ABSTRACT. To be considered drought-tolerant, a tomato cultivar is required to present some level of tolerance at all developmental stages of plant growth. Since drought tolerance is a stage-specific phenomenon, genotype assessment must be performed separately at all developmental stages. In this study, we used a multi-trait index based on factor analysis and genotype-ideotype distance (FAI-BLUP index) to properly rank 49 tomato genotypes according to their tolerance to drought stress conditions at germination and seedling stages. Seeds of 47 introgression lines, which cultivar M82 is considered drought-sensitive, and the Solanum pennellii wild accession LA 716, which is considered drought-tolerant, were subjected to a control condition, where seeds were soaked in distilled water, and a drought condition, where seeds were soaked in a polyethylene glycol (PEG) solution (-0.3 MPa). Drought stress, induced by PEG, had a significant impact on all nine germination and growth performance-related traits; there was a reduction in shoot length (SL), total length (TL), initial germination percentage (IGP), final germination percentage (FGP), germination velocity index (GVI), and germination rate (GR). In contrast, the root-to-shoot ratio (R/S) and time to reach 50% germination (T50) increased under drought stress. Root length (RL) was less affected by drought, and in some genotypes, it was even increased. As expected, LA 716 ranked closest to the drought tolerance ideotype. IL 1-4-18, IL 2-3, IL 1-2, IL 9-2, and IL 10-1 were the most drought-tolerant at the germination stage. These results will serve as guidance for breeders who are aiming at developing drought-resistant tomato cultivars.

RESUMO Hancornia speciosa Gomes é uma das espécies frutíferas nativas mais frequentes no Cerrado. Estudos sobre a variabilidade genética de caracteres quantitativos para essa espécie são escassos e a identificação de acessos com as melhores características agronômicas pode subsidiar estratégias de programas de conservação e melhoramento genético. Objetivou-se estimar a diversidade genética de acessos da coleção de germoplasma de H. speciosa da Universidade Federal de Goiás e classificá-los com base em um índice de seleção combinando onze características agronômicas. Foram avaliados 192 acessos individuais de 57 progênies, de 29 populações naturais. Os dados foram submetidos a análise multivariada e os indivíduos e progênies avaliados pelo índice de seleção FAI-BLUP. A análise de agrupamento de Tocher permitiu agrupar as progênies em dez agrupamentos divergentes e os indivíduos em 18 agrupamentos divergentes. A seleção simultânea de caracteres com base no índice FAI-BLUP pode ser recomendada, mantendo-se a variabilidade potencial na população resultante da recombinação. A seleção individual mostrou-se mais eficaz do que a seleção baseada em médias de progênies, por explorar a variação genética entre e dentro das progênies.

ABSTRACT Hancornia speciosa Gomes is one of the native fruit species most frequent in the Brazilian Savanna. Studies on the genetic variability of quantitative traits for this species are scarce and the identification of accessions with the best agronomic traits may support strategies for conservation and breeding programs. This study aimed to estimate the genetic diversity of accessions from the H. speciosa germplasm collection of the Universidade Federal de Goiás (Goiânia, Goiás state, Brazil) and rank them based on a selection index combining eleven agronomic traits. A total of 192 individual accessions from 57 progenies, from 29 natural populations, were evaluated. The data were subjected to multivariate analysis and the individuals and progenies evaluated using the FAI-BLUP selection index. The Tocher cluster analysis allowed grouping the progenies into ten divergent clusters and the individuals into 18 divergent clusters. The simultaneous selection of traits based on the FAI-BLUP index may be recommended while maintaining the potential variability in the population resulting from the recombination. The individual selection proved to be more effective than the selection based on progenies means, because it exploits the genetic variation among and within progenies.

ABSTRACT Germplasm classification by species requires specific knowledge on/of the culture of interest. Therefore, efforts aimed at automation of this process are necessary for the efficient management of collections. Automation of germplasm classification through artificial neural networks may be a viable and less laborious strategy. The aims of this study were to verify the classification potential of Capsicum accessions regarding/ the species based on morphological descriptors and artificial neural networks, and to establish the most important descriptors and the best network architecture for this purpose. Five hundred and sixty-four plants from 47 Brazilian Capsicum accessions were evaluated. Neural networks of multilayer perceptron type were used in order to automate the species identification through 17 morphological descriptors. Six network architectures were evaluated, and the number of neurons in the hidden layer ranged from 1 to 6. The relative importance of morphological descriptors in the classification process was established by Garson's method. Corolla color, corolla spot color, calyx annular constriction, fruit shape at pedicel attachment, and fruit color at mature stage were the most important descriptors. The network architecture with 6 neurons in the hidden layer is the most appropriate in this study. The possibility of classifying Capsicum plants regarding/ the species through artificial neural networks with 100 % accuracy was verified.