Tang Shou-Jie, Li Si-Fa, Cai Wan-Qi, Zhao Yan
Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Dongwuxue Yanjiu. 2014 Mar;35(2):108-17. doi: 10.11813/j.issn.0254-5853.2014.2.108.
In the present study, the genetic diversity of one selected strain (Pujiang No. 1), two domesticated populations (GA and HX) and four wild populations (LZ, YN, SS and JL) of blunt snout bream (Megalobrama amblycephala) was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles (A); an average of 3.20-5.33 effective alleles (Ne); average observed heterozygosity (Ho) of 0.6985-0.9044; average expected heterozygosity (He) of 0.6501-0.7805; and the average polymorphism information content (PIC) at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei's standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations (GA and HX) were significantly lower than those found in three wild populations (LZ, SS and JL), but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise FST value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected heterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.
在本研究中，利用17个微卫星标记分析了团头鲂（Megalobrama amblycephala）一个选育品系（浦江1号）、两个驯化群体（GA和HX）以及四个野生群体（LZ、YN、SS和JL）的遗传多样性。结果表明，平均等位基因数（A）为4.88 - 7.65个；平均有效等位基因数（Ne）为3.20 - 5.33个；平均观测杂合度（Ho）为0.6985 - 0.9044；平均期望杂合度（He）为0.6501 - 0.7805；平均多态信息含量（PIC）为0.5706 - 0.7226。群体间的成对FST值在0.0307 - 0.1451之间，群体间的Nei标准遗传距离为0.0938 - 0.4524。驯化群体（GA和HX）中的期望杂合度显著低于三个野生群体（LZ、SS和JL），但与野生YN群体相比未检测到差异。同样，四个野生群体之间或两个驯化群体之间也未发现差异。浦江1号的期望杂合度高于两个驯化群体且低于四个野生群体。关于群体间的成对FST值，GA、HX和PJ群体之间的置换检验P值显著，但四个野生群体之间不显著。这些结果表明，经过七代选育的团头鲂选育品系的期望杂合度低于野生群体，但该品系保留的遗传多样性水平高于驯化群体。野生群体、驯化群体和遗传改良团头鲂品系之间的遗传差异和分化将为种质资源的保护标准和利用提供重要指导。
