtained by backcrossing, which is the method used in the development of lines originating from interspecific crosses and in obtaining dwarf plants in saladtype tomatoes (Finzi et al, 2020). In addition, progenies agronomically superior to the donor parent with characteristics from the genetic constitution of the recurrent parent can be assured (Borém & Miranda, 2013).…”

“…In addition to the potential use of dwarf strains in tomato breeding programs, it is important to consider the susceptibility of the crop to pests and the demand for better looking and quality fruit (Andrade et al, 2014;Finzi et al, 2020).…”

“…The characterization of germplasm in terms of agronomic variables, fruit quality and resistance to pests provides relevant information for the selection of promising genotypes (Peixoto et al, 2019;Finzi et al, 2020;Londoño-Giraldo et al, 2020).…”

“…A study has reported obtaining dwarf tomato plant populations of the salad segment (Finzi et al, 2020); however, there are no studies on the use of introgression technology in saladette-type tomatoes, whose consumption has remarkably increased (CONAB, 2019).…”

Evaluation of families derived from backcrosses of processed tomato with dwarfism gene

“…They recommended the use of the bu gene, due to the possibility of early identification of dwarf progenies, and found a higher fruit yield per plant. More compact plants, i.e., with shorter leaf and internode length, should be one of the objectives of breeding for processed tomato since such plants are better suited for mechanical harvesting (Finzi et al 2017, Martínez-Gómez 2019, Finzi et al 2020).…”