Herança do hábito de crescimento e desempenho agronômico de híbridos de minitomate provenientes de linhagens anãs

Abstract

Among the types of tomatoes, minitomatoes stand out because of their smaller fruit and sweeter taste. Due to increasing demand, breeding programs have sought to develop more productive minitomatoes hybrids. It is known that the architecture is one of the characteristics that influence the most the agronomic performance of the tomato plant; and the plant size or architecture can be directly influenced by the genes that control the growth habit, as well as the genes that confer the dwarfism in the culture. Therefore, the objective of this study was to evaluate the growth habit and the agronomic performance of mini-tomato hybrids obtained by crossing a dwarf line with regular line of indeterminate, determinate and semi-determinate growth. This research was carried out in two stages: first, the inheritance of growth habit was studied and, then, the agronomic performance of minitomato hybrids which came from dwarf lines. Both trials were carried out at the vegetable trial station at the Federal University of Uberlandia - Monte Carmelo Campus, MG, Brazil. The growth habit inheritance study consisted of reciprocal biparental crosses [dwarf line versus normal lines (determinate, semideterminate and indeterminate growth habits)], backcrosses of the Fi to the parents [normal lines (Pi) and dwarf line (P2)], and obtaining F2 generation. It was observed that the inheritance of growth habit in the hybrids depends of the dwarf linegrowth. This inheritance is from the allele that conditions for the indeterminate plant phenotype. The dwarf-sized line has an indeterminate growth habit. For the second study, a completely randomized design with 17 treatments and four replications was used. The genetic material consisted of 16 experimental minitomato hybrids (belonging to the UFU tomato plant germplasm bank) and a commercial hybrid(control). In general, the hybrids of minitomato from dwarf and the control lines were differentiated in all variables, except for the number of fruits plant-1, number of fruits bunch-1 and in the diameter of the stem. In general, hybrids from dwarf lines presented higher yield (20%), shorter internodes (11%) and shorter distance from the first bunch to the soil (30%) when compared to the control line. It can be concluded that the exploitation of dwarf lines proves to be viable in obtaining minitomato hybrids, since they have commercial potential.