Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conif...Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conifers due to local adaptation.However,few empirical studies have revealed relevant relationships between climatic factors in provenance environments and photosynthetic phenology.This study evaluated the effects of environmental conditions of the growing site and seed source provenance on the seasonal changes in maximal photochemical quantum yield of photo systemⅡ(Fv/Fm)in a common garden experiment with 2-year-old seedlings of Sakhalin fir(Abies sachalinensis),a representative species with local adaptation,from four seed source provenances.A logistic model was constructed to explain the seasonal variation of Fv/Fmfrom July to October and the relationships between the estimated model parameters and representative factors featuring provenance environments were evaluated.The landscape gradient of the detected model parameters responsible for the provenance environments was visualized in a map of the distribution area.The lowest temperature was the most plausible factor in the growing environment to explain the seasonal changes of Fv/Fm.Among the representative meteorological factors of provenance environments,the lowest temperatures in July showed significant relationships with two model parameters,explaining the lower limit of Fv/Fmand the higher sensitivity of autumn Fv/Fmdecline.The estimated spatial maps of model parameters consistently showed that the higher the lowest temperature in July in the provenance environment,the lower the Fv/Fmin October and the greater the decrease in the autumn Fv/Fmdecline.Therefore,the lowest summer temperature could be associated with the local adaptation of autumn photosynthetic phenology in A.sachalinensis.展开更多
Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of l...Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of latitude,longitude and altitude.We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse(Apodemus uralensis)across the species range,based on field data and on data from the literature.Sexual dimorphism in adult A.uralensis was not expressed at a large scale,while local patterns were inconsistent.Age-dependent size changes were most expressed in adult individuals:most characters of adults exceeded in size those of subadults,while subadult-juvenile size differences were only significant in body weight and length,zygomatic skull width,length of cranial diastema and breadth of braincase.Despite central morphological niches along the clines being separated,A.uralensis populations showed a high degree of size overlap in morphological space.We found the species to be characterized by high size variability,with the largest individuals inhabiting the eastern and southern edges of the distribution range.Tail,hind foot and ear lengths were largest in the southern part of the range,in agreement with Allen’s rule.The main measurements that we analyzed,namely body mass,zygomatic skull width and condylobasal skull length,show the presence of 3 clines in the size of adult A.uralensis:(i)a decreasing south-north cline,opposing Bergmann’s rule;(ii)an increasing west-east cline,in accordance with Murphy’s rule;and(iii)an increasing altitudinal cline.展开更多
Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa a...Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa and their progenitors are,however,less clearly defined.This study investigated the genetic structure and clines in Pinus densata,a pine of hybrid origin on the southeastern Tibetan Plateau,to gain an understanding of the contemporary dynamics of species barriers.We analyzed genetic diversity in a range-wide collection of P.densata and representative populations of its progenitors,Pinus tabuliformis and Pinus yunnanensis,using exome capture sequencing.We detected four distinct genetic groups within P.densata that reflect its migration history and major gene-flow barriers across the landscape.The demographies of these genetic groups in the Pleistocene were associated with regional glaciation histories.Interestingly,population sizes rebounded rapidly during interglacial periods,suggesting persistence and resilience of the species during the Quaternary ice age.In the contact zone between P.densata and P.yunnanensis,3.36%of the analyzed loci(57849)showed exceptional patterns of introgression,suggesting their potential roles in either adaptive introgression or reproductive isolation.These outliers showed strong clines along critical climate gradients and enrichment in a number of biological processes relevant to high-altitude adaptation.This indicates that ecological selection played an important role in generating genomic heterogeneity and a genetic barrier across a zone of species transition.Our study highlights the forces that operate to maintain species boundaries and promote speciation in the Qinghai-Tibetan Plateau and other mountain systems.展开更多
基金Japan Society for the Promotion of Science,KAKENHI(18J2013908)。
文摘Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conifers due to local adaptation.However,few empirical studies have revealed relevant relationships between climatic factors in provenance environments and photosynthetic phenology.This study evaluated the effects of environmental conditions of the growing site and seed source provenance on the seasonal changes in maximal photochemical quantum yield of photo systemⅡ(Fv/Fm)in a common garden experiment with 2-year-old seedlings of Sakhalin fir(Abies sachalinensis),a representative species with local adaptation,from four seed source provenances.A logistic model was constructed to explain the seasonal variation of Fv/Fmfrom July to October and the relationships between the estimated model parameters and representative factors featuring provenance environments were evaluated.The landscape gradient of the detected model parameters responsible for the provenance environments was visualized in a map of the distribution area.The lowest temperature was the most plausible factor in the growing environment to explain the seasonal changes of Fv/Fm.Among the representative meteorological factors of provenance environments,the lowest temperatures in July showed significant relationships with two model parameters,explaining the lower limit of Fv/Fmand the higher sensitivity of autumn Fv/Fmdecline.The estimated spatial maps of model parameters consistently showed that the higher the lowest temperature in July in the provenance environment,the lower the Fv/Fmin October and the greater the decrease in the autumn Fv/Fmdecline.Therefore,the lowest summer temperature could be associated with the local adaptation of autumn photosynthetic phenology in A.sachalinensis.
文摘Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of latitude,longitude and altitude.We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse(Apodemus uralensis)across the species range,based on field data and on data from the literature.Sexual dimorphism in adult A.uralensis was not expressed at a large scale,while local patterns were inconsistent.Age-dependent size changes were most expressed in adult individuals:most characters of adults exceeded in size those of subadults,while subadult-juvenile size differences were only significant in body weight and length,zygomatic skull width,length of cranial diastema and breadth of braincase.Despite central morphological niches along the clines being separated,A.uralensis populations showed a high degree of size overlap in morphological space.We found the species to be characterized by high size variability,with the largest individuals inhabiting the eastern and southern edges of the distribution range.Tail,hind foot and ear lengths were largest in the southern part of the range,in agreement with Allen’s rule.The main measurements that we analyzed,namely body mass,zygomatic skull width and condylobasal skull length,show the presence of 3 clines in the size of adult A.uralensis:(i)a decreasing south-north cline,opposing Bergmann’s rule;(ii)an increasing west-east cline,in accordance with Murphy’s rule;and(iii)an increasing altitudinal cline.
基金supported by grants from the Swedish Research Council(VR 2017-04686)T4F program,Sweden.
文摘Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa and their progenitors are,however,less clearly defined.This study investigated the genetic structure and clines in Pinus densata,a pine of hybrid origin on the southeastern Tibetan Plateau,to gain an understanding of the contemporary dynamics of species barriers.We analyzed genetic diversity in a range-wide collection of P.densata and representative populations of its progenitors,Pinus tabuliformis and Pinus yunnanensis,using exome capture sequencing.We detected four distinct genetic groups within P.densata that reflect its migration history and major gene-flow barriers across the landscape.The demographies of these genetic groups in the Pleistocene were associated with regional glaciation histories.Interestingly,population sizes rebounded rapidly during interglacial periods,suggesting persistence and resilience of the species during the Quaternary ice age.In the contact zone between P.densata and P.yunnanensis,3.36%of the analyzed loci(57849)showed exceptional patterns of introgression,suggesting their potential roles in either adaptive introgression or reproductive isolation.These outliers showed strong clines along critical climate gradients and enrichment in a number of biological processes relevant to high-altitude adaptation.This indicates that ecological selection played an important role in generating genomic heterogeneity and a genetic barrier across a zone of species transition.Our study highlights the forces that operate to maintain species boundaries and promote speciation in the Qinghai-Tibetan Plateau and other mountain systems.
