坛紫菜洞头传统养殖品系和新品系遗传多样性分析

为探究坛紫菜(Neoporphyra haitanensis)温州洞头传统养殖品系与两个新品系(SW-81,HR-5)的遗传差异,利用CO I和rbcL基因片段对这3个品系共60株个体进行了遗传多样性分析研究。经过比对分析,得到398 bp的CO I基因序列和488 bp的rbcL基因序列等长同源序列,联合分析长度为886 bp,所有获得的序列中T、C、A、G 4种碱基的相对含量分别为35.100%、14.220%、34.320%和16.360%；变异位点共6个,其中单变异位点5个,简约信息位点1个；3个品系的核苷酸多样性为0.000 30±0.001,单倍型多样性为0.249±0.074；60株个体定义了6个单倍型(Hap1~Hap6),其中Hap3是核心单倍型,占全部个体的88.600%；单倍型构建的NJ系统发育树表明,各品系存在基因交流,尚未发生遗传分化。研究结果表明,坛紫菜新品系的遗传多样性较低,因此应加大种质保护和选育范围,防止种质退化。建议在坛紫菜育苗生产过程中采用多个品系联合应用,以适应多变的海洋环境。

Genetic diversity analysis of traditional and new strains of Neoporphyra haitanensis in Dongtou district

In order to explore the genetic differences between the traditional and new strains(SW-81,HR-5) of Neoporphyra haitanensis in Dongtou district,Wenzhou,the genetic diversity of 60 individuals in these three strains was studied using CO I and rbcL gene fragments.After comparative analysis,the 398 bp CO I gene sequence and 488 bp rbcL gene sequence were obtained with an isologous sequence,the joint analysis length was 886 bp,and the content of T,C,A and G in all obtained sequences was 35.100%,14.220%,34.320% and 16.360%,respectively.There were 6 mutation sites,including 5 single mutation sites and 1 simple information site;The nucleotide diversity of the three strains was 0.000 30±0.001,and the haplotype diversity was 0.249±0.074.60 individuals defined 6 haplotypes,and Hap3 was the core haplotype,accounting for 88.600% of all individuals,respectively;The haplotype-constructed NJ phylogenetic tree showed that there was gene communication in each strain,and genetic differentiation had not yet occurred.The results showed that the genetic diversity of the new strain of N. haitanensis was low,so the scope of germplasm protection and breeding should be improved to prevent germplasm degradation.It is recommended to use multiple strains in the production process of seaweed seedlings to adapt to the changing marine environment.