Forest management may have significant effects on forest connectivity and natural population sizes.Harvesting old-growth single trees may also change natural patterns of genetic variation and spatial genetic structure...Forest management may have significant effects on forest connectivity and natural population sizes.Harvesting old-growth single trees may also change natural patterns of genetic variation and spatial genetic structure.This study evaluated the impacts of forest management using a silvicultural system of seed trees on the genetic diversity and spatial genetic structure of Eremanthus erythropappus(DC.)MacLeish.A complete survey of 275 trees on four plots was undertaken out to compare the genetic variation of a managed stand with an unmanaged stand.We genotyped all adult and juvenile individuals 60 months after the management and compared the genetic diversity and the spatial genetic structure parameters.Genetic diversity was considered high because of an efficient gene flow between stands.There were no genetic differences between stands and no evidence of inbreeding.Genetic clustering identified a single population(K=1),indicating no genetic differentiation between managed and unmanaged stands.Adult and juvenile individuals of the unmanaged stand were more geographically structured than individuals from the managed one.There was a tendency of coancestry among juveniles at the first class of distance of the managed stand,suggesting a drift of genetic structure possibly caused by management.Understanding early responses to management on genetic diversity and stand structure is a first step to ensuring the effectiveness of conservation practices of tree species.The sustainability of forest management of E.erythropappus on genetic diversity,and more accurately,on spatial genetic structure needs evaluation over time to promote effective conservation of the population size and genetic variability.展开更多
Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures...Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures of tissue rejuvenation/reinvigoration in different propagated materials of Eucalyptus microcorys by analyzing the total protein profile,peroxidase activity,macro-and micronutrient contents,and adventitious rooting of mini cuttings.The analyses were performed on E.microcorys shoots which were successfully obtained by seminal and grafting propagation,micropropagation with epicormic shoots,and indirect organogenesis.Among four mature trees used in the propagation,tissues from the one with the best propagation results were investigated for signs of tissue rejuvenation and/or reinvigoration.Five individuals from each technique were randomly selected and transferred to a semi-hydroponic"channel"system.After four weeks in the seedbed,the total protein,peroxidase activity,nutrient content and rooting of the mini cuttings were evaluated.SDS-PAGE enabled the differentiation of leaf samples obtained by grafting from the other propagation techniques,as revealed by two distinct bands.Materials obtained by micropropagation with epicormic shoots showed the highest peroxidase activity,while those obtained by seminal propagation and from the selected mature tree showed the lowest peroxidase activity.A portable X-ray fluorescence spectroscope(pXRF)identified adequate nutrient content in most of the nutrients tested in materials obtained by seminal and grafting propagation,and by indirect organogenesis.The analysis of adventitious rooting showed that the highest rooting percentage was observed in mini cuttings from seminal propagation(75%)followed by indirect organogenesis(35%).Based on principal component analysis,it was concluded that rooting of mini cuttings from both seminal propagation and indirect organogenesis was associated with phosphorous,sulphur,and potassium contents,which suggests a higher level of tissue rejuvenation/reinvigoration in these propagated plants.Further studies are recommended to search for other methods that present similarities with the responses to adventitious rooting in forest species and thus optimize the rescue and propagation of plants with distinct ontogenetic stages.展开更多
基金supported by the Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)[CRA APQ-02641-14]in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil(CAPES)-Finance Code 001。
文摘Forest management may have significant effects on forest connectivity and natural population sizes.Harvesting old-growth single trees may also change natural patterns of genetic variation and spatial genetic structure.This study evaluated the impacts of forest management using a silvicultural system of seed trees on the genetic diversity and spatial genetic structure of Eremanthus erythropappus(DC.)MacLeish.A complete survey of 275 trees on four plots was undertaken out to compare the genetic variation of a managed stand with an unmanaged stand.We genotyped all adult and juvenile individuals 60 months after the management and compared the genetic diversity and the spatial genetic structure parameters.Genetic diversity was considered high because of an efficient gene flow between stands.There were no genetic differences between stands and no evidence of inbreeding.Genetic clustering identified a single population(K=1),indicating no genetic differentiation between managed and unmanaged stands.Adult and juvenile individuals of the unmanaged stand were more geographically structured than individuals from the managed one.There was a tendency of coancestry among juveniles at the first class of distance of the managed stand,suggesting a drift of genetic structure possibly caused by management.Understanding early responses to management on genetic diversity and stand structure is a first step to ensuring the effectiveness of conservation practices of tree species.The sustainability of forest management of E.erythropappus on genetic diversity,and more accurately,on spatial genetic structure needs evaluation over time to promote effective conservation of the population size and genetic variability.
基金supported by the Coordination for the Improvement of Higher Education Personnel–Brazil (CAPES)the National Council for Scientific and Technological Development (CNPq)the Research Support Foundation of the State of Minas (FAPEMIG)。
文摘Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures of tissue rejuvenation/reinvigoration in different propagated materials of Eucalyptus microcorys by analyzing the total protein profile,peroxidase activity,macro-and micronutrient contents,and adventitious rooting of mini cuttings.The analyses were performed on E.microcorys shoots which were successfully obtained by seminal and grafting propagation,micropropagation with epicormic shoots,and indirect organogenesis.Among four mature trees used in the propagation,tissues from the one with the best propagation results were investigated for signs of tissue rejuvenation and/or reinvigoration.Five individuals from each technique were randomly selected and transferred to a semi-hydroponic"channel"system.After four weeks in the seedbed,the total protein,peroxidase activity,nutrient content and rooting of the mini cuttings were evaluated.SDS-PAGE enabled the differentiation of leaf samples obtained by grafting from the other propagation techniques,as revealed by two distinct bands.Materials obtained by micropropagation with epicormic shoots showed the highest peroxidase activity,while those obtained by seminal propagation and from the selected mature tree showed the lowest peroxidase activity.A portable X-ray fluorescence spectroscope(pXRF)identified adequate nutrient content in most of the nutrients tested in materials obtained by seminal and grafting propagation,and by indirect organogenesis.The analysis of adventitious rooting showed that the highest rooting percentage was observed in mini cuttings from seminal propagation(75%)followed by indirect organogenesis(35%).Based on principal component analysis,it was concluded that rooting of mini cuttings from both seminal propagation and indirect organogenesis was associated with phosphorous,sulphur,and potassium contents,which suggests a higher level of tissue rejuvenation/reinvigoration in these propagated plants.Further studies are recommended to search for other methods that present similarities with the responses to adventitious rooting in forest species and thus optimize the rescue and propagation of plants with distinct ontogenetic stages.
