North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the s...North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.展开更多
Since ancient times,humans have bred several plants that we rely on today.However,little is known about the divergence of most of these plants.In the present study,we investigated the divergence of Mibuna(Brassica rap...Since ancient times,humans have bred several plants that we rely on today.However,little is known about the divergence of most of these plants.In the present study,we investigated the divergence of Mibuna(Brassica rapa L.subsp.nipposinica L.H.Bailey),a traditional leafy vegetable in Kyoto(Japan),by combining genetic analysis and a survey of ancient literature.Mibuna is considered to have been bred 200 years ago from Mizuna,another traditional leafy vegetable in Kyoto.Mibuna has simple spatulate leaves,whereas Mizuna has characteristic serrated leaves.The quantitative trait loci(QTL)and gene expression analyses suggested that the downregulation of BrTCP15 expression contributed to the change in the leaf shape from serrated to simple spatulate.Interestingly,the SNP analysis indicated that the genomic region containing the BrTCP15 locus was transferred to Mibuna by introgression.Furthermore,we conducted a survey of ancient literature to reveal the divergence of Mibuna and found that hybridization between Mizuna and a simple-leaved turnip might have occurred in the past.Indeed,the genomic analysis of multiple turnip cultivars showed that one of the cultivars,Murasakihime,has almost the same sequence in the BrTCP15 region as Mibuna.These results suggest that the hybridization between Mizuna and turnip has resulted in the establishment of Mibuna.展开更多
To determine the eVolutionary history of Asparagus cochinchinensis (Asparagaceae), we investigated the geographic pattern of its nucleotide sequence variations in Japan, Taiwan, South Korea and China. We found 21 poly...To determine the eVolutionary history of Asparagus cochinchinensis (Asparagaceae), we investigated the geographic pattern of its nucleotide sequence variations in Japan, Taiwan, South Korea and China. We found 21 polymorphic nucleotide sites by sequencing the internal transcribed spacer (ITS) region, which gave rise to a total of 15 haplotypes, labeled A to O. The A-type was found only in inland China (Guizhou and Sichuan), and the other haplotypes in China extended to several lineages;therefore, A. cochinchinensis may have its origin in the interior of China. The I-type has large distribution area and it also experienced a quick expansion in relative recent years. Haplotype differentiation was observed between the eastern and western side of the Central Mountain Ridge in Taiwan. Two lineages were found in Japan, one in the Yaeyama Islands and the other in remaining areas of Japan, implying that A. cochinchinensis independently colonized in Japan at least twice.展开更多
To describe the phylogeographic structures of Asparagus schoberioides Kunth (Asparagaceae) in Japan, we investigated its nucleotide sequence variations with respect to its geographic distribution pattern. Sequencing o...To describe the phylogeographic structures of Asparagus schoberioides Kunth (Asparagaceae) in Japan, we investigated its nucleotide sequence variations with respect to its geographic distribution pattern. Sequencing of the internal transcribed spacer (ITS) 1 region in 29 samples of A. schoberioides revealed 20 polymorphic nucleotide sites. As a result, the 29 samples of A. schoberioides fell into 15 distinct haplotypes and phylogenetic analyses revealed these haplotypes fell into two major clades, Clade 1 and Clade 2. The haplotypes of Clade 1 were distributed chiefly along the Pacific Ocean side of Japan, while those of Clade 2 occurred mainly along the Japan Sea side. This result suggests that A. schoberioides has migrated via two routes in Japan.展开更多
文摘North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.
基金This research was supported by grants in aid from the Japan Society for the Promotion of Science(KAKENHI grant numbers 16H01472 and 18H04787)the MEXT-Supported Program for the Strategic Research Foundation at Private Universities(grant number S1511023)from the Ministry of Education,Culture,Sports,Science,and Technology of Japan to S.K+2 种基金This work was also financially supported by the Sasakawa Scientific Research Grant from The Japan Science Society to Y.KThis study was supported by a Joint Usage/Research program of the Center for Ecological Research,Kyoto University,the Ministry of Education,Culture,Sports,Science,and Technology of Japan(MEXT)[Grant-in-Aid for Scientific Research on Innovative Areas(19H04870)]Research Funding for the Computational Software Supporting Program from Meiji University.
文摘Since ancient times,humans have bred several plants that we rely on today.However,little is known about the divergence of most of these plants.In the present study,we investigated the divergence of Mibuna(Brassica rapa L.subsp.nipposinica L.H.Bailey),a traditional leafy vegetable in Kyoto(Japan),by combining genetic analysis and a survey of ancient literature.Mibuna is considered to have been bred 200 years ago from Mizuna,another traditional leafy vegetable in Kyoto.Mibuna has simple spatulate leaves,whereas Mizuna has characteristic serrated leaves.The quantitative trait loci(QTL)and gene expression analyses suggested that the downregulation of BrTCP15 expression contributed to the change in the leaf shape from serrated to simple spatulate.Interestingly,the SNP analysis indicated that the genomic region containing the BrTCP15 locus was transferred to Mibuna by introgression.Furthermore,we conducted a survey of ancient literature to reveal the divergence of Mibuna and found that hybridization between Mizuna and a simple-leaved turnip might have occurred in the past.Indeed,the genomic analysis of multiple turnip cultivars showed that one of the cultivars,Murasakihime,has almost the same sequence in the BrTCP15 region as Mibuna.These results suggest that the hybridization between Mizuna and turnip has resulted in the establishment of Mibuna.
文摘To determine the eVolutionary history of Asparagus cochinchinensis (Asparagaceae), we investigated the geographic pattern of its nucleotide sequence variations in Japan, Taiwan, South Korea and China. We found 21 polymorphic nucleotide sites by sequencing the internal transcribed spacer (ITS) region, which gave rise to a total of 15 haplotypes, labeled A to O. The A-type was found only in inland China (Guizhou and Sichuan), and the other haplotypes in China extended to several lineages;therefore, A. cochinchinensis may have its origin in the interior of China. The I-type has large distribution area and it also experienced a quick expansion in relative recent years. Haplotype differentiation was observed between the eastern and western side of the Central Mountain Ridge in Taiwan. Two lineages were found in Japan, one in the Yaeyama Islands and the other in remaining areas of Japan, implying that A. cochinchinensis independently colonized in Japan at least twice.
文摘To describe the phylogeographic structures of Asparagus schoberioides Kunth (Asparagaceae) in Japan, we investigated its nucleotide sequence variations with respect to its geographic distribution pattern. Sequencing of the internal transcribed spacer (ITS) 1 region in 29 samples of A. schoberioides revealed 20 polymorphic nucleotide sites. As a result, the 29 samples of A. schoberioides fell into 15 distinct haplotypes and phylogenetic analyses revealed these haplotypes fell into two major clades, Clade 1 and Clade 2. The haplotypes of Clade 1 were distributed chiefly along the Pacific Ocean side of Japan, while those of Clade 2 occurred mainly along the Japan Sea side. This result suggests that A. schoberioides has migrated via two routes in Japan.