Repetibilidade de caracteres de fruto, estabilidade fenotípica e divergência genética em cultivares de pessegueiro

• Autor(a) principal: Matias, Rosana Gonçalves Pires
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1396
• topic: Pêssego - Melhoramento genético; Prunus persica; Diversidade genética; Peach - Genetic improvement; Prunus persica; Genetic diversity; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

This study aimed to assess the relationships among traits of peach and nectarine fruit, as well as its direct and indirect effects through path analysis on the concentration of ascorbic acid and carotenoids. There were estimated the number of fruits and years required to predict the real value of cultivars based on 14 fruit traits, the presence of interaction between genotypes and years; as well as stability to the fruit weigth, SS/TA ratio and cycle duration, and genetic diversity of peach and nectarine cultivars grown in Viçosa-MG. The work was developed in the Department of Plant Science, Universidade Federal de Viçosa, evaluating 28 cultivars of peach and two of nectarine. The traits evaluated were skin and pulp color (coordinate b* and hue angle - °h), fruit weight (FW), suture (SD), equatorial (ED) and polar (PD) diameters, firmness, soluble solids content (SS), titratable acidity (TA), SS/TA ratio, concentration of ascorbic acid and carotenoids, and cycle duration. The results indicate that the highest correlations are between the FW, SD, ED and PD characteristics and between carotenoids content and °h of pulp and hue of yellow flesh color is associated with the carotenoids content, with potential to be used in the selection indirect this characteristic. Four fruits of peach and nectarine trees are sufficient to predict the actual value of individuals with 80% accuracy with respect to fruit weight, suture, equatorial and polar diameters, firmness, soluble solids (SS), titratable acidity (TA), SS/TA ratio, ascorbic acid and carotenoids, b* of skin, °h of skin, b* of pulp and °h of pulp, and with four years of evaluation, it is possible to predict the actual value of individuals with 80% of accuracy with respect to 14 fruit characteristics evaluated in this study. Interaction cultivars x years in relation to fruit weight, SS/TA ratio and cycle duration was observed. None of the cultivars showed high adaptability to Viçosa-MG on the three evaluated traits. 'Josefina' showed the general adaptability for SS/TA ratio, and 'Flordaprince' and 'Tropical' for cycle duration. To favorable environments there are indicated the cultivars 'Capdebosq' and 'Maciel' for fruit weigth, and 'Coral' and 'Talismã' for SS/TA. 'Rubimel' is adaptable for unfavorable environment with respect to fruit weight. The genetic diversity existing in peach cultivars enabled the formation of seven, six and six distinct groups in cycles of 2011, 2012 and 2013, respectively. Fruit weight, °h of skin, °h of pulp and firmness are the characteristics that most contributed to the genetic diversity of peach and nectarine cultivars. Greatest genetic divergence was observed between 'Marli' and 'Rubrosol', 'Josefina' and 'Maciel', and 'Maciel' and 'Rubrosol' in the years 2011, 2012 and 2013, respectively.