Phylogenetic relationships of the 'higher' hamamelids were estimated based on nucleotide sequences of the non-coding region of chloroplast trnL-F. Twenty-five species were sampled, representing 24 genera of al...Phylogenetic relationships of the 'higher' hamamelids were estimated based on nucleotide sequences of the non-coding region of chloroplast trnL-F. Twenty-five species were sampled, representing 24 genera of all eight families of the 'higher' hamamelids. A parsimony analysis of data set indicated that the 'higher' hamamelids formed a strongly supported clade with 100% bootstrap value in the strict consensus tree. Nothofagus was the basal lineage and the Fagaceae was sister to a well-supported core 'higher' hamamelids clade containing Myricaceae, Rhoipteleaceae, Juglandaceae, Casuarinaceae, Ticodendraceae and Betulaceae. Three clades were recognized in the core ' higher' hamamelids: (1) Casuatina ( Ticodendron, ( Betu-laceae)), (2) Juglandaceae-Rhoipteleaceae, and (3) Myricaceae. Compared with the previous studies, familial relationships of the 'higher' hamamelids were better resolved.展开更多
The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape c...The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape classification system is an important scientific basis for landscape protection and tourism development in this region. By combining geology and geography and referring to the concepts of "system tract" and "tectonic system" in geology, this paper comes up with grading standards for the geoscience landscape system of this region. Based on the regional stratigraphic structure, tectonic fault marks and geomorphological differentiation, this paper comes up with 2 Grade Ⅰ geoscience landscape system tracts, 8 Grade Ⅱ geoscience landscape systems, 21 Grade Ⅲ geoscience landscape areas, and 165 representative Grade Ⅳ geoscience landscape attractions. According to the main classification methods for the geological heritage and tourism landscapes, the geoscience landscapes can be divided into 4 categories, 16 types and 19 subtypes. On this basis, 23 eco-tourism areas of the mid-southern section of the Hengduan Mountains can be delimited. The study provides a theoretical direction and method reference for the geoscience landscape division and tourism zonation, which has an importantsignificance on the mountain landscape protection and tourism development in the regions of complex geo-environments.展开更多
Chlorophyta species are common in the southern and northern coastal areas of China. In recent years, frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientis...Chlorophyta species are common in the southern and northern coastal areas of China. In recent years, frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists. In this paper, we sequenced the 18S rDNA genes, the internal transcribed spacer （ITS） regions and the rbcL genes in seven organisms and obtained 536-566 bp long ITS sequences, 1 377-I 407 bp long rbcL sequences and 1 718-1 761 bp long partial 18S rDNA sequences. The GC base pair content was highest in the ITS regions and lowest in the rbcL genes. The sequencing results showed that the three Ulvaprolifera （or U. pertusa） gene sequences from Qingdao and Nan＇ao Island were identical. The ITS, 18S rDNA and rbcL genes in U. prolifera and U. pertusa from different sea areas in China were unchanged by geographic distance. U.flexuosa had the least evolutionary distance from U. californica in both the ITS regions （0.009） and the 18S rDNA （0.002）. These data verified that Ulva and Enteromorpha are not separate genera.展开更多
A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analy...A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analytic methods were used to clarify the current taxonomic classification and to assess phylogenetic relationships and the evolutionary history of this genus.The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber.We confirmed that S.japonicus and S.colias were genetically distinct.Although morphologically and ecologically similar to S.colias,the molecular data showed that S.japonicus has a greater molecular affinity with S.australasicus,which conflicts with the traditional taxonomy.This phylogenetic pattern was corroborated by the mtDNA data,but incompletely by the nuclear DNA data.Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes supports an Atlantic origin for Scomber.The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus.The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events.In addition,our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution,from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.展开更多
Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they ...Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they are believed to play an important role in plant’s defense against pests. Phytocystatins contain the conserved QXVXG motif and show some features on their sequence different to animal cystatins. After sequencing the protein directly and the cDNA clone, a large number of plant cystatins have been characterized. A multialignment with BLAST software and a detail analysis of 38 phytocystatins show that phytocystatins possess a specific conserved amino acid sequence [LRVI]-[AGT]-[RQKE]-[FY]- [AS]-[VI]-X-[EGHDQV]-[HYFQ]-N different to the conserved sequence demonstrated by Margis in 1998. This conserved sequence can be enough to detect with exclusivity phytocystatin sequences on protein data banks. A classification of these phytocystatins is performed and they can be divided into 3 groups according to their features on amino acid sequence, and the group-I can be still divided into 3 subgroups based on the feature of their amino acid and genomic sequence. By the CLUSTALX software, the most conserved nucleotide sequences of phytocystatins were found, which could be used to design the degenerate premiers to search new phytocystatins with PCR reaction.展开更多
文摘Phylogenetic relationships of the 'higher' hamamelids were estimated based on nucleotide sequences of the non-coding region of chloroplast trnL-F. Twenty-five species were sampled, representing 24 genera of all eight families of the 'higher' hamamelids. A parsimony analysis of data set indicated that the 'higher' hamamelids formed a strongly supported clade with 100% bootstrap value in the strict consensus tree. Nothofagus was the basal lineage and the Fagaceae was sister to a well-supported core 'higher' hamamelids clade containing Myricaceae, Rhoipteleaceae, Juglandaceae, Casuarinaceae, Ticodendraceae and Betulaceae. Three clades were recognized in the core ' higher' hamamelids: (1) Casuatina ( Ticodendron, ( Betu-laceae)), (2) Juglandaceae-Rhoipteleaceae, and (3) Myricaceae. Compared with the previous studies, familial relationships of the 'higher' hamamelids were better resolved.
基金supported by the Sichuan Tourism Youth Expert Training Program in Sichuan Provincial Tourism Development Committee (Grant No. SCTYETP2017L05) the Young Scholars Training Program in Chengdu University of Technology (Grant No. KYGG201424)
文摘The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape classification system is an important scientific basis for landscape protection and tourism development in this region. By combining geology and geography and referring to the concepts of "system tract" and "tectonic system" in geology, this paper comes up with grading standards for the geoscience landscape system of this region. Based on the regional stratigraphic structure, tectonic fault marks and geomorphological differentiation, this paper comes up with 2 Grade Ⅰ geoscience landscape system tracts, 8 Grade Ⅱ geoscience landscape systems, 21 Grade Ⅲ geoscience landscape areas, and 165 representative Grade Ⅳ geoscience landscape attractions. According to the main classification methods for the geological heritage and tourism landscapes, the geoscience landscapes can be divided into 4 categories, 16 types and 19 subtypes. On this basis, 23 eco-tourism areas of the mid-southern section of the Hengduan Mountains can be delimited. The study provides a theoretical direction and method reference for the geoscience landscape division and tourism zonation, which has an importantsignificance on the mountain landscape protection and tourism development in the regions of complex geo-environments.
基金Supported by the National Natural Science Foundation of China (No.30570125)the Key Construction Laboratory of Marine Biotechnology of Jiangsu Province (No. 2010HS03)
文摘Chlorophyta species are common in the southern and northern coastal areas of China. In recent years, frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists. In this paper, we sequenced the 18S rDNA genes, the internal transcribed spacer （ITS） regions and the rbcL genes in seven organisms and obtained 536-566 bp long ITS sequences, 1 377-I 407 bp long rbcL sequences and 1 718-1 761 bp long partial 18S rDNA sequences. The GC base pair content was highest in the ITS regions and lowest in the rbcL genes. The sequencing results showed that the three Ulvaprolifera （or U. pertusa） gene sequences from Qingdao and Nan＇ao Island were identical. The ITS, 18S rDNA and rbcL genes in U. prolifera and U. pertusa from different sea areas in China were unchanged by geographic distance. U.flexuosa had the least evolutionary distance from U. californica in both the ITS regions （0.009） and the 18S rDNA （0.002）. These data verified that Ulva and Enteromorpha are not separate genera.
基金Supported by the International Cooperation and Exchange of the National Natural Science Foundation of China (No. 31061160187)Special Fund for Agro-scientific Research in the Public Interest(No. 200903005)
文摘A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analytic methods were used to clarify the current taxonomic classification and to assess phylogenetic relationships and the evolutionary history of this genus.The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber.We confirmed that S.japonicus and S.colias were genetically distinct.Although morphologically and ecologically similar to S.colias,the molecular data showed that S.japonicus has a greater molecular affinity with S.australasicus,which conflicts with the traditional taxonomy.This phylogenetic pattern was corroborated by the mtDNA data,but incompletely by the nuclear DNA data.Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes supports an Atlantic origin for Scomber.The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus.The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events.In addition,our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution,from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.
基金Supported by The National Basic Research Program (973 Program) ( G1999016003), Graduate Students’ Research Foundation of BeijingForestry University and the Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University
文摘Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they are believed to play an important role in plant’s defense against pests. Phytocystatins contain the conserved QXVXG motif and show some features on their sequence different to animal cystatins. After sequencing the protein directly and the cDNA clone, a large number of plant cystatins have been characterized. A multialignment with BLAST software and a detail analysis of 38 phytocystatins show that phytocystatins possess a specific conserved amino acid sequence [LRVI]-[AGT]-[RQKE]-[FY]- [AS]-[VI]-X-[EGHDQV]-[HYFQ]-N different to the conserved sequence demonstrated by Margis in 1998. This conserved sequence can be enough to detect with exclusivity phytocystatin sequences on protein data banks. A classification of these phytocystatins is performed and they can be divided into 3 groups according to their features on amino acid sequence, and the group-I can be still divided into 3 subgroups based on the feature of their amino acid and genomic sequence. By the CLUSTALX software, the most conserved nucleotide sequences of phytocystatins were found, which could be used to design the degenerate premiers to search new phytocystatins with PCR reaction.
