ABSTRACT Sweet sorghum (Sorghum bicolor L.) is a promising energy crop for bioethanol production. This study aimed to investigate the influence of genetic structure on the adaptability and phenotypic stability of sweet sorghum lines and hybrids regarding the main agro-industrial traits, as well as selecting hybrids that associate high ethanol yield and yield stability in different growing environments. A total of 45 genotypes were evaluated in experiments conducted in a 5×9 triple alpha lattice design in three locations in the state of Minas Gerais, Brazil. The following traits were measured: fresh matter production, juice extraction percentage, total soluble solids content, tons of Brix per hectare, and ethanol production. Adaptability and phenotypic stability were assessed by the Wricke and Annicchiarico methods. Sweet sorghum adaptability and phenotypic stability depend on genotype genetic structure, with hybrids being more stable than parental lines. Additionally, H2x9 and H3x8 were the most promising hybrids. Sorghum L. L production agroindustrial agro industrial environments 4 59 5 9 5× Gerais Brazil measured percentage content hectare methods Additionally Hx H x H2x H3x

RESUMO O sorgo sacarino (Sorghum bicolor (L.)) é uma cultura energética promissora para a produção de bioetanol. O objetivo deste trabalho foi verificar a influência da estrutura genética na adaptabilidade e estabilidade fenotípica de linhagens e híbridos de sorgo sacarino quanto aos principais caracteres agroindustriais, bem como selecionar híbridos que associem elevado rendimento de etanol e estabilidade produtiva nos ambientes de cultivo testados. Foram avaliados 45 genótipos em experimentos conduzidos no delineamento alfa-látice triplo 5 x 9 em três localidades do Estado de Minas Gerais, Brasil. Foram mensurados os caracteres produção de massa verde, porcentagem de extração de caldo, teor de sólidos solúveis totais, toneladas de brix por hectare e produção de etanol. A adaptabilidade e a estabilidade fenotípica foram aferidas pelos métodos de Wricke e Annicchiarico. Observou-se que a adaptabilidade e estabilidade fenotípica em sorgo sacarino depende da estrutura genética dos genótipos, no qual os híbridos foram mais estáveis do que as linhagens parentais. Além disso, os híbridos H2x9 e H3x8 foram os mais promissores. Sorghum L. L (L.) bioetanol agroindustriais testados 4 alfalátice alfa látice Gerais Brasil verde caldo totais Annicchiarico Observouse Observou se parentais disso Hx H H2x H3x promissores (L. (L

Resumo O objetivo deste trabalho foi propor a utilização de distribuições tradicionais com base em modelos de regressão distribucional, para analisar a produtividade do milho. O experimento foi realizado em um delineamento alfa látice, com três repetições e 24 blocos. Os dados usados referem-se a 102 plantas de milho que são parte da coleção permanente do Centro de Desenvolvimento Científ ico e Tecnológico para a Agr icultura, da Universidade Federal de Lavras. Para a avalição da produtividade do milho utilizaram-se as seguintes variáveis explicativas: peso de 100 sementes, altura da planta, altura da espiga e dias para a maturação. As análises iniciais envolveram o ajuste de quatro distribuições (gama, gama generalizada, inversa Gaussiana e inversa Gaussiana generalizada) aos dados, em que a dist r ibuição gama foi a que melhor se ajustou, com base nos critérios de informação de Akaike e bayesiano (AIC e BIC). Notavelmente, a altura da espiga tem uma influência considerável sobre a variabilidade da produtividade porque conforme a altura aumenta, a produtividade diminui, enquanto as covariáveis peso de 100 sementes e dias para a maturação explicam a média crescente da produtividade. A análise residual mostra que o modelo baseado na distribuição gama é adequado para explicar os dados e fornecer informações úteis para a pesquisa e a prática agrícolas. distribucional látice 2 blocos referemse referem 10 icultura Lavras utilizaramse utilizaram explicativas planta gama, (gama generalizada ajustou AIC BIC. BIC . BIC) Notavelmente aumenta diminui agrícolas 1

Abstract The objective of this work was to propose the use of traditional models based on distributional regression models to analyze maize productivity. The experiment was carried out in an alpha lattice design, with three replicates and 24 blocks. Data used refer to 102 maize plants from the permanent collection of the Centro de Desenvolvimento Científico e Tecnológico para a Agricultura of the Universidade Federal de Lavras. For the maize productivity evaluation, the following explanatory variables were used: weight of 100 seed, plant height, ear height, and days to maturation. The initial analyses involved the fitting of four distributions (gamma, generalized gamma, inverse Gaussian, and generalized inverse Gaussian) to the data, in which the gamma distribution showed the best fit based on the Akaike and Bayesian information criteria (AIC and BIC). Cob height has a considerable influence on the productivity variability because as cob height increases, the productivity variability decreases, whereas the covariates weight of 100 seed and days to maturity explain the increasing average of the productivity. The residual analysis shows that the model based on gamma distribution is suitable for explaining the data and providing useful insights for agricultural research and practice. design 2 blocks 10 Lavras evaluation maturation (gamma Gaussian AIC BIC. BIC . BIC) increases decreases practice 1

Abstract The objective of this work was to quantify the genetic potential of full-sib maize progenies subjected to a reciprocal recurrent selection, in order to obtain high-yielding hybrids. The experiment was carried out in the alpha lattice design, with three replicates and 24 blocks. One hundred and two full sib maize progenies, from the crossing of two populations and two checks, were evaluated for the following traits: grain yield, seed mass, number of ears per plant, days to maturity, days to anthesis, days to silking, anthesis-silking interval, ear height, plant height, ear position, and stem lodging. Genetic parameters were estimated through REML/BLUP and multivariate analyses (correlation and similarity network, cluster heat map, and genetic gains). There are genetic variability and divergent clusters among the studied full-sib maize progenies. Seed mass, number of ears per plant, and anthesis silking interval are the traits that most contribute to the improvement of grain yield and divergence among the full-sib maize progenies. Genetic potential should be exploited through the selection and recombination in reciprocal recurrent selection to obtain high-yielding hybrids. fullsib highyielding high yielding hybrids design 2 blocks checks mass maturity anthesissilking height position lodging REMLBLUP REML BLUP correlation network map gains. gains . gains)

Resumo O objetivo deste trabalho foi quantificar o potencial genético de progênies de irmãos germanos de milho, em uma seleção recorrente recíproca, para obtenção de híbridos com alto rendimento. O experimento foi realizado em delineamento alfa látice, com três repetições e 24 blocos. Foram avaliadas 102 progênies de irmãos germanos de milho, do cruzamento de duas populações e duas testemunhas, quanto às seguintes características: produtividade de grão, massa de sementes, número de espigas por planta, dias para a maturação, dias para o florescimento masculino, dias para o florescimento feminino, intervalo de florescimento, altura da espiga, altura da planta, posição da espiga e acamamento do caule. Os parâmetros genéticos foram estimados via REML/BLUP e análises multivariadas (rede de correlações e similaridade, agrupamento de mapa de calor e ganhos genéticos). Há variabilidade genética e agrupamentos divergentes entre as progênies de irmãos germanos de milho estudadas. A massa de sementes, o número de espigas por planta e o intervalo de florescimento são as características que mais contribuem para o melhoramento da produtividade e a divergência entre progênies de irmãos germanos de milho. O potencial genético deve ser explorado por meio de seleção e recombinação, na seleção recorrente recíproca, para a obtenção de híbridos de alto rendimento. recíproca rendimento látice 2 blocos 10 testemunhas grão sementes maturação masculino feminino caule REMLBLUP REML BLUP rede similaridade genéticos. . genéticos) estudadas recombinação 1

Resumen La mancha foliar del trigo causada por Zymoseptoria tritici es una enfermedad devastadora en el cultivo de trigo a nivel internacional. El control químico y el uso de variedades resistentes son las principales estrategias de control. El Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT), cuenta con líneas de trigo con resistencia cuantitativa a la enfermedad por lo que el objetivo fue hacer un mapeo de loci para un carácter cuantitativo (QTL) asociados con la resistencia genética a la mancha foliar en la línea élite Mutus#1 (resistente), en una población de 275 líneas endogámicas recombinantes (LER) derivadas de la cruza de Mutus#1 con la línea élite Huirivis#1 (susceptible). En 2018 y 2019, en la estación del CIMMYT-Toluca se estableció un experimento en campo bajo un diseño experimental Alpha Lattice. Se generó una epidemia artificial con Z. tritici y se calculó el área bajo la curva del progreso de la enfermedad (ABCPE). Las 275 LER y los progenitores se secuenciaron utilizando la plataforma DArTSeq. Los mapas de ligamiento se construyeron con el programa IciMapping empleando la información del fenotipo y genotipo. Se identificaron cinco QTL de efecto menor, tres ubicados en los cromosomas 1B, 4A y 4B y dos en el cromosoma 5B, los cuales explicaron menos de síntomas y producción de picnidios en planta adulta portados por Mutus#1, pueden utilizarse con otros genes de resistencia o QTL para reducir la selección de nuevas cepas patogénicas de Z. tritici.

Abstract Wheat leaf spot caused by Zymoseptoria tritici is a devastating disease in wheat cultivation internationally. Chemical control and the use of resistant varieties are the main control strategies. The International Maize and Wheat Improvement Center (CIMMYT) has wheat lines with quantitative resistance to the disease, so the objective was to map quantitative trait loci (QTL) associated with genetic resistance to leaf spot in the elite line Mutus#1 (resistant), in a population of 275 recombinant inbred lines (RILs) derived from the cross of Mutus#1 with the elite line Huirivis#1 (susceptible). In 2018 and 2019, a field experiment was established at the CIMMYT-Toluca station under an Alpha Lattice experimental design. An artificial epidemic was generated with Z. tritici and the area under the disease progress curve (AUDPC) was calculated. The 275 RILs and parents were sequenced using the DArTSeq platform. The linkage maps were constructed with the IciMapping program using phenotype and genotype information. Five minor-effect QTLs were identified, three located on chromosomes 1B, 4A and 4B and two on chromosome 5B, which explained less of the symptoms and production of pycnidia in adult plants carried by Mutus#1, they can be used with other resistance genes or QTLs to reduce the selection of new pathogenic strains of Z. tritici.

RESUMEN La Orinoquía colombiana y en particular, la subregión de la Altillanura presenta ventajas comparativas y competitivas para la producción de soya (condiciones edafoclimáticas, relación costo-beneficio, área potencial y ubicación), alimento esencial por su contenido proteico (~37%), especialmente para aves y cerdos. Sin embargo, las alternativas varietales adaptadas y de alto rendimiento de grano son escasas para esta vasta región. Por ello, la presente investigación fue orientada hacia la selección de líneas mejoradas o variedades potenciales con alto mérito genético mediante la aplicación del mejor predictor lineal insesgado estandarizado (REML/BLUPe). Se evaluaron 60 líneas avanzadas y cuatro variedades comerciales en un diseño Alfa látice 8x8. El rendimiento de grano (RG) osciló entre 1117 y 4431 kg ha-1, el promedio poblacional fue de 2682 kg ha-1 y los predictores BLUPe oscilaron entre 5.37 y -3.71. Con una significancia t del 5% (1.67) y un comparador de predictores (t1-t2)≥1.67 (√2), se identificaron 6 líneas sobresalientes con BLUPe superiores a la media (P<0.05) y RG>3500 kg ha-1. En orden descendente el RG fue: L-041 (4431), L-019 (4326), L-104 (3923), L-149 (3832), L-202 (3536) y L-201 (3519 kg ha-1). El predictor estandarizado BLUPe permitió una selección efectiva (92%) de líneas.

ABSTRACT The Colombian Orinoquía and the Altillanura subregion show comparative and competitive advantages for soybean production (edaphoclimatic conditions, cost-benefit ratio, potential area, and location) essential food with a high protein content (~37%) and used mostly for poultry and pig nutrition. However, this immense region has scarce varietal alternatives of high grain yield and quality that are adapted to its climatic and edaphic conditions. The current research is based on the selection of superior lines or potential varieties with high genetic merit using the restricted maximum likelihood/standardized best linear unbiased predictor (REML/BLUPe) procedure. Sixty advanced lines and four commercial varieties were tested in an 8x8 alpha lattice design. Grain yield (GY) oscillated between 1,117 and 4,431 kg ha-1, the population average yield was 2,682 kg ha-1, and BLUPe predictors ranged between 5.37 and -3.71. With a t-test at a significance of 5% (1.67) and a predictor comparator of (t1-t2)≥1.67 (√2), six outstanding lines were identified with superior BLUPe values compared to the mean (P<0.05) and GY>3,500 kg ha-1. In descending order (kg ha-1), the GY was: L-041 (4,431), L-019 (4,326), L-104 (3,923), L-149 (3,832), L-202 (3,536), and L-201 (3,519 kg ha-1). The BLUPe standardized predictor allowed an effective selection (92%) of lines.

RESUMEN La expansión del cultivo de soya en Colombia genera la necesidad de buscar variedades con alto mérito genético y su mejoramiento, la generación de variedades con rendimientos competitivos y con alta calidad de grano, adaptadas a las condiciones del trópico bajo. El objetivo fue determinar, mediante herramientas biométricas, los parámetros genéticos y las ganancias esperadas, en caracteres cuantitativos de interés, para el proceso de mejora de soya. Se evaluaron 60 líneas y 4 variedades comerciales, en un diseño alfa látice 8x8, en oxisoles de la Altillanura. La estimación de los parámetros, se realizó mediante la aplicación de modelos mixtos, con ajuste de efectos aleatorios, por el método REML. Se observó amplia variabilidad genética para todos los rasgos evaluados, exceptuando la altura de planta. Se registraron valores altos de heredabilidad, para los caracteres de floración y madurez. En los componentes de rendimiento, la heredabilidad fue alta para número de vainas y peso de 100 granos. El efecto ambiental fue bajo, con valores cercanos o superiores a 1, con excepción de abortos embrionarios, número de vainas vanas y rendimiento de grano. La ganancia genética, como porcentaje de la media fue alta, para altura de planta; moderada, para rendimiento de grano y baja, para el resto de los caracteres. La heredabilidad y la ganancia moderadas de rendimiento de grano indican una acción aditiva de los genes, ideal para la selección recurrente. Los caracteres más discriminantes en las condiciones evaluadas fueron rendimiento de grano, peso de 100 granos y número de vainas.

ABSTRACT Soybean cultivation expansion in Colombia has generated the need to seek varieties with high genetic merit. A soybean genetic breeding program seeks to generate varieties with competitive and sustainable yields, and high-quality grain adapted to the conditions of the low tropics. The aim was to determine the genetic parameters and expected gains in quantitative traits of interest in a soybean breeding process using biometric tools. Sixty lines and four commercial varieties were evaluated in an 8x8 alpha lattice design (genotypes x blocks) planted in oxisols from the Altillanura region of Colombia. The estimation of the parameters was performed by applying mixed models with a random-effects adjustment through the REML method. Wide genetic variability was observed for all the evaluated traits, except for plant height. High heritability values were registered for the characters at flowering and maturity. Heritability was high for yield components such as the number of pods and the weight of 100 grains. Overall, the environmental effect was low, with values close to or higher than 1, except for embryonic abortions, number of empty pods, and grain yield. The genetic gain as a mean percentage was high for plant height, moderate for grain yield, and low for the rest of the characters. Moderate heritability and grain yield gain indicate an additive action of the genes ideal for recurrent selection. The most discriminating characters in the evaluated conditions were the grain yield, weight of 100 grains, and number of pods.

Resumo Informações quanto à diversidade genética de espécies nativas visando identificar melhores progênies viáveis para conservação in situ e ex situ, além de futuros programas de melhoramento florestal são incipientes. Objetivamos conhecer a diversidade genética de 64 progênies de Peltophorum dubium (Spreng.) Taub. (Fabaceae). Determinamos os caracteres dendrométricos dessa espécie, e ao utilizarmos técnicas multivariadas e análises de agrupamento verificamos as diferenças entre as progênies e grupos de menor heterogeneidade. O teste de progênies e procedências foi instalado em Dourados (MS), cujas sementes foram coletadas em três regiões de MS (Vale do Ivinhema, Serra de Maracaju e Serra da Bodoquena) e na microrregião de Lavras-MG. O experimento foi conduzido em alfa-látice 8 x 8, com quatro repetições. Constatamos variabilidade genética entre e dentro das populações de P. dubium para todos os caracteres altura, diâmetro, circunferência à altura do peito, volume e área basal. Sugerimos que as populações de P. dubium tem alta variabilidade genética, o que indicou possibilidade de melhoramento genético pela seleção das melhores progênies. Os métodos UPGMA e Tocher agruparam as progênies em três e nove grupos, respectivamente, em que os indivíduos mais divergentes são procedentes de MG e da região de Bonito em MS. As progênies de P. dubium de identificação 45, 47, 49, 50, 55 e 59, todas de MG, são as mais promissoras, enquanto que as progênies 6 e 9, foram as menos promissoras, baseando-se nos caracteres morfológicos.

Abstract There is little information regarding the genetic diversity of native species aimed at identifying the best viable progenies for in situ and ex situ conservation. Furthermore, there is a lack of future forest improvement programs. We aimed to know the genetic diversity of 64 Peltophorum dubium (Spreng.) Taub. (Fabaceae) progenies. We determined this species' dendrometric characteristics, and when using multivariate techniques and cluster analysis, we verified the differences between the progenies and groups with less heterogeneity. The progeny and provenance test was installed in Dourados (Mato Grosso do Sul - MS), with seeds collected in three MS regions (Vale do Ivinhema, Serra de Maracaju, and Serra da Bodoquena) and in the micro-region of Lavras (Minas Gerais - MG). The experiment was conducted in an alpha lattice 8 x 8 with four repetitions. We found genetic variability among and within P. dubium populations for all height, diameter, circumference at breast height, volume, and basal area characters. We suggest that P. dubium populations have high genetic variability, which indicates possible genetic improvement through best progeny selection. The UPGMA and Tocher methods grouped the progenies into three and nine groups, respectively, in which the most divergent individuals come from MG and the Bonito region in MS. Based on morphological characters, P. dubium progenies identified as 45, 47, 49, 50, 55, and 59 from MG are the most promising, while progenies 6 and 9 were the least promising.

Abstract Knowledge of the genetic variability and yield heritability and its components within the plant breeding allows to optimize the selection process. The objective of the research was to determine the genetic variability of yield and its components, as well as their correlations to identify selection criteria for increased grain productivity. 19 genotypes, planted in the spring-summer cycle, were used in 7 locations of rainfed in Mexico’s High Valleys. The experimental design was Alpha lattice with two repetitions in each environment. The experimental unit was four grooves 3 m long with a separation of 30 cm. The variables evaluated were: days at maturity, plant height, grains per spigot, number of spikes of wheat and grains per square meter, as well as harvest index, weight of a thousand grains and grain yield. The highest coefficients of genetic variation 20.8 and 18.4 were for grain and grain yield per spigot, respectively. But the highest genetic variations and heritability are presented by the weight of a thousand grains and grains per spigot which facilitates the selection of these characters. The yield had significant correlations with number of grains per square meter, grains per spigot, number of spikes and harvest index with values of 0.92, 0.57, 0.54 and 0.54, respectively. So, they can be used as selection criteria to promote productivity. For this group of genotypes, it is necessary to increase the genetic variability for spigot per square meter and weight of a thousand grains. It is proposed to the genotypes Don Carlos M2015, 6, 11 and 8 as genetic sources to increase the weight of grain, number of grains per spike, greater number of spikes and grains per square meter to promote grain yield.

Resumen El conocimiento de la variabilidad genética y heredabilidad del rendimiento y sus componentes dentro del fito mejoramiento permite optimizar el proceso de selección. El objetivo de la investigación fue determinar la variabilidad genética del rendimiento y de los componentes, así como sus correlaciones para identificar criterios de selección para mayor productividad de grano en trigo harinero. Se utilizaron 19 genotipos, sembrados en el ciclo primavera-verano en siete localidades de temporal en los Valles Altos de México. El diseño experimental fue alfa látice con dos repeticiones en cada ambiente. La unidad experimental fue de cuatro surcos de 3 m de longitud con una separación de 30 cm. Las variables evaluadas fueron: días a madurez, altura de planta, granos por espiga, número de espigas y granos por metro cuadrado, así como índice de cosecha, peso de mil granos y rendimiento de grano. Los mayores coeficientes de variación genética 20.8 y 18.4 fueron para rendimiento de grano y granos por espiga, respectivamente. Pero las variaciones genéticas y herededabilidades más altas las presento el peso de mil granos y granos por espiga lo cual facilita la selección de estos caracteres. El rendimiento presentó correlaciones significativas con número de granos por metro cuadrado, granos por espiga, número de espigas e índice de cosecha con valores de 0.92, 0.57, 0.54 y 0.54, respectivamente, que se pueden utilizar como criterios de selección para la productividad. Para este grupo de genotipos es necesario incrementar la variabilidad genética para espigas por metro cuadrado y peso de mil granos. Se propone a Don Carlos M2015, 6, 11 y 8 como fuentes genéticas para incrementar el peso de grano, número de granos por espiga, mayor número de espigas y granos por metro cuadrado para el rendimiento.

Abstract In Mexico 7.5 million hectares of corn are grown, with an average grain yield of 3.2 t ha-1, a strategy to increase yield is the use of improved varieties. The objectives of this study were 1) estimate genetic parameters in a segregating population of tropical maize; 2) select S1lines based on grain yield and earliness; and 3) determine the phenotypic and genetic correlation between traits. The germplasm under study consisted of 193 segregating S1 lines, parents and a control, S1 lines come from the F2 population from crossing Ac7643 x B-39. The lines were evaluated under irrigation using an alpha lattice design with two replications during the spring-summer 2013 and autumn-winter 2013/2014 cycle, in Ayala, Morelos. The variables recorded were days to male (FM) and female silking (FF), floral synchrony (SF), plant height (AP) and cob (AM) and grain yield (RG). The results indicate that the coefficient of additive genetic variation for RG was 17% and for FM 4%; heritability for the same traits was 0.42 and 0.80, respectively. The expected genetic gain for RG was 0.143 t ha-1 and for FM -0.62 d. The LUM-80 line turned with positive transgressive inheritance in RG. Phenotypic and genetic correlations between RG and the rest of the traits were low. The high degree of genetic variability present in the segregating population allows continuing with the breeding program.

Resumen En México se cultivan 7.5 millones de hectáreas con maíz, con un rendimiento de grano promedio de 3.2 t ha-1, una estrategia para incrementar el rendimiento es el uso de variedades mejoradas. Los objetivos del presente estudio fueron: 1) estimar los parámetros genéticos en una población segregante de maíz tropical; 2) seleccionar líneas S1 con base en el rendimiento de grano y precocidad; y 3) determinar la correlación fenotípica y genética entre caracteres. El germoplasma de estudio fueron 193 líneas S1 segregantes, los progenitores y un testigo, las líneas S1 provienen de la población F2 de la cruza de Ac7643 x B-39. Las líneas se evaluaron bajo riego usando un diseño látice alfa con dos repeticiones, en los ciclos primavera-verano 2013 y otoño-invierno 2013/2014, en Ayala, Morelos. Las variables registradas fueron días a floración masculina (FM) y femenina (FF), sincronía floral (SF), altura de planta (AP) y mazorca (AM), y rendimiento de grano (RG). Los resultados indican que el coeficiente de variación genético aditivo para RG fue de 17% y en FM de 4%; la heredabilidad para los mismos caracteres resultó de 0.42 y 0.80, respectivamente. La ganancia genética esperada para RG fue de 0.143 t ha-1 y para FM de -0.62 d. La línea LUM-80 resultó con herencia transgresiva positiva en RG. Las correlaciones fenotípicas y genéticas entre RG y el resto de caracteres fueron bajas. El alto grado de variabilidad genética presente en la población segregante permite continuar con el programa de mejoramiento genético.

Breeding for heat tolerance in bread wheat (Triticum aestivum L.) is a serious global concern due to the increasing threats of high temperature. Thus, 189 wheat genotypes coded from 1 to 189 were evaluated for heat tolerance in normal and late seasons in the International Centre for Agricultural Research in Dry Areas (ICARDA), Tel Hadya, Syria, from 2010 to 2012. The experiments were laid out in alpha lattice designs with two replicates. Data collected on the grain yield, days to heading and maturity, grain filling duration and plant height were subjected to restricted maximum likelihood (REML) analysis for generation of the best linear unbiased estimates (BLUEs). Very highly significant effects (p < 0.001) of genotype, season, and genotype by season interaction on grain yield and other traits were obtained. The grain yield and other traits performance of the wheat genotypes were significantly (p < 0.05) higher in the normal season than in the late season. Genotype 148 was among the 30 top grain yielding genotypes in all the environments, while genotypes 172 and 124 were among the top yielding genotypes in all the environments except in late season 2. The relative heat tolerance of the genotypes ranged from -33.69% to -77.95% in late season 1 vs. normal season 1 and -65.28% to -95.83% in late season 2 vs. normal season 2. The high variability obtained in the germplasm underlies sufficient genetic variability for improving heat tolerance in bread wheat.

El objetivo de este trabajo fue determinar la adaptación de híbridos experimentales de maíz en Costa Rica. Se evaluaron veinticuatro híbridos experimentales de grano blanco en las condiciones agroecológicas de bosque tropical húmedo, durante el período 2009-2011, en las localidades de Concepción, Guagaral, Chánguena, El Águila, Veracruz, Los Chiles y Upala, con temperaturas entre 26 y 35°C y una precipitación entre los 2700-3200 mm, esto con el fin de obtener el rendimiento y respuesta a los principales factores abióticos y bióticos. Se empleó un diseño de alfa látice con tres repeticiones. Los híbridos fueron evaluados en dos ciclos de siembra por localidad y por año. Los resultados del análisis combinado indicaron diferencias significativas al 0,05 entre genotipos y el gráfico del AMMI-biplot evidenció que los materiales con mayor estabilidad fueron: CLQRCWQ121/CLQR- CWQ122)//CML491 (QPM); CML494/CML495 (Normal); (CLQRCWQ121/CLQRCWQ26)//CML491 (QPM); (CL- QRCWQ121/CML502)//CML491 (QPM) con rendimientos promedio de 9,3; 9,0; 8,7 y 8,8 t/ha, respectivamente. Las localidades donde se obtuvo mayor rendimiento fueron El Águila y Guagaral, 9,8 y 8,5 t/ha, respectivamente. En cuanto a la interacción de localidades y genotipos el AMMI biplot mostró que El Águila y Guagaral tuvieron condiciones agro- climáticas más favorables para la expresión del potencial de los híbridos evaluados. Por su parte, Veracruz y Concepción presentaron condiciones agroclimáticas menos favorables para el desempeño de los materiales. La interacción genotipo x ambiente tuvo un valor de 62,1% en la prueba de Gollob.

The objective of this work was determine the adaptation of experimental maize hybrids in Costa Rica. Twenty four white grain experimental hybrids were evaluated in agroecological conditions of humid tropical forest during 2009-2011, at Concepción, Guagaral, Chánguena, El Águila, Veracruz, Los Chiles and Upala with temperatures between 26 and 35°C and rainfall between 2700-3200 mm, in order to evaluate its performance, yield and adaptation to major abiotic and biotic conditions. Trials were established in twelve locations using an alpha lattice design with three replications. The hybrids were evaluated in two planting cycles per location per year. The results of the combined analysis indicated significant differences between genotypes at 0.05, and AMMI-biplot graphs showed that the more stable materials were: CLQRCWQ121/ CLQRCWQ122)//CML491 (QPM); CML494/CML495 (Normal); (CLQRCWQ121/CLQRCWQ26)//CML491 (QPM); (CLQRCWQ121/CML502)//CML491 (QPM) with average yields of 9.3, 9.0, 8.7 and 8.8 t/ha, respectively. The locations where yield was higher were Guagaral and El Águila with 9.8 and 8.5 t/ha, respectively. As for the interaction of locations and genotypes, AMMI-biplots showed that locations Guagaral and El Águila offered more favorable growing conditions for the expression of the potential of the hybrids evaluated. Meanwhile, Veracruz and Concepción had less favorable growing conditions for the performance of the materials. AMMI analysis showed that PCA1 explains significantly genotype x environment interaction with a value of 62.1% in the test Gollob.

The identification of hybrids formed with three outstanding lines with germplasm from different research institutions could contribute to increase the heterosis in grain's yield and the stability of maize planted in the High Valleys of Central Mexico. This work was conducted in 2009 in ten environments of this region with the aim to identifying outstanding genetic material. In an alpha lattice experimental design with two 8*5 replicates per environment, we evaluated 40 genotypes of maize: early white trilinear 32 hybrids, four single crosses (testers) and four controls from CIMMYT. The most outstanding results indicated the following: a) the environments recorded with a higher production than 9.5 t ha-1 were Tlahuelilpan, Batán (+) and Batán (AC) but, Tlaxcoapan was the one with average stability and yield b) fifteen cob genotypes had statistically similar yields between 8.2 and 9.4 t ha-¹, but the none s with the highe st production were identified by the codes 21, 28, 27, 29 and 20 (CMS989001//Mexico gpo. 10; CMS 989003//Tuxpeño Cream 1; CMS 989003//SB1; CMS 989003//Mexico gpo. 10; CMS 989001//Tuxpeño Cream 1), with very acceptable arithmetic means in favorable environments and under conditions of low fertility and drought, but unstable, due that, out of these, only genotype 27 was the most stable over the ten contrasting environments. The best testers were identified by codes 35 and 36 [CMS 989 001 (P3) and CMS 989 003 (P4)], both with 9.3 t ha-1. The best trilinear hybrid control was identified with the key 39 and, the origin CMT 089,005, with 8.5 t ha-1. The best control and, the best testing had ear yields statistically identical as the 15 most outstanding hybrids. The subgroput of genotypes composed of the five trilinear hybrid and, the two testers, with the largest ear productions, are the most prominent genetic material for use in a new breeding program, and generate production technology or planting recommendation trade in this region of Mexico.

La identificación de híbridos de tres líneas sobresalientes formados con germoplasma, proveniente de diferentes instituciones de investigación, podría contribuir a incrementar la heterosis en rendimiento de grano y la estabilidad de los maíces que se siembran en los Valles Altos del centro de México. El presente trabajo se realizó en 2009 en diez ambientesde esta región, con el objetivo de identificar material genético sobresaliente. En un diseño experimental alpha látice 8*5 con dos repeticiones por ambiente, fueron evaluados 40 genotipos de maíz: 32 híbridos trilineales blanco precoz, cuatro cruzas simples (probadores) y cuatro testigos del CIMMYT. Los resultados más sobresalientes indicaron lo siguiente: a) los ambientes donde se registró una producción de mazorca mayor a 9.5 t ha-1 fueron Tlahuelilpan, Batán (+) y Batán (AC), pero Tlaxcoapan fue el ambiente con rendimiento y estabilidad promedio, b) quince genotipos tuvieron rendimientos de mazorca estadísticamente iguales entre 8.2 y 9.4 t ha-¹, pero los de mayor producción fueron los identificados con los códigos 21, 28, 27, 29 y 20 (CMS989001//México gpo. 10; CMS 989003//Tuxpeño Crema 1; CMS 989003//SB1; CMS 989003//México gpo. 10; CMS 989001//Tuxpeño Crema 1), con promedios aritméticos muy aceptables en ambientes favorables y en condiciones de baja fertilidad y sequía pero inestables, debido que de éstos sólo el genotipo 27 fue el más estable a través de los diez ambientes contrastantes. Los mejores probadores fueron los identificados con los códigos 35 y 36 [CMS 989001 (P3) y CMS 989003 (P4)], ambos con 9.3 t ha-¹. El mejor testigo fue el hibrido trilineal identificado con la clave 39 y con el origen CMT 089005, con 8.5 t ha-¹. El mejor testigo y los mejores probadores tuvieron rendimientos de mazorca estadísticamente iguales que los 15 híbridos más sobresalientes. El subconjunto de genotipos integrado por los cinco híbridos trilineales y por los dos probadores, con las mayores producciones de mazorca, constituyen el material genético más sobresaliente, para emplearse en un nuevo programa de mejoramiento genético, y generar tecnología de producción o para recomendación en siembra comercial en esta región de México.

The seedling vigor of 80 barley recombinant chromosome substitution lines (RCSLs) was measured for selecting high seedling vigor genotypes. The RCSLs were derived from a cross between H. vulgare subsp. spontaneum and H. vulgare subsp. vulgare 'Harrington'. The work was carried out under greenhouse conditions during the summer of 2008. The experimental design was an alpha lattice with 3 replicates. In each replicate, 40 plants were established, distributed in eight polyethylene pots containing sand as substrate, which were fertilized an irrigated. The emergence of seedlings, number of leaves and shoots, dry matter of leaves, shoots and roots and leaf area of fully expanded leaves were measured. In addition, growth indices were calculated: emergence rate, leaf appearance rate, relative leaf expansion rate, relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR) and the allometric coefficient (K) between root and shoot dry matter. All calculated indices varied significantly among genotypes (P≤0.05) and some RCSLs showed better early vigor associated traits than 'Harrington'. The dry matter accumulation 30 DAS (when the experiment ended) was significant and positively correlated with the RGR (r=0.61; P≤ 0.05) and NAR (r=0.41; P≤0.05). The K coefficient was negatively correlated with NAR (r=-0.40, P≤0.05). The genotypes with the greatest seminal vigor were the RCSLs 45, 92, 112 and 'Harrington', whereas the RCSLs 5, 19, 47 and 121 presented the lowest seminal vigor.

Se estudió el vigor seminal de 80 líneas recombinantes con sustitución de cromosomas (RCSLs), derivadas de la cruza entre H. vulgare subsp. spontaneum y H. vulgare subsp. vulgare 'Harrington'. El trabajo se realizó bajo invernadero durante el verano del 2008. Se usó un diseño experimental de alpha lattice con tres repeticiones. En cada repetición, 40 plantas de cada línea se establecieron en 8 macetas que contenían arena como sustrato. Se realizó 8 muestreos, en los que se evaluó emergencia de plántulas, número de hojas y tallos, materia seca de hojas, tallos y raíces y área foliar de hojas plenamente expandidas. Además, se calculó índices de crecimiento como tasa de emergencia, tasa de aparición de hojas, tasa relativa de expansión foliar, tasa de crecimiento relativo (TCR), tasa de asimilación neta (TAN), proporción de área foliar (PAF) y el coeficiente alométrico de la relación entre materia seca radical y aérea (K). Todos los parámetros variaron significativamente entre genotipos (P ≤ 0,05) y algunas RCSLs fueron superiores a Harrington. La acumulación de materia seca en el último muestreo se correlacionó significativa y positivamente con la TCR (r =0,613; P ≤ 0,05) y la TAN (r=0,414; P ≤ 0,05). El K se correlacionó negativa y significativamente con la TAN (r=-0,393; P ≤ 0,05). Los genotipos con mayor vigor seminal fueron las RCSLs 45, 92, 112 y Harrington; mientras que los con menor vigor seminal fueron las RCSLs 5, 19, 47 y 121.

Between 2005 and 2008 high-quality protein maize hybrids were evaluated, validated and characterized in order to know their yield, agricultural characteristics and nutritional an industrial features. In 2005, hybrids were evaluated in Cotaxtla, Tlalixcoyan and Ignacio de la Llave, Veracruz, under an alpha lattice 9*2 design with 18 treatments and three repetitions, in fields with two five-meter long furrows, with a density of 62 500 plants ha-1. Hybrids HQ1, HQ2, HQ3 and HQ4, were identified; they stand out for their yield, agricultural characteristics and their tolerance to corn stunt. In the 2006 spring-summer cycle, six validation fields were set in Cotaxtla, Mata de Agua, Tlalixcoyan, Ignacio de la Llave, Martínez de la Torre and Rodríguez Clara, in the state of Veracruz. The fields were established with a random block design with nine treatments and two repetitions in fields with eight 25-meter long furrows, and a density of 62 500 plants ha-1. With the combined variance analysis, a highly significant difference was found for genotypes (G), locations (L) and the interaction G*L, in grain yield variables, days to male and female, aspect and plant health. The genotypes that stood out for their yield, aspect and plant and ear health were HQ4, H-520, HQ3 and HQ1, with 5.42, 5.38, 5.13 y 5.06 t ha-1, respectively. The HQ1 produced the best tortillas with the traditional method for dough and tortillas. Hybrid HQ4 can be successfully processed by the nixtamalized flour industry. This hybrid registered 72% more lysine and 56% more tryptophan in the whole grain than regular maize. In 2007 and 2008, HQ4 was defined for its official registration as H-564C with the number 2257-MAZ-1133-300609/C.

Durante 2005 a 2008 se evaluaron, validaron y caracterizaron híbridos de maíz con alta calidad proteínica, con los objetivos de conocer su rendimiento, características agronómicas y propiedades nutricionales e industriales. En 2005 se evaluaron híbridos en las localidades de Cotaxtla, Tlalixcoyan e Ignacio de la Llave, Veracruz; bajo un diseño alpha látice 9*2 con 18 tratamientos y tres repeticiones, en parcelas de dos surcos de 5 m con una densidad de 62 500 plantas ha-1. Se identificaron los híbridos HQ1, HQ2, HQ3 y HQ4, sobresalientes por su rendimiento, características agronómicas y por su tolerancia a la enfermedad del "achaparramiento". En el ciclo primavera verano 2006 se establecieron seis parcelas de validación en las localidades de Cotaxtla, Mata de Agua, Tlalixcoyan, Ignacio de la Llave, Martínez de la Torre y Rodríguez Clara, en el estado de Veracruz. Los lotes fueron establecidos bajo diseño bloques al azar con nueve tratamientos y dos repeticiones en parcelas de ocho surcos de 25 m, con una densidad de 62 500 plantas ha-1. De los análisis de varianza combinados, se encontró diferencia altamente significativa para genotipos (G), localidades (L) y para la interacción G*L, en las variables rendimiento de grano, días a floración masculina y femenina, aspecto y sanidad de planta. Los genotipos sobresalientes por su rendimiento, aspecto y sanidad de planta y mazorca, fueron: HQ4, H-520, HQ3 y HQ1, con 5.42, 5.38, 5.13 y 5.06 t ha-1, respectivamente. Con el HQ1 se produjeron las mejores tortillas siguiendo el método tradicional de la masa y la tortilla. El híbrido HQ4, puede ser procesado exitosamente por la industria de la harina nixtamalizada. Este híbrido registró 72% más lisina y 56% más triptófano en el grano entero que el maíz normal. Durante 2007 y 2008 se hizo la caracterización del HQ4, para su registro oficial como H-564C con el número: 2257-MAZ-1133-300609/C.

Doscientas cincuenta y tres familias F2 de alta calidad de proteína (ACP) provenientes del CIMMYT (Centro Internacional de Mejoramiento de Maíz y Trigo) fueron evaluadas en dos ensayos diferentes en Menegua, una localidad ubicada en el departamento del Meta de los Llanos Orientales de Colombia. El diseño experimental utilizado fue de alpha lattice con 2 repeticiones y en cada ensayo se incluyó testigos ACP y normales. Los datos fueron analizados siguiendo el método REML (Restricted máximum Likelihood Method) del procedimiento GLM de SAS 9.1.3. Los criterios principales de selección fueron rendimiento de grano y textura de grano. Se seleccionaron 44 F2s con rendimiento superior al del testigo ACP y comparable al rendimiento de los testigos normales. La textura de grano de las familias seleccionadas fue semi-cristalino con buena dosis de genes modificadores lo que indica que el gen o2 está presente. El paso siguiente será seguir el proceso de autofecundación de las familias F2 hasta llegar a F5 en que se hará los cruzamientos con probadores a fin de identificar líneas deseables para la formación de híbridos y sintéticos.

The objective of the work was to select genotypes with high quality protein maize (QPM) and adapted to acid soils. Corn populations F2 of QPM were evaluated in the eastern plains of Colombia, by the International Maize and Wheat Improvement Center (CIMMYT) México. Populations were divided in two groups of 70 and 90 genotypes. The experimental designs consisted on a Alpha Lattice of 10x7 and 10x9, with two repetitions, were. The main criteria of selection were grain yield (t/ha) and texture of endosperm, as indicator of modifier genes. The experiments were analyzed using the procedures MIXED and GLM with the Maxima method Restricted Probability (REML) of SAS 9.1.3. With the Alpha Lattice of 10x7, the results indicated that under conditions of acidity, the best genotype, accession 54 with 4,86t/ha, was similar to the commercial hybrid H-108 check. This material showed good texture also. In the Alpha Lattice of 10x9, the commercial material with greater yield was HEZC- 318 (7.57 t/ha) and the best accession, 33 and 77 did not out yield it, but the texture was good. The evaluation for modification of endosperm with the light table, 44 families F2 showed the presence of the gene opaque 2 that transfers the ACP characteristics and high yield.