RESUMO
ABSTRACT In this paper, the existence of a genotype x environment interaction for the average daily weight in GIFT Nile tilapia (Oreochromis niloticus) in different regions in the state of Paraná (Brazil) was analyzed. The heritability results were high in the uni-characteristic analysis: 0.71, 0.72 and 0.67 for the cities of Palotina (PL), Floriano (FL) and Diamond North (DN), respectively. Genetic correlations estimated in bivariate analyzes were weak with values between 0.12 for PL-FL, 0.06 for PL and 0.23 for DN-FL-DN. The Spearman correlation values were low, which indicated a change in ranking in the selection of animals in different environments in the study. There was heterogeneity in the phenotypic variance among the three regions and heterogeneity in the residual variance between PL and DN. The direct genetic gain was greater for the region with a DN value gain of 198.24 g/generation, followed by FL (98.73 g/generation) and finally PL (98.73 g/generation). The indirect genetic gains were lower than 0.37 and greater than 0.02 g/generation. The evidence of the genotype x environment interaction was verified, which indicated the phenotypic heterogeneity of the variances among the three regions, weak genetic correlation and modified rankings in the different environments.
Assuntos
Animais , Masculino , Feminino , Peso Corporal/genética , Característica Quantitativa Herdável , Ciclídeos/genética , Interação Gene-Ambiente , Brasil , Teorema de Bayes , Ciclídeos/anatomia & histologia , GenótipoRESUMO
ABSTRACT Genetic parameters for reproductive traits in female Nile tilapia were estimated in this study using Bayesian inference method. The data set presented information from 451 Nile tilapia females that were evaluated at two different places in Maringá - Paraná - Brazil (hapas of 1 and 10 m³) and at one location in Alfenas - Minas Gerais - Brazil. A spawning examination was conducted once a week from October 2012 to March 2013 for a total of 23 weeks of evaluation. Single-trait analyses for spawning success, multiple spawning, spawning frequency, and volume of eggs/female were performed by using the software MTGSAM Threshold. The heritability estimates were 0.14, 0.16, 0.53, and 0.08 for spawning success, multiple spawning, spawning frequency and volume of eggs/female, respectively, indicating it is possible to achieve a substantial genetic gain using these reproductive traits as selection criteria.
Assuntos
Animais , Feminino , Oviposição/genética , Reprodução/genética , Característica Quantitativa Herdável , Ciclídeos/genética , Genitália Feminina , Oviposição/fisiologia , Fenótipo , Reprodução/fisiologia , Teorema de Bayes , Ciclídeos/anatomia & histologia , Ciclídeos/fisiologiaRESUMO
O presente trabalho objetivou estudar a biologia de Agistemus brasiliensis Matioli, Ueckermann & Oliveira nas temperaturas de 15; 20; 25; 30 e 35°C, alimentada com Brevipalpus phoenicis (Geijskes) e pólen de Thypha sp. em condições de laboratório. Tabelas de vida de fertilidade foram calculadas para determinar os parâmetros biológicos. A temperatura ideal para o desenvolvimento de A. brasiliensis foi 29°C. Os valores de T (ciclo de vida - dias), R0 e r m, na temperatura de 30°C, foram de 13,95; 16,25 e 0,20, respectivamente. A potencialidade de predação de A. brasiliensis foi estudada para as densidades populacionais de 5; 10; 20; 40 e 60 adultos de B. phoenicis a 29°C, em arenas de 3 cm de diâmetro, sobre frutos de laranja-pêra. A densidade de 20 ácaros foi suficiente para que o predador consumisse seu número máximo de presas (7,6 ácaros por dia). Densidades acima de 40 ácaros da leprose proporcionaram 4,7 ovos por dia, em comparação aos 2,5 ovos por dia obtidos na densidade de 20 ácaros da leprose.
The present work aimed to study the biology of Agistemus brasiliensis Matioli, Ueckermann & Oliveira at the following temperatures, namely 15, 20, 25, 30 and 35°C, fed with Brevipalpus phoenicis (Geijskes) and Typha pollen, in laboratory conditions. Life tables were calculated to evaluate the biological parameters. The optimal development of A. brasiliensis took place at 29°C. The values of T (time of generation - days), R0 and r m at 30°C were, 13.95, 16.25 and 0.20, respectively. The prey consumption of A. brasiliensis was studied at the densities of 5, 10, 20, 40 and 60 leprosis mite females per cage (3 cm in diameter) on citrus fruits at 29°C. The maximum prey, namely 7.6 B. phoenicis females per day, were consumed at a density of 20 leprosis mites. At densities of above 40 leprosis mites per cage, A. brasiliensis oviposits 4.7 eggs per day, in comparison to 2.5 eggs per day at 20 mites per cage.