Multivariate techniques in the determination of genetic diversity in pest-resistant mini tomato genotypes

Resumo

The objective of this work was to compare different methods of multivariate analysis in the evaluation of genetic diversity in pest-resistant mini tomato. The experiment was conducted at the Vegetable Experiment Station of the Universidade Federal de Uberlândia - Monte Carmelo campus, from April 2013 to November 2016. The experimental design was a randomized complete block design with 16 treatments and four replications totaling 64 plots, and each plot was represented by five plants. There were characterized sixteen genotypes, 12 from the F₂RC₁ generation, obtained through the interspecific crossing between wild access LA-716 (Solanum pennellii) versus pre-commercial lines of mini tomato (UFU-73 and UFU-2) (Solanum lycopersicum) and the UFU-2 lines. The content of acyl sugar, the amount of glandular trichomes (types I, IV, VI and VII), twospotted spider mite and whitefly resistance were evaluated. It can be concluded that there is genetic variability between the genotypes. The number of groups formed by the canonical variated analysis was higher (four groups) than that obtained by the Tocher method (three groups) and UPGMA (three groups), demonstrating a greater discrimination power. The Tocher and UPGMA methods were consistent in the analysis of the genetic divergence in pest resistant germplasm of tomato, with the acyl sugar content being the most important variable.