RESUMO Os programas de melhoramento vegetal têm investido no desenvolvimento de cebolas com alto padrão comercial e para tal dependem dos recursos genéticos disponíveis para a obtenção de híbridos comerciais. O objetivo deste estudo foi avaliar parâmetros genéticos, diversidade genética e as correlações fenotípicas e genotípicas de caracteres relacionados à produção de cebola. O experimento foi realizado em Uberlândia - Minas Gerais, Brasil. Foram avaliadas 53 linhagens de cebola. Foi utilizado o delineamento em blocos ao acaso. Foram avaliadas 13 características de planta e bulbo. As análises estatísticas foram realizadas no programa Genes e R. Observou-se a existência de variabilidade genética entre os genótipos para a maioria dos caracteres ao nível de 1% pelo teste F. A herdabilidade da maioria dos caracteres apresentou valores moderados a altos (≥ 70%) e relação CVg/CVe alta (≥1). O método UPGMA possibilitou separar os genótipos em 20 grupos e de forma semelhante o método de Tocher separou os mesmos em 19 grupos. Os grupos que mais se destacaram foram V, XIV, XV, XVI, XVII, XVIII, XIX e XX. Houve seis correlações fenotípicas significativas pelo teste t com grau de associação baixo a moderado, e as correlações genotípicas, em sua maioria, mostraram-se superiores às fenotípicas e apresentaram o mesmo sinal. A partir dos parâmetros genéticos estudados existe alta possibilidade de ganhos na seleção. Há ampla variabilidade genética para os caracteres estudados o que permitiu a separação de grupos de genitores divergentes. Adicionalmente, as correlações fenotípicas e genotípicas mostraram inviabilidade para seleção indireta.

ABSTRACT Plant breeding programs have been investing in the development of high commercial standard onions; thus, they depend on the genetic resources available for obtaining commercial hybrids. The objective of this study was to evaluate genetic parameters and diversity, and phenotypic and genotypic correlations of characters related to onion production. The experiment was conducted in Uberlândia, Minas Gerais, Brazil. Fifty-three onion strains were evaluated, and a randomized block design was used. The number of plant and bulb characteristics evaluated was 13. The statistical analyses were performed using Genes and R software. A genetic variability among the genotypes was found for most of the characters at 1% level of significance in the F test. The heritability of most characters presented moderate to high values (≥ 70%) and high CVg/CVe ratio (≥ 1). The UPGMA method separated the genotypes into 20 groups, while the Tocher method separated them into 19 groups. The groups that stood out were V, XIV, XV, XV, XVI, XVII, XVIII, XIX, and XX. The results of t-test showed six significant phenotypic correlations with low to moderate degree of association, and the genotypic correlations, in most cases, were higher than the phenotypic ones and showed the same sign. From the genetic parameters studied, the possibility of gains in the selection is high. The separation of groups of divergent genitors was possible due to the wide genetic variability for the studied characters. Moreover, the phenotypic and genotypic correlations showed that indirect selection is not feasible.

Abstract: Background and Aims: Cashew (Anacardium occidentale) is a native Brazilian tree, cultivated in various warm climates across the world. The cashew kernels production has been an important economic activity for many tropical countries, providing a variety of food with great nutrition value. The genetic diversity among the early dwarf cultivars used to production is poorly understood, as is the nutritional composition among nuts from those plants. This work aimed to evaluate the physicochemical characteristics of cashew kernels and to study genetic diversity among twelve cultivars to indicate superior genotypes for future breeding programs. Methods: Cashew kernels from twelve cultivars were evaluated for pH, titratable acidity, moisture, ash, lipids and proteins. The genetic variability was assessed using RAPD and ISSR molecular markers. Data from molecular and physicochemical analyses were used to estimate the genetic distances and Mantel test approach was applied to calculate Pearson’s correlation between the data. Key results: A high genetic variability was found among the cultivars. BRS 274 and BRS 275 were the closest genetically, while CCP 09 and BRS 189 were the most distant ones. On the other hand, EMBRAPA 51 and BRS 226 showed cashew kernels with more similar physicochemical characteristics, while BRS 189 and BRS 253 had the more different ones. Moreover, no correlation was found between the physicochemical and molecular results. Cashew kernels had pH close to neutrality, low acidity, considerable moisture content, and high lipid and protein contents. Conclusions: The cashew kernels from the cultivars studied here had low acidity and pH, considerable moisture and ash contents, and high protein and lipid contents. BRS 189, BRS 253, and CCP 1001 showed the best values for proteins, lipids, acidity, and pH. In addition, those cultivars have maximum distance genetic among them, which can be used as parents in future gene combinations in breeding programs.

Resumen: Antecedentes y Objetivos: El marañón (Anacardium occidentale) es un árbol nativo de Brasil y cultivado en varios climas cálidos en todo el mundo. La producción de nueces de marañón ha sido una actividad económica importante para muchos países tropicales, proporcionando una variedad de alimentos con un gran valor nutricional. La diversidad genética entre los primeros árboles de marañón enanos utilizados para la producción es poco conocida, así como la composición nutricional entre los frutos secos de estas plantas. Este trabajo tuvo como objetivo evaluar las características fisicoquímicas de los granos de marañón y estudiar la diversidad genética entre doce cultivares para indicar genotipos superiores para futuros programas de mejoramiento. Métodos: Se evaluó el pH, acidez titulable, humedad, ceniza, lípidos y proteínas de los granos de marañón de doce cultivares. La variabilidad genética se evaluó mediante marcadores moleculares RAPD e ISSR. Se utilizaron datos de análisis moleculares y fisicoquímicos para estimar las distancias genéticas y se aplicó el método de prueba de Mantel para calcular la correlación de Pearson entre los datos. Resultados clave: Se encontró una alta variabilidad genética entre los cultivares. BRS 274 y BRS 275 fueron los más cercanos genéticamente, mientras que CCP 09 y BRS 189 fueron los más distantes. Por otro lado, EMBRAPA 51 y BRS 226 mostraron granos con características fisicoquímicas más similares, mientras que BRS 189 y BRS 253 tuvieron los más diferentes. Además, no se encontró correlación entre los resultados fisicoquímicos y moleculares. Los granos de marañón tenían un pH cercano a la neutralidad, baja acidez, considerable contenido de humedad y alto contenido de lípidos y proteínas. Conclusiones: Los granos de marañón de los doce cultivares estudiados aquí tenían baja acidez y pH, contenido considerable de humedad y cenizas, y alto contenido de proteínas y lípidos. BRS 189, BRS 253 y CCP 1001 mostraron los mejores valores de proteínas, lípidos, acidez y pH. Además, esos cultivares tienen una distancia genética máxima entre ellos, que pueden usarse como progenitores en futuras combinaciones de genes en programas de mejoramiento genético.