坛紫菜不同品系亲缘关系的SSR标记分析

Phylogenetic relationship of the lines of Porphyra haitanensis (Rhodophyta,Bangials) determined by microsatellite DNA markers

利用SSR标记对9个坛紫菜(Porphyra haitanensis)品系(2个野生品系,2个优良品系,2个杂交品系,3个色素突变品系)的丝状体进行了亲缘关系分析。结果表明:从52对微卫星引物中筛选出7对引物,它们的反应稳定并且其PCR产物具有多态性。9个品系的平均有效等位基因数(Ne)为1.7166,平均期望杂合度(He)为0.4074,平均多态信息含量(PIC)为0.3308,Shannon多样性指数(I)为0.6239。用Nei氏法计算出这9个品系的遗传距离和遗传相似性系数,再用UPMGA和Neighbor-joining2种方法所获得的系统学关系图,其结果均基本上反映了各品系间的亲缘关系。在引物PC-40界定的遗传座位上,2个优良品系申福1号和优质6号(以申福1号为母本选育出来的品系)的丝状体和叶状体均出现了区别于其他品系的等位基因,显示对这2个优良品系进行SSR特异性标记是可能的。

Molecular analysis of nine different lines（2 wild-type,2 improved varieties,2 hybrid and 3 pigmentation mutants）of Porphyra haitanensis with microsatellite markers was performed.Results showed that 7 SSR primer-pairs selected from a total of 52 SSR primer-pairs gave good amplification patterns.Effective number of alleles,expected heterozygosity and Shannon＇s Information index was 1.617 4,0.377 6 and 0.523 1,respectively.Genetic distances and genetic similarity were calculated using Nei＇s matching coefficient.Phylogenetic relationship analysis of UPMGA and Neighbor-joining based on Nei＇s genetic distance showed a good truly relationship among these lines.Samples of conchocelis and gametophytic baldes of both SF-1 and Y-6（isolated from SF-1 line）lines had a unique allele on PC40 locus,indicating that it can be used as a marker to distinguish these two lines from the others.