摘要
从同一遗传背景、同环境下培养的1龄中间球海胆(Strongylocentrotus intermedius)中,分别选择大个体50只、小个体30只,分别组成大小2组海胆,两组之间壳径、壳高2个指标均存在显著差异。共选用6对AFLP引物组合对2组海胆进行PCR扩增,发现43个标记在大小2组海胆间存在显著的频率差异(P<0.05),其中29个位点差异极显著(P<0.01)。所有存在显著频率差异的位点中,2个位点在大海胆组中缺失,4个位点在小海胆组中缺失,14个位点在大海胆组中出现的频率显著高于小海胆组(P<0.05),而23个位点在小海胆组中出现的频率高于大海胆组(P<0.05)。这一系列谱带可能与中间球海胆生长性状之间存在一定的相关关系。遗传多样性分析结果表明,大海胆组的平均Shannon氏指数、Nei氏杂合度2个指标均显著高于小海胆组(P<0.05),提示杂种优势可能与中间球海胆的快速生长存在一定联系。
Sea urchin（Strongylocentrotus intermedius）is one of the most economically important echinoderm, whose genetic improvement in economic traits such as growth,disease resistance and reproductive potential can help increase its output.While in most cases,growth of farmed sea urchin is irregular and uneven,which is called growth differentiation.This fact restricts large-scale production of sea urchin and increase the cost of farmers.Early selection on growth traits would solve this problem.It is difficult to detect the genetic essences because the economical traits are mostly quantitatively controlled by polygene.AFLP markers was used in this study in order to screen the genes and markers which control the quantitative traits in sea urchin.50 large and 30 small size sea urchins were selected from a huge population with the same genetic background and curing environment.Shell diameter and height were （2.962±0.286）cm and（1.561±0.168）cm in large-size group and（1.480±0.255）cm,（0.821±0.213）cm in smallsize one.These two indices were significantly correlated with each other,and there were significant differences between two groups on these two indicators.Sea urchins from two groups were all subjected to AFLP analysis with primer combinations of E32-M49,E33-M48,E33-M49,E33-M50,E35-M62 and E38-M61.243 and 212 loci were respectively detected in large and small-size groups,with polymorphic percentage of 87.26%and 92.86%.X2 test showed that 43 loci showed significant differences in frequency between two groups（P0.05）,among which 29 had extremely significant differences（P0.01）·Locus BXf212 and EVf198 found in small-size group,with frequency of 0.241 4 and 0.166 7,were lost in large-size group.And four loci of AXf1497,AXf290,BYf880 and BXf916 detected in large-size group with frequency of 0.530 6,0.204 1,0.166 7 and 0.183 7,were absent in smallsize group.14 loci had significantly higher frequencies in large-size group than those in small-size one,while 23 loci had reverse frequencies（P0.05）.These results suggested that these loci would have positive or negative effects on growth traits in sea urchins.The loci with higher frequencies in large-size group may be preferred in urchin molecular marker assistant breeding and those with higher frequencies in small-size group may be eliminated through selection.However,these markers would also be related with random factors and the next work would be concerned on extending the scope of molecular markers and verifying the correlation of growth trait and markers in sea urchin. Shannon’s index and Nei’s gene diversity in the large-size group were 0.342 3±0.221 3 and 0.213 7±0.165 4, which were significantly higher than those in small-size group which were 0.286 0±0.244 9 and 0.180 2±0.172 3, respectively.These results showed that growth traits in sea urchin would be positively associated with heterosis to some extent.
出处
《中国水产科学》
CAS
CSCD
北大核心
2010年第3期448-455,共8页
Journal of Fishery Sciences of China
基金
国家自然科学基金项目(30800849)
大连市科学技术基金项目(2007J23JH024)
关键词
中间球海胆
生长分化
AFLP
Strongylocentrotus intermedius
growth differentiation
AFLP
