Genetic Analysis of Five Porphyra Species by Isozyme Markers

Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porphyra haitanensis, and a hybridize species （Porphyra yezoensis x Porphyra haitanensis） sampled from China. Whereafter, the analyses of probable minimum loci numbers, observed alleles sum, genetic diversity, and unweighted pair-group arithmetic average （UPGMA） cluster were carded out. After initial activity and resolution testing of bands of 23 enzymes, 6 of them （MDH, ME, LDH, GDH, IDH and G-6-PDH） were proved to be appropriate for analysis of the full sample set. The probable minimum numbers of loci and alleles analyses showed that the five species of Porphyra had an extraordinary consistent result in ME loci and alleles. However, P. katadai and P. oligospermatangia differed from other three species of Porphyra in LDH and GDH loci and alleles. P. katadai was independent in the analyses of MDH and P. oligosperTnatangia and P. haitanensis differed from other three species in IDH analyses. Moreover, P. yezoensis and P. haitanensis were apart from other three species in G-6-PDH analysis. Taking one with another, P. katadai was relatively separated in the probable minimum numbers of loci and alleles analyses. The results indicated that the genetic variation among the five Porphyra species was limited with a genetic identity of 0.7550. The hybridize species （P. yezoensis x P. haitanensis） seemed to be high homologue with P. oligospermatangia, unexpectedly got relatively lower average genetic identities with both P. yezoensis and P. haitanensis. The 4 strains of P. yezoensis were relatively divergent with an average genetic identity of 0.7428, and P. katadai presented the most differentiated, compared with other species, which consistented with the result summarized in the probable minimum numbers of loci and alleles analyses.

Genetic Diversity of Three Aristichthys nobilis Populations and One Inbreeding Stock

Genetic diversity of threeAristichthys nobilis populations and one inbreeding stock was studied using random amplified polymorphic DNA (RAPD) method. Materials of natural populations were collected from two counties of Guangxi Province, Hengxian (NH) and Shanglin (NS) and one city of Hubei Province, Wuhan city. (NW). Shanglin and Hengxian's river system respectively belongs to Qianjiang and Yujiang River, two tributaries confluencing to Xunjiang River, main tributary of Xijiang River, which is the biggest tributary of the Zhujiang River system, and Wuhan's water system belongs to the Yangtse River system. The inbreeding stock (RS) was the more than 10 generation descendant by brother-sister mating system whose parents were collected from Shanglin. The results showed that the genetic variety of individuals of RS was very low (0.105 4), whereas that of natural populations was relatively high, which from high to low was 0.158 1 (NW), 0.132 0 (NH) and 0.110 5 (NS). As an index for genetic distance pair-wise populations, the genetic variety between populations was studied, which characterized the genetic distance between populations. The genetic distance of NW and NH, NW and NS, NW and RS were respectively high, whereas that of NH and NS, NS and RS, NH and RS was low. Chi-test (χ 2) and the analysis of the genetic variety pair-wise populations was taken as efficient approach for studying population difference.