| The random amplified polymorphic DNA(RAPD) and inter-simple sequence repeat(ISSR) analysis were used to estimate population genetics of Fenneropenaeus chinensis. We analyzed the genetic diversity and genetic structure of the populations, and also studied the genetic divergency among populations and geographic populations. The main results shown as follows:1. 116 natural individuals from 6 populations of Fenneropenaeus chinensis were investigated using 13 random primers. A totle of 96 reproducible RAPD bands ranging from 200 to 2500bp were obtained. The mean percentage of polymorphic loci of 6 populations were ranging from 29.17% to 39.58%,while Nei's gene diversity were between 0.0952 and 0.1262.And the average Shannon's indices of phenotypic of the populations were ranged from 0.1447 to 0.1904. All these polymorphic indices revealed the genetic diversity in different populations differed from each other.The lowest genetic diversity was in Liaodong population and the highest was in the south coast of Korean Peninsula.The results revealed that the diversity of Fenneropenaeus chinensis was low. Shannon indices suggested that the differetiation of the Fenneropenaeus chinensis was divided into two parts,24.0% from inter-populations and 76.0% from intra-populations. The hierarchy analysis of the population answered for Shannon indices, that is, 78.81% of the variance was from intra-populations. At the same time, the results of Analysis of Molecular Variation (AMOVA) revealed that the variance of inter-populations and inter-groups affected the total variance of Fenneropenaeus chinensis significantly. The analysis of genetic structure indicated that the coastal population of Yellow sea and Bohai sea was constituted of several populations that has differentiated, which proofed the hypothesis of Kong Jie.2. At first, we tested and optimized the conditions of the ISSR technique. 15 ISSR primers were used to investigate 24 individuals from 3 natural populations. Every primer amplified different number of loci that ranged from 11 to 44. 323 loci were obtained of which 175 were polymorphic, that is, the percentage ofpolymorphic loci was 54.18%. The proportion of each populations was as follows, 41.49% was for LD population, 45.82% was for BH population and 42.41% for HZ population. The genetic distance between populations showed that the genetic diversity is according to the geographic distance.3. We compared the result of RAPD and that of ISSR. The results suggested that ISSR was sensitive than RAPD in revealing polymorphism. ISSR could amplify bands more than RAPD, much more loci were checked by ISSR and more abundant genetic information was discovered, so ISSR can reflect higher level of genetic diversity than RAPD. At the aspect of examining genetic similarity and distance, there was difference between the results obtained by two techniques. The genetic diversity revealed by ISSR was higher than that obtained by RAPD.4. As a whole, the result of population genetic structure detected by RAPD and ISSR was consistent, yet there was a little difference between intra-population genetic diversity. This was mainly because of the ability of detecting genetic variance of the two techniques.5. At the end of this paper, we compared the parameters that were used in population genetics.
|
PDF Full Text Request