The Moroccan populations of Alnus glutinosa(L.)Gaertn.(Betulaceae)They are located at the southern limit of the species'distribution and are represented by tetraploid cytotypes.Assessing phenotypic variability in ...The Moroccan populations of Alnus glutinosa(L.)Gaertn.(Betulaceae)They are located at the southern limit of the species'distribution and are represented by tetraploid cytotypes.Assessing phenotypic variability in reproductive traits is crucial for understanding the persistence,evolution,and range dynamics of plant populations.However,no previous studies have analyzed the relative importance of variability in explaining inter-or intra-population differences in reproductive traits.To address this gap,we investigated phenotypic variation in reproductive organs by examining 10 traits in 3.600 male catkins,3.600 female catkins,and seeds from 12 populations across the Moroccan Rif Mountains.Our results highlighted the significance of inter-population variability.However,we found that the contribution of within-tree variation to total phenotypic variability was greater than that of both inter-and intra-population variation.Principal component analysis(PCA)revealed a phenotypic gradient among populations,primarily driven by female catkin size,though this gradient was not associated with geographic conditions.This finding was further supported by Mantel test results,which showed no correlation between phenotypic variability and population conditions.These findings have important implications for the genetic improvement,conservation,and resource management of Alnus glutinosa in the future.展开更多
Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean ...Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional agroecosystems.Several studies have focused on its morphological,biochemical,and genetic diversity.However,less is known about the intraspecific variation of seed traits.In this regard,and as an overall objective,we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical landscapes.In addition,we investigated how the climate along the study area affects the extent of carob seed variability.Using image analysis techniques,we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous C.siliqua distributed along a latitudinal transect in Morocco under different bioclimatic conditions.Results:The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic factors.Seed trait analysis revealed high intraspecific variability,explained by differences between and among carob populations and geographic zones.Seed area,perimeter,length,and width showed the largest variability between geographic zones.However,circularity,aspect ratio,and seed roundness showed higher variability at the tree level.Finally,our results show that seed traits vary depending on altitude and climate condition.Conclusions:Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological conditions.Therefore,intraspecific variation of seed traits should be integrated into trait‑based functional ecology to assess plant species responses to environmental changes.展开更多
文摘The Moroccan populations of Alnus glutinosa(L.)Gaertn.(Betulaceae)They are located at the southern limit of the species'distribution and are represented by tetraploid cytotypes.Assessing phenotypic variability in reproductive traits is crucial for understanding the persistence,evolution,and range dynamics of plant populations.However,no previous studies have analyzed the relative importance of variability in explaining inter-or intra-population differences in reproductive traits.To address this gap,we investigated phenotypic variation in reproductive organs by examining 10 traits in 3.600 male catkins,3.600 female catkins,and seeds from 12 populations across the Moroccan Rif Mountains.Our results highlighted the significance of inter-population variability.However,we found that the contribution of within-tree variation to total phenotypic variability was greater than that of both inter-and intra-population variation.Principal component analysis(PCA)revealed a phenotypic gradient among populations,primarily driven by female catkin size,though this gradient was not associated with geographic conditions.This finding was further supported by Mantel test results,which showed no correlation between phenotypic variability and population conditions.These findings have important implications for the genetic improvement,conservation,and resource management of Alnus glutinosa in the future.
基金This study was supported by the Agencia Andaluza de Cooperación Internacional para el Desarrollo(AACID)and the project“Amélioration de la productivitédes cultures forestières d’intérêt socio-économiqueélevédans les zones rurales du nord du Maroc,n°2018004”.
文摘Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional agroecosystems.Several studies have focused on its morphological,biochemical,and genetic diversity.However,less is known about the intraspecific variation of seed traits.In this regard,and as an overall objective,we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical landscapes.In addition,we investigated how the climate along the study area affects the extent of carob seed variability.Using image analysis techniques,we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous C.siliqua distributed along a latitudinal transect in Morocco under different bioclimatic conditions.Results:The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic factors.Seed trait analysis revealed high intraspecific variability,explained by differences between and among carob populations and geographic zones.Seed area,perimeter,length,and width showed the largest variability between geographic zones.However,circularity,aspect ratio,and seed roundness showed higher variability at the tree level.Finally,our results show that seed traits vary depending on altitude and climate condition.Conclusions:Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological conditions.Therefore,intraspecific variation of seed traits should be integrated into trait‑based functional ecology to assess plant species responses to environmental changes.
