Diversidade genética de dourado utilizado em programas de repovoamento no rio Paranapanema

Abstract

Resumo -O objetivo deste trabalho foi avaliar a diversidade genética de um estoque de Salminus brasiliensis utilizado em programas de repovoamento do rio Paranapanema, por meio do marcador RAPD. Dez reprodutores (cinco machos e cinco fêmeas) e sua progênie (40 larvas e 40 alevinos) foram analisados. Os oito iniciadores analisados produziram 96 fragmentos, dos quais 81,2% foram polimórficos. Houve diferença significativa na frequência de 32 dos 96 fragmentos, com a presença de um fragmento exclusivo nos alevinos. O índice de Shannon, a percentagem de fragmentos polimórficos e a distância e a identidade genética mostraram menor divergência genética entre os reprodutores e as larvas, além de diminuição da variabilidade nos alevinos. A divergência genética foi menor nos alevinos em comparação às larvas e aos reprodutores. A análise de variância molecular mostrou que a maior parte da variação está dentro de cada grupo (90,05%) e não entre os grupos (9,95%). O estoque de reprodutores apresenta alta variabilidade genética e houve diferenciação genética entre a fase de larva e alevino.Termos para indexação: Salminus brasiliensis, marcador molecular, peixe, RAPD, programas de repovoamento.Abstract -The objective of this work was to estimate by RAPD markers the genetic diversity of a Salminus brasiliensis lot used in stock enhancement programs in the Paranapanema River, Paraná, Brazil. Ten broodstocks (five males and five females) and their progeny (40 larvae and 40 fingerlings) were analyzed. Eight analyzed primers produced 96 fragments, of which 81.2% were polymorphic. There was significant difference in the frequency of 32 out of the 96 fragments, with the presence of an exclusive fragment in the fingerlings. The Shannon index, the percentage of polymorphic fragments, and the genetic distance and identity showed less genetic divergence between broodstocks and larvae, besides a decrease of genetic variability in the fingerlings. Genetic divergence was lower in the fingerlings in comparison to the larvae and broodstocks. The molecular variance results showed that most of the genetic variation is within (90.05%) and not between groups (9.95%). The broodstock lot has high genetic variability, and genetic differences were observed between the larval and fingerling stages.

Genetic diversity of Salminus brasiliensis wild populations in downstream and upstream Cachoeira Branca, Verde River MS Brazil: a preliminary view

“…Dominant marker in current assay proved efficient in the study of genetic variability. Other studies with the same marker for S. brasiliensis (ALMEIDA et al, 2013;GOMES et al, 2011GOMES et al, , 2013LOPES et al, 2007) and in other fish species (JACOMETO et al, 2010;, 2010LOPES et al, 2009;PAULA et al, 2006;POVH et al, 2008b) also gave positive results. In fact, dominant markers still have great possibilities of information for the initial review of genetic processes in natural populations or in fish stocks.…”

“…Some studies on S. brasiliensis provided number of fragments and polymorphism very similar to current assay. Gomes et al (2011) studied restocking programs and detected 96 fragments analyzed for 8 starters and between 7 and 17 fragments per starter, of which 78 (81.25%) were polymorphic. Gomes et al (2013) obtained 105 amplified fragments (79 or 75.2% were polymorphic) from the same species captured in the transposition ladder in the Canoas I hydroelectric plant.…”

Genetic variability of wild populations of Leporinus elongatus in the São Domingos River - MS Brazil: a preliminary view on the construction of the hydroelectric plant

“…Current analysis showed that dominant markers may be a simple tool to achieve these aims. According to Hilsdorf (2013), the employment of dominant markers to estimate variability is common in fresh water fish and is corroborated by several recent research works in Brazilian native species (ALMEIDA et al, 2013;GOMES et al, 2011GOMES et al, , 2013JACOMETO et al, 2010;LOPERA-BARRERO et al, 2010;RAMOS et al, 2012).…”

“…Above results coupled to exclusive and fixed fragments demonstrated that even populations with low-frequency fragments have a high intrapopulation genetic variability plus a trend for genetic differentiation. Shannon´s Index and the percentage of polymorphic fragments are genetic parameters successfully employed to estimate the genetic variability of the population (ALMEIDA et al, 2013;GOMES et al, 2011GOMES et al, , 2013JACOMETO et al, 2010;LOPERA-BARRERO et al, 2010;PAULA, 2006). The analysis of molecular variance (AMOVA) between the populations revealed a greater intra-population rather than an inter-population variation.…”

“…Further, other recent research works demonstrated the efficiency of these techniques in restocking programs or in broodstocks of other native species (ALMEIDA et al, 2013;GOMES et al, 2011GOMES et al, , 2013JACOMETO et al, 2010;LOPERA-BARRERO et al, 2010). Due to easy techniques and extensive polymorphism, markers are highly common in research on neotropical fish (HILSDORF, 2013).…”