Analysis of the mitochondrial DNA as a resource for the pre-breeding program of the pacu Piaractus mesopotamicus

Author(s)

Milena Vieira de Freitas

• Document type: Master's Dissertation
• Press: Botucatu. 2017-08-29.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2017-07-21
• Advisor: Diogo Teruo Hashimoto

Abstract

The Brazilian aquaculture has experienced significant growth in recent years. However, the national potential of production will certainly be better explored with the use of products resulting from breeding programs. The pacu, Piaractus mesopotamicus (Characiformes, Serrasalmidae), is a fish of occurrence in the Paraná-Paraguay River Basin and it is one of the main native species used for production in aquaculture. The use of molecular markers in fish farming has been shown to be essential, especially for genetic monitoring of populations and pre-breeding programs. The mitochondrial molecular markers (mtDNA) have a higher rate of mutations and exclusively maternal inheritance, being useful for monitoring the genetic variability of a population and generate information about the founder stock. The objective of this study was to analyze the genetic variability of wild and cultivated stocks of Piaractus mesopotamicus using mitochondrial molecular marker (Control Region). In general, the diversity indexes presented moderate values (Hdwild = 0.692 and Hdfarm = 0.711; πwild = 0.0045845 and πfarm = 0.00660) and similarity was observed between these values in the wild and cultivated populations. In addition, high genetic structuring was observed among wild and cultivated populations (FST = 0.14404). The low values of diversity found in some of the wild populations together with the equilibrium deviations (D Tajima p <0.05) may be related to several anthropic factors that have been influencing pacu populations over the years, such as fishing pressures and hydroelectric power dams. In relation to cultivated stocks, the lower indices of variability may be associated with different management techniques in fish farms, often using few and inbreeding individuals for the formation of the broodstock. The results obtained in this work increase the information about the populations of pacu and they are fundamental for the development of future breeding programs for this species. (AU)

• FAPESP's process: 15/14185-8 - Analysis of the mitochondrial DNA as a resource for the pre-breeding program of the pacu Piaractus mesopotamicus
• Grantee: Milena Vieira de Freitas
• Support Opportunities: Scholarships in Brazil - Master