Phylogenic And Taxonomic Research Of Hypolepis In China Based On The Complete Chloroplast Genome

Hypolepis is a large branch of Dentaedtiaceae,with some ancient specimens.The DNA fragmentation is serious,or there is no other collection record except the model producing area,so PCR amplification is difficult to achieve.In addition,its morphological characteristics are difficult to be used as an effective basis for classification,which makes the phylogenetics of Hypolepis in China more confused,and the work of natural resource defense and exploition can not be carried out.Therefore,based on 11 samples in 10 species of the whole chloroplast genome sequencing,the phylogeny and gene diversity of hypolepis from China were analyzed.The main conclusions are as follows:1.The whole chloroplast genome of Hypolepis punctata has a total length of 151685 bp and 132 genes,including 89 coding sequences(CDS),35 tRNA genes and 8 rRNA genes.The GC content of IR region was higher than that of the other two regions.In the boundary of IR region,the high variation region is mainly in the non coding region,such as psbM-petN,ndhC-trnV,petA-psbJ,ycf1-rps15,rps8-rpl14.ndhB gene in the coding region is a highly variable gene in hypolepis.2.Phylogenetic trees were constructed by the complete genome sequence and coding region sequence of chloroplast.The Chinese species are divided into two main branches,namely,the Hypolepis punctata-complex and the non complex group.Among them,in the Hypolepis punctata-complex,Hypolepis polypodioides,Hypolepis tenera and Hypolepis glabrescence gather as one branch,H.punctata and Hypolepis glandulosopilosa gather as another branch;in the non complex group,Hypolepis yunnanensis and Hypolepis pallida gather as one branch.The result of other Chinese species are consistent with the previously published taxonomic revision.3.Morphological evidence:(1)H.glandulosopilosa is similar to H.punctata.It is different from H.punctata.former in three types of glandular hair(gangliform glandular hair,short glandular hair,and single-celled glandular hair).That were also found in H.punctata.In addition,no significant difference was found between the two species by measuring their pinnae length,rachis length and lamina length.The type specimen of H.glandulosopilosa was collected from the sandstones along the gully and the river bank,which was supposed to be the arid plant of the H.punctata,so it was suggested that should be treated as the heteronym of H.punctata.(2)Hypolepis tenera and Hypolepis glabrescence,which are ecdemic to Yunnan Province,are similar to Hypolepis polypodioides.The difference among them is the width of the segments is about 4mm,and the width of the segments is less than 2mm.The results showed that the variation range of the width of the segments of Hypolepis polypodioides contains the width of the segments of Hypolepis tenera and Hypolepis glabrescence.(3)The morphology of Hypolepis yunnanensis and Hypolepis punctata is quite different.The end of H.yunnanensis' s segment is obtuse,the soral protection has well-developed reflexed flap and there is no glandular hair.Hypolepis yunnanensis is morphologically more similar in Hypolepis pallida.