Estimativas de parâmetros genéticos e identificação de QTLs candidatos em cajueiro.

• Ano de defesa: 2012
• Autor(a) principal: Santos, Francisco Herbeth Costa dos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Agronomia; Anacardium occidentale L.; Melhoramento genético; Locos de características quantitativas; Clones de cajueiro; Caju - Melhoramento genético; Genética vegetal
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/8484

Knowledge about genetic parameters, identification of quantitative trait loci (QTL) and marker-assisted selection have great interest for genetic improvement. The objectives of this research were to evaluate the yield potential of eighty four clones of cashew, to estimate their genetic parameters and to identify QTLs associated with plant height, canopy diameter, anthracnose, black mold, number of hermaphrodite flower/panicle and nut weight. Considering these objectives, two trials were planted in two different countries (Pacajús and Paraipaba), state of Ceará, Brazil. The experimental phase was conducted in a randomized block design with two replications, two plants per plot. Apart the traits were evaluated during years 2009, 2010 and 2011. Detection of candidate QTLs were realized using the methods non-parametric mapping, interval mapping and multiple QTL mapping. The evidence of genotypic variability was detected in F1 generation to all characters analyzed. The high potential for the selection of genotypes with the best characteristics to resistance to anthracnose and black mold, hermaphrodite flower and yield. The generation F1 clones named as: 1, 16, 17, 41, 57, 65, 76 and 78 were considered the most promising materials for breeding propose. The joint analysis indicated significant genotype by environment interaction for all traits studied. QTLs for traits of agronomic importance were identified with potential for marker-assisted selection. There is presence of QTLs for all traits, explaining between 2.16 to 19.47% of the total phenotypic variation in the traits canopy diameter and hermaphrodite flowers, respectively. QTL analysis over years and places revealed important effects of genotype by environment interaction on QTL detection. This result agrees with the differences found for the average trait among years and places related, among other causes, the alternation of some clones (genotypes) for traits analyzed and the amount of rain for the environment.