Seleção de genitores e predição do potencial genético de populações segregantes de trigo

• Autor(a) principal: Pimentel, Adérico Júnior Badaró
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4728
• topic: Triticum aestivum L.; Potencial genético; Capacidade de combinação; Diversidade genética; Média parental; Triticum aestivum L.; Genetic potential; Combining ability; Genetic diversity; Parental average; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

The correct choice of parental strains for hybridization and segregating populations to be conducted constitutes the most important decision to be taken by the plant breeder. Prior knowledge of the genetic potential of a breeding, obtained by different methodologies, allows efforts to be concentrated on those most promising combinations, favoring the genetic progress of the culture and avoiding the loss of financial resources and time. Thus, the purpose of this work was to identify superior parental strains and promising segregating populations in order to obtain high grain yield strains using different methodologies and to assess the degree of correlation between these methodologies. The methods used in this study were the diallel analysis, the Jinks and Pooni method (1976), the parental average and assessment of the genetic diversity. The study evaluated 36 segregating populations and 12 parental strains in Viçosa MG during 2008 and 2009. Variability between and within the segregating populations was observed. A significant difference was verified for GCA by diallel analysis of the F2 and F3 generations, however a non-significant difference for SCA was also observed in this analysis. The BRS 264, IAC 364, Aliança, Pioneiro and VI 98053 cultivars presented greater potential for increasing the grain yield, therefore they were recommended to be utilized in the hybridization blocks. The populations that presented the greatest potential were BRS264/Aliança, BRS264/VI98053, BRS264/Pioneiro, IAC364/Aliança, IAC364/VI98053 and IAC364/Pioneiro. The parental average was useful in predicting the average grain yield in the segregating populations assessed in two generations. In addition, it presented good concordance with the selected populations through diallel analysis. Instead, by the Jinks and Pooni methodology analysis (1976) the populations with greater potential did not corresponded to those considered superior by the other methodologies. The analysis of the diversity proved the existence of dissimilarity between the parental strains evaluated. However, similarly to the parental average it was observed that when the analysis of the diversity is applied individually it is not an effective prediction method. Among all the methodologies used, the diallel analysis demonstrated to be the most consistent for the selection of parental strains and segregating populations.