https://repositorio.ufu.br/handle/123456789/18943 2026-06-25T11:57:30Z https://repositorio.ufu.br/handle/123456789/48768 Title: Parâmetros genéticos e seleção de populações F2 provenientes de cruzamentos simples e duplos de alfaces biofortificadas e tropicalizadas Abstract: Lettuce is one of the most widely consumed leafy vegetables worldwide, with continuous cultivation throughout the year. In Brazil, its performance is limited by tropical conditions, especially high temperatures that induce early bolting, compromising commercial and nutritional quality. At the same time, the demand for functional foods is increasing, driving research focused on the biofortification of lettuce with bioactive compounds through genetic improvement. This study aimed to estimate genetic parameters in F2 populations derived from single and double hybrids of biofortified and tropicalized lettuces, with the goal of selecting outstanding populations. Fifteen F2 populations and three commercial cultivars were evaluated for agronomic traits and bioactive compound content. The hybrid populations showed superior performance compared to the controls, particularly in number of leaves, delayed bolting, and higher levels of chlorophyll, carotenoids, and anthocyanins, with bioactive compounds exhibiting medium to high heritability. Genetic analysis revealed CVG/CVA values close to 1 for Chlorophyll a (0.93), Carotenoids (0.74), and Anthocyanins (0.70), indicating the feasibility of genetic selection. The results confirmed that bioactive compound content in lettuce is determined by genetic factors, enabling the identification and selection of populations for biofortification and tropicalization, contributing to the development of cultivars adapted to Brazilian edaphoclimatic conditions. 2025-09-26T00:00:00Z https://repositorio.ufu.br/handle/123456789/48756 Title: Parâmetros genéticos, estratégias de seleção e diversidade genética em genótipos de soja Abstract: This thesis is divided into three chapters. In the first chapter, the objective was to study the combinatorial capacity of three parental lines through diallel crosses, using Griffing's method I (1956). Additive effects were more significant than non-additive effects for all traits evaluated. The TMG 801 parent contributed to an increase in most of traits evaluated, while the BRSGO 7560 parent contributed to a decrease in those traits. The most promising cross for shortening the growing season was BRSGO 7560 x TMG 801, while the cross UFUS 7415 x TMG 801 stood out for increasing grain yield. The combination that presented the most favorable values for cycle reduction and increased grain production was TMG 801 x BRSGO 7560. In the second chapter, the objective was to develop three soybean populations and estimate genetic parameters and breeding gains, with the aim of shortening the growing season and increasing grain yield, through the analysis of generations. Overall, for each cross, the means for agronomic and production traits in the F2, RC1, and RC2 generations were intermediate between those of their parents, and the values for the backcrosses were close to those of their respective parent. The heritability estimates (%) for the BRSGO 7560 x TMG 801 cross were: NDF (114.66%), NNTo (78.92%), NTV (102.21%), and PG (69.02%); in the combination TMG 7161 RR x UFUS 7415 they were: NNTo (107.2%), NTV (94.06%), and PG (104.91%); and in the combination TMG 801 x UFUS 7415 they were: NDF (94.84%), NDM (168.40%), NTV (71.05%), and PG (70.69%). The greatest gains per selection for cycle reduction (NDM) were obtained in the TMG 801 x UFUS 7415 cross (-21.09%), while, for increased grain production (g), the greatest gains were observed in the TMG 7161 RR x UFUS 7415 cross (97.88%). In the third chapter, the objective was to evaluate different strategies for selecting early-cycle, high-grain-yielding progenies using direct and indirect selection indices, as well as to conduct studies of genetic diversity using different clustering techniques, with the aim to identify divergent parents. Thirty progenies, F6-F7 and F7-F8, were evaluated in two growing seasons, in addition to four control lines (UFUS 7415, UFUS Tupi, UFUS 7910, and UFUS MLX). Genetic variability was detected among the evaluated progenies at a 1% or 5% probability level using the F-test for all evaluated traits. Direct and indirect selection provided the greatest genetic gains. Among the selection índices, the highest total genetic gain were obtained using the Mulamba and Mock indices. The NDM and NDF traits contributed most to determining genetic diversity. The Tocher, UPGMA, and canonical variable analysis methods clusteres the genotypes in a similar manner, forming five groups in the summer crop and four groups in the winter crop. The S128P3 and S128P4 progenies presented short cycle and high yield, desirable characteristics for use in crossbreeding with divergent genotypes. 2026-02-25T00:00:00Z https://repositorio.ufu.br/handle/123456789/48432 Title: Análise dialélica de genitores de soja visando precocidade, produtividade e teores de proteína e óleo Abstract: The careful selection of parents through combining ability methods, as well as the estimation of genetic parameters and correlations, constitute fundamental tools in breeding programs to identify segregating populations with high genetic potential and to ensure the development of superior soybean cultivars. This thesis was divided into three chapters in the article format. The first chapter aimed to evaluate the combining ability of five soybean parents for agronomic traits and protein and oil contents, with the objective of identifying promising combinations for the extraction of superior lines. The trials were conducted in Uberlândia (MG) in the 2022/23 (F3 generation) and 2023/24 (F4 generation) growing seasons, involving the parents UFUS 7010, UFUS 7101, IAC Foscarin-31, TMG 803, and BRS 511. Through diallel analysis, it was concluded that the parents IAC Foscarin-31 and BRS 511 contribute to earlier maturity and higher protein content, while TMG 803 favors productivity, and UFUS 7101 increases oil content. The most promising combinations for earliness and grain yield were TMG 803 × BRS 511 and IAC Foscarin-31 × TMG 803, whereas the combination IAC Foscarin-31 × BRS 511 stood out for increasing protein content. The second chapter aimed to estimate the combining ability of nine soybean parents through a partial diallel and to identify promising segregating combinations for agronomic traits. The trials were conducted in Uberlândia-MG in the 2023/24 (F2) and 2024/25 (F3) growing seasons, using a partial diallel between five elite genotypes (UFUS 7010, UFUS 7101, UFUS 7201, UFUS 7910, and UFUS 8401) and four genotypes serving as sources of resistance to the soybean cyst nematode (TMG 2381 IPRO, TMG 4182, BRS 7380 RR, and BRS 7581 RR). Additive gene effects predominated, indicating that the parents UFUS 7201, UFUS 8401, TMG 2381 IPRO, and TMG 4182 provided the greatest gains for yield and number of pods. The most promising combinations for obtaining superior genotypes with high productive potential were UFUS 7101 × TMG 2381 IPRO, UFUS 7910 × TMG 2381 IPRO, and UFUS 7910 × TMG 4182. The third chapter aimed to estimate genetic parameters in segregating populations and to select those with the highest potential for earliness, grain yield, and protein and oil content. Eight segregating populations and six parents were evaluated in the early generations (F2, F3, and F4), conducted in Uberlândia (MG) between the 2021/22 and 2023/24 growing seasons. The analyses showed significant genetic variability and high-magnitude heritabilities for cycle and biochemical quality. The populations UFUS 4 (for earliness and oil), UFUS 7 (for protein), and UFUS 8 (for productivity, medium cycle, and oil) stood out as the most promising for the extraction of superior genotypes. In all experiments, phenological, agronomic, yield components, and grain biochemical quality traits were evaluated. 2026-02-13T00:00:00Z https://repositorio.ufu.br/handle/123456789/48298 Title: Imagens RGB obtidas por VANT na fenotipagem de alto rendimento para seleção de genótipos de soja Abstract: The current promising soybean scenario in Brazil reflects the contributions of numerous areas, including biotechnology, precision agriculture and advances in plant breeding programs. In the current phase of plant breeding, high-throughput phenotyping (HTP) stands out to be a promising tool, enabling the evaluation of multiple variables with a high level of spatial and temporal detail, what showed to mean until now unattainable with traditional methodologies. The objective of this research aimed not only to select superior soybean genotypes in different growing and sowing seasons by applying direct, indirect and selection index, but also to evaluate the use of RGB images obtained with UAVs in the analysis of agronomic variables in soybean for genetic breeding purposes, in Buriti Alegre city - GO. The experiments were conducted on the field of this city, with sowings carried out on November 30, 2023, December 10, 2023, December 30, 2023, December 10, 2024, and December 30, 2024. 60 soybean genotypes, 41 lines and 19 control cultivars were used for this purpose. The studied genotypes were subjected to different selection techniques, considering the genotype x environment interaction, involving direct and indirect selection as well as selection indices by sum of ranks, for the following variables: plant height at maturity, number of days to maturity and grain yield. A principal component analysis (PCA) indicated the distribution of soybean genotypes (dots) and its evaluated variables (arrows), of the agronomic variables: plant height at maturity, number of days to maturity, number of pods, productivity and vegetation indices obtained from RGB images (ExG, NGRDI and VARI) at different phenological stages (R5 to R8). The study of BLUPs reinforced the selection criteria indicated by the vegetation indices, mainly VARI and NGRDI. Different numbers of relative maturity groups of genotypes were observed, ranging from 5, 4, 2, 4, and 3 groups, respectively, for the sowing dates: 11/30/2023, 12/20/2023, 12/30/2023, 12/10/2024, and 12/30/2024, which strongly means that the relative maturity was influenced by the environment. The heritability study revealed that the specifically agronomic variables number of days to maturity and plant height at maturity exceeded the heritability value for grain yield. Furthermore, the application of high-performance phenotyping (HTP) using RGB images proved to be an efficient, non-destructive and low-cost strategy for the phenotypic evaluation of soybean genotypes. Moreover, the vegetation indices ExG, VARI and NGRDI submitted evidence of a strong relation with the agronomic variables average plant height (APM), number of pods (NV), grain yield (PROD) and number of days to maturity (NDM), setting forth potential for its application in the indirect selection of promising genotypes. 2025-10-30T00:00:00Z