中国近海栉孔扇贝群体遗传结构及遗传变异与生长的关系

IOCAS-IR > 海洋环流与波动重点实验室

	中国近海栉孔扇贝群体遗传结构及遗传变异与生长的关系
	张国范
学位类型	博士
	1992
学位授予单位	中国科学院海洋研究所
学位授予地点	中国科学院海洋研究所
学位专业	海洋生物学
关键词	群体遗传结构遗传变异生长栉孔扇贝
摘要	本文以凝胶电泳方法，以等位基因酶和可溶性蛋白为探针研究了中国近海栉孔扇贝(Chlamys farreri)5个不同自然分布群体的遗传结构及遗传变异与生长的关系。在所研究的23个位点中，只有Mdh-1在5个群体中为纯合状态，其余位点都不同程度地处于多态或杂合态。大多数位点的等位基因及基因型分布频率都处在不平衡状态。对各位点的D值检验表明，大多数位点都杂合子缺失。杂合子过剩或处于Hardy-Weinberg平衡的位点为19.64-22.32%。杂合度以海洋岛和长岛群体最高，都是0.304，荣成和大连群体次之，分别为0.290和0.287，青岛群体为0.219。位点有效等位基因数及密码子差数在群体间的变化与杂合度基本一致。用这三个参数构建的遗传变异综合评价指数在这5个群体从北至南依次为0.726，0.542，0.658，0.547和0.133。多态位点比例在P ≤ 0.99水平下，海洋、大连、长岛及荣成4个群体都在0.800以上，仅青岛群体为0.565。在Est7个位点从高纬度向低纬度在等位基因数目上存在梯度递减渐变性。在某些等位基因的分布频率或从高纬度或从低纬度向相对方向递变。除了单向渐变外，也存在双向渐变现象。栉孔扇贝这5个群体在遗传相似性方面基本上是群体间的差异（I > 0.900）。相比之下，大连、长岛两群体间的相似性最大。由于辽东沿岸流和黄海冷水团的作用，海洋岛群体与邻近群体的基因交流较差，使之在遗传上相对较为独立。从遗传变异不平、杂合子缺失特征及等位基因的渐变性也证明，该群体已具相当程度的分化，这主要是由于环境隔离所造成的“孤岛效应”的结果。通过对5个群体形态数量性状生与群体遗传变异的比较表明，遗传变异不平较高的群体，其生长速度也较快，二者基本呈平行关系，唯海洋岛与长岛的结果相悖，其原因可能与两海区间初级生产力水平有关。从个体杂合度与第一年生长壳高关系的研究可以发现，海洋、大连和青岛群体在杂合度与生长间基本呈正相关关系，而在长岛与荣成群体内存在杂合度与生长具不同相关性的子群体，并证明个体杂合度超过0.300以上，其与生长的关系基本上处于不定向状态。在环境和遗传双重压力下，青岛群体的变异水平较低。
其他摘要	The genetic population structure and the relationship between genetic variation and growth of the 5 populations of Chinese scallop, Chlamys farreri, stocking in the Chinese coastal waters of northern Yellow Sea have been investigated based on the starch gel electrophoresis of 23 loci of 8 allozyms, AAT, EST, GDH, GPI, IDH, MDH, PGM, SOD, and 1 soluable protein. Twenty two of 23 loci studied are polymorphic, only is Mdh-1 homogeneous in the populations. Most of loci studied depart from the Hardy-Weinberg equilibrium in the frequencies of the allele and genotype. The observed average heterozygosity (Ho) is in the Hardy-Weinberg equilibrium for each population. However, heterozygote efficiencies have been observed in most loci according to the indexes of Hardy-Weiberg equilibrium (D). The loci of the heterozygote excess and equilibrium are 19.64-22.32%, the rest are defficient or homogeneous. The heterozygosities (Ho) of populations of Haiyangdao, Dalian, Changdao, Rongcheng and Qingdao are 0.304, 0.303, 0.287, 0.290 and 0.219, respectively. The tendencies of variation of the number of effective allele (Ne) and the difference of coden per locus (Dx) are similar to that of Ho in 5 populations. The comprehensive indexes for assessing the genetic variation (CIGV), constructed upon Ho, Ne and Dx, are 0.726, 0.542, 0.658, 0.547 and 0.133, respectively. The proportions of polymorphic loci (p < 0.99) populations of Haiyangdao, Dalian, Changdao and Rongcheng are around 0.8, and Qingdao 0.5. The cline for the number of allele per locus in the 7 loci of Est has been observed in populations from Haiyangdao to Qingdao. The allelic frequency for Aat-2 reduced in populations from Qingdao to Haiyangdao. The bicline for the allelic frequency has been discoveried with a peak appeared at the population of Dalian or Changdao. The discontinued distributions of the alleles and genotypes are popular. The genetic similarities (Ⅰ) among the populations are over 0.900 with the maximum being observed between the populations of Dalian and Changdao. Although the geographic distance between Haiyangdao and Dalian is close to that between Haiyangdao and Rongcheng, the genetic similarity is less than that between the populations of Haiyangdao and Rongcheng. One reasons is that the Haiyangdao population is isolated by a off shore current which lied between Dalian and Haiyangdao and the other is that the Haiyangdao is covered by the low temperature mass of Yellow Sea, whose effect reduced in the coastal waters of Dalian. Based on the the level of genetic variation, heterozygote deficiency and the biclines of allelic frequency of Haiyangdao population of is relatively isolated in genetics and would probably develope a new subspecies.
页数	135
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1069
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	张国范. 中国近海栉孔扇贝群体遗传结构及遗传变异与生长的关系[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,1992.

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