五种紫菜同工酶标记的遗传分析

用垂直凝胶电泳来研究采自中国的（条斑紫菜×坛紫菜）杂交种、坛紫菜、条斑紫菜、少精紫菜、半叶紫菜的同工酶多态性。然后分析最小可能位点数和观察同位基因数、遗传差异性和采用平均连接聚类法。选取23种酶带中的六个酶（MDH，ME，LDH，GDH，IDH和G-6-PDH）进行分析。最小可能等位基因位点数显示五种紫菜在ME等位基因位点都只有一个。LDH和GDH等位基因位点半叶紫菜和少精紫菜和另外的三种紫菜不同，而在分析MDH时半叶紫菜比较独特。在IDH位点分析时少精紫菜和坛紫菜和其他三种不同，而条斑紫菜和坛紫菜和其他三种不同在G-6-PDH位点不一致。总的来看，最小可能等位基因位点数分析半叶紫菜是最分离的。遗传多样性结果分析表明当遗传相似度为0．7550时，五种紫菜中的遗传变异研究受到限制。条斑紫菜和坛紫菜的杂交种非常接近少精紫菜。当遗传相似度达到0．8937时，出乎意料的是条斑紫菜和坛紫菜遗传同一。性很低。条斑紫菜4个株系的平均遗传相似度仅为0．7428，差异比较大。在所有紫菜中半叶紫菜是最分化的分支，它与最小可能等位基因位点数分析一致。

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 × 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 carried 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. oligospermatangia 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 × 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.