ABSTRACT Shade-tolerant soybean genotypes will allow their greater adoption for use in agroforestry or intercropped systems in tropical and subtropical regions. These genotypes can be obtained from the selection of existing superior genotypes or through breeding programs. This study, was verified such genetic variability and select those genotypes with cultivation potential at reduced levels of photosynthetically active radiation (PAR). Morphophysiological and yield characteristics of 16 soybean genotypes were evaluated in two experiments conducted in a controlled environment and laid in a randomized block design with three replications. Genetic parameters, correlations and genetic diversity were estimated and path analysis was performed. The soybean cultivars used showed genetic variability with a high variation index and heritability, which is advantageous for the selection of superior cultivars. Leaf area showed genotypic correlation and had a direct effect on seed weight per plant, regardless of shading. Additionally, the number of pods, hypocotyl diameter, and leaf area, all indirectly contributed to seed weight per plant regardless of shading. Seven genotypes (NS7780, NS8338, NS7667, NS7901, RK8115, CZ37B43 and 8579RSF) were selected based on genetic gain obtained by the Mulamba and Mock index at the two levels of PAR reduction tested. Furthermore, five of these genotypes (CZ37B43, RK8115, NS7901, NS8338 and 8579RSF) were identified by the Unweighted Pair-Group method Arithmetic Mean, as suitable either as a shaded crop or, as parental materials in breeding programs.

ABSTRACT present study aimed to determine the effects of different light restriction levels (shading levels) on soybean genetic parameters using a Bayesian multi-trait model (MTM) and select high-yielding soybean cultivars. Eighteen commercial soybean cultivars bred in a soybean breeding program were evaluated over two agricultural seasons. Three shading levels were used over two agricultural crop seasons, giving six treatments (light restriction × crop season). The experiments were arranged in a randomized complete block design with six treatments replicated thrice. The genetic values and parameters were estimated using a Monte Carlo Markov Chain algorithm. Broad-sense heritability range from 0.2093 to 0.7153. The lowest genotypic variance estimate was observed at the 45 % photosynthetically active radiation level in the 2019/2020 crop season year compared with that of other shading levels. Furthermore, a 40 % selection intensity had the highest soybean yield under different shading levels. The Bayesian MTM combined with the factor analysis and genotype-ideotype distance method can be used to evaluate and select soybean genotypes considering different shading levels. The soybean cultivars 8579RSF, NS8338, NS7901, NS7667, RK8115, and 8473RSF had higher genetic potential than other cultivars under different shading levels. multitrait multi trait (MTM highyielding high yielding seasons season. . season) thrice algorithm Broadsense Broad sense 02093 0 2093 0.209 07153 7153 0.7153 4 20192020 2019 2020 2019/202 Furthermore genotypeideotype genotype ideotype 8579RSF RSF NS8338 NS NS7901 NS7667 RK8115 RK 0209 209 0.20 0715 715 0.715 2019202 201 202 2019/20 NS833 NS790 NS766 RK811 020 20 0.2 071 71 0.71 201920 2019/2 NS83 NS79 NS76 RK81 02 2 0. 07 7 0.7 20192 2019/ NS8 NS7 RK8

Abstract The objective of this work was to evaluate the influence of using a semi-hydroponic system on the agronomic and postharvest variables of strawberry cultivars. The experiment was conducted in a randomized complete block design, with cultivars Aromas, Camarosa, Festival, Merced, Oso Grande, and San Andreas, with eight plants per plot and five replicates. Agronomic and postharvest variables were evaluated. Cultivar San Andreas showed the highest values for the agronomic variables number of commercial fruits and total and commercial yield per plant, with the highest yield in October, November, and December. The postharvest variables moisture, firmness, pH, titratable acidity, and reducing sugars did not differ between cultivars. In a semi-hydroponic system, the San Andreas cultivar presents the best results for the agronomic variables related to fruit yield, with the highest yield in October and November. semihydroponic semi hydroponic design Aromas Camarosa Festival Merced Grande replicates evaluated plant November December moisture firmness pH acidity

Resumo O objetivo deste trabalho foi avaliar a influência do uso de sistema semi-hidropônico sobre as variáveis agronômicas e de pós-colheita de cultivares de morangueiro. O experimento foi conduzido em delineamento de blocos ao acaso, com as cultivares Aromas, Camarosa, Festival, Merced, Oso Grande e San Andreas, com oito plantas por parcela e cinco repetições. Foram avaliadas variáveis agronômicas e de pós-colheita. A cultivar San Andreas apresentou os maiores valores para as variáveis agronômicas número de frutos comerciais e produção total e comercial por planta, com as maiores produtividades em outubro, novembro e dezembro. As variáveis de pós-colheita umidade, firmeza, pH, acidez titulável e açúcares redutores não diferiram entre as cultivares. Em sistema semi-hidropônico, a cultivar San Andreas apresenta os melhores resultados para as variáveis agronômicas de produção de frutos, com as maiores produtividades em outubro e novembro. semihidropônico semi hidropônico póscolheita pós colheita morangueiro acaso Aromas Camarosa Festival Merced repetições póscolheita. colheita. planta dezembro umidade firmeza pH semihidropônico, hidropônico,

ABSTRACT Kale is one of the most widely cultivated leafy vegetables in Brazil, but its breeding genetic is still limited. Therefore, it is crucial to develop research that explores the genetic diversity of the available germplasms, aiming to establish promising crosses in the studied populations. The present study aimed to evaluate the genetic divergence between half-sibling progenies of kale, obtained through recurrent selection, using multivariate methods to select the most promising progenies for forming a recombinant population. The plants obtained from the seeds of 25 pre-selected half-sibling progenies and three commercial cultivars were evaluated as treatment groups. These seeds were produced in 2018 by subjecting the clones of the progenies to recombination, followed by the selection of appropriate seeds from plants with superior agronomic performance. In the present study, plants in each plot were evaluated for twelve quantitative and fifteen qualitative traits. Genetic divergence was studied based on canonical variables to obtain quantitative data. The UPGMA method was applied to the quantitative, qualitative, and combined data, and Mahalanobis genetic distance was adopted. The first three canonical variables explained 73.75% of the total cumulative variation compared to the commercial cultivars and 55.29% when considering the half-sibling progenies exclusively. The half-sibling progenies P1, P2, P3, P4, P5, P9, P11, P15, P16, P18, P20, P22, P23, P24, and P25 were the most divergent and should, therefore, be prioritized when composing the recombinant population for the third cycle of recurrent selection because, in addition to genetic variation, these progenies also present characteristics of interest to the kale genetic breeding program. The commercial cultivars exhibited the most divergent genotypes and should, therefore, be included in the next recombination cycle. Brazil limited Therefore germplasms populations halfsibling half sibling 2 preselected pre selected groups 201 performance traits data adopted 7375 73 75 73.75 5529 55 29 55.29 exclusively P1 P P2 P3 P4 P5 P9 P11 P15 P16 P18 P20 P22 P23 P24 should therefore because program 20 737 7 73.7 552 5 55.2 73. 55.

RESUMO A couve-de-folhas é uma das hortaliças folhosas mais cultivadas no Brasil, porém seu melhoramento ainda é limitado. Portanto, é crucial desenvolver pesquisas que explorem a diversidade genética dos germoplasmas disponíveis, visando estabelecer cruzamentos promissores nas populações estudadas. O objetivo deste estudo foi avaliar a divergência genética entre progênies de meios-irmãos de couve-de-folhas obtidas por seleção recorrente e selecionar as progênies mais promissoras para compor uma população recombinante utilizando métodos multivariados. Como tratamentos, foram avaliadas plantas obtidas a partir de sementes de 25 progênies de meio-irmãos pré-selecionadas e três cultivares comerciais. Para produzir essas sementes, clones das progênies foram submetidos a recombinação em 2018, com subsequente seleção de sementes de plantas com desempenho agronômico superior. Foram avaliadas doze características quantitativas e quinze qualitativas em cada parcela, totalizando vinte e sete características avaliadas. O estudo da divergência genética foi realizado através de variáveis canônicas para os dados quantitativos. O método UPGMA foi aplicado a dados quantitativos, qualitativos e combinados, utilizando-se a distância genética de Mahalanobis. As três primeiras variáveis canônicas explicaram 73,75% da variação total acumuladas quando comparadas às cultivares comerciais, e 55,29% quando considerado exclusivamente as progênies meios-irmãos. As progênies de meios-irmãos P1, P2, P3, P4, P5, P9, P11, P15, P16, P18, P20, P22, P23, P24 e P25 foram as mais divergentes e devem ser priorizadas na composição da população recombinante para o terceiro ciclo de seleção recorrente, pois além de variação genética, também apresentam características de interesse ao programa de melhoramento genético da couve. As cultivares comerciais apresentaram-se como os genótipos mais divergentes e deverão ser incluídas no próximo ciclo de recombinação. couvedefolhas couve folhas Brasil limitado Portanto disponíveis estudadas meiosirmãos meios irmãos multivariados tratamentos 2 meioirmãos meio préselecionadas pré selecionadas 2018 superior parcela quantitativos combinados utilizandose se Mahalanobis 7375 73 75 73,75 5529 55 29 55,29 meiosirmãos. irmãos. P1 P P2 P3 P4 P5 P9 P11 P15 P16 P18 P20 P22 P23 apresentaramse apresentaram 201 737 7 73,7 552 5 55,2 20 73, 55,

ABSTRACT Increasing orchard productivity is among the main objectives of pitaya producers. However, the commercial productivity may reduce due to reduction of fruit size as a function of the high amount per plant. This study evaluated the influence of the number of fruit per cladode in commercial productivity and in quality of fruits of two pitaya species at different harvest times. The experiment was carried out in a six-year-old orchard formed by the species Selenicereus undatus and Hylocereus polyrhizus. At each flowering time, the number of fruits set per cladode was counted and plants with two, four, five and six fruits per cladode were selected, and surplus fruits removed. The evaluations followed a split plot design over time, with the main plot as the number of fruit per cladode and the subplot as the harvest seasons: December, February and March, with four replicates and one plant per plot. Plants grown with two fruits per cladode presented the highest percentage of fruits with commercial size and commercial productivity. Both species showed fruits with commercial size in the first harvest of the cycle (December). S. undatus fruits classified as Class I and H. polyrhizus fruits classified as Extra and Class I showed the best quality. producers However times sixyearold year old time selected removed seasons December March December. . (December) S H (December

Abstract The structure of urban secondary forests and their potential for meliponiculture in the eastern Amazon was studied in the municipality of Belterra, Pará. The sampling was carried out in 25 plots of 40 m2 in two areas (0.1 ha) of secondary forests (SF), in which three classes of DBH values were considered (C1:1 cm ≤ DBH ≤ 5 cm; C2: 5 cm < DBH ≤ 10 cm and C3: DBH ≥ 10 cm). a total of 230 individuals were registered in SF I, comprising 66 species and 27 botanical families and 185 individuals in SF II, comprising 43 species distributed in 24 botanical families. The highest richness and abundance were verified for C1, followed by C2 in both areas. In SF I, the basal area values (G=1.509) were higher than in SF II, while the total volume (V=20.21) was higher than SF I, the mean height for C3 was higher in SF II, and C1 and C2 were higher in SF I. The Shannon-Wiener diversity index was higher in SF I (H = 3.722) than in SF II (H=3.197). It was observed that 75% species have bee pollination systems (mellitophilous flora) and are thus considered sources of honey resources.

Resumo O objetivo deste trabalho foi estimar os parâmetros genéticos de genótipos de mandioca (Manihot esculenta) cultivados em campo, bem como a divergência genética entre eles, para identificar quais apresentam maior resistência à antracnose e à bacteriose. Foram realizados três experimentos independentes, tendo-se avaliado 133 acessos e nove cultivares comerciais de mandioca distribuídos em cinco blocos, com cinco plantas por parcela, em cada experimento. No primeiro experimento, as plantas foram submetidas à inoculação de Xanthomonas phaseolis pv. manihotis (bacteriose). No segundo, as plantas foram submetidas à inoculação de Colletotrichum gloeosporioides f. sp. manihotis (antracnose). No terceiro, realizado em delineamento de blocos aumentados e sob ocorrência natural das doenças, foram feitas avaliações visuais das plantas por escala de notas. A herdabilidade foi utilizada como parâmetro genético, e o método de grupos de pares não ponderados com média aritmética foi aplicado para determinação de divergência genética e agrupamento. No terceiro experimento, detectaram-se diferenças genéticas entre os acessos, que foram avaliados quanto à área abaixo da curva de progressão da doença (AUDPC) para antracnose e bacteriose. No primeiro e no terceiro experimento de bacteriose, as chances de sucesso na seleção de acessos resistentes são maiores, em razão dos altos valores de herdabilidade obtidos. Os acessos BGM-1170 e BGM-1134 mostram as menores médias de AUDPC e são considerados resistentes à antracnose e à bacteriose.

Abstract The objective of this work was to estimate the genetic parameters of cassava (Manihot esculenta) genotypes cultivated in the field, as well as the genetic divergence between them, in order to identify which ones show a greater resistance to anthracnose and bacteriosis. Three independent experiments were carried out, evaluating 133 accessions and nine commercial cultivars of cassava distributed in five blocks, with five plants per plot in each experiment. In the first experiment, the plants were subjected to inoculation with Xanthomonas phaseoli pv. manihotis (bacteriosis). In the second, the plants were subjected to inoculation with Colletotrichum gloeosporioides f. sp. manihotis (anthracnose). In the third, carried out in an augmented block design and under naturally occurring diseases, visual evaluations of the plants were performed using a rating scale. Heritability was used as a genetic parameter, and the unweighted pair group method with arithmetic mean was applied to determine genetic divergence and clustering. In the third experiment, genetic variability was detected among accessions, which were evaluated for the area under the disease progress curve (AUDPC) for anthracnose and bacteriosis. In the first and third experiments of bacteriosis, the chances of success in the selection of resistant accessions are higher due to the high heritability values obtained. The BGM-1170 and BGM-1134 accessions show the lowest mean for AUDPC and are considered resistant to anthracnose and bacteriosis.

Resumo O objetivo deste trabalho foi avaliar as correlações fenotípicas entre características agronômicas de alho (Allium sativum) e realizar análise de trilha, tendo-se utilizado a produtividade comercial de bulbos como característica principal. O experimento foi conduzido sob condições de campo em duas safras (2018 e 2019), no município de Diamantina, no estado de Minas Gerais, Brasil. Um total de 13 genótipos de alho foram avaliados, sendo 11 experimentais e 2 cultivares comerciais. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições. Foram avaliadas características relacionadas à biometria da planta e à produção de bulbos. Foram realizadas as correlações fenotípicas e a análise de trilha das características estudadas. As correlações fenotípicas que apresentaram efeito positivo significativo ocorreram entre produção comercial de bulbos e altura de planta, diâmetro do bulbo, número de bulbos comerciais, massa média de bulbo total, massa média de bulbo comercial, produtividade total de bulbos e número de bulbilhos por bulbo. No entanto, apenas o número de bulbos comerciais e o diâmetro do bulbo tiveram efeitos significativos (direto e indireto) sobre a produtividade comercial de bulbos. Portanto, em programas de melhoramento de genótipos na região estudada, a seleção deve buscar maior diâmetro de bulbos e maior número de bulbos comerciais para incrementar a produtividade comercial.

Abstract The objective of this work was to evaluate the phenotypic correlations between agronomic characters of garlic (Allium sativum) and to carry out the path analysis, using commercial bulb yield as the main character. The experiment was conducted under field conditions in two harvests (2018 and 2019) in the municipality of Diamantina, in the state of Minas Gerais, Brazil. A total of 13 garlic genotypes were evaluated, of which 11 were experimental and 2 were commercial cultivars. The experimental design used was randomized complete blocks with four replicates. Characters related to plant biometry and bulb yield were evaluated. The phenotypic correlations and the path analysis of the studied characters were carried out. The phenotypic correlations that showed significant positive effects occurred between commercial bulb yield and plant height, bulb diameter, number of commercial bulbs, mean total bulb mass, mean commercial bulb mass, total bulb yield, and number of bulbils per bulb. However, only number of commercial bulbs and bulb diameter had significant effects (direct and indirect) on commercial bulb yield. Therefore, in genotype genetic breeding programs in the studied region, selection should seek a larger diameter of bulbs and a higher number of commercial bulbs to increase commercial yield.

Aim To elaborate and validate an instrument for Brazilian Portuguese speakers, to assess dentists’ knowledge about care of patients with diabetes mellitus (Dental-Diabetes). Methods Methodological study comprising four stages: a) Elaboration of instrument; b) Content validation (computing Content Validity Index - CVI) based on Expert Committee assessment; c) Pre-test with 30 dentists, followed by assessment of suggestions by Expert Committee; d) Psychometric validation through instrument application in a sample of 127 dentists by means of the web tool e-Surv. Cronbach’s alpha and intraclass correlation coefficients were used to evaluate, respectively, internal consistency and reproducibility. Results The final version of the instrument consists of 22 questions (7 on sociodemographic data and 15 querying dentists’ knowledge) and those submitted for validation attained a CVI of 0.95 [95% CI 0.916-0,981], showing satisfactory internal consistency, with 0.794 Cronbach’s alpha [95% CI 0.741-0.842] and an intraclass correlation coefficient of 0.799 [95% CI: 0.746-0.846] between the test and retest scores. Conclusions Dental-Diabetes is a comprehensive instrument, culturally adequate and validated to assess dentists’ knowledge about care of patients with diabetes.

Resumo O objetivo deste trabalho foi avaliar o desempenho agronômico de milho (Zea mays) solteiro e consorciado com Urochloa ruziziensis em sucessão à soja (Glycine max) inoculada com Bradyrhizobium japonicum, bem com a inoculação e a reinoculação do milho com Azospirillum brasilense, em dois solos contrastantes. O experimento foi realizado em duas safras, em delineamento de blocos ao acaso, em arranjo fatorial 2x2x3, com cinco repetições. O primeiro fator avaliado foi composto pelos dois solos contrastantes: Latossolo Vermelho eutrófico argiloso e Latossolo Vermelho distrófico arenoso. O segundo fator foi o cultivo de milho: solteiro e consorciado com U. ruziziensis. Já o terceiro fator consistiu na inoculação em soja e milho em sucessão, como a seguir: sem inoculação nos dois cultivos, inoculação com Bradyrhizobium japonicum em soja e com A. brasilense em milho, e reinoculação com B. japonicum + A. brasilense em soja e com A. brasilense em milho. Nos dois anos de cultivo, as maiores produtividades de milho são observadas no solo argiloso com sementes reinoculadas com A. brasilense. A reinoculação anual com A. brasilense resulta em maior produtividade de grãos de milho no consórcio com U. ruziziensis no solo argiloso. A inoculação e a reinoculação reduzem as perdas de produtividade do milho causadas pela competição com U. ruziziensis no consórcio.

Abstract The objective of this work was to evaluate the agronomic performance of corn (Zea mays) grown single and intercropped with Urochloa ruziziensis in succession to soybean (Glycine max) inoculated with Bradyrhizobium japonicum, as well as the inoculation and reinoculation of corn with Azospirillum brasilense, in two contrasting soils. The experiment was carried out in two crop years, in a randomized complete block design, in a 2x2x3 factorial arrangement, with five replicates. The first evalauted factor was composed of the two constrasting soils: a clayey Rhodic Eutrustox and a sandy Rhodic Haplustox. The second factor was corn cultivation: single and intercropped with U. ruziziensis. The third factor consisted of the inoculation onto soybean and corn in succession, as follows: no inoculation in both crops, inoculation with B. japonicum onto soybean and with A. brasilense onto corn, and reinoculation with B. japonicum + A. brasilense onto soybean and with A. brasilense onto corn. In both crop years, the highest corn yields are observed in clayey soil with seeds reinoculated with A. brasilense. The annual reinoculation with A. brasilense results in a higher corn grain yield in the intercropping with U. ruziziensis in the clayey soil. Inoculation and reinoculation reduce corn yield losses caused by the competition with U. ruziziensis in intercropping.

Resumo: O objetivo deste trabalho foi avaliar o efeito da poda e do tipo de sistema de condução sobre o desempenho agronômico do cultivo perene de fisalis (Physalis peruviana), em regiões de clima tropical de altitude e temperado úmido no Sudeste brasileiro. Os experimentos foram realizados nos municípios de Diamantina (clima temperado úmido) e Couto de Magalhães de Minas (clima tropical de altitude), ambos no estado de Minas Gerais, em dois ciclos (2017/2018 e 2018/2019). No primeiro ciclo, foram avaliados dois tipos de sistema de condução, um com poda de formação para definir o número de hastes para condução em espaldeira e outro livre (sem poda e espaldeira). No segundo ciclo, avaliou-se a poda de renovação em cada sistema de condução. O cultivo de fisalis em regiões de clima temperado úmido, com temperaturas amenas, favorece produções altas e frutos grandes. O sistema de condução em espaldeira com poda de formação facilita o manejo das plantas e aumenta a produtividade. A viabilidade do cultivo perene de fisalis varia de acordo com as condições climáticas do local de cultivo e o sistema de condução adotado.

Abstract: The objective of this work was to evaluate the effect of pruning and training system type on the agronomic performance of the perennial cultivation of physalis (Physalis peruviana), in high-altitude tropical and humid temperate regions in Southeastern Brazil. The experiments were carried out in the municipalities of Diamantina (humid temperate climate) and Couto de Magalhães de Minas (high-altitude tropical climate), both in the state of Minas Gerais, in two cycles (2017/2018 and 2018/2019). In the first cycle, two types of training system were evaluated, one with formation pruning to define the number of stems for espalier training and the other free (without pruning and espalier). In the second cycle, renewal pruning was evaluated in each training system. Physalis cultivation in regions with humid temperate climate and mild temperatures favors high yields and large fruits. The training system in espalier with formation pruning facilitates plant management and increases productivity. The viability of the perennial cultivation of physalis varies according to the climatic conditions of the cultivation site and to the training system adopted.

RESUMO Avaliou-se os teores de matéria seca (MS), proteína bruta (PB), matéria mineral (MM), carboidratos solúveis (CHOS), nitrogênio amoniacal (N-NH3), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA), de silagens de cana-de-açúcar adicionadas de diferentes níveis de inclusão (NI) de farelo de crambe (FC), nas proporções de 0; 3; 10; 17 e 20%, e avaliados em diferentes tempos de armazenamento (TA), em dias. Utilizou-se silos laboratoriais, abertos nos tempos 0; 3; 7; 12; 24; 36; 41 e 60 dias após a ensilagem. Para a análise estatística utilizou-se a metodologia de superfície de resposta, em que os fatores independentes foram os NI e os TA, e os fatores dependentes foram as variáveis respostas. Os teores de MS e de PB aumentaram linearmente com os NI, mas não apresentaram respostas significativas quanto aos TA. Os teores de CHOS reduziram linearmente com os NI e apresentaram resposta quadrática com os TA. Houve efeito significativo da interação entre NI e TA para os teores de N-NH3, pois os teores reduziram com os NI e TA, de forma conjunta. Os teores de FDN e FDA reduziram linearmente com os NI, e apresentaram resposta quadrática com os TA. O FC apresentou eficácia para melhorar o processo fermentativo da cana ensilada, com adição e conservação de nutrientes, em todos os NI avaliados e ao longo do tempo de armazenamento. O FC é uma alternativa viável para a ensilagem da cana-de-açúcar, além de destinar os resíduos gerados com a produção de biodiesel de forma sustentável.

ABSTRACT We evaluated the contents of dry matter (DM), crude protein (CP), mineral matter (MM), soluble carbohydrates (CHOS), ammonia nitrogen (N-NH3), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in sugarcane silages to which different levels of inclusion (LI) of crambe bran (CB) were added in proportions of 0, 3, 10, 17 and 20% at different storage times (ST). Laboratory silos were used, predetermined ST being 0, 3, 7, 12, 24, 36, 41, and 60 days after silage. For statistical analysis, the response surface methodology was used, in which LI and ST served as independent factors and response variables as dependent factors. The levels of DM and CP increased linearly with NI; however, it did not show any significant response regarding ST. The CHOS contents were reduced linearly with NI and displayed a quadratic response with ST. The interaction between NI and ST for the levels of N-NH3 was significant, as the levels reduced with the NI and ST. The levels of NDF and ADF reduced linearly with NI and displayed a quadratic response with ST. The CB showed high efficacy to improve fermentation of ensiled cane, with the addition and conservation of nutrients in all NI evaluated and over the storage time. In addition to the residues generated with the production of biodiesel in a sustainable way, CB is a viable alternative to the sugarcane silage.

RESUMO A ocorrência da correlação negativa entre produtividade de grãos (PG) e capacidade de expansão (CE) no milho-pipoca contribui para dificultar o processo seletivo. No intento de contornar esse inconveniente, foi proposto, o caráter de importância, volume por pipoca expandida por hectare (VP). O objetivo deste estudo foi desenvolver o nono ciclo da população UENF-14 de milho-pipoca, estimar o efeito direto e indireto de VP e averiguar o progresso genéticos entre todos os ciclos seletivos. Duzentas progênies endogâmicas foram obtidas e avaliadas em blocos casualizados, com arranjos em repetições dentro de sets, sendo nove sets, oito constituídos por 25 progênies e um set com todos ciclos anteriores (oito) com três repetições. Avaliou-se a altura média da planta, prolificidade, peso de cem grãos, produtividade de grãos, capacidade de expansão e volume por pipoca expandida por hectare. Realizou-se a análise de trilha para desdobrar os efeitos diretos e indiretos e o índice de seleção Mulamba e Mock para seleção de quarenta progênies superiores. Houve variabilidade genética entre as progênies para todas características. Existe relação de causa e efeito entre o VP com a PG e CE, permitindo ganhos simultâneos com a seleção indireta. A seleção das progênies superiores com a utilização do peso atribuído por alternativas proporcionou maiores ganhos preditos de VP (20,73%). As médias obtidas em todos os ciclos indicaram aumentos, demonstrando a eficiência do uso da seleção recorrente em programas de melhoramento de milho-pipoca.

ABSTRACT The occurrence of negative correlations between grain yield (GY) and popping expansion (PE) in popcorn complicates the selection process. In an attempt to overcome this inconvenience, we proposed the use of the importance characteristic volume per popcorn per hectare (PV). The objectives of this study were to develop the ninth cycle of the UENF-14 popcorn population, to estimate the direct and indirect effects of PV and to verify the genetic progress among all selective cycles. We obtained and evaluated 200 inbred progenies in randomised blocks arranged in replicates within sets, with nine sets consisting of 25 progenies and one set with all previous eight cycles with three replicates. The average height of the plants, prolificacy, 100-grain weight, grain yield, grain popping expansion and volume per popcorn per hectare were evaluated. Track analysis was performed to determine the direct and indirect effects, and the Mulamba and Mock selection index was calculated for the selection of the 40 superior progenies. There was genetic variability among progenies in all evaluated traits, with a cause-and-effect relationship between PV with GY and PE, allowing simultaneous gains with indirect selection. The selection of the best progenies was more effective when using arbitrarily assigned weights, which provided higher predicted gains for PV (20.73%). The means obtained in all cycles indicated increases, demonstrating the efficiency of using continuous recurrent selection in popcorn breeding programs.

ABSTRACT The present study resulted from the lack of information on the genotypic expression ruling the resistance to rust and on the main traits of economic importance to the herein addressed crop. The combining ability of 16 popcorn lines and hybrids was assessed in partial diallel cross in two representative locations in Rio de Janeiro State, Brazil, where forty simple hybrids were obtained. The experiments followed a completely randomized block design with four repetitions and were conducted under natural infestation conditions in order to test the southern rust severity in the entire plant (SSW) and in the leaf of the first ear (SFPE), as well as the morpho-agronomic traits of greater interest: grain yield (GY) and popping expansion (PE). Additive gene effects prevailed in PE and the non-additive ones stood out in GY; however, both gene effects were important to the southern rust resistance characteristics (SSW and SFPE). Hybrids L65 × P10 and P7 × L70 presented appropriate specific combining ability (SCA) values in all traits; therefore, they were promising for the selection of superior genotypes. Lines L80, L76 and L77 expressed negative general combining ability (GCA) values in SSW and SFPE; line P10 recorded high and positiveGCA values in GY and PE.

RESUMO A seleção recorrente embora permita sucessivos ganhos para caracteres de interesse econômico, sem provocar estreitamento genético na população, tem sido raramente utilizada em programas de melhoramento com milho-pipoca, sobretudo em se tratando da estratégia de utilização de progênies de irmãoscompletos, em que são possíveis ganhos mais expressivos. O objetivo deste estudo foi estimar o ganho genético na população UENF-14, de milho-pipoca, por meio de seleção recorrente e averiguar a evolução dos ganhos entre os ciclos quatro e oito de seleção. Foram avaliadas 200 progênies de irmãos-completos, em blocos casualizados, com arranjos em sets dentro de três repetições em dois ambientes, no total de oito sets, sendo que cada set continha vinte e cinco progênies e seis testemunhas (ciclos 4, 5, 6 e 7 de seleção em UENF-14, BRS Angela e IAC 125). Avaliou-se a altura média da planta, prolificidade, peso de cem grãos, peso de espiga, produtividade de grãos e capacidade de expansão. Na seleção das trinta progênies superiores para o oitavo ciclo, foi utilizado o índice de seleção Mulamba e Mock, que proporcionou ganhos genéticos estimados de 4,60 e 3,61%, respectivamente, para produtividade de grãos e capacidade de expansão. Houve incremento de 111,99 kg ha-1 e de 1,75 mL g-1, por ciclo, para a produtividade de grãos e capacidade de expansão, nesta ordem. A evolução dos ciclos revelou ganho genético acumulado para os principais caracteres de importância econômica da cultura, possibilitando a antevisão de sucesso, na continuidade da seleção recorrente.

ABSTRACT Recurrent selection can generate successive gains for characters of economic interest without causing genetic narrowing in the population. However, it has rarely been used in breeding programs in popcorn, especially when using full-sibling progenies to generate more expressive gains. The objective of this study was to estimate the genetic gain of the UENF-14 popcorn population through recurrent selection, and verify the evolution of the gains between the selection cycles four and eight. A total of 200 full-sibling progenies were evaluated in randomized blocks arranged in eight sets within three replicates in two environments; each set containing twenty-five progenies and six controls (selection cycles 4, 5, 6 and 7 of the UENF-14, BRS-Angela and IAC-125). The average height, prolificacy, 100-grain weight, ear weight, grain yield, and grain popping expansion of the plants were evaluated. In the selection of the thirty superior progenies for the eighth cycle, the Mulamba and Mock selection index was used, which generated estimated genetic gains of 4.60 for grain yield and 3.61% for popping expansion. The grain yield increased 111.99 kg ha-1 and the popping expansion increased 1.75 mL g-1 per cycle. The evolution of the cycles resulted in an accumulated genetic gain for the main characters of economic importance, allowing the prediction of success in the continuity of the recurrent selection.