In the last decades many of negative effects, as different hydraulic structure, hydropower plant, and dams and river regulation influenced on the Danube river system. These artificial structures alter the water dynamic of river, the morphology of the bed-load, and the river bank. As a result of the changed hydro –ecology conditions, had been degradated the important spawning sites and habitat of sturgeon. The crucially migration to the the upper-river basin of the sturgeon was restricted, after the construction of the two dams of Iron Gate. Of the five native sturgeon species, only the sterlet (A. ruthenus) has naturally breeding population in the Hungarian region of the Middle-Danube basin. However, the size of their population is extremely decreasing. The HAKI ex situ gene bank reserves nearly 200 sexually matured sterlet speciments however, no further information about the genetic structure of this stock is avaiable. The aim of this study was to gain a preliminary knowledge on the genetic structure of broodstock in relation to the wild population. Four microsatellite loci were used this far to assess the genetic diversity of two sterlet population. 57 speciment originated from HAKI broodstock (25% of the total broodstock), and 37 individual sampled in 2016 from the Hungarian part of the Danube. Allele frequency, number of polymorphic loci, effective alleles as well as, expected and observed heterozygozities were determined by GenAlex statistical software package. Altogether 44 alleles were detected in the two observed populations. Based on four microsatellite loci data, there is no genetic differences (Fst=0,051) between the two populations this far. In the future this genotyping data can be used to improve the genetic management of the ex-situ genebank, and it will be usefull in the restocking program also. Although, for more detailed and reliable genetic results, genotypic data from further microsatellite loci are needed.

Sterlet,Genetic, Microsatellite, Danube River, Restocking, Hungary

biology

Presentation: oral