Components of resistance to Olivea neotectonae in Tectona grandis Linn F. as a criterion for selecting promising genotypes

The aim of this paper was to identify the best components involving resistance to the O. neotectonae fungus, allowing for adequate selection of promising teak genotypes to explore in improvement programs or for disease management. Thirty different clonal teak genotypes were evaluated in a greenhouse from PROTECA Biotecnologia Florestal. The experimental design was a randomized block design with three replications and three plants per plot. The following characteristics were evaluated: average latent period, number of pustules per cm2, area below the number of pustules progress curve (ABNPPC), frequency of infection, and number of urediniospores per pustule. The data for the resistance characteristics were submitted to ANOVA and multivariate analysis applying grouping techniques and canonical variables. High genetic variability was observed among the 30 T. grandis genotypes regarding resistance to the O. neotectonae fungus. Both for the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), the canonical variables method and Best Linear Unbiased Prediction (BLUP) the genotypes that showed the greatest resistance to the fungus were genotypes 03 and 10