Phylogenetic And Evolution Analysis Of Roegneria And Its Related Genera(Triticeae;Poaceae)

Roegneria C.Koch is important perennial genera in the tribe Triticeae(Poaceae).It includes about 130 species in the world and about 70 species distribute in China.The genera status of Roegneria is controversial at present.Some authors include the species in Roegneria while some one regard it as a part of the genus Elymus.Furthermore,chromosome number and genome constitutions of 60 Roegneria taxa in China are still unknown.Some Roegneria species had similar morphological characters,but containing different genome constitutions.However,some species in Roegneria had the same genome constitutions,but showed different morphological forms.Thus,in this study,we carried out the taxonomic status of Roegneria and biosystematic studies on its species through four nuclear DNA genes(DMC1,Acc1,Pgk1 and ITS;)and three chloroplast regions(ndhF,t rnH-psbA and trnL-F)The objectives are:(1)to investigate taxonomic status of genus Roegneria;(2)to discuss the generic delimitation and the phylogenetic relationships among Roegneria,Elymus,Campeiostachys and the related genera;(3)to determine the genomic constitutions of the Roegneria species and solve the problem of taxonomic treatment some specific species of Roegneria;(4)to reveal the origin of genome in Roegneria,especially the origin of Y genome;(5)to identify the maternal genome donor to Roegneria.The main results are as follows:1.phylogenetic analyses of ITS sequences of 52 Roegneria species and its affinitive genera species were carried out in this study.The phylogenetic analysis and network results showed that:(1)the Y genomes in Roegneria species and its affinitive genera species might be created by evolutionary dynamic change,such as genes silence or lost,rearrangement of genesor,it may also be "colonized" by the St genome;(2)the Y and St genomes have originated from distinct diploid species;(3)There are differentiation of St genome in diploid,tetraploid or hexaploid and might be created by genetic bottleneck.2.phylogenetic analyses of disrupted meiotic cDNA(DMCI)sequences of 74 Roegneria species and its affinitive genera species were carried out in this study.The phylogenetic analysis and network results showed that:(1)Our data showed that it is reasonable to recognize that species containing the StY genomes should be treated as Roegneria,species with the StH genomes should be included in the genus Elymus,while species containing the StYH genomes should be treated as Campeiostachys;(2)The present DMC1 sequences data provided evidence for the questionable species in Reogneria,which the genome constitutions were still unknown.R.alashanica,R.grandis,R.sinica and R.schugnanica seemed to be containing the StY genomes,R.seriotina,R.glaucifolia and R.tschimganica have the St and Y genomes,while E.calcicolus might contain the StYH genomes and should be transferred into the genus Campeiostachys;(3)St and Y genome have originated from different donors and the donor of the Y genome could not be identified;(4)There are differentiation of St genome in diploid,tetraploid or hexaploid.3.phylogenetic analyses of Accl sequences of 70 Roegneria species and its affinitive genera species were carried out in this study.The phylogenetic analysis and network results showed that:(1)Based on genomic constitutions,the genus Roegneria as an independent genus with StY,StStY genomes,the genus Campeiostachys as an independent genus with StYH genomes;(2)R.alashanica,R.grandis,R.sinica and R.schugnanica appear to contain the StY genomes,R.seriotina,R.glaucifolia and R.tschimganica have the St and Y genomes,whereas E.calcicolus might contain the StYH genomes and should be transferred to Campeiostachys;(3)The Y genome homoeologous types were grouped independently,with V gemomes.The results suggested that the Y and St genomes have originated from distinct diploid species;(4)The differentiation of the St genome in diploid species;(5)the possibility that StY tetraploid species was the direct ancestor of the StYH hexaploid species.4.phylogenetic analyses of Pgkl sequences of 70 Roegneria species and its affinitive genera species were carried out in this study.The phylogenetic analysis and network results showed that:(1)Based on genomic constitutions,the genus Roegneria as an independent genus with StY,StStY genomes,the genus Campeiostachys as an independent genus with StYH genomes;(2)R.alashanica,R.grandis,R.sinica and R.schugnanica appear to contain the StY genomes,R.seriotina have the St and Y genomes,R.glaucifolia and R.tschimganica have the StStY genomes,whereas E.calcicolus might contain the StYH genomes and should be transferred to Campeiostachys,(3)The Y genome homoeologous types were grouped independently,with Xp gemomes.The results suggested that the Y and St genomes have originated from distinct diploid species;(4)The differentiation of the St genome in diploid species;(5)the possibility that StY tetraploid species was the direct ancestor of the StYH hexaploid species.5.phylogenetic analyses of ndhF?trnH-psbA and trnL-F sequences of 67 Roegneria species and its affinitive genera species were carried out in this study.The phylogenetic analysis and network results showed that:(1)Pseudoroegneria might serve as the maternal genome donor of Roegneria;(2)Lophopyrum(Ee),Thinopyrum(Eb)and Dasypyrum(V)associated with Pseudoroegneria;(3)R.sinica,R.schugnanica,R.seriotina and E.calcicolus containing one set of St genome and the maternal genome donor is Pseudoroegneria;(4)The St genome has differentiation during polyploidization in diploid,tetraploid and hexaploid species.