| The genus Ostrinia Hübner,1825(Crambidae Pyraustinae)includes 23 species,25subspecies,and 16 species 10 subspecies in China.The taxonomic and phylogenetic relationships of this genus are still controversial because of their short divergence times,complexity of the phylogenetic relationships and intrasepcific variation of morphological features.In this study,the mitogenomics of the genus Ostrinia and sympatry of Asian corn borer and European coren borer were studied by morphometrics,comparative morphology,and comparative mitogenomics.We sequenced and compared mitogenomes of the genus Ostrinia,and the phylogenetic relationships of this genus was constructed based on mitogenome sequences.Based on molecular and morphological analyses of the sympatry of O.nubilalis and O.furnacalis specimens,we found that the Yili area of Xinjiang Uyghur Autonomous Region and other potential sympatric areas exist in China.The molecular and morphology evidence of the sympatry and allopatry of O.furnacalis and O.nubilalis were comprehensive analyzed and evaluation.The results are shown as follows:(1)We newly sequenced five mitogenomes of the genus Ostrinia(O.kasmirica,O.nubilalis,O.furnacalis,O.scapulalis,and O.zealis)using the next generation sequencing technique,and downloaded a published complete mitogenome(O.palustralis)from Genbank in this study.The results indicated that the mitogenonmes were compact cicular double-stranded,contiaining 37 typically encoding mitochondrial genes and a control region.All of these mitogenomes have the same mitochondrial genes organization.All Protein-coding genes initiated with ATN and terminated with TAN,with exception that cox1 started with CGA and cox1,cox2,and nad5 terminated with incomplete codon T(T--).There are 22 transfer RNA genes with the length from 65 to 71 bp of these six complete mitogenomes.Except the trn S1lack DHU arm,the remaining t RNAs presented the typical clover-leaf secondary structure.Both the length and the base composition of rrn S and rrn L were relative conserved.(2)There are three conserved blocks in control region.The first conserved block(about25 bp)located at the downstream of rrn S ending with‘TTAGA’which proceed a Poly-T stretch.The second conserved block(about 70 bp)was a microsatellite-like region(TA)_n.The third conserved block(about 34 bp)located at the upstream of trn M including a Poly-T stretch and a Ploy-A stretch.(3)The analysis of nucleotide diversity showed that atp6 and nad6 had higher diversity and more relaxed purifying selection.That implied that atp6 and nad6 were suitable molecular markers to investigate interspecies and intraspecies taxonomic relationships of the genus Ostrinia.(4)Based on the five newly sequenced mitogenomes and published mitogenome sequences of Ostrinia from Genbank,the phylogenetic relationship of the genus Ostrinia were analyzed.The results showed that O.penitalis was not basal split of the genus instead of O.palustralis.O.kasmirica of the second species group was recovered as sister relationship with the third species group.The third species group was monophyly,with O.scapulalis and O.nubilalis were clustered into a clade.O.scapulalis and O.nubilalis formed a clade and sister to O.furnacalis.(5)Based on COI,COII,and Cytb concatenated sequences of newly sequenced from 70individuals in sympatric area in China,ML and BI trees showed that the Yili area of Xinjiang Uyghur Autonomous Region was sympatry of O.furnacalis and O.nubilalis.We found that the Northern China,including Qiqihar City and Suihua City,Heilongjiang Province,Zhalantun City and Manzhouli City,Inner Mongolia,Gongzhuling City,Jilin Provience,and Ji county,Tianjin City are the sympatric area of O.nubilalis and O.furnacalis.These evidence implied that the Yili area of Xinjiang Uyghur Autonomous Region was not the only area of sympatric area of O.nubilalis and O.furnacalis.(6)Based on the morphometrics and comparative morphological of male genital characters of O.nubilalis and O.furnacalis individuals in sympatric area,the results indicated that the length of middle and lateral lobe of uncus,spiniferous zone and spineless basal zone of sacculus present individual variation.This implys that these diagnostic features are unstable morphological characters,and it is unreliable evidence for delimiting sibling species of the genus Ostrinia.The principal component analysis of six male genital measurements indicated O.nubilalis and O.furnacalis in symparty are similar in male genital features male genital rather than the allopatric same species.It may be caused by convergent evolution or geographical isolation. |
