Aims Hybridization usually leads to gene introgression between related spe-cies in hybrid zones,associated with complex patterns of morpho-logical variation.Nevertheless,previous studies have tended to ignore the effe...Aims Hybridization usually leads to gene introgression between related spe-cies in hybrid zones,associated with complex patterns of morpho-logical variation.Nevertheless,previous studies have tended to ignore the effects of geographic variation in hybridization rates on species taxonomy.This study aims to investigate the variation of morphologi-cal traits between two sympatric and taxonomically confused oak spe-cies,Quercus liaotungensis and Q.mongolica,and reveal the effects of hybridization rates on morphological traits and the taxonomic boundary.Methods We used seven microsatellite loci to evaluate species status and measured 15 morphological traits in 26 trees in the recent hybrid zone between Q.liaotungensis and Q.mongolica,and we char-acterized the differences between the two oak species and their hybrids for the investigated traits.Important Findingsmolecular analyses indicated that 74%of 78 sampled maternal trees were hybrids between Q.liaotungensis and Q.mongolica although the observed morphological variation suggested that they had remained distinct species.across all of the differentiated leaf and reproductive traits,the hybrids expressed patterns similar to Q.liaotungensis,which may suggest dominant expression of paren-tal characters.These results are consistent with our expectation that hybrids will be difficult to distinguish from parental species in a recent hybrid zone.展开更多
Abundant fossil records show that the Fagaceae has remained a dominant component in the Northern Hemisphere since the Cenozoic. However, due to the large number of living species, it is not easy to identify leaves to ...Abundant fossil records show that the Fagaceae has remained a dominant component in the Northern Hemisphere since the Cenozoic. However, due to the large number of living species, it is not easy to identify leaves to a particular species. Consequently, the identification of fossil leaves belonging to the Fagaceae is problematic.展开更多
Background: Global change is causing an increase in the incidence of natural and anthropogenic disturbances on forests, which frequently interact synergistically and promote changes in forest structure, composition an...Background: Global change is causing an increase in the incidence of natural and anthropogenic disturbances on forests, which frequently interact synergistically and promote changes in forest structure, composition and functioning. In this study we evaluate the regeneration of Pinaceae and Fagaceae species in pure and mixed stands in Mexico to determine if current regeneration patterns are indicative of changes in the relative dominance of these two tree families, as observed in other temperate regions. We also identify the environmental factors that determine the regeneration patterns of Pinaceae and Fagaceae species in these forests.Results: We use data from two consecutive surveys of the National Inventory of Forests and Soils of Mexico(INFyS),obtained in 2004–2009 and 2009–2014. Our results show that the spatial patterns of regeneration are affected by forest structure, by climate, by the type and intensity of disturbances and by land tenure. Importantly, the presence and abundance of Fagaceae regeneration is generally higher than that of Pinaceae, and tends to be favoured(relative to Pinaceae) under warmer climates and by the presence of wildfires.Conclusions: The higher regeneration of Fagaceae relative to Pinaceae under warmer and fire-prone conditions could have important impacts on the composition and functioning of Mexican temperate forests under ongoing climate change, as well as affect their resilience to future disturbances.展开更多
Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation me...Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680?bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.展开更多
On Page 1428,Table 5 is missing.It should be placed after this paragraph“In this study,a total of 19 endemic species of Borneo were recorded(Table 5).The highest number of endemic species was found in S1 followed by ...On Page 1428,Table 5 is missing.It should be placed after this paragraph“In this study,a total of 19 endemic species of Borneo were recorded(Table 5).The highest number of endemic species was found in S1 followed by S2 and S3.Four endemic Dipterocarpaceae(Shorea crassa at S2;Shorea isopteran,Shorea parvistipulata and Vatica micrantha at S1)were found in this study area(Table 5).Three endemic species each from Fagaceae,Lauraceae and Myrtaceae were also documented during this study(Table 5).At a similar elevation range to S3,Kueh et al.(2017)recorded 12 endemic species in their study.”.展开更多
基金National Natural Science Foundation of China(31370398,31421063,J1210075)Fundamental Research Funds for the Central Universities.
文摘Aims Hybridization usually leads to gene introgression between related spe-cies in hybrid zones,associated with complex patterns of morpho-logical variation.Nevertheless,previous studies have tended to ignore the effects of geographic variation in hybridization rates on species taxonomy.This study aims to investigate the variation of morphologi-cal traits between two sympatric and taxonomically confused oak spe-cies,Quercus liaotungensis and Q.mongolica,and reveal the effects of hybridization rates on morphological traits and the taxonomic boundary.Methods We used seven microsatellite loci to evaluate species status and measured 15 morphological traits in 26 trees in the recent hybrid zone between Q.liaotungensis and Q.mongolica,and we char-acterized the differences between the two oak species and their hybrids for the investigated traits.Important Findingsmolecular analyses indicated that 74%of 78 sampled maternal trees were hybrids between Q.liaotungensis and Q.mongolica although the observed morphological variation suggested that they had remained distinct species.across all of the differentiated leaf and reproductive traits,the hybrids expressed patterns similar to Q.liaotungensis,which may suggest dominant expression of paren-tal characters.These results are consistent with our expectation that hybrids will be difficult to distinguish from parental species in a recent hybrid zone.
文摘Abundant fossil records show that the Fagaceae has remained a dominant component in the Northern Hemisphere since the Cenozoic. However, due to the large number of living species, it is not easy to identify leaves to a particular species. Consequently, the identification of fossil leaves belonging to the Fagaceae is problematic.
基金supported by “‘Consejo Nacional de Ciencia y Tecnología-CONACYT’“by a national research grant/scholarship(CVU 225254)to TARby the Spanish government through grant CGL2013–46808-R.JMV benefits from an ICREA Academia award
文摘Background: Global change is causing an increase in the incidence of natural and anthropogenic disturbances on forests, which frequently interact synergistically and promote changes in forest structure, composition and functioning. In this study we evaluate the regeneration of Pinaceae and Fagaceae species in pure and mixed stands in Mexico to determine if current regeneration patterns are indicative of changes in the relative dominance of these two tree families, as observed in other temperate regions. We also identify the environmental factors that determine the regeneration patterns of Pinaceae and Fagaceae species in these forests.Results: We use data from two consecutive surveys of the National Inventory of Forests and Soils of Mexico(INFyS),obtained in 2004–2009 and 2009–2014. Our results show that the spatial patterns of regeneration are affected by forest structure, by climate, by the type and intensity of disturbances and by land tenure. Importantly, the presence and abundance of Fagaceae regeneration is generally higher than that of Pinaceae, and tends to be favoured(relative to Pinaceae) under warmer climates and by the presence of wildfires.Conclusions: The higher regeneration of Fagaceae relative to Pinaceae under warmer and fire-prone conditions could have important impacts on the composition and functioning of Mexican temperate forests under ongoing climate change, as well as affect their resilience to future disturbances.
基金financially supported by Tarbiat Modares University
文摘Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680?bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.
文摘On Page 1428,Table 5 is missing.It should be placed after this paragraph“In this study,a total of 19 endemic species of Borneo were recorded(Table 5).The highest number of endemic species was found in S1 followed by S2 and S3.Four endemic Dipterocarpaceae(Shorea crassa at S2;Shorea isopteran,Shorea parvistipulata and Vatica micrantha at S1)were found in this study area(Table 5).Three endemic species each from Fagaceae,Lauraceae and Myrtaceae were also documented during this study(Table 5).At a similar elevation range to S3,Kueh et al.(2017)recorded 12 endemic species in their study.”.
