Preliminary Studies On Genetic Relationships Among Five Species (Subspecies) Of Schizothoracinae In Yalong River

Schizothoracinae fishes, endemic species of altiplano in Asia, have adapted well to an arctic climate and the circumstance of strong ultraviolet radiation and low-pressure. They have important dietary value and nonreplaceable value of science research. Five species and subspecies of Schizothoracinae, Schizopygopsis malacanthus malacanthus, S. malacanthus chengi, S. stoliczkai, Schizothorax wangchiachii and S. dolichonema in Yalong River were collected to ascertain their genetic relationships through morphological and molecular way. Multivariate morphometrics was conducted on five species of schizothoracinae in order to investigate the morphological variations. Chi-square test was performed for four countable characters, principal component analysis (PCA) for thirty-two measurable characters, as well cluster analysis by some meristic characters. The morphological differences were analyzed to evaluate the genetic relationships of schizothoracinae fishes. In this paper, random amplified polymorphic DNA (RAPD) was used for molecular biology analysis of DNA polymorphism and genetic relationships among these five species for the first time, to evaluate the polymorphism of their species resource, and to provide the theoretical foundation for their resource conservation. The main results were as follows:1. By chi-square test, no significant differences were found in countable characters among five species of Schizothoracinae (P<0.05).2. There was absolutely dispersal between Schizopygopsis and Schizothorax, and dispersal in a certain extent between species through principal components analysis.3. The clustering scheme can be constructed by clustering analysis about some proportional value. The results showed that the genera examined were roughly divided into two groups. The first group contained three species belonging to the genus Schizopygopsis, whereas the second group contained two species belonging to the genus Schizothorax.4. Genomic DNA from five fishes was extracted successfully by SDS optimized method. And RAPD optimization system was founded.5. Out of 40 primers screened, 20 primers generated reproducible profiles. Twenty primers did not amplify at all or produced highly inconsistent ampliation products from the same individual and were excluded from further analysis. A total of 214 loci, were detected from five species by 20 primers. The average percentage of polymorphic loci total DNA of the five fishes was 95.33%. The Shannon's information index was 0.1521～0.253 and the Nei's value was 0.1063～0.1740 for genetic diversity among these...