Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic rela...Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus.In the present study,we reconstructed the phylogenetic relationships by utilizing one nuclear DNA(nrITS)and seven plastid genes(rbcL,trnS,trnG,matK,trnL,psbA,and atpI)from 70 species(varieties)in Cymbidium.We also examined the occurrence of phylogenetic conflict between nuclear(nrITS)and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus.We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics.Our results do not support previous classification of the subgenera and sections within Cymbidium.Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium.Overall,our study indicates that Cymbidium has undergone a complex evolution.展开更多
DNA barcoding is a powerful technique for species identification with little morphological knowledge, by using short sections of DNA from a specific region of the genome. Two core barcode markers, rbcL and matK, and a...DNA barcoding is a powerful technique for species identification with little morphological knowledge, by using short sections of DNA from a specific region of the genome. Two core barcode markers, rbcL and matK, and a supplementary nuclear ribosomal internal transcribed spacer region were used to examine the effectiveness of the markers for Poaceae barcoding using 133 individuals of 36 taxa across 23 genera of Korean Panicoideae. We also aimed to establish a DNA barcode database for the major weeds of Korean Panicoideae. All three markers revealed a good level of amplification and sequencing success. As a single DNA marker, the ITS region achieved the highest species resolution, followed by matK. Resolving power was increased when nrlTS was incorporated into the core barcode markers. The best resolving power was obtained with a combination of matK ＋ ITS with 89.7%, followed by rbcL ＋ matK ＋ ITS with 89.3%. Thus, rbcL may be not necessary as a DNA barcode for Panicoideae species identification, when considering cost and effectiveness. Instead, a combination of matK ＋ ITS is proposed as the most suitable DNA barcode for the species identification of Panicoideae, Poaceae. We conclude that DNA barcoding using a combination of matK ＋ ITS could be one of powerful techniques for the identification of Poaceae species, The barcode sequences were deposited to the National Center for Biotechnology Information （NCBI） database for public use.展开更多
An interesting luminescent Mycena was collected from dead bamboo culms on several occasions from an evergreen forest in Kerala State,India.Detailed morphological and molecular studies with nrITS sequence data confirme...An interesting luminescent Mycena was collected from dead bamboo culms on several occasions from an evergreen forest in Kerala State,India.Detailed morphological and molecular studies with nrITS sequence data confirmed it as Mycena chlorophos.A reappraisal of the species along with comprehensive description,photographs and a discussion with related species is provided.This forms the first record of this species from India.展开更多
基金funded by The National Key Research and Development Program of China(Nos.2018YFD1000401 and 2018YFD1000400)the Natural Science Foundation of Guangdong Province(No.2017A030312004)the Science and Technology Plan Project of Shenzhen(No.JCYJ20170817151501595).
文摘Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus.In the present study,we reconstructed the phylogenetic relationships by utilizing one nuclear DNA(nrITS)and seven plastid genes(rbcL,trnS,trnG,matK,trnL,psbA,and atpI)from 70 species(varieties)in Cymbidium.We also examined the occurrence of phylogenetic conflict between nuclear(nrITS)and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus.We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics.Our results do not support previous classification of the subgenera and sections within Cymbidium.Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium.Overall,our study indicates that Cymbidium has undergone a complex evolution.
文摘DNA barcoding is a powerful technique for species identification with little morphological knowledge, by using short sections of DNA from a specific region of the genome. Two core barcode markers, rbcL and matK, and a supplementary nuclear ribosomal internal transcribed spacer region were used to examine the effectiveness of the markers for Poaceae barcoding using 133 individuals of 36 taxa across 23 genera of Korean Panicoideae. We also aimed to establish a DNA barcode database for the major weeds of Korean Panicoideae. All three markers revealed a good level of amplification and sequencing success. As a single DNA marker, the ITS region achieved the highest species resolution, followed by matK. Resolving power was increased when nrlTS was incorporated into the core barcode markers. The best resolving power was obtained with a combination of matK ＋ ITS with 89.7%, followed by rbcL ＋ matK ＋ ITS with 89.3%. Thus, rbcL may be not necessary as a DNA barcode for Panicoideae species identification, when considering cost and effectiveness. Instead, a combination of matK ＋ ITS is proposed as the most suitable DNA barcode for the species identification of Panicoideae, Poaceae. We conclude that DNA barcoding using a combination of matK ＋ ITS could be one of powerful techniques for the identification of Poaceae species, The barcode sequences were deposited to the National Center for Biotechnology Information （NCBI） database for public use.
基金The authors are thankful to the Director,JNTBGRI for facilities and Arya C.P.acknowledges financial support from the CSIR,India in the form of Junior Research Fellowship(File No:09/592(0031)/2019-EMR-I).
文摘An interesting luminescent Mycena was collected from dead bamboo culms on several occasions from an evergreen forest in Kerala State,India.Detailed morphological and molecular studies with nrITS sequence data confirmed it as Mycena chlorophos.A reappraisal of the species along with comprehensive description,photographs and a discussion with related species is provided.This forms the first record of this species from India.
