从Cyt b基因序列探讨Grophosoma属和Dybowskyia属的分类地位(半翅目:蝽科)

对蝽科11种昆虫的线粒体细胞色素b（Cyt b）基因部分序列进行测定和分析,在获得的长度为432bp的序列片段中,碱基T、C、 A、G的平均含量分别为38.8%、18.0%、31.6%和11.6%, A＋T平均含量为70.4%,明显高于G＋C含量（29.6 %）.密码子第三位点的A＋T含量高达86.1%.属种间序列变异丰富,有179个核苷酸位点发生变异,变异率为41.4%,碱基替换多发生于第三位点.以筛豆龟蝽Megacopta cribraria为外群构建的系统发育树表明：滴蝽属与蝽亚科其它属关系较远,条蝽属与蝽亚科其它属关系较近,结合形态特征与序列变异情况,支持将滴蝽属从蝽亚科划出并入舌盾蝽亚科,但条蝽属的分类地位仍需要进一步探讨.

Discussion on Classification of Genus Grophosoma and Dybowskyia Based on Sequences of Cytochrome b Gene (Hemiptera:Pentatomidae)

The mitochondrial DNA Cyt b gene sequences fragments(432 bp) were analysed in 11 species of Pentatomidae.The results showed: The average contents of T,C,A and G were 38.8%,18.0%,31.6%,and 11.6%respectively.The content of A+T(70.4%) was obviously higher than that of C+G(29.6%),and came up to 86.1% at third position of codon.The divergence of sequences was higher among genera and species.There were 179 variable sites(about 41.4%),and substitutions of nucleotides mostly occured at third position.The phylogenetic tree reconstructed by NJ and MP methods that regarded Megacopta cribraria as outgroup showed: In comparison with the genus Grophosoma,Dybowskyia had more distant relationship with the other genus of Pentatominae.Combined with morphology characters.The authors agree upon the opinion that Dybowskyia should be separated from Pentatominae and put into Podopinae.The classification of Grophosoma still need more extensive discussion.