ABSTRACT. The continuous gains in cycles of recurrent selection have raised disagreement among researchers. Two hundred and forty-two full-sib families were obtained from CIMMYT and Piranão populations and evaluated in a simple lattice design in two environments to estimate the response to selection in the 11 th cycle of the UENF reciprocal recurrent selection program. No genotype x environment interaction was observed for most of the traits evaluated, indicating that a single recurrent selection program can be conducted for both sites. The population studied exhibited wide genotypic variability and heritability estimates ranged from 33 to 73%, indicating prospects of selection gain for the following cycles. The predicted genetic gain in yield was 12.90%. It is possible to conclude that the populations studied may be promising for the achievement of new selection cycles, which provides a continuous concentration of favorable alleles and the production of hybrids for the North and Northwest regions of the state of Rio de Janeiro.Keywords: genetic gains, selection index, interpopulation hybrids, longevity of recurrent selection.Resposta a seleção no 11º ciclo de seleção recorrente recíproca entre famílias de irmãos-completos de milho RESUMO. A contínua obtenção de ganhos em ciclos de seleção recorrente tem sido motivo de controvérsia entre pesquisadores. 242 famílias de irmãos-completos foram obtidas entre as populações CIMMYT e Piranão, e avaliadas em delineamento látice simples, em dois ambientes para investigar as estimativas da resposta à seleção no 11º ciclo do programa de seleção recorrente recíproca da UENF. Não houve interação genótipos por ambiente para a maioria das características avaliadas, indicando que um único programa de seleção recorrente pode ser conduzido para ambos os locais. A população avaliada revelou ampla variabilidade genotípica, com estimativas de herdabilidade variando de 33 a 73%, indicando perspectivas de ganho de seleção para os próximos ciclos. O ganho genético predito para produtividade foi de 12,90%. Conclui-se que as populações avaliadas são promissoras para a consecução de novos ciclos de seleção, proporcionando concentração contínua de alelos favoráveis e a produção de híbridos para as regiões Norte e Noroeste Fluminense.Palavras-chave: ganhos genéticos, índice de seleção, híbridos interpopulacionais, longevidade da seleção recorrente.
ABSTRACT. Morpho-agronomic and molecular (RAPD and ISSR markers) data were used to evaluate genetic distances between papaya backcross progenies in order to help identify agronomically superior genotypes. Thirty-two papaya progenies were evaluated based on 15 morpho-agronomic characteristics, 20 ISSR and 19 RAPD primers. Manhattan, Jaccard and Gower distances were used to estimate differences based on continuous and binary data and combined analyses, respectively. Except for production, there were significant differences in the continuous variables among the genotypes. The molecular analysis revealed 193 dominant markers (ISSR and RAPD), being 53 polymorphic loci. Among the various clusters that were generated, the one based on a combined analysis of morpho-agronomic and molecular data gave the highest cophenetic correlation (0.72) compared to individual Multivariate analysis to estimate divergence in papaya analysis, consistently allocating the progenies into six groups. We found that the Gower algorithm was more coherent in the discrimination of the genotypes, demonstrating that a combination of molecular and agronomic data is valuable for studies of genetic dissimilarity in papaya.
Os pomares de abacaxizeiro no Brasil sofrem constantemente com as perdas de plantas e frutos ocasionadas pela fusariose, pois as cultivares plantadas atualmente são suscetíveis a esta doença. Novas cultivares mais resistentes têm surgido, no entanto não há registros de que já tenham sido avaliadas sensorialmente por consumidores. O objetivo deste trabalho foi avaliar a aceitação sensorial de duas novas cultivares resistentes à fusariose, Vitória e EC-93, comparando-as com outras já estabelecidas no mercado consumidor de frutas in natura, Pérola e Gold. A aceitação dos frutos foi avaliada por 52 consumidores com relação a aroma, sabor, impressão global, textura, aparência da fatia, aparência do fruto inteiro, utilizando-se da escala hedônica estruturada de nove pontos, acidez e doçura ideais, com escala do ideal, e intenção de compra, com escala estruturada de 5 pontos. Sólidos solúveis totais, acidez titulável e ratio foram avaliados. A cultivar Gold obteve maiores médias de aceitação para a maior parte dos parâmetros avaliados, enquanto a cv EC-93, as menores. Exceto no atributo aparência da fatia, a cv Vitória não diferiu das cultivares mais aceitas nos parâmetros avaliados. Os frutos diferiram significativamente quanto a SST, entre 12,0 e 16,0°Brix, AT entre 0,52 e 0,81% de ácido cítrico e ratio entre 19,12 e 28,46. Dentre as cultivares resistentes à fusariose, os resultados sugerem baixo potencial de mercado para a cv EC-93 e bom para a cv Vitória.
ABSTRACT.We examined the effect of incorporation of molecular markers on variability between and within populations in order to maximize heterotic effects and longevity of a maize reciprocal recurrent selection program. Molecular variability was quantified by inter-simple sequence repeat (ISSR) markers between and within the maize populations Cimmyt and Piranão in the 10th cycle of a reciprocal recurrent selection program. Forty-two S 1 progenies of each population were analyzed, these being families of full-sibs selected according to their agronomic traits. Thirteen primers were selected, which produced 140 bands; 114 of them were polymorphic and 26 monomorphic. Based on UPGMA grouping analysis and by genetic distances, it was possible to identify "contaminant" progenies. These progenies belong to the Piranão or Cimmyt groups, but cluster in the opposite heterotic group. Identification of "contaminant" progenies is relevant for selection, because, besides identifying genotypes that should be eliminated at the recombination stage, it allows increased heterosis expression in crosses between more genetically distinct individuals. After the elimination of the "contaminant" progenies and those that were allocated between the heterotic groups, a new statistical analysis was carried out, which demonstrated increased genetic distances
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