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The control of the impact of diseases on plants can be carried out via breeding, through the development of cultivars less susceptible to pathogens. Therefore, this study aimed to assess the severity of fungal diseases in upland rice strains from the Cultivation and Use Value test, belonging to the Upland Rice Breeding Program” of Federal University of Lavras (UFLA), in partnership with “EMBRAPA Rice and Beans” and the “Minas Gerais Agricultural Research Company” (EPAMIG). The experiment was installed in the municipalities of Lambari and Lavras, both in Minas Gerais, Brasil, in the 2015/2016 and 2016/2017 seasons, in a randomized block design with three replications. Were evaluated 14 lines, 11 lines of the program and 3 commercial witnesses, regarding the intensity of diseases (leaf and neck blast, brown spot, grain spot and scalding). There was a significant difference between lineages for all traits, except brown spot, indicating the presence of genetic variability for the characters in question. The study of the interaction was performed, decomposing the statistically significant ones in simple and complex interactions. The experiment presented a coefficient of variation from 29% to 56% and accuracy from 56% to 95.5%, indicating that the estimates were obtained with good to medium experimental precision. It is essential to evaluate diseases in breeding programs in order to select cultivars that are increasingly resistant, as these affect not only productivity, but the quality and final yield of grains. The genotypes CMG 2119 (5), CMG 2162 (1), CMG 1896 (13) and CMG 2168 (2) were shown to be more tolerant to all diseases simultaneously, being, therefore, the most suitable for the launch, considering the character disease resistance. The Upland Rice Breeding Program of UFLA has lines with variability for resistance, strains with potential for release.

The aim of the present study was to evaluate the response of different doses and sources of nitrogen (N) on agronomic characteristics in upland riceas well astheclimaticand environmentalinfluence on nitrogen fertilization results. Theexperiments were conducted in the University of Lavras, during 2015/2016 and 2016/2017 crop seasons, the plots consisted of 4 lines of 3 linear meters, with spacing among rows of 35 cm and a useful plot of 4.2 m2. The experimental design was a randomized complete block design with three replications in a 4x4x 2factorial design. The factor doseconsisted in 0, 50,100 e 200 kg ha-1N and the factor sourcesconsisted in ammonium nitrate, ammonium sulphate, urea and polycote, totaling 16 treatments. The characteristics evaluatedwere plant height, grain yield, grain chalkness, 1000 grainsweight andyield. It was concluded that the addiction of doses and Nsources didnot change the agronomic performanceof the upland rice crop. There is an influence of the environment on the responses of plants to nitrogen application, being observed different results in different cropseasons.

Salinity is recognized as one of the main abiotic stresses, causing declines in the productivity of many crops, such as rice. Considering the importance of rice as a staple food crop, the generalized pattern of salinization in soils around the globe and the sensitivity of the crop to saline soils, the aim of this study was to evaluate the sensitivity / tolerance of upland rice lines. The upland rice lines used in this work were obtained from the Genetic Improvement Program of the Universidade Federal de Lavras. The experiment was carried out in a greenhouse, with a block design and factorial scheme, with 10 lines and four NaCl treatments (0, 3, 15 and 45 mmol·L-1) on the substrate. Parameters related to the emergence rate, seedling survival rate, growth and architecture, biomass allocation, gas exchange and productivity were evaluated. Salinity levels influenced the emergence and survival rates, especially at the highest levels of NaCl, with lines L1, L4 and L5 showing survival below 60%. These lines were excluded from the experiment, and the other seven lines were carried out until the end of the crop cycle. Grain weight per plant (GWP) was used as an indicator of greater tolerance to salinity, and lines L6, L7 and L8 showed outstanding performance under treatments with increased NaCl. L6 had the highest GWP, while L7 and L8 had less pronounced decreases with increasing NaCl doses. These three lines may be recommended for further studies about the impacts of NaCl on rice production.

In the context of plant breeding programs, it is necessary to evaluate the efficiency of genotype selection over successive years. However, evaluating the genotype selection efficiency is not an easy task, since there is not just a single way to precede it. Besides that, the programs need to be dynamic; that is, they should be able to track the introduction and discard of genotypes each year. As a result, the available data is quite unbalanced, leading to difficulties in certain analyses. Thus, the present study aims to propose some approaches to verify the genetic progress in the preliminary trial of the Federal University of Lavras (UFLA) upland rice breeding program. We utilized mixed models for grain yield and plant height. Trials were performed with a total of 120 genotypes in seven environments, defined by the interaction between locations and years. Due to the imbalance in the available data, the mixed model approach, i.e., Restricted Maximum Likelihood/Best Linear Unbiased Prediction (REML/BLUP), was adopted for the joint analysis. Besides the genetic and phenotypic parameters, the expected gains were also obtained with the selection, genetic progress, renewal rate (RR%), and dynamism of preliminary trials. The efficiency of the selection of superior genotypes per year was verified, with genetic progress favorable for reducing the medium-sized plants associated with high yield. RESUMO Dentro dos programas de melhoramento torna-se necessária a avaliação da eficiência de seleção dos genótipos ao longo dos anos. Entretanto, avaliar essa eficiência nem sempre é uma tarefa fácil. Uma vez que não existe uma abordagem única, além disto, os programas de melhoramento necessitam ser dinâmicos com a adição e descarte de genótipos ano a ano. Como resultado tem-se ao final dados muito desbalanceados, o que pode trazer dificuldades para a análise dos dados. Assim, objetivou-se propor abordagens para verificar o progresso genético do experimento Preliminar do Programa de Melhoramento de Arroz de Terras Altas da Universidade Federal de Lavras (UFLA), para produtividade de grãos e altura de plantas. Os experimentos foram conduzidos em sete ambientes, ao longo de quatro safras com um total de 120 genótipos. Para a análise conjunta, em função do desbalanceamento dos dados, foi adotada a abordagem por meio de modelos mistos pelo procedimento de máxima verossimilhança restrita/melhor predição linear não viciada (REML/BLUP). Além de parâmetros genéticos e fenotípicos, foram obtidos também ganhos com a seleção, taxa de renovação (RR%), progresso genético e o dinamismo dos experimentos Preliminares. Foi verificada a eficiência na seleção de genótipos superiores para todos os anos, com ganhos genéticos favoráveis para a redução da altura média de plantas associada com altas produtividades.

The hypothesis here proposed is that, in primary fields of mass selection (F1) of sugarcane, herbicides exert a selective action when applied in the early post-emergence of seedlings (POST-i) and supplemented after their establishment phase (POST-l) even in sandy soils. To verify such hypothesis, the selectivity of herbicides was studied on seedlings of three sugarcane families, after their application both at early and late post-emergence in primary selection fields (F1). The field had a randomized blocks design, with five replications, and the subdivided plots scheme was used. Twelve herbicide treatments were allocated in the plots (27 m-2), whereas the sub-plots (9 m-2) contained three families of seedlings. Each sub-plot consisted of a transplanted row (0.5 x 1.50 m) with 12 individuals of the same family. Six treatments were employed, namely, T1: tebuthiuron (1200 g ha-1) post-i + ametryn (3000 g ha-1) post-l; T2: diuron (1404 g ha-1) + hexazinone (396 g ha-1) post-i + ametryn (3000 g ha-1) post-l; T3: sulfentrazone (800 g ha-1) post-i + ametryn (3000 g ha-1) post-l; T4: diuron (1404 g ha-1) + hexazinone (396 g ha-1) post-i + metribuzin (1920 g ha-1) post-l; T5: sulfentrazone (800 g ha-1) post-i + metribuzin (1920 g ha-1) post-l, and T6: weeded plot. The sugarcane families were: F400 (♀IAC086155 x ♂unknown), F43 (♀IACBIO264 × ♂IAC911099), and F14 (♀IACSP991305 × ♂GlagaH). We concluded that the herbicides tebuthiuron (1200 g ha-1), diuron (104 g ha-1) + hexazinone (396 g ha-1), or sulfentrazone (800 g ha-1), when applied in the early post-emergence and supplemented with ametryn (3000 g ha-1) or metribuzin (1920 g ha-1) in late post-emergence (60 days from planting) of the sugarcane families studied, were selective to the seedlings. That is, no toxicity symptoms with a potential to impede the final selection of seedlings occurred.

Novas linhagens para obterem sucesso no mercado precisam reunir uma serie de caracteres desejados. Ha dificuldade nos programas de melhoramento em mensurar varios caracteres de forma simultânea. A utilizacao de indices de selecao e uma boa alternativa para o melhorista, pois permite combinar as multiplas informacoes contidas na unidade experimental. O objetivo foi estudar a eficiencia dos indices de selecao com emprego das estimativas de herdabilidades como caracteristica de peso economico em genotipos de arroz de terras altas. Foram avaliadas 36 linhagens do programa de Melhoramento Genetico de Arroz de Terras Altas da UFLA em delineamento de blocos casualizados, com tres repeticoes do experimento preliminar conduzido na cidade de Lavras. As parcelas foram constituidas por quatro linhas de cinco metros, a densidade da semeadura foi de 80 sementes por metro linear com espacamento entre linhas de 40 cm. Foram avaliados os caracteres altura de plantas, incidencia de brusone foliar, numero de dias para o florescimento, produtividade, peso de mil graos, renda, rendimento e relacao comprimento/largura. As analises foram realizadas utilizando o programa computacional GENES. Os indices de selecao utilizados foram o Indice Base, indice com base na soma de postos ou Ranks, somatorio das variaveis padronizadas ou Indice Z e Selecao Direta com base na produtividade de graos. Excluindo brusone foliar houve significância para todos os caracteres dos tratamentos. O indice Z e o Ranks apresentaram 100% de coincidencia, o mesmo ocorreu com o Indice Base e a selecao direta. O uso da herdabilidade como peso economico nao alterou os genotipos selecionados nos indices testados.

The culture of rice has great potential to constitute the production systems of annual perennial crops, mainly in small properties. This allows this system to integrate with other activities such as the dairy industry, taking advantage of the milk by-product, reducing the environmental liability for disposal in the environment. Therefore, the objective was to evaluate the growth and productivity of rice grains under different doses of acid milk serum (0 m3 ha-1, 5 m3 ha-1, 10 m3 ha-1, 20 m3 ha-1, 50 m3 ha-1, 100 m3 ha-1, and 150 m3 ha-1), in soil applications with monitoring of fertility and electrical conductivity levels. The rice was sown in the UFLA experimental field, using the BRSMG Esmeralda lineage. Seven different doses were used, divided into two applications via soil. No cover fertilization was carried out. Yield and crop growth variables were determined by monitoring the nutrient content in the soil profile and the sodification and salinization capacity of the residue. It was found that the increase in serum doses increased the electrical conductivity and the percentage of exchangeable sodium by 1.75 and 7.75 compared to the control, but did not cause the process of sodification and salinization of the soil. As acid milk serum is a significant source of potassium, its use in the soil did not promote significant grain yield. It was concluded that the acid milk serum in the doses used did not cause sodification or salinization of the soil. This residue is the safe dose that can be used as potassium and nitrogen. The acid milk serum in the tested conditions did not increase the growth of the culture.

The alternative adopted in the breeding programs to decrease the effect of the genotype x environment interaction (G x E), is through the evaluation of the lineages in a network of experiments, these being conducted in several years and representative environments of the edaphoclimatic regions of cultivation. Therefore, the objective of this work was to evaluate the adaptability and productive stability of upland rice genotypes from the Minas Gerais, using the graphical tool for analysis of data, the GGE biplot. Grain yield data were used, derived from the evaluation of twenty rice lineages from the Cultivation Value and Use test of the Upland Rice Breeding Program at the Federal University of Lavras in partnership with Embrapa and Epamig. The tests were conducted in a complete block design, with three replications in the 2013/2014, 2014/2015 and 2015/2016 agricultural years. The experiments were conducted in a total of nine locations divided into the three agricultural years in the cities of Lambari, Lavras and Patos de Minas, all located in the state of Minas Gerais. It was concluded with this work that the lineages were almost entirely more adapted and stable than the commercial cultivars. The genotypes 10 and 13 were higher than the general average for productivity and showed high stability, being future candidates for launch as new cultivars. La alternativa adoptada en los programas de mejoramiento para disminuir el efecto de la interacción genotipo x ambiente (G x A), es a través de la evaluación de las cepas en una red de experimentos, estos se llevan a cabo en varios años y ambientes representativos de las regiones edafoclimáticas de cultivo. Por lo tanto, el objetivo de este trabajo fue evaluar la adaptabilidad y estabilidad productiva de genotipos de arroz de secano en el estado de Minas Gerais, utilizando la herramienta gráfica para análisis de datos, el biplot GGE. Se utilizaron datos de productividad de grano, de la evaluación de veinte líneas de arroz de la prueba de Valor de Cultivo y Uso del programa de mejoramiento de arroz de secano de la Universidad Federal de Lavras en alianza con Embrapa y Epamig. Las pruebas se realizaron en un diseño de bloque completo, con tres réplicas en las temporadas 2013/2014, 2014/2015 y 2015/2016. Los experimentos se realizaron en un total de nueve localidades divididas dentro de las tres cosechas en las ciudades de Lambari, Lavras y Patos de Minas, todas ubicadas en el estado de Minas Gerais. Con este trabajo se concluyó que las cepas estaban casi completamente más adaptadas y estables que los cultivares comerciales. Los genotipos 10 y 13 fueron superiores al promedio general en productividad y mostraron alta estabilidad, siendo futuros candidatos para el lanzamiento como nuevos cultivares. A alternativa adotada nos programas de melhoramento genético para diminuir o efeito da interação genótipo x ambiente (G x A), é através da avaliação das linhagens em uma rede de experimentos, sendo esses, conduzidos em vários anos e ambientes representativos das regiões edafoclimáticas de cultivo. Diante disso, o objetivo desse trabalho foi avaliar a adaptabilidade e estabilidade produtiva de genótipos de arroz de terras altas no estado de Minas Gerais, utilizando a ferramenta gráfica para análise de dados, o GGE biplot. Foram utilizados dados de produtividade de grãos, provenientes da avaliação de vinte linhagens de arroz do ensaio de Valor de Cultivo e Uso do programa de melhoramento de arroz de terras altas da Universidade Federal de Lavras em parceria com a Embrapa e Epamig. Os ensaios foram conduzidos em delineamento de blocos completos, com três repetições nas safras de 2013/2014, 2014/2015 e 2015/2016. Os experimentos foram conduzidos em um total de nove locais divididos dentro das três safras nas cidades de Lambari, Lavras e Patos de Minas, todas localizadas no estado de Minas Gerais. Concluiu-se com este trabalho que as linhagens foram em quase sua totalidade mais adaptadas e estáveis que as cultivares comerciais. Os genótipos 10 e 13 foram superiores à média geral para produtividade e apresentaram alta estabilidade, sendo candidatos futuros para lançamento como novas cultivares.

A assimilação de nitrogênio é um processo vital que controla o crescimento e desenvolvimento da planta, garantindo bons níveis de produtividade de grãos. A enzima nitrato redutase (NR) catalisa o primeiro passo enzimático da assimilação de nitrogênio pelas plantas superiores por meio da redução do nitrato (NO3-) a nitrito (NO2-). Assim, objetivou-se estudar a atividade da enzima redutase do nitrato em genótipos de arroz de terras altas e correlacioná-la com os demais caracteres agronômicos. O experimento foi conduzido em dois ambientes distintos, com e sem irrigação suplementar. As análises de atividade enzimática foram realizadas em laboratório. Foram avaliados 20 genótipos de um experimento de VCU na safra 2014/2015. O delineamento experimental foi em blocos casualizados com três repetições. Foi obtida a quantidade de nitrito liberado pelos tecidos vegetais na solução de incubação (µmoles NO2- gmf -1 h-1) em sete coletas realizadas aos 7, 14, 21, 28, 45, 75 e 100 dias após emergência (DAE), sempre no período da manhã, em todas as parcelas. Diante dos resultados, observou-se que a atividade da enzima NR, na cultura do arroz, é dependente do genótipo, do período de desenvolvimento vegetal e das condições ambientais, sendo de maior expressão no início do ciclo da cultura e em ambientes sem a ocorrência de estresse hídrico. A atividade da enzima RN não deve ser utilizada isoladamente para seleção indireta no caráter produtividade na cultura do arroz de terras altas, é necessário avaliar outras características que complementem à seleção.Palavras-chave: Oryza sativa; nitrogênio; melhoramento de plantas; expressão enzimática. ACTIVITY OF THE NITRATE REDUCTASE ENZYME IN UPLAND RICE UNDER WATER STRESS CONDITIONS ABSTRACT:Nitrogen uptake is a vital process that controls plant growth and development, ensuring great grain yield levels. The enzyme nitrate reductase (NR) catalyzes the first enzymatic step of nitrogen uptake by higher plants by reducing nitrate (NO3-) to nitrite (NO2-). Thus, the objective was to study the activity of nitrate reductase enzyme in upland rice genotypes and to correlate it with other agronomic traits. The experiment was conducted in two distinct environments, with and without supplemental irrigation. The enzymatic activity assays were performed in the laboratory. Twenty genotypes of a VCU experiment in the 2014/2015 crop were evaluated. The experimental design was in randomized blocks with three replications. The amount of nitrite released by the plant tissues in the incubation solution (µmoles NO2-gmf -1 h-1) was obtained in seven collections performed at 7, 14, 21, 28, 45, 75 and 100 days after emergence (DAE). always in the mornings, in all installments. Given the results, it was observed that the activity of NR enzyme in rice culture is dependent on genotype, plant development period and environmental conditions, being more expressive at the beginning of the crop cycle and in environments without occurrence of water stress. The activity of the RN enzyme should not be used alone for indirect selection in the productivity character in the upland rice crop, it is necessary to evaluate other characteristics that complement the selection.Keywords: Oryza sativa; nitrogen; plant breeding; enzymatic expression.

Background: Rice crop is known as very sensitive to water deficit, especially during the reproductive phase when growth of vegetative organs and formation of spikelets are concomitant. The present study questioned whether the maintenance of vegetative organ expansion during a water deficit at the reproductive phase affects the reproductive structure organogenesis, and if relevant traits for adaptation can be identified. To answer these queries, the response to a same reproductive water deficit of six contrasted japonica genotypes has been analyzed under two contrasted climates differing in incident radiation, air hygrometry and temperature (greenhouse in Brazil, Sitis, and growth chamber in France, GC).Results: Under irrigation, plant growth rate was reduced in GC while crop duration was extended: the trade-offs resulted in similar plant height and biomass. From a method able to determine a posteriori the date of panicle initiation (PI), elementary processes were positioned in time, allowing to evaluate how much each process was affected, despite the diversity in phenology across genotypes. Elongation rate decreased with water deficit and was highly associated with an increase in soluble sugars in stem and flag leaf in both experiments, while starch was reduced in Sitis and negligible in GC. This unique response, however, induced a different effect across experiments on branch and spikelet formation. In short, in both experiments, maintenance of spikelet number was highly associated with maintenance of flag leaf and internode width. All variables, including branch and spikelet number, were highly affected with IAC 25 in both experiments, while variations were non-significant with Cirad 409. In addition, some other genotypes expressed a differential response between Sitis and GC, conveying a specific sensitivity to low radiation or to high air temperature. Conclusions: This study highlighted the importance of finely mapping in time elementary growth processes, thanks to PI date determination, in order to detect key traits of adaptation to abiotic stress through phenotyping across genotypes of diverse phenology. The maintenance of flag leaf width or internode diameter under a mild water deficit was highlighted here as a trait associated with the maintenance of yield components.

Weed management is important for the increase of agricultural crops, since they have a negative influence on yield and harvest quality. To optimize the management it is possible to use the coffee infusion residues, which has caffeine contents, a substance that has an allelopathic effect to some plants. Thus, the goal was to evaluate the allelopathic effect of coffee residues in the emergence and growth of Urochloa brizantha under product doses, gathering and application seasons in pre- and post-emergence. The experiment was carried out at UFLA, in a greenhouse with potting, with Urochloa brizantha seeds, cultivar Piata, in DBC with three replicates in the factorial (3 × 4 × 2): time of gathering (A, B, C); concentration of ground (0, 20, 50 and 100 (% W/V)) and pre- and post-emergence application. The height, fresh and dry weight, Emergence Speed Index—ESI and phytotoxicity were evaluated. It was verified the significance for pre-emergence treatments, reducing plant height, increasing phytotoxicity and reducing fresh weight. For the ESI, it was identified that only for gathering season obtained a significant result. In the phytotoxicity evaluations, it obtained interaction for the season of application with residue gathering season. For product doses and applications in pre- and post-emergence interaction was observed for phytotoxicity. It is concluded that the residue has allelopathic effect reducing growth and increasing phytotoxicity up to a maximum dose of 55.83 and 86.76 for pre- and post-emergence applications of Urochloa brizantha.