| Tenthredopsis is an extremely complex genus. In addition to a small amount of species, the similarity of most speciesis is very high, and their intraspecific variation is very complicated. Otherwise, few of Tenthredopsis phylogenetic was studied. Therefore, we studied Tenthredopsis phylogenetic by molecular markers in this paper.In this study, we set Aglaostigma and Lagidina as outgroup, and constructed the phylogenetic relationships of partial species of Tenthredopsis based on molecular markers of COI gene,16SrRNA gene, ITS2rDNA and combind database of the three genes (COI&16S&ITS2) by using three methods of NJ, BI and ML. The resultes are showed as follows:(1) The average sequence length of mitochondrial gene COI,16S and nuclear genes ITS2were845bp,383bp,694bp respectively. And the proportion of conserved sites of the three genes were64.6%,65.5%,53.1%, indicating that the three gene sequences were conservative in some degree. The average contents of A+T to COI and16S gene were70.8%and79.6%, much higher than the average contents of G+C, which shows a strong A+T bias. And the third codon of COI gene have the highest A+T content (91.4%). The amino acids composition and the codon frequency also show a bias after we translated its into amino acids. The average contents of A+T to ITS2rDNA is45.0%, less than the average contents of G+C.(2) Respectively, ratio of transition to transversion (R) of the COI,16S, ITS2genes were1.33,0.48,0.97. The bases with transition or transversion were different in different genes,and all the three genes have a saturation trend in different degree. The result of substitution saturation analysis showed that the substitution not reach saturation yet, therefore, these datasets can be used for the phylogenetic analysis of Tenthredopsis.(3) The P distance among Tenthredopsis (except Tenthredopsis excisa), Tenthredopsis excisa, Aglaostigma, Lagidina were calculated and counted. The data shows that the average P distance winthin Tenthredopsis is the lowest, even to zero, indicating that the relationships of these groups were very close; the average distance between Tenthredopsis and Tenthredopsis excisa is larger than the distance within Tenthredopsis, and less than the average distance between Tenthredopsis and Aglaostigma, the average distance between Tenthredopsis and Lagidina is the largest.(4) The results of analysis of the gene trees in this study as follow:A. Tenthredopsis excisa is distantly related to other Tenthredopsis species, suggesting that the European species and east Asia species within Tenthredopsis have obvious differentiation.B.125Tenthredopsis auriculata and126Tenthredopsis carinata always clustered into one branch with a high node support rates, also the P distance of them is almost zero. Therefore, there may be a synonyms between Tenthredopsis carinata and Tenthredopsis auriculata.C. The phylogenetic relationships of partial species of Tenthredopsis were very close and stable, and the P distance among them also small, even to zero, so we surmise that they could be the same group.For example,138T. insularis wugang and145T. insularis wugang B clustered into one branch with a high node support rates, and their P distant is zero, thus they could be the same group. On the other hand,012T. insularis ruficornis A,041T. insularis ruficornis B,028T. insularis ruficornis B,042T. insularis ruficornis C,031T. insularis ruficornis C,059T. insularis ruficornis B of different trees were located in different positions, but all of them belong to a same branch, indicating that their relationships were close, but it is still not clear and requires further study in the future.(5) The genitals structure of male or female of corresponding samples were compared, which features consistent with the results of molecular data.(6) As some species lack of samples, further studies needed to do to determine the relationships among them. |
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