Seleção de populações de cebola tipo valenciana para o Vale do São Francisco

Abstract

In the present work were estimated genetic gains in two environments due to recurrent selection practiced in population CNPH6400 for the type Valenciano, as well as parameters of adaptability and stability in five environments, with the final objective to evaluate the potential for recommendation of Valencian populations for the Sao Francisco Valley. The experiments were carried out in the municipalities of Petrolina - PE, Juazeiro - BA, and Belem San Francisco - PE, during the years 2013 to 2014. It was adopted the experimental design of randomized blocks, with three replications and twelve treatments to evaluate the genetic gain and fourteen treatments, including eight Valencianas for adaptability and stability parameters. The characteristics evaluated were total and commercial bulb yields, which were. Adjusted by covariance from the average plant stand of each experiment. Were estimated heritability, differential selection, genetic gain. Adaptability and stability parameters were estimated by the methods of Eberhart & Russel and Lin & Binns. Significant differences were observed for bulbs commercial production in the two environment, except for the population 25CA10 in Juazeiro - BA. The mean genetic gain for bulbs commercial production in the yellow Valenciana population 25CA10 were 378.88% in Petrolina - PE and 16.30% in Juazeiro - BA, while the purple population T811CR13 the gains were 340.76% to Petrolina - PE and 55 01% to Juazeiro - BA. The genetic gains were not linear to the sequence of the evaluated cycles, and these oscillations were attributed to genetic drift and selection emphasizing the thickness of cataphylls in recent cycles. It was observed genotype x environment interaction for all variables. The two methodologies presented discrepant results for the cultivar Alfa San Francisco. The Valencianas 25CA10 populations and T811CR13 showed average bulb productions close or above experiments means, combined with wide adaptability and stability, having the potential to be recommended as new cultivars for the region of the São Francisco Valley.