2012 Vol. 30 No. 2
2012, (2): 107-115.
DOI: 10.3724/SP.J.1142.2011.20107
Abstract：
The seed micromorphology of 36 taxa (including 35 species and one variety) from Eurya was investigated using scanning electron microscopy (SEM).Micromorphological cha-racters, including seed relative size (length譿idth, RS) and ornamentation of the seed-coat were investigated.Three seed sizes were recognized: (i) mini type (RS<1.0), (ii) middle type (1.03.0).The relative sizes of the smallest seeds were less than 0.5 mm2 and the largest seeds were more than 10 mm2.Two types of ornamentation of the seed-coat were described: (i) reticulate grain and (ii) negative net grain.The orientation, shape and depth of lumina, and the characters of muri varied among different species, which could be used to identify species.The systematic and phylogenetic implications of seed size and seed-coat micromorphology in the genus Eurya are discussed based on our results.The evolutionary route of seed-coat ornamentation is also conjectured.Our study showed that seed micromorphological characters provided useful data for studying the evolution of Eurya and formulating the phylogenetic positions of several key species in this genus.
The seed micromorphology of 36 taxa (including 35 species and one variety) from Eurya was investigated using scanning electron microscopy (SEM).Micromorphological cha-racters, including seed relative size (length譿idth, RS) and ornamentation of the seed-coat were investigated.Three seed sizes were recognized: (i) mini type (RS<1.0), (ii) middle type (1.0
2012, (2): 116-121.
DOI: 10.3724/SP.J.1142.2011.20116
Abstract：
Sequence-related amplified polymorphism (SRAP) was employed to analyze gene-tic relationships of 5 species of Pinellia in China. With 38 SRAP primer combinations,752 loci were identified, of which 628 were polymorphic and accounted for 83.51% of total amplified loci, showing a high polymorphism among Pinellia in China. The genetic similarity among the 5 species ranged from 0.6513 to 0.7312. Based on the results of cluster and principal coordinate analysis, the 5 species were divided into two groups. P.ternata, P.cordata, P.integrifolia, and P.peltata were clustered into group Ⅰ, while P.pedatisecta was in group Ⅱ. Group Ⅰ comprised two subgroups, namely subgroup A and B.Both P.ternata and P.integrifolia were clustered into subgroup A, while P.cordata and P.peltata were clustered into subgroup B. These results suggest that P.cordata had the closest genetic relationship with P.peltata, and P.ternata was closely related to P.integrifolia. Pinellia pedatisecta was a sister group to the other four species. The results of this research might be useful for guiding exploitation and preservation of Pinellia in China.
Sequence-related amplified polymorphism (SRAP) was employed to analyze gene-tic relationships of 5 species of Pinellia in China. With 38 SRAP primer combinations,752 loci were identified, of which 628 were polymorphic and accounted for 83.51% of total amplified loci, showing a high polymorphism among Pinellia in China. The genetic similarity among the 5 species ranged from 0.6513 to 0.7312. Based on the results of cluster and principal coordinate analysis, the 5 species were divided into two groups. P.ternata, P.cordata, P.integrifolia, and P.peltata were clustered into group Ⅰ, while P.pedatisecta was in group Ⅱ. Group Ⅰ comprised two subgroups, namely subgroup A and B.Both P.ternata and P.integrifolia were clustered into subgroup A, while P.cordata and P.peltata were clustered into subgroup B. These results suggest that P.cordata had the closest genetic relationship with P.peltata, and P.ternata was closely related to P.integrifolia. Pinellia pedatisecta was a sister group to the other four species. The results of this research might be useful for guiding exploitation and preservation of Pinellia in China.
2012, (2): 122-132.
DOI: 10.3724/SP.J.1142.2012.20122
Abstract：
Based on field investigation and identification of 2198 collected samples,302 species (including infraspecific taxa) belonging to 130 genera of 47 families in Daiyunshan National Nature Reserve were identified, among which 3 families, 11 genera, and 74 species were new records to Fujian province. The moss flora of Daiyunshan was characterized by sub-tropical elements.The total elements dominated by East Asia type,representing 33.33% of the entire species,followed by Tropical Asia element (22.22%) and North Temperate element (16.67%).The result showed that Daiyunshan had more characteristics of Linnan Region through the comparsion of the moss flora of Daiyunshan with Yushan (Taiwan province),Yangjifeng (Jiangxi province),Dapanshan (Zhejiang province),Maoershan (Guangxi pro-vince),Jiuwanshan (Guangxi province),Eastern Jiufengshan (Fujian province),Daweishan (Yunnan province) and Emeishan (Sichuan province).Cluster Analysis of these 9 regions showed that Daiyunshan was closer to Maoershan,Jiuwanshan,Daweishan from Lingnan Region,and nearby Emeishan.Therefore,we suggest that the boundaries between Lingnan Region and East China Region should be slightly moved northward.
Based on field investigation and identification of 2198 collected samples,302 species (including infraspecific taxa) belonging to 130 genera of 47 families in Daiyunshan National Nature Reserve were identified, among which 3 families, 11 genera, and 74 species were new records to Fujian province. The moss flora of Daiyunshan was characterized by sub-tropical elements.The total elements dominated by East Asia type,representing 33.33% of the entire species,followed by Tropical Asia element (22.22%) and North Temperate element (16.67%).The result showed that Daiyunshan had more characteristics of Linnan Region through the comparsion of the moss flora of Daiyunshan with Yushan (Taiwan province),Yangjifeng (Jiangxi province),Dapanshan (Zhejiang province),Maoershan (Guangxi pro-vince),Jiuwanshan (Guangxi province),Eastern Jiufengshan (Fujian province),Daweishan (Yunnan province) and Emeishan (Sichuan province).Cluster Analysis of these 9 regions showed that Daiyunshan was closer to Maoershan,Jiuwanshan,Daweishan from Lingnan Region,and nearby Emeishan.Therefore,we suggest that the boundaries between Lingnan Region and East China Region should be slightly moved northward.
2012, (2): 133-140.
DOI: 10.3724/SP.J.1142.2012.20133
Abstract：
The effect of forest gap disturbance on the diversity and stability of species in the regeneration layers of natural Castanopsis kawakamii forest were studied by applying biodiversity indices and improved M.Godron’s stability methods in C.kawakamii natural reserve.The results showed that: forest gap disturbance improved its micro-environment,as reflected in the differences in importance values and biodiversity in the tree and shrub layers of forest gap and understory.The biodiversity indices of richness index R,domination index D,Shannon-Wiener diversity index H,and evenness-dominance-abundance index Z in the forest gap tree layer were higher than those of the forest understory,while evenness index Js and community domi- nance C were lower than those of the forest understory.The biodiversity indices of R, D, H, Js, and Z in the forest gap shrub layer were higher than those of the forest understory,while C were lower than those of forest understory.Biodiversity in the forest gap was richer with less evident ecological dominant species,which indicated that the population in the forest gap was developing in the direction of complexity and homogeneity.The similarity coefficients of Cj, Cs, and CN were relatively low,while CmH was relatively high in the tree layer of the forest gap and understory,which demonstrated that the forest gap promoted the regeneration of trees.The similarity coefficients of Cj, Cs, CN, and CmH were relatively high without exception and the species composition in the forest gap were basically identical with those of the understory.According to the theory of M.Godron and the simulated the optimum stability model,the logarithm model and quadratic objective function model were the best stability models in tree layer of the forest gap and understory, respectively,and the optimum stability model of the shrub layer in both the forest gap and understory was the logarithm model.The plants in the tree layer of the forest gap were stable,but were unstable in the understory.The plants in the shrub layer of both the forest gap and understory were stable.The importance value of Litsea subcoriacea was the highest in the tree layer of the forest gap and understory,which showed that it played an important role in forest regeneration and would likely have a greater impact on the regeneration of C.kawakamii population.The importance value of C.kawakamii was relatively low in the tree layer of the forest understory,which impacted its regeneration.However,forest gap di-sturbance improved the upward growth and importance value of C.kawakamii,which could achieve the regeneration and restoration of the C.kawakamii population effectively.
The effect of forest gap disturbance on the diversity and stability of species in the regeneration layers of natural Castanopsis kawakamii forest were studied by applying biodiversity indices and improved M.Godron’s stability methods in C.kawakamii natural reserve.The results showed that: forest gap disturbance improved its micro-environment,as reflected in the differences in importance values and biodiversity in the tree and shrub layers of forest gap and understory.The biodiversity indices of richness index R,domination index D,Shannon-Wiener diversity index H,and evenness-dominance-abundance index Z in the forest gap tree layer were higher than those of the forest understory,while evenness index Js and community domi- nance C were lower than those of the forest understory.The biodiversity indices of R, D, H, Js, and Z in the forest gap shrub layer were higher than those of the forest understory,while C were lower than those of forest understory.Biodiversity in the forest gap was richer with less evident ecological dominant species,which indicated that the population in the forest gap was developing in the direction of complexity and homogeneity.The similarity coefficients of Cj, Cs, and CN were relatively low,while CmH was relatively high in the tree layer of the forest gap and understory,which demonstrated that the forest gap promoted the regeneration of trees.The similarity coefficients of Cj, Cs, CN, and CmH were relatively high without exception and the species composition in the forest gap were basically identical with those of the understory.According to the theory of M.Godron and the simulated the optimum stability model,the logarithm model and quadratic objective function model were the best stability models in tree layer of the forest gap and understory, respectively,and the optimum stability model of the shrub layer in both the forest gap and understory was the logarithm model.The plants in the tree layer of the forest gap were stable,but were unstable in the understory.The plants in the shrub layer of both the forest gap and understory were stable.The importance value of Litsea subcoriacea was the highest in the tree layer of the forest gap and understory,which showed that it played an important role in forest regeneration and would likely have a greater impact on the regeneration of C.kawakamii population.The importance value of C.kawakamii was relatively low in the tree layer of the forest understory,which impacted its regeneration.However,forest gap di-sturbance improved the upward growth and importance value of C.kawakamii,which could achieve the regeneration and restoration of the C.kawakamii population effectively.
2012, (2): 141-146.
DOI: 10.3724/SP.J.1142.2012.20141
Abstract：
Neighbor effects of three dominant species Cyclobalanopsis glauca,Castanopsis eyrei and Quercus serrata var.brevipetiolata in an old-growth evergreen-deciduous mixed forest in Jiugongshan Natural Reserve were examined by nearest neighbor distance statistics,and the importance of competition/facilitation and implications for local species co-existence were explored.There were no lower limits of nearest neighbor distance for any species.The size (e.x.DBH) of Cyclobalanopsis glauca was positively correlated with its intraspecific nearest neighbor distance (p=0.029),but the size of Quercus serrata var.brevipetiolata was negatively correlated with its interspecific nearest neighbor distance (p= 0.040).No significant correlations were detected between size of Castanopsis eyrei and either of its interspeci-fic/intraspecific nearest neighbor distance (p≥0.360).Intraspecific nearest neighbor distances differed insignificant from interspecific ones for all species (p≥ 0.122).Our results imply that local competition has not been fully sharpened in the old-growth evergreen-deciduous mixed forest in Jiugongshan Natural Reserve.Neighbor effects were species-specific,with intraspecific competition in Cyclobalanopsis glauca being evident,competitive/facilitative effects of Castanopsis eyrei unobvious if not negligible,and dependence of Quercus serrata var.brevipetiolata on interspecific facilitation over competition.The insignificant differences between interspecific and intraspecific nearest neighbor distance for all species suggest that stochastic processes rather than negative density-dependent processes drove local species co-exis-tence.
Neighbor effects of three dominant species Cyclobalanopsis glauca,Castanopsis eyrei and Quercus serrata var.brevipetiolata in an old-growth evergreen-deciduous mixed forest in Jiugongshan Natural Reserve were examined by nearest neighbor distance statistics,and the importance of competition/facilitation and implications for local species co-existence were explored.There were no lower limits of nearest neighbor distance for any species.The size (e.x.DBH) of Cyclobalanopsis glauca was positively correlated with its intraspecific nearest neighbor distance (p=0.029),but the size of Quercus serrata var.brevipetiolata was negatively correlated with its interspecific nearest neighbor distance (p= 0.040).No significant correlations were detected between size of Castanopsis eyrei and either of its interspeci-fic/intraspecific nearest neighbor distance (p≥0.360).Intraspecific nearest neighbor distances differed insignificant from interspecific ones for all species (p≥ 0.122).Our results imply that local competition has not been fully sharpened in the old-growth evergreen-deciduous mixed forest in Jiugongshan Natural Reserve.Neighbor effects were species-specific,with intraspecific competition in Cyclobalanopsis glauca being evident,competitive/facilitative effects of Castanopsis eyrei unobvious if not negligible,and dependence of Quercus serrata var.brevipetiolata on interspecific facilitation over competition.The insignificant differences between interspecific and intraspecific nearest neighbor distance for all species suggest that stochastic processes rather than negative density-dependent processes drove local species co-exis-tence.
2012, (2): 147-152.
DOI: 10.3724/SP.J.1142.2012.20147
Abstract：
The chromosomes of 18 populations of Viola inconspicua Blume polyploid complex were observed. The chromosome numbers of 4 populations were 2n= 4x= 24,and 14 populations were 2n= 8x= 48.The distribution of tetraploid and octaploid populations of V.inconspicua is discussed,as is the origin of octaploid and the reason for the distribution is conjectured.
The chromosomes of 18 populations of Viola inconspicua Blume polyploid complex were observed. The chromosome numbers of 4 populations were 2n= 4x= 24,and 14 populations were 2n= 8x= 48.The distribution of tetraploid and octaploid populations of V.inconspicua is discussed,as is the origin of octaploid and the reason for the distribution is conjectured.
2012, (2): 153-160.
DOI: 10.3724/SP.J.1142.2012.20153
Abstract：
Magnolia sieboldii is placed in the third class in rank of key species for conservation in China.To determine their living status,reproductive potential,ecological countermeasures and provide a theoretical basis for the conservation of this endangered plant,this paper studies the species’ dynamics and reproductive strategy of the endangered plant in four sampling sites using age class,fecundity schedule and reproductive value.The results showed that: (1) Magnolia sieboldii seedlings were less (8.8-12.3 individual/100 m2),while the number of middle aged individuals (12.0-15.0 individual /100 m2) was more than other plants. (2) The population fecundities were low and differed in the four plots,with the lowest fecundity (177.0 seed/individual) in better habitat and the highest (218.3 seed/individual) in poor habitat.(3) The maximum reproductive value increased with decreasing stability of the community,which often led to Magnolia sieboldii reaching maximum reproductive stage in poor habitat at the shortest time.(4) Ecological countermeasures of Magnolia sieboldii showed mainly the k-strategy characteristics,but in less stable community the reproductive parameters were greatly changed,showing an r-strategy characteristics.(5) Altitude,slope aspect,canopy density,and percentage of exposed rock,significantly affected the reproductive index of Magnolia sieboldii.Stepwise regression analysis showed that multiple linear relationships appeared between reproductive index of Magnolia sieboldii and environment factors, removed the moisture content of soil and litter layer.
Magnolia sieboldii is placed in the third class in rank of key species for conservation in China.To determine their living status,reproductive potential,ecological countermeasures and provide a theoretical basis for the conservation of this endangered plant,this paper studies the species’ dynamics and reproductive strategy of the endangered plant in four sampling sites using age class,fecundity schedule and reproductive value.The results showed that: (1) Magnolia sieboldii seedlings were less (8.8-12.3 individual/100 m2),while the number of middle aged individuals (12.0-15.0 individual /100 m2) was more than other plants. (2) The population fecundities were low and differed in the four plots,with the lowest fecundity (177.0 seed/individual) in better habitat and the highest (218.3 seed/individual) in poor habitat.(3) The maximum reproductive value increased with decreasing stability of the community,which often led to Magnolia sieboldii reaching maximum reproductive stage in poor habitat at the shortest time.(4) Ecological countermeasures of Magnolia sieboldii showed mainly the k-strategy characteristics,but in less stable community the reproductive parameters were greatly changed,showing an r-strategy characteristics.(5) Altitude,slope aspect,canopy density,and percentage of exposed rock,significantly affected the reproductive index of Magnolia sieboldii.Stepwise regression analysis showed that multiple linear relationships appeared between reproductive index of Magnolia sieboldii and environment factors, removed the moisture content of soil and litter layer.
2012, (2): 161-168.
DOI: 10.3724/SP.J.1142.2012.20161
Abstract：
We investigated changes in soil nutrients in different eroded soils in Pinus massoniana forest ecosystems in Changting County,Fujian Province,by field investigation and laboratory analysis.Our results showed that soil erosion significantly changed soil organic matter (OM),available nitrogen (AN),total potassium (TK),available potassium (AK),and pH,but did not significantly affect available phosphorus (AP).Soil OM and AN decreased with increasing soil erosion from mid-level eroded soils in Pinus massoniana forest ecosystems due to a decline in plant coverage,while TK and AK increased with increasing soil erosion across the whole-level eroded soils.Soil AP did not significantly change with increasing soil erosion.Soil pH value increased with increasing soil erosion and soil depth.Pearson correlation analysis indicated that OM was related to AN,TK,and pH.Although soil erosion was a critical control on soil nutrients,grey relational analysis showed that the slope had a great influence on all the soil nutrients and pH,and the plant coverage was important for OM,AN and AP.Our results suggested that plant restoration and comprehensive management of habitat would be an effective approach for recovering red soil erosion.
We investigated changes in soil nutrients in different eroded soils in Pinus massoniana forest ecosystems in Changting County,Fujian Province,by field investigation and laboratory analysis.Our results showed that soil erosion significantly changed soil organic matter (OM),available nitrogen (AN),total potassium (TK),available potassium (AK),and pH,but did not significantly affect available phosphorus (AP).Soil OM and AN decreased with increasing soil erosion from mid-level eroded soils in Pinus massoniana forest ecosystems due to a decline in plant coverage,while TK and AK increased with increasing soil erosion across the whole-level eroded soils.Soil AP did not significantly change with increasing soil erosion.Soil pH value increased with increasing soil erosion and soil depth.Pearson correlation analysis indicated that OM was related to AN,TK,and pH.Although soil erosion was a critical control on soil nutrients,grey relational analysis showed that the slope had a great influence on all the soil nutrients and pH,and the plant coverage was important for OM,AN and AP.Our results suggested that plant restoration and comprehensive management of habitat would be an effective approach for recovering red soil erosion.
2012, (2): 169-177.
DOI: 10.3724/SP.J.1142.2012.20169
Abstract：
The organization patterns of 18S-25S rRNA gene (45S rDNA) in the meristematic cells of ten plants belonging to five families were comparatively analyzed using fluorescence in situ hybridization (FISH).The 45S rDNA probe produced two types of signals in the interphase nuclei of all tested species: strongly fluorescing perinucleolar knobs and weakly fluorescing intranucleolar spots,indicating the existence of similar organization patterns of rDNA chromatin at interphase in higher plants.The spots associated with or emanating from the knobs were observed in a portion of the interphase nuclei in each tested species.It was obvious that the more spots produced,the smaller the knobs became,and the number of spots was positively correlated with the activity of the cell.These findings indicated that the spots resulted from the decondensation of knobs,the decondensation of rDNA heterochromatin was the cytogenetic ma-nifestation of active rRNA gene transcription,and the number of spots represented the degree of transcription activity of rRNA gene at interphase.Our results supported the speculation that these spots were the structural units in the organization of active ribosomal genes and the sites that rRNA synthesis took place.Our results also revealed some differences in the organization of rDNA chromatin at interphase among species.The maximal number of spots in the nucleolus differed considerably among the tested species.In prometaphase cells of each tested species,the rDNA sites displayed incompact signal blocks and many spots by FISH with rDNA probe,indicating an active rDNA transcription during prometaphase.
The organization patterns of 18S-25S rRNA gene (45S rDNA) in the meristematic cells of ten plants belonging to five families were comparatively analyzed using fluorescence in situ hybridization (FISH).The 45S rDNA probe produced two types of signals in the interphase nuclei of all tested species: strongly fluorescing perinucleolar knobs and weakly fluorescing intranucleolar spots,indicating the existence of similar organization patterns of rDNA chromatin at interphase in higher plants.The spots associated with or emanating from the knobs were observed in a portion of the interphase nuclei in each tested species.It was obvious that the more spots produced,the smaller the knobs became,and the number of spots was positively correlated with the activity of the cell.These findings indicated that the spots resulted from the decondensation of knobs,the decondensation of rDNA heterochromatin was the cytogenetic ma-nifestation of active rRNA gene transcription,and the number of spots represented the degree of transcription activity of rRNA gene at interphase.Our results supported the speculation that these spots were the structural units in the organization of active ribosomal genes and the sites that rRNA synthesis took place.Our results also revealed some differences in the organization of rDNA chromatin at interphase among species.The maximal number of spots in the nucleolus differed considerably among the tested species.In prometaphase cells of each tested species,the rDNA sites displayed incompact signal blocks and many spots by FISH with rDNA probe,indicating an active rDNA transcription during prometaphase.
2012, (2): 178-187.
DOI: 10.3724/SP.J.1142.2012.20178
Abstract：
To clarify the genetic relationship of 96 jute (Corchorus L.) accessions including 6 species from 13 countries,sequence-related amplified polymorphism (SRAP) molecular mar-kers were used in the present study.The results showed that: (1) Genetic distance of 96 jute germplasms exhibited a large variation from 0.0169 to 0.9667,among which the relative wild species had the largest genetic distance with other germplasms,while the C.capsularis cultivars had the least genetic distance with others.(2) All 96 germplasms were classified into 3 groups and 5 unique types at the level of L1=0.53.(3) Each group was classified into different sub-groups at the level of L2=0.33,which showed classification according to their origins.(4) The classification of jute germplasms based on SRAP markers did not necessarily show a relationship with morphological performance.
To clarify the genetic relationship of 96 jute (Corchorus L.) accessions including 6 species from 13 countries,sequence-related amplified polymorphism (SRAP) molecular mar-kers were used in the present study.The results showed that: (1) Genetic distance of 96 jute germplasms exhibited a large variation from 0.0169 to 0.9667,among which the relative wild species had the largest genetic distance with other germplasms,while the C.capsularis cultivars had the least genetic distance with others.(2) All 96 germplasms were classified into 3 groups and 5 unique types at the level of L1=0.53.(3) Each group was classified into different sub-groups at the level of L2=0.33,which showed classification according to their origins.(4) The classification of jute germplasms based on SRAP markers did not necessarily show a relationship with morphological performance.
2012, (2): 188-192.
DOI: 10.3724/SP.J.1142.2012.20188
Abstract：
Embryo sac development in Phaius tankervilliae(Aiton)Bl.was observed under transmission electron microscope.Three phases of functional megaspore and two phases of mature embryo sac were captured in this study.At the functional megaspore and 4-nucleate embryo sac stages,plasmodesmata were present between nucellar cells and embryo sac at the chalazal end.Plasmodesmata are cellular communicating junctions that link adjacent cells to form symplast of a plant.They provide a direct channel for material transport and signal transduction,therefore megagametogenesis is not at an absolutely insulated situation.A big vacuole was observed at the early stage of functional megaspore before it disappeared during the first mitotic division.However,many small vacuoles appeared at the interspaces of separating chromosomes.Distinct vacuoles were also observed in the synergid cells and egg cell during the early stage of mature embryo sac,but vanished when synergid cells degenerated.The change of vacuoles probably resulted from the cell physiological change.Our results may provide insights into reproductive biology of Phaius tankervilliae.
Embryo sac development in Phaius tankervilliae(Aiton)Bl.was observed under transmission electron microscope.Three phases of functional megaspore and two phases of mature embryo sac were captured in this study.At the functional megaspore and 4-nucleate embryo sac stages,plasmodesmata were present between nucellar cells and embryo sac at the chalazal end.Plasmodesmata are cellular communicating junctions that link adjacent cells to form symplast of a plant.They provide a direct channel for material transport and signal transduction,therefore megagametogenesis is not at an absolutely insulated situation.A big vacuole was observed at the early stage of functional megaspore before it disappeared during the first mitotic division.However,many small vacuoles appeared at the interspaces of separating chromosomes.Distinct vacuoles were also observed in the synergid cells and egg cell during the early stage of mature embryo sac,but vanished when synergid cells degenerated.The change of vacuoles probably resulted from the cell physiological change.Our results may provide insights into reproductive biology of Phaius tankervilliae.
2012, (2): 193-197.
DOI: 10.3724/SP.J.1142.2012.20193
Abstract：
After exposing fully expanded poplar (Populus alba L.) leaves to continuous irradiation,the photosynthetic rate and isoprene emissions increased.Continuous irradiation also enhanced the levels of total respiration and the capacities of the cytochrome and alternative respiratory pathways.Pretreatments with cytochrome and alternative respiratory pathways inhibitors,salicylhydroxamic acid and KCN,decreased the photosynthetic rate and isoprene emissions.These treatments also decreased the immediate quantum yield of PSⅡ electron transport and photochemical quenching.These results suggest that respiration plays a role in mediating photosynthesis and isoprene emissions.
After exposing fully expanded poplar (Populus alba L.) leaves to continuous irradiation,the photosynthetic rate and isoprene emissions increased.Continuous irradiation also enhanced the levels of total respiration and the capacities of the cytochrome and alternative respiratory pathways.Pretreatments with cytochrome and alternative respiratory pathways inhibitors,salicylhydroxamic acid and KCN,decreased the photosynthetic rate and isoprene emissions.These treatments also decreased the immediate quantum yield of PSⅡ electron transport and photochemical quenching.These results suggest that respiration plays a role in mediating photosynthesis and isoprene emissions.
2012, (2): 198-203.
DOI: 10.3724/SP.J.1142.2012.20198
Abstract：
To study the heat tolerance of chrysanthemum (Chrysanthemum morifolium),the electrical impedance spectroscopy (EIS) parameters of chrysanthemum'Jinba’stems and leaves under high temperature stress (25℃ to 50℃) were measured,and the relationship between electrolyte leakage (relative conductivity) and EIS parameters was analyzed.The results showed that extracellular resistance, intracellular resistance,and relaxation time of stems and leaves first increased and then decreased significantly with increasing temperature. However,the trends of distribution coefficient of relaxation time of stems and leaves showed irregular decrease under high temperature stress.The relative conductivity of chrysanthmum increased,then decreased,and finally increased significantly. Heat tolerance of chrysanthemum estimated by EIS parameters was close to that assessed by the EL method.Significant correlation between relative conductivity and extracellular resistance (stem: p<0.01,leaf p<0.05) and relaxation time (p<0.05) of stem and leaf were found.In conclusion,extracellular resistance and relaxation time could be suitable parameters for determining heat tolerance of chrysanthemum.
To study the heat tolerance of chrysanthemum (Chrysanthemum morifolium),the electrical impedance spectroscopy (EIS) parameters of chrysanthemum'Jinba’stems and leaves under high temperature stress (25℃ to 50℃) were measured,and the relationship between electrolyte leakage (relative conductivity) and EIS parameters was analyzed.The results showed that extracellular resistance, intracellular resistance,and relaxation time of stems and leaves first increased and then decreased significantly with increasing temperature. However,the trends of distribution coefficient of relaxation time of stems and leaves showed irregular decrease under high temperature stress.The relative conductivity of chrysanthmum increased,then decreased,and finally increased significantly. Heat tolerance of chrysanthemum estimated by EIS parameters was close to that assessed by the EL method.Significant correlation between relative conductivity and extracellular resistance (stem: p<0.01,leaf p<0.05) and relaxation time (p<0.05) of stem and leaf were found.In conclusion,extracellular resistance and relaxation time could be suitable parameters for determining heat tolerance of chrysanthemum.
2012, (2): 204-212.
DOI: 10.3724/SP.J.1142.2012.20204
Abstract：
Jatropha curcas L.is an energy plant of the Euphorbiaceae family.Using seeds and seedlings of J.curcas as materials,the effect of different concentrations of gibberellin or calcium treatment,or combination treatment of different concentrations of gibberellin,calcium, and betaine on seed germination and resistance of seedlings to low temperature or drought stress were investigated.The application of 10 mg/L gibberellin or 10 mmol/L calcium not only improved germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),but also alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000) compared with the control. In addition,combination treatments with 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine also enhanced germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),and alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000),illustrating that treatment with 10 mg/L gibberellin or 10 mmol/L calcium,or combination treatments of 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine increased germination percentage of J.curcas seeds under low temperature and drought stress,and resistance of seedlings to low temperature or drought stress.
Jatropha curcas L.is an energy plant of the Euphorbiaceae family.Using seeds and seedlings of J.curcas as materials,the effect of different concentrations of gibberellin or calcium treatment,or combination treatment of different concentrations of gibberellin,calcium, and betaine on seed germination and resistance of seedlings to low temperature or drought stress were investigated.The application of 10 mg/L gibberellin or 10 mmol/L calcium not only improved germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),but also alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000) compared with the control. In addition,combination treatments with 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine also enhanced germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),and alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000),illustrating that treatment with 10 mg/L gibberellin or 10 mmol/L calcium,or combination treatments of 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine increased germination percentage of J.curcas seeds under low temperature and drought stress,and resistance of seedlings to low temperature or drought stress.
