Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in...Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.展开更多
Studying the dynamics of plant populations is crucial to the conservation and management of endangered plants.The diameter at breast height(DBH),tree height,crown width,and environmental factors of a total of 15 plots...Studying the dynamics of plant populations is crucial to the conservation and management of endangered plants.The diameter at breast height(DBH),tree height,crown width,and environmental factors of a total of 15 plots in five populations in Guizhou Province,China were measured in this study.The method of substituting diameter at breast height for age was used to divide the population into 7 age classes.The age structure,static life table,and relationship between the population characteristics and environmental factors of the Litsea coreana Levl.var.sinensis population were studied.Moreover,the time series model was used to predict the population dynamics.Results showed that the age structure of population in Zhengan County(Population ZA)had an inverted Jshape with abundant seedlings and insufficient middle-aged and elderly individuals.The age structures of populations in Daozhen County(Population DZ),Kaiyang County(KY),Meitan County(Population MT),and Xishui County(Population XS)were spindle-shaped with few young individuals and many middle-aged and elderly individuals.The mortality rate of each population fluctuated with the increase in age class,and the populations were extremely unstable.The survival curve was close to the Deevey III type,and the degree of deviation was related to the lack of young individuals.After the age stages II,IV,and VI,the number of aged plants in the different populations initially increased then decreased,and population stability was difficult to maintain.Redundancy analysis showed that the DBH,tree height and crown width of the population decreased with the increase of annual mean temperature,and the population density was restricted by soil nutrient conditions to a certain extent.The results of this work provide scientific basis for the conservation and sustainable utilization of natural populations of L.coreana var.sinensis in Guizhou Province,China.展开更多
Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to divers...Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.展开更多
Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical...Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.展开更多
Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses...Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses that infect fruit trees.One of the best examples is papaya ringspot virus(PRSV).It belongs to the genus Potyvirus and it is limited to cause diseases on the family Chenopodiaceae,Cucurbitaceae and Caricaceae.This virus has a serious threat to the production of papaya,which is famous for its high nutritional and pharmaceutical values.The plant parts such as leaves,latex,seeds,fruits,bark,peel and roots may contain the biological compound that can be isolated and used in pharmaceutical industries as a disease control.Viral disease symptoms consist of vein clearing and yellowing of young leaves.Distinctive ring spot patterns with concentric rings and spots on fruit reduce its quality and taste.The virus has two major strains P and W.The former cause disease in papaya and cucurbits while the later one in papaya.Virion comprises 94.4%protein,including a 36 kDa coat protein which is a component responsible for a non-persistent transmission through aphids,and 5.5%nucleic acid.Cross protection,development of transgenic crops,exploring the resistant sources and induction of pathogen derived resistance have been recorded as effective management of PRSV.Along with these practices reduced aphid population through insecticides and plant extracts have been found ecofriendly approaches to minimize the disease incidence.Adoption of transgenic crops is a big challenge for the success of disease resistant papaya crops.The aim of this review is to understand the genomic nature of PRSV,detection methods and the different advanced control methods.This review article will be helpful in developing the best management strategies for controlling PRSV.展开更多
Phloem is the woody tissue for the storage and long-distance transport of organic matter in vascular bundles.To reveal the process of secondary phloem development and differentiation in Pinus massoniana,the structure ...Phloem is the woody tissue for the storage and long-distance transport of organic matter in vascular bundles.To reveal the process of secondary phloem development and differentiation in Pinus massoniana,the structure of the secondary phloem and the distribution of cell inclusions were observed by histochemical staining,spontaneous fluorescence of phenolic substances and cell segregation.Based on tissue development and differentiation characteristics of P.massoniana secondary phloem,the secondary phloem development was divided into seven stages:the functional phloem stage;the sieve cell lignification stage;the phloem ray bending stage;the parenchyma cell dedifferentiation and division stage;the dedifferentiated parenchyma cell population formation stage;the periderm alteration stage,and the rhytidome stage.An analysis of cell morphology and inclusion distribution characteristics showed that the sieve cells were deformed during lignification,the quantities of parenchyma and resin ducts increased with development and the crystal content in cells,as well as the levels of sugars and lipids in phloem parenchyma cells,increased with development.The results indicate that the P.massoniana phloem first lost longitudinal transport function and then increased its secretory,storage and mechanical functions.Ultimately,the parenchyma differentiated into the cortex and periderm,and the tissue outside the new periderm lignified to form the rhytidome,which fully developed into the protective tissue of the stem.展开更多
Background The prevalence of understory removal and anthropogenic nitrogen(N)deposition has significantly altered the ecological processes of forest ecosystems at both regional and global scales.However,it remains a p...Background The prevalence of understory removal and anthropogenic nitrogen(N)deposition has significantly altered the ecological processes of forest ecosystems at both regional and global scales.However,it remains a pressing challenge to understand how N deposition and understory removal affect leaf nutrient dynamics,nutrient resorption,litter decomposition,and their linkages for better managing forest ecosystems under nutrient imbalances induced by N enrichment.To address this research gap,a field manipulation experiment was carried out in a subtropical Cunninghamia lanceolata plantation with four treatments including:control(CK),canopy N addition(CN),understory removal(UR),and canopy N addition plus understory removal(CN×UR).Green and senesced leaf N and phosphorus(P)concentrations,N and P resorption efficiencies,litter decomposition,and their correlations were measured.Results The results revealed that the average N concentrations of green early and late leaves in UR were increased by 6.61 and 18.89%compared to CK.UR had the highest whereas CN had the lowest P concentrations in green leaves across the two sampling seasons.Following this,UR,leaf type,season,and their interactions significantly affected leaf N,P,and N:P(P<0.05).The highest leaf N resorption(32.68%)and P resorption efficiencies(63.96%)were recorded in UR.Litter decomposition was significantly retarded in UR(P<0.01)relative to CN.The regression analysis demonstrated that leaf nutrient status was significantly interconnected with leaf nutrient resorption efficiencies.In addition,leaf nutrient dynamics were strongly correlated with litter nutrients,indicating that both were coupled.Conclusion These findings can deepen our knowledge of biogeochemical cycling and reveal contrasting nutrientacquisition strategies on N and P limitation in response to UR and CN.Considering the P limitation,it is important to note that P was resorbed more efficiently,illustrating a remarkable nutrient preservation approach for nutrientlimitations.Resorption may be a crucial mechanism for keeping nutrients in these forests,so better understory management practices are required to prevent reliance on external nutrient pools.Overall,this study sheds meaningful insights into the ability of forest adaptation in response to global climatic change.展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant No.31870613)Guizhou Province High-level Innovative Talents Training Plan Project(2016)5661.
文摘Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.
基金supported by the National Natural Science Foundation of China(32060349)China Scholarship Council([2021]15)。
文摘Studying the dynamics of plant populations is crucial to the conservation and management of endangered plants.The diameter at breast height(DBH),tree height,crown width,and environmental factors of a total of 15 plots in five populations in Guizhou Province,China were measured in this study.The method of substituting diameter at breast height for age was used to divide the population into 7 age classes.The age structure,static life table,and relationship between the population characteristics and environmental factors of the Litsea coreana Levl.var.sinensis population were studied.Moreover,the time series model was used to predict the population dynamics.Results showed that the age structure of population in Zhengan County(Population ZA)had an inverted Jshape with abundant seedlings and insufficient middle-aged and elderly individuals.The age structures of populations in Daozhen County(Population DZ),Kaiyang County(KY),Meitan County(Population MT),and Xishui County(Population XS)were spindle-shaped with few young individuals and many middle-aged and elderly individuals.The mortality rate of each population fluctuated with the increase in age class,and the populations were extremely unstable.The survival curve was close to the Deevey III type,and the degree of deviation was related to the lack of young individuals.After the age stages II,IV,and VI,the number of aged plants in the different populations initially increased then decreased,and population stability was difficult to maintain.Redundancy analysis showed that the DBH,tree height and crown width of the population decreased with the increase of annual mean temperature,and the population density was restricted by soil nutrient conditions to a certain extent.The results of this work provide scientific basis for the conservation and sustainable utilization of natural populations of L.coreana var.sinensis in Guizhou Province,China.
基金funded by the Natural Science Foundation of Guizhou Province,P.R.China(20161051)the National Natural Science Foundation of China(31660185)the Doctoral Fund Project of Guizhou University,P.R.China(201464)。
文摘Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.
基金the National Natural Science Foundation of China(32060349)China Scholarship Council([2021]15)。
文摘Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.
文摘Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses that infect fruit trees.One of the best examples is papaya ringspot virus(PRSV).It belongs to the genus Potyvirus and it is limited to cause diseases on the family Chenopodiaceae,Cucurbitaceae and Caricaceae.This virus has a serious threat to the production of papaya,which is famous for its high nutritional and pharmaceutical values.The plant parts such as leaves,latex,seeds,fruits,bark,peel and roots may contain the biological compound that can be isolated and used in pharmaceutical industries as a disease control.Viral disease symptoms consist of vein clearing and yellowing of young leaves.Distinctive ring spot patterns with concentric rings and spots on fruit reduce its quality and taste.The virus has two major strains P and W.The former cause disease in papaya and cucurbits while the later one in papaya.Virion comprises 94.4%protein,including a 36 kDa coat protein which is a component responsible for a non-persistent transmission through aphids,and 5.5%nucleic acid.Cross protection,development of transgenic crops,exploring the resistant sources and induction of pathogen derived resistance have been recorded as effective management of PRSV.Along with these practices reduced aphid population through insecticides and plant extracts have been found ecofriendly approaches to minimize the disease incidence.Adoption of transgenic crops is a big challenge for the success of disease resistant papaya crops.The aim of this review is to understand the genomic nature of PRSV,detection methods and the different advanced control methods.This review article will be helpful in developing the best management strategies for controlling PRSV.
基金supported by the Guizhou provincial scientific and technological program 20185261。
文摘Phloem is the woody tissue for the storage and long-distance transport of organic matter in vascular bundles.To reveal the process of secondary phloem development and differentiation in Pinus massoniana,the structure of the secondary phloem and the distribution of cell inclusions were observed by histochemical staining,spontaneous fluorescence of phenolic substances and cell segregation.Based on tissue development and differentiation characteristics of P.massoniana secondary phloem,the secondary phloem development was divided into seven stages:the functional phloem stage;the sieve cell lignification stage;the phloem ray bending stage;the parenchyma cell dedifferentiation and division stage;the dedifferentiated parenchyma cell population formation stage;the periderm alteration stage,and the rhytidome stage.An analysis of cell morphology and inclusion distribution characteristics showed that the sieve cells were deformed during lignification,the quantities of parenchyma and resin ducts increased with development and the crystal content in cells,as well as the levels of sugars and lipids in phloem parenchyma cells,increased with development.The results indicate that the P.massoniana phloem first lost longitudinal transport function and then increased its secretory,storage and mechanical functions.Ultimately,the parenchyma differentiated into the cortex and periderm,and the tissue outside the new periderm lignified to form the rhytidome,which fully developed into the protective tissue of the stem.
基金funded by National Natural Science Foundation of China(Nos.32371733,31570444 and 32201368)the Xingdian Scholar Fund of Yunnan Provincethe Double Top University Fund of Yunnan University
文摘Background The prevalence of understory removal and anthropogenic nitrogen(N)deposition has significantly altered the ecological processes of forest ecosystems at both regional and global scales.However,it remains a pressing challenge to understand how N deposition and understory removal affect leaf nutrient dynamics,nutrient resorption,litter decomposition,and their linkages for better managing forest ecosystems under nutrient imbalances induced by N enrichment.To address this research gap,a field manipulation experiment was carried out in a subtropical Cunninghamia lanceolata plantation with four treatments including:control(CK),canopy N addition(CN),understory removal(UR),and canopy N addition plus understory removal(CN×UR).Green and senesced leaf N and phosphorus(P)concentrations,N and P resorption efficiencies,litter decomposition,and their correlations were measured.Results The results revealed that the average N concentrations of green early and late leaves in UR were increased by 6.61 and 18.89%compared to CK.UR had the highest whereas CN had the lowest P concentrations in green leaves across the two sampling seasons.Following this,UR,leaf type,season,and their interactions significantly affected leaf N,P,and N:P(P<0.05).The highest leaf N resorption(32.68%)and P resorption efficiencies(63.96%)were recorded in UR.Litter decomposition was significantly retarded in UR(P<0.01)relative to CN.The regression analysis demonstrated that leaf nutrient status was significantly interconnected with leaf nutrient resorption efficiencies.In addition,leaf nutrient dynamics were strongly correlated with litter nutrients,indicating that both were coupled.Conclusion These findings can deepen our knowledge of biogeochemical cycling and reveal contrasting nutrientacquisition strategies on N and P limitation in response to UR and CN.Considering the P limitation,it is important to note that P was resorbed more efficiently,illustrating a remarkable nutrient preservation approach for nutrientlimitations.Resorption may be a crucial mechanism for keeping nutrients in these forests,so better understory management practices are required to prevent reliance on external nutrient pools.Overall,this study sheds meaningful insights into the ability of forest adaptation in response to global climatic change.
