Resumo: O objetivo deste trabalho foi determinar os parâmetros genéticos e a eficiência de diferentes índices de seleção para linhagens de alface de folhas vermelhas (Lactuca sativa var. crispa) biofortificada e com potencial agronômico e nutricional. O experimento foi conduzido em delineamento de blocos ao acaso, com três repetições e 31 genótipos de alface do tipo crespa e com pigmentação roxa: a cultivar Belíssima, com baixa quantidade de carotenoides e rica em antocianina; e 30 linhagens provenientes do cruzamento entre as cultivares Belíssima e Uberlândia 10000, rica em carotenoides e com baixo teor de antocianina. As características avaliadas foram: massa verde total (g), diâmetro do caule (cm), número de folhas, diâmetro da planta (cm), temperatura foliar (°C), índice de desenvolvimento de análise de planta de solo (SPAD), teor de antocianina (mg por 100 g de amostra) e pendoamento (dias após a semeadura). Para as estimativas dos ganhos de seleção, foram selecionados 12 genótipos por meio de índices de seleção. O índice clássico proposto por Smith & Hazel e o índice da soma de “ranks” de Mulamba & Mock proporcionaram os maiores ganhos de seleção na alface biofortificada. O coeficiente de determinação genotípica para número de folhas, teor de antocianina, pendoamento e índice SPAD é de alta magnitude.

Abstract: The objective of this work was to determine the genetic parameters and the efficiency of different selection indices for biofortified red leaf lettuce (Lactuca sativa var. crispa) lines with agronomic and nutritional potential. The experiment was carried out in a randomized complete block design with three replicates and 31 crisp-textured and red-tinted leaf lettuce genotypes: the Belíssima cultivar, with a low carotenoid content and rich in anthocyanins; and 30 lines from the cross between the Belíssima and Uberlândia 10000 cultivars, rich in carotenoids and with a low anthocyanin content. The assessed traits were: total green mass (g), stem diameter (cm), leaf count, plant diameter (cm), foliar temperature (°C), soil plant analysis development (SPAD) index, anthocyanin content (mg 100 g-1 sample), and bolting (days after sowing). To estimate selection gains, 12 genotypes were selected through selection indices. The traditional index proposed by Smith & Hazel and the sum of ranks index by Mulamba & Mock provided the highest selection gains in the biofortified lettuce. The coefficient of genotypic determination for leaf count, anthocyanin content, bolting, and SPAD index is of high magnitude.

ABSTRACT Developing biofortified foods such as lettuce is a frequent goal of breeding programs. One obstacle to the success of these efforts is the high temporal and financial cost of determining leaf constituents. Image phenotyping has been increasingly used in crop breeding, but not in lettuce breeding. Until now, the use of image phenotyping to indirectly select carotenoid-rich lettuce inbred lines has not been reported. Therefore, the goal of this study was to use image phenotyping to select lettuce inbred lines with different carotenoid levels. Twenty-two inbred lettuce lines, resulting from the hybridization of the cultivars Pira 72 and Uberlândia 10000 and six successive selfings were evaluated. ‘Grand Rapids’, ‘UFU-Biofort’ and ‘Uberlândia 10000’ were used as controls. The following variables were evaluated: agronomic potential, apparent genetic diversity and image phenotyping. The data were submitted to the ANOVA F test (p ≤ 0.05) and means compared by the Scott–Knott test (p ≤ 0.05). Genetic divergence was represented by dendrograms constructed by UPGMA and the Tocher optimization method. The relative contribution of characters was assessed to identify the most relevant response variable. The genetic diversity of the evaluated germplasm bank was the greatest regarding soil plant analysis development (SPAD)/carotenoid values. Image phenotyping was successfully used to detect different levels of SPAD/carotenoid levels and could be a useful tool for plant breeding. The results of this study can be used to predict the nutritional values of the carotenoid content in lettuce leaves before commercialization.

RESUMO Vantagens agronômicas e econômicas tem sido observadas com o uso de linhagens anãs para obtenção de híbridos em minitomate. No Brasil, predomina-se o cultivo de tomate do tipo salada. A exploração dos beneficios proporcionados pelo uso do parental anão em híbridos de tomateiro do tipo salada ainda não é uma realidade. A avaliação e seleção de populações de porte anão pode aumentar a eficiência do desenvolvimento de tais linhagens. Sendo assim, torna-se necessário o desenvolvimento de linhagens anãs do tipo salada. O retrocruzamento é o método mais adequado para se desenvolver tais linhagens. Portanto, o objetivo deste trabalho foi selecionar populações F2RC1 de tomateiro anão com potencial agronômico e qualidade de fruto.O experimento foi conduzido na Estação Experimental de Hortaliças da Universidade Federal de Uberlândia (UFU). Utilizou-se o delineamento de blocos casualizados com 15 tratamentos e três repetições. O material genético avaliado consistiu de 12 populações F2RC1 de tomateiro anão, mais ambos os genitores (recorrente e doador) e um híbrido comercial. As características avaliadas foram: massa média (g), teor de sólidos solúveis (ºBrix), número de lóculos (lóculos fruto-1), formato, espessura da polpa (cm), diâmetro longitudinal (cm) e transversal do fruto (cm); comprimento dos internódios (cm) e altura das plantas (cm). Os dados foram analisados por meio de teste de médias, análises multivariadas e índice de seleção. De maneira geral, a massa média dos frutos das populações anãs aumentou significativamente após o primeiro retrocruzamento e algumas destas apresentaram o formato de fruto próximo ao do segmento salada. Ao selecionaras populações UFU-DTOM7, UFU-DTOM10, UFU-DTOM5, UFU-DTOM9 e UFU-DTOM3 foi estimado um incremento de até 6% no número de lóculos, diâmetro transversal, relação DT/DL e peso médio do fruto. As populações anãs F2RC1 UFU-DTOM7 e UFU-DTOM10 se destacaram sendo promissoras para obtenção de linhagens. Apesar do avanço considerável obtido na presente pesquisa, sugere-se a realização do segundo retrocruzamento e posterior obtenção de linhagens para formar híbridos.

ABSTRACT The use of dwarf lines to obtain mini-tomato hybrids has provided agronomic and economic benefits. In Brazil, round tomatoes predominate over other varieties. The benefits of using a dwarf parent in round tomato hybrids has yet to be explored, making it important to develop dwarf round tomato lines. Backcrossing is the most suitable method to develop these lines. Evaluation and selection of the dwarf populations can improve the development of such lines. Thus, the aim of this study was to select BC1F2 populations of dwarf round tomatoes with agronomic potential and high-quality fruit. The study was conducted at the Vegetable Experimental Station of the Federal University of Uberlândia (UFU). A randomized block design was used, with 15 treatments and three replicates. The genetic material analyzed consisted of 12 BC1F2 dwarf tomato populations, plus both parents (recurrent and donor) and a commercial hybrid. The characteristics assessed were: average fruit weight (g), total soluble solids (ºBrix), number of locules (locules per fruit-1), fruit shape, pulp thickness (cm), longitudinal (cm) and transverse fruit diameter (cm), internode length (cm) and plant height (cm). The data were submitted to mean testing, multivariate analyses and a selection index. In general, average fruit weight in the dwarf populations increased significantly after the first backcross, with some fruits exhibiting a similar shape to round tomatoes. Selection of the populations UFU-DTOM7, UFU-DTOM10, UFU-DTOM5, UFU-DTOM9, and UFU-DTOM3 resulted in an estimated 6% increase in the number of locules, transverse diameter, TD/LD ratio and average fruit weight. The BC1F2 dwarf populations UFU-DTOM7 and UFU-DTOM10 were the most promising for develop inbred lines with round fruits. Despite the considerable progress achieved in this study, we suggest a second backcross, in order to obtain lines and, posteriorly, hybrids with round fruits and compact plants.

Abstract The objective of this study was to characterize and select genotypes which displayed aptitude for genetic improvement for tomatoes consumed in natura as well as for those used in industrial processing. There were ten genotypes evaluated, being those from seven lines (CVR 1, CVR 3, CVR 4, CVR 5, CVR 8, CVR 21 and CVR 22) and three commercial hybrids (AP-533, SVR-0453 and Kátia) and analyzing the physicochemical characteristics of the produced fruits as: soluble solids rates, acidity in citric acid, total titratable acidity, soluble solids and total titratable acidity relation, pH, vitamin C, mass, transversal and longitudinal diameter and fruit firmness. In face of the analyzed characteristics, it was concluded that all genotypes produce fruits with aptitude to be consumed in natura. The fruits present soluble solids content above 3 °Brix, oblong shape and “moderately soft” texture. Line CVR 22 showed the highest values for soluble solid and total titratable acidity relation, producing fruit with more pleasant and mild flavor, while lines CVR 3 and CVR 8 produced fruits with higher acidity and lower pH, with red coloration accentuated, characteristics indicated for genetic improvement of industrial tomato.