Banca de QUALIFICAÇÃO: CARLOS ALBERTO REYES MALDONADO JUNIOR

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : CARLOS ALBERTO REYES MALDONADO JUNIOR
DATA : 01/04/2026
HORA: 08:00
LOCAL: Cáceres
TÍTULO:

Characterization of Teak Rust Resistance and Isolate Preservation, of Tectona grandis Genotypes.

PALAVRAS-CHAVES:

Teak, Plant breeding, Olivea neotectonae.

PÁGINAS: 40
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:

Tectona grandis (teak) is a forest species of high economic, social, and environmental importance. Brazil stands out as the largest producer in Latin America, with crops concentrated mainly in the states of Mato Grosso and Pará. Internationally, teak wood is recognized as one of the most valuable in the tropical market, due to attributes such as durability, dimensional stability, natural resistance to pests, and aesthetic beauty, which give it noble and high-value applications. The global expansion of teak forestry, driven by its rapid growth and high profitability, faces, however, a serious phytosanitary challenge: leaf rust, caused by the fungus Olivea neotectonae. This disease causes premature defoliation and can reduce plantation productivity by up to 30%. In Brazil, genetic improvement of teak is still in its infancy, with a significant gap in research focused on disease resistance, which limits the exploitation of available genetic variability. Given the absence of resistant commercial cultivars and the need for sustainable management strategies, genetic improvement emerges as a fundamental approach. In this context, the objectives of this study were: (a) assess the severity of rust in nine commercial teak clones; (b) identify clones resistant to the pathogen; and (c) develop and test efficient methods for preserving O. neotectonae spores. The research was conducted in a greenhouse, in a completely randomized design (CRD), in a 9 x 2 factorial scheme, comprising nine clones (provided by TRC) and two types of inoculation (suspension of pathogen spores vs. autoclaved water as control), with three replicates, totaling 54 plants. At the same time, six methods of preserving urediniospores collected from symptomatic leaves were evaluated: 1) dehydration in silica gel; 2) freeze-drying; 3) storage at -20°C; 4) storage at -80°C; 5) thermal shock in liquid nitrogen (-196°C) followed by storage at -80°C; and 6) maintenance at room temperature (20°C). Spore viability was monitored monthly for seven months through germination tests and microscopic analysis. After 60 days, the inoculum from each treatment was reactivated and used for inoculation by spraying susceptible clonal seedlings, which remained in a humid chamber for 24 hours. The severity of the disease was quantified by counting pustules, and the data were submitted to analysis of variance (ANOVA) and Tukey's test (5% significance). The results of this study will enable the formation of a collection of viable regional isolates and the selection of promising genetic materials, contributing to technical autonomy in forest pathology and the development of improved cultivars. These actions are expected to strengthen the sustainability and productivity of techniculture in the region.

MEMBROS DA BANCA:
Presidente - 132048001 - LEONARDA GRILLO NEVES
Interno - 326534002 - ANTONIO MARCOS CHIMELLO
Externa ao Programa - 301272001 - GILCIANNY PIGNATA CAVALCANTE
Externo à Instituição - 025.733.472-65 - DALCIRLEI PINHEIRO ALBUQUERQUE - UFV