The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of wate...The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of water was investigated. It established the reduction of seed germination both under direct and indirect effects due to water action of attenuated geomagnetic field. A negative effect of hypomagnetic field on grown characteristics of seeds under indirect effect via water was decreased by the low doses of γ-irradiation, and was increased by low doses of α-irradiation, i.e. ionized radiation was the dominant factor in their combined action. It was revealed the increasing of the value of the oxidation-reduction potential of water under the influence of low-intensive α-ir-radiation (239Pu), γ-irradiation (137Cs) and also that the magnetic induction attenuated pointing to a natural decline. The increasing of the oxidation-reduction potential value testifies about “the regular decreasing of internal energy of water molecules” and the increasing of its oxidative properties, which, in our opinion, is caused the inhibition of the germination of seeds. It is supposed that namely water is the main component in the effects of studying factors on bio-objects, which acts due to the alterations of the properties and structural content of water.展开更多
Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors a...Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.展开更多
The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size.This technique used plant seeds to array templates and centrifugal slip casting to obta...The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size.This technique used plant seeds to array templates and centrifugal slip casting to obtain cell struts with high packing density.Aqueous Al2O3-ZrO2 slurries with up to 50 vol.% solid contents were prepared and the rheological characteristic of the slurries was investigated.Consolidation was performed at an acceleration of 2,860 g for 60 min.The effect of the characteristic of plant seeds on the drying behavior of Al2O3-ZrO2 green compact was analyzed.The effects of the solid contents of slurries on segregation phenomena of Al2O3 and ZrO2 particles and green compact uniformity were investigated.The compressive stress-strain curve and deformation behavior of Al2O3-ZrO2 ceramic foams prepared using plant seed template were analyzed.The results showed segregation phenomenon is negligible for highly stable slurry with 50 vol.% solid loading.The prepared cell struts of Al2O3-ZrO2 foams have high green density (61.9% TD), sintered density (99.1% TD) and homogeneous microstructure.When sintered at 1,550 ℃ for 2 h, the cell size of Al2O3-ZrO2 foam is approximately uniform and the diameter is about 1.1 mm.The porosity and compressive strength of sintered products is 66.2% and 5.86 MPa, respectively.展开更多
A fragile political pact in Zimbabwe allows for a glimmer of optimism in agricultura and economic growth KNOWN,in the past,as the bread basket of Southern Africa, Zimbabwe’s economic stability and agricultural streng...A fragile political pact in Zimbabwe allows for a glimmer of optimism in agricultura and economic growth KNOWN,in the past,as the bread basket of Southern Africa, Zimbabwe’s economic stability and agricultural strength was a reference point for most people involved in Africa.For over 10 years the situation changed.President Robert Mugabe’s decision in 2000 to redistribute the land to the black population saw the country lose about $12 billion in agricultural output. The Commercial Farmer’s Union said that previous to展开更多
The tropical Asian and Australasian floras have a close relationship,and is a vital distribution pattern of seed plants worldwide.As estimated,more than 81 families and 225 genera of seed plants distributed between tr...The tropical Asian and Australasian floras have a close relationship,and is a vital distribution pattern of seed plants worldwide.As estimated,more than 81 families and 225 genera of seed plants distributed between tropical Asia and Australasia.However,the evolutionary dynamics of two floras were still vague.Here,a total of 29 plant lineages,represented the main clades of seed plants and different habits,were selected to investigate the biotic interchange between tropical Asia and Australasia by integrated dated phylogenies,biogeography,and ancestral state reconstructions.Our statistics indicated that 68 migrations have occurred between tropical Asia and Australasia since the middle Eocene except terminal migrations,and the migration events from tropical Asia to Australasia is more than 2 times of the reverse.Only 12 migrations occurred before 15 Ma,whereas the remaining56 migrations occurred after 15 Ma.Maximal number of potential dispersal events(MDE) analysis also shows obvious asymmetry,with southward migration as the main feature,and indicates the climax of bi-directional migrations occurred after 15 Ma.We speculate that the formation of island chains after the Australian-Sundaland collision and climate changes have driven seed plant migrations since the middle Miocene.Furthermore,biotic dispersal and stable habitat may be crucial for floristic interchange between tropical Asia and Australasia.展开更多
Large-scale patterns of biodiversity and the underlying mechanisms that regulate these patterns are central topics in biogeography and macroecology.The Qinghai-Tibet Plateau serves as a natural laboratory for studying...Large-scale patterns of biodiversity and the underlying mechanisms that regulate these patterns are central topics in biogeography and macroecology.The Qinghai-Tibet Plateau serves as a natural laboratory for studying these issues.However,most previous studies have focused on the entire Qinghai-Tibet Plateau,leaving independent physical geographic subunits in the region less well understood.We studied the current plant diversity of the Kunlun Mountains,an independent physical geographic subunit located in northwestern China on the northern edge of the Qinghai-Tibet Plateau.We integrated measures of species distribution,geological history,and phylogeography,and analyzed the taxonomic richness,phylogenetic diversity,and community phylogenetic structure of the current plant diversity in the area.The distribution patterns of 1911 seed plants showed that species were distributed mainly in the eastern regions of the Kunlun Mountains.The taxonomic richness,phylogenetic diversity,and genera richness showed that the eastern regions of the Kunlun Mountains should be the priority area of biodiversity conservation,particularly the southeastern regions.The proportion of Chinese endemic species inhabiting the Kunlun Mountains and their floristic similarity may indicate that the current patterns of species diversity were favored via species colonization.The Hengduan Mountains,a biodiversity hotspot,is likely the largest source of species colonization of the Kunlun Mountains after the Quaternary.The net relatedness index indicated that 20 of the 28 communities examined were phylo-genetically dispersed,while the remaining communities were phylogenetically clustered.The nearest taxon index indicated that 27 of the 28 communities were phylogenetically clustered.These results suggest that species colonization and habitat filtering may have contributed to the current plant diversity of the Kunlun Mountains via ecological and evolutionary processes,and habitat filtering may play an important role in this ecological process.展开更多
Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance...Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance using molecular marker-assisted selection is able to facilitate the development of drought-tolerant soybean varieties.In this study,we used a high-yielding and drought-sensitive cultivar‘Zhonghuang 35’and a drought-tolerant cultivar‘Jindou 21’to establish F6:9 recombinant inbred lines.We constructed a highdensity genetic map using specific locus amplified fragment sequencing(SLAF-Seq)technology.The genetic map contained 8078 SLAF markers distributing across 20 soybean chromosomes with a total genetic distance of 3780.98 c M and an average genetic distance of0.59 c M between adjacent markers.Two treatments(irrigation and drought)were used in the field tests,the Additive-Inclusive Composite Interval Mapping(ICIM-ADD)was used to call QTL,and plant height and seed weight per plant were used as the indicators of drought tolerance.We identified a total of 23 QTL related to drought tolerance.Among them,seven QTL(q PH2,q PH6,q PH7,q PH17,q PH19-1,q PH19-2,and q PH19-3)on chromosomes 2,6,7,17,and 19 were related to plant height,and five QTL(q SWPP2,q SWPP6,q SWPP13,q SWPP17,and q SWPP19)on chromosomes 2,6,13,17,and 19 were related to seed weight and could be considered as the major QTL.In addition,three common QTL(q PH6/q SWPP6,q PH17/q SWPP17,and q PH19-3/q SWPP19)for both plant height and seed weight per plant were located in the same genomic regions on the same chromosomes.Three(q PH2,q PH17,and q PH19-2)and four novel QTL(q SWPP2,q SWPP13,q SWPP17,and q SWPP19)were identified for plant height and seed weight per plant,respectively.Two pairs of QTL(q PH2/q SWPP2 and q PH17/q SWPP17)were also common for both plant height and seed weight per plant.These QTL and closely linked SLAF markers could be used to accelerate breeding for drought tolerant cultivars via MAS.展开更多
Medicinal plants are important source for Oriental and Western medicines. There are more than 500 herbs commonly used
today in China, in which near 30% of them are seed medicines and over 65% are propagated from seed.
文摘The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of water was investigated. It established the reduction of seed germination both under direct and indirect effects due to water action of attenuated geomagnetic field. A negative effect of hypomagnetic field on grown characteristics of seeds under indirect effect via water was decreased by the low doses of γ-irradiation, and was increased by low doses of α-irradiation, i.e. ionized radiation was the dominant factor in their combined action. It was revealed the increasing of the value of the oxidation-reduction potential of water under the influence of low-intensive α-ir-radiation (239Pu), γ-irradiation (137Cs) and also that the magnetic induction attenuated pointing to a natural decline. The increasing of the oxidation-reduction potential value testifies about “the regular decreasing of internal energy of water molecules” and the increasing of its oxidative properties, which, in our opinion, is caused the inhibition of the germination of seeds. It is supposed that namely water is the main component in the effects of studying factors on bio-objects, which acts due to the alterations of the properties and structural content of water.
基金This study was funded by the National Natural Science Foundation of China(grant no.31901212)Talent Start-up Foundation of Guangzhou University(grant no.RP2020079).
文摘Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.
基金supported by the National Natural Science Foundation of China (50672014)Innovation Research Team Program of the Ministry of Education (IRT0713)
文摘The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size.This technique used plant seeds to array templates and centrifugal slip casting to obtain cell struts with high packing density.Aqueous Al2O3-ZrO2 slurries with up to 50 vol.% solid contents were prepared and the rheological characteristic of the slurries was investigated.Consolidation was performed at an acceleration of 2,860 g for 60 min.The effect of the characteristic of plant seeds on the drying behavior of Al2O3-ZrO2 green compact was analyzed.The effects of the solid contents of slurries on segregation phenomena of Al2O3 and ZrO2 particles and green compact uniformity were investigated.The compressive stress-strain curve and deformation behavior of Al2O3-ZrO2 ceramic foams prepared using plant seed template were analyzed.The results showed segregation phenomenon is negligible for highly stable slurry with 50 vol.% solid loading.The prepared cell struts of Al2O3-ZrO2 foams have high green density (61.9% TD), sintered density (99.1% TD) and homogeneous microstructure.When sintered at 1,550 ℃ for 2 h, the cell size of Al2O3-ZrO2 foam is approximately uniform and the diameter is about 1.1 mm.The porosity and compressive strength of sintered products is 66.2% and 5.86 MPa, respectively.
文摘A fragile political pact in Zimbabwe allows for a glimmer of optimism in agricultura and economic growth KNOWN,in the past,as the bread basket of Southern Africa, Zimbabwe’s economic stability and agricultural strength was a reference point for most people involved in Africa.For over 10 years the situation changed.President Robert Mugabe’s decision in 2000 to redistribute the land to the black population saw the country lose about $12 billion in agricultural output. The Commercial Farmer’s Union said that previous to
基金supported by the National Natural Science Foundation of China (31670212,3206005631300181)+1 种基金the National Natural Science Foundation of China-Yunnan Joint Fund Project (U1802242)Guangxi Key Laboratory Construction Project (19-185-7)。
文摘The tropical Asian and Australasian floras have a close relationship,and is a vital distribution pattern of seed plants worldwide.As estimated,more than 81 families and 225 genera of seed plants distributed between tropical Asia and Australasia.However,the evolutionary dynamics of two floras were still vague.Here,a total of 29 plant lineages,represented the main clades of seed plants and different habits,were selected to investigate the biotic interchange between tropical Asia and Australasia by integrated dated phylogenies,biogeography,and ancestral state reconstructions.Our statistics indicated that 68 migrations have occurred between tropical Asia and Australasia since the middle Eocene except terminal migrations,and the migration events from tropical Asia to Australasia is more than 2 times of the reverse.Only 12 migrations occurred before 15 Ma,whereas the remaining56 migrations occurred after 15 Ma.Maximal number of potential dispersal events(MDE) analysis also shows obvious asymmetry,with southward migration as the main feature,and indicates the climax of bi-directional migrations occurred after 15 Ma.We speculate that the formation of island chains after the Australian-Sundaland collision and climate changes have driven seed plant migrations since the middle Miocene.Furthermore,biotic dispersal and stable habitat may be crucial for floristic interchange between tropical Asia and Australasia.
基金We thank the generations of Chinese botanists who have conducted extensive research on the plants in the study region.This study was supported by Key Program of National Natural Science Foundation China(No.41671038)National Key Research and Development Program of China(2017YFC0504801).
文摘Large-scale patterns of biodiversity and the underlying mechanisms that regulate these patterns are central topics in biogeography and macroecology.The Qinghai-Tibet Plateau serves as a natural laboratory for studying these issues.However,most previous studies have focused on the entire Qinghai-Tibet Plateau,leaving independent physical geographic subunits in the region less well understood.We studied the current plant diversity of the Kunlun Mountains,an independent physical geographic subunit located in northwestern China on the northern edge of the Qinghai-Tibet Plateau.We integrated measures of species distribution,geological history,and phylogeography,and analyzed the taxonomic richness,phylogenetic diversity,and community phylogenetic structure of the current plant diversity in the area.The distribution patterns of 1911 seed plants showed that species were distributed mainly in the eastern regions of the Kunlun Mountains.The taxonomic richness,phylogenetic diversity,and genera richness showed that the eastern regions of the Kunlun Mountains should be the priority area of biodiversity conservation,particularly the southeastern regions.The proportion of Chinese endemic species inhabiting the Kunlun Mountains and their floristic similarity may indicate that the current patterns of species diversity were favored via species colonization.The Hengduan Mountains,a biodiversity hotspot,is likely the largest source of species colonization of the Kunlun Mountains after the Quaternary.The net relatedness index indicated that 20 of the 28 communities examined were phylo-genetically dispersed,while the remaining communities were phylogenetically clustered.The nearest taxon index indicated that 27 of the 28 communities were phylogenetically clustered.These results suggest that species colonization and habitat filtering may have contributed to the current plant diversity of the Kunlun Mountains via ecological and evolutionary processes,and habitat filtering may play an important role in this ecological process.
基金supported by the National Key Research and Development Program of China(2016YFD0100201 and 2016YFD0100304)the National Science and Technological Innovation Program of China。
文摘Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance using molecular marker-assisted selection is able to facilitate the development of drought-tolerant soybean varieties.In this study,we used a high-yielding and drought-sensitive cultivar‘Zhonghuang 35’and a drought-tolerant cultivar‘Jindou 21’to establish F6:9 recombinant inbred lines.We constructed a highdensity genetic map using specific locus amplified fragment sequencing(SLAF-Seq)technology.The genetic map contained 8078 SLAF markers distributing across 20 soybean chromosomes with a total genetic distance of 3780.98 c M and an average genetic distance of0.59 c M between adjacent markers.Two treatments(irrigation and drought)were used in the field tests,the Additive-Inclusive Composite Interval Mapping(ICIM-ADD)was used to call QTL,and plant height and seed weight per plant were used as the indicators of drought tolerance.We identified a total of 23 QTL related to drought tolerance.Among them,seven QTL(q PH2,q PH6,q PH7,q PH17,q PH19-1,q PH19-2,and q PH19-3)on chromosomes 2,6,7,17,and 19 were related to plant height,and five QTL(q SWPP2,q SWPP6,q SWPP13,q SWPP17,and q SWPP19)on chromosomes 2,6,13,17,and 19 were related to seed weight and could be considered as the major QTL.In addition,three common QTL(q PH6/q SWPP6,q PH17/q SWPP17,and q PH19-3/q SWPP19)for both plant height and seed weight per plant were located in the same genomic regions on the same chromosomes.Three(q PH2,q PH17,and q PH19-2)and four novel QTL(q SWPP2,q SWPP13,q SWPP17,and q SWPP19)were identified for plant height and seed weight per plant,respectively.Two pairs of QTL(q PH2/q SWPP2 and q PH17/q SWPP17)were also common for both plant height and seed weight per plant.These QTL and closely linked SLAF markers could be used to accelerate breeding for drought tolerant cultivars via MAS.
文摘Medicinal plants are important source for Oriental and Western medicines. There are more than 500 herbs commonly used
today in China, in which near 30% of them are seed medicines and over 65% are propagated from seed.