斑节对虾4个地理种群自交与杂交F_1的形态特征分析

Morphological variability in reciprocal hybrids F_1 of Penaeus monodon from four geographical populations

为研究三亚(S)、泰国(T)、印尼(Y)和非洲(F)4个斑节对虾地理群体的形态亲缘关系,实验运用多元分析方法,采用8个测量性状4个斑节对虾地理群体杂交与自交的10个F1形态进行了比较研究。方差分析结果显示,三亚和非洲杂交SF(S♀×F♂)与泰国和非洲杂交TF(T♀×F♂)的F18个性状无显著性差异(P>0.05),但与以S、T、Y为亲本的7个杂交与自交F1间存在显著差异性(P<0.05)。斑节对虾形态特征主成分分析,共构建了2个主成分,累积贡献率为72.54%。主成分1主要反映了斑节对虾第三腹节长(TSL)、第二腹节长(SSL)、第六腹节长(SISL)和头胸甲宽(CW)特征,方差贡献率48.15%;主成分2反映了体长与头胸甲长的变化,方差贡献率24.39%。10个F1辨别准确率较低。聚类分析结果显示,ST(S♀×T♂)、TS(T♀×S♂)、TT(T♀×T♂)的F1形态距离最近,首先聚为一支,SF、TF、YF(Y♀×F♂)的F1形态距离较近,聚为另一支。

Based on 8 morphological characters, three multivariation analysis methods（principal component analysis,discriminant analysis and cluster analysis）were used to compare and investigate the morphological variations of the first generation of three self-bred （ TT, SS, YY） and seven corresponding hybrids （ ST, TS, YT, TY, SF, TF and YF）in Penaeus monodon from four geographical populations, and approached the relative relationships among the populations. ANOVA analysis indicated that the first generation of different mating groups showed some morphological variations except SF and TF. The principal component analysis of the first generation of Penaeus monodon yielded two principal components （ PCs）, which accounted for 72.54% of the total variation. In the first PC, which explained 48. 15% of the total variance, the most important characters were numbered of the third pleon segment length （ TSL）, second pleon segment length （SSL）, sixth pleon segment length （SISL）and carapace width （CW）of the shrimps. In the second PC （24.39%） , expressed variables exclusively associated with the carapace length（CL） and body length （BL）. Based on DFA evaluation, the proportion of individuals correctly classified into their original groups was very low. The cluster analysis indicated that there were most similar morphological characters among the stocks of ST,TS,TT and SF,TF,YF.