Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new...Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new polyploid lineage can succeed only if it establishes a new ecological niche divergent from its progenitor lineages.We tested the hypothesis that Rhodiola integrifolia from North America is an allopolyploid produced by R. rhodantha and R.rosea and determined whether its survival can be explained by the niche divergence hypothesis.To this end,we sequenced two low-copy nuclear genes(ncpGS and rpb2) in a phylogenetic analysis of 42 Rhodiola species and tested for niche equivalency and similarity using Schoener’s D as the index of niche overlap.Our phylogeny-based approach showed that R integrifolia possesses alleles from both R. rhodantha and rosea Dating analysis showed that the hybridization event that led to R.integrifolia occurred ca.1.67 Mya and niche modeling analysis showed that at this time,both R.rosea and R.rhodantha may have been present in Beringia,providing the opportunity for the hybridization event.We also found that the niche of R.integrifolia differs from that of its progenitors in both niche breadth and optimum.Taken together,these results confirm the hybrid origin of R.integrifolia and support the niche divergence hypothesis for this tetraploid species.Our results underscore the fact that lineages with no current overlapping distribution could produce hybrid descendants in the past,when climate oscillations made their distributions overlap.展开更多
以采自福建省山区的正红菇Russula griseocarnosa为研究材料,进行ITS(internal transcribed spacer)、RPB2(the second largest subunit of the nuclear RNA polymerase enzyme II)保守区段克隆测序和序列同源性比对。将从GenBank中获...以采自福建省山区的正红菇Russula griseocarnosa为研究材料,进行ITS(internal transcribed spacer)、RPB2(the second largest subunit of the nuclear RNA polymerase enzyme II)保守区段克隆测序和序列同源性比对。将从GenBank中获得的部分红菇属物种ITS和RPB2序列与正红菇序列通过最大简约法进行系统发育分析。基于ITS序列构建的系统发育树表明,福建正红菇与云南大红菌Russula griseocarnosa X.H.Wang,Zhu L.Yang&Knudsen,sp.nov.间序列差异较小,亲缘关系较近,以99%的支持率聚为一簇。福建正红菇与欧洲红菇Russula vinosa及玫瑰红菇Russula rosea间序列差异较大,亲缘关系较远,在系统发育树上聚为不同分枝。基于RPB2序列构建的系统发育树也表明福建正红菇与云南大红菌聚为一簇(支持率94%),而与玫瑰红菇聚为不同分支。展开更多
After a short historical overview of past systematic studies on Cantharellus,discussing delimitation and species diversity of the genus as well as previous,morphology-based,infrageneric classifications,this paper pres...After a short historical overview of past systematic studies on Cantharellus,discussing delimitation and species diversity of the genus as well as previous,morphology-based,infrageneric classifications,this paper presents the first molecularly-based infrageneric classification of this genus using a multigene phylogenetic approach(nucLSU,mitSSU,RPB2 and tef-1)on a dataset that covers approximately halve of the described chanterelles worldwide,including many type specimens.Six subgenera are recognized and the recognition of subgenus Afrocantharellus as a separate genus is not accepted.The taxonomic value of individual morphological features is discussed as challenged by this new multigene phylogeny which comprises five new sections,one new subgenus and many emendations for previously recognized infrageneric groups.The paper discusses the observed discrepancy in biodiversity of Cantharellus when comparing between studies that focus either on below-or above-ground presence.A preliminary biogeographic hypothesis suggests an‘out of Africa’Gondwanan origin as a result of vicariance and subsequent migrations.展开更多
基金supported by the Fundamental Research Funds for the Central University of Shaanxi Normal University (GK202103077 to J.Q,Zhang)the National Natural Science Foundation of China(Grant nos.31870194,32070236)。
文摘Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new polyploid lineage can succeed only if it establishes a new ecological niche divergent from its progenitor lineages.We tested the hypothesis that Rhodiola integrifolia from North America is an allopolyploid produced by R. rhodantha and R.rosea and determined whether its survival can be explained by the niche divergence hypothesis.To this end,we sequenced two low-copy nuclear genes(ncpGS and rpb2) in a phylogenetic analysis of 42 Rhodiola species and tested for niche equivalency and similarity using Schoener’s D as the index of niche overlap.Our phylogeny-based approach showed that R integrifolia possesses alleles from both R. rhodantha and rosea Dating analysis showed that the hybridization event that led to R.integrifolia occurred ca.1.67 Mya and niche modeling analysis showed that at this time,both R.rosea and R.rhodantha may have been present in Beringia,providing the opportunity for the hybridization event.We also found that the niche of R.integrifolia differs from that of its progenitors in both niche breadth and optimum.Taken together,these results confirm the hybrid origin of R.integrifolia and support the niche divergence hypothesis for this tetraploid species.Our results underscore the fact that lineages with no current overlapping distribution could produce hybrid descendants in the past,when climate oscillations made their distributions overlap.
文摘以采自福建省山区的正红菇Russula griseocarnosa为研究材料,进行ITS(internal transcribed spacer)、RPB2(the second largest subunit of the nuclear RNA polymerase enzyme II)保守区段克隆测序和序列同源性比对。将从GenBank中获得的部分红菇属物种ITS和RPB2序列与正红菇序列通过最大简约法进行系统发育分析。基于ITS序列构建的系统发育树表明,福建正红菇与云南大红菌Russula griseocarnosa X.H.Wang,Zhu L.Yang&Knudsen,sp.nov.间序列差异较小,亲缘关系较近,以99%的支持率聚为一簇。福建正红菇与欧洲红菇Russula vinosa及玫瑰红菇Russula rosea间序列差异较大,亲缘关系较远,在系统发育树上聚为不同分枝。基于RPB2序列构建的系统发育树也表明福建正红菇与云南大红菌聚为一簇(支持率94%),而与玫瑰红菇聚为不同分支。
基金Supported by the National Natural Science Foundation of China(No.31270073)Ministry of Science and Technology of China for Fundamental Research(No.2013FY110400)
基金Supported by the National Natural Science Foundation of China(31270073)Ministry of Science and Technology of China for Fundamental Research(2013FY110400)
基金Part of the sequencing for this study was performed by A.Couloux at the Genoscope or“Consortium National de Recherche en Génomique”near Paris(France)as part of the agreement n°2005/67 on the project“Macrophylogeny of life”between the Genoscope and the“service de systématique moléculaire”(CNRS IFR 101)of the Muséum national d’histoire naturelleFor sequencing,this study also received continuing support from the ATM-project“Barcode of life”of the Muséum national d’histoire naturelle(Dirs.L.Legall and S.Samadi).
文摘After a short historical overview of past systematic studies on Cantharellus,discussing delimitation and species diversity of the genus as well as previous,morphology-based,infrageneric classifications,this paper presents the first molecularly-based infrageneric classification of this genus using a multigene phylogenetic approach(nucLSU,mitSSU,RPB2 and tef-1)on a dataset that covers approximately halve of the described chanterelles worldwide,including many type specimens.Six subgenera are recognized and the recognition of subgenus Afrocantharellus as a separate genus is not accepted.The taxonomic value of individual morphological features is discussed as challenged by this new multigene phylogeny which comprises five new sections,one new subgenus and many emendations for previously recognized infrageneric groups.The paper discusses the observed discrepancy in biodiversity of Cantharellus when comparing between studies that focus either on below-or above-ground presence.A preliminary biogeographic hypothesis suggests an‘out of Africa’Gondwanan origin as a result of vicariance and subsequent migrations.
