被子植物是现存高等植物最为繁盛的类群,约30万种,是陆地植被的主要组成成分。搞清科、属和种的数量和范畴对认识全球和区域生物多样性有重要价值。分子系统学的快速发展,使很多被子植物的科和属的范畴发生了变化。本文结合APGⅢ系统和...被子植物是现存高等植物最为繁盛的类群,约30万种,是陆地植被的主要组成成分。搞清科、属和种的数量和范畴对认识全球和区域生物多样性有重要价值。分子系统学的快速发展,使很多被子植物的科和属的范畴发生了变化。本文结合APGⅢ系统和一些新的系统发育研究动态,对中国原产和引入的被子植物科属名单进行了整理,确认被子植物在中国原产258科,引入55科(其中6科归化),中国原产2,872属,引入1,605属(含归化152属),并简要介绍了中国被子植物科属范畴的历史沿革和新变化。新的名录与《中国植物志》相比,新增115科1,729属,与Flora of China相比,新增85科1,531属。展开更多
This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in...This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertiliz展开更多
Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatel...Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.展开更多
Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patte...Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patterns in species-specific responses to extreme droughts.Here,we conducted a study integrating dendrochronology and remote sensing methods to investigate the mosaic-distributed maple-oak(native)natural forests and poplar plantations(introduced)in the Horqin Sandy Land,Northeast China.We assessed the impacts of extreme droughts on tree performances by measuring interannual variations in radial growth and vegetation index.The results showed that precipitation and self-calibrated palmer drought severity index(scPDSI)are the major factors influencing tree-ring width index(RWI)and normalized difference vegetation index(NDVI).The severe droughts between 2000 and 2004 resulted in reduced RWI in the three studied tree species as well as led to NDVI reductions in both the maple-oak natural forests and the poplar plantations.The RWI reached the nadir during the2000-2004 severe droughts and remained at low levels two years after the severe drought,creating a legacy effect.In contrast to the lack of significant correlation between RWI and scPDSI,NDVI exhibited a significant positive correlation with scPDSI indicating the greater sensitivity of canopy performance to droughts than radial growth.Furthermore,interspecific differences in RWI and NDVI responses were observed,with the fast-growing poplar species experiencing a more significant RWI decrease and more negative NDVI anomaly during severe droughts than native species,highlighting the species-specific trade-offs between drought resilience and growth rate.This study emphasizes the importance of combining tree-level radial growth with landscape-scale canopy remote sensing to understand forest resilience and response.Our study improves our understanding of forest responses to extreme drought and highlights species differences in climate responses,offering crucial 展开更多
The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factor...The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factors such as plant type,resistance and drought tolerance of introduced flowering shrubs.The results show that the application effect of grade-I introduced flowering shrubs(including 12 kinds,e.g.Lantanacamara)was the best(j≥2.6),and that of grade-II introduced flowering shrubs(including 14 kinds,e.g.Abelia×grandiflora‘Francis Mason’)was better(2.2≤j<2.6),while that of grade-III introduced flowering shrubs(including 4 kinds,e.g.Ligustrum×vicaryi)was moderate(j<2.2).The evaluation results can provide reference for the application effect of introduced flowering shrubs in landscape in Hefei City.展开更多
Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aqu...Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aquatic plants.In this study,we divided 21 aquatic plants(including five introduced plants)into multiple plant groups(different life forms,monocot/eudicot and introduced/native)with the goal of addressing two questions:(i)what root structures do aquatic plants exhibit,and(ii)are there differences among these plant groups?Methods Twenty-one aquatic plants belonging to four life forms(free-float-ing,emergent,floating-leaved and submerged)were collected at the near flowering stage from a typical macrophyte-dominated lake in the yangtze River Basin,China.The following root topological parameters were quantified:altitude(a),path length(pe),magnitude(M),mean topological length(b),topological index(TI)and normed indices qa and qb.Important Findings The root topological indices TI,qa and qb for the 21 aquatic plants were 0.724±0.013,0.290±0.031 and 0.152±0.024(means±S.E.),respectively,revealing a general pattern of dichotomous branching,except for the aquatic root of Myriophyllum aquati-cum(Vell.)Verdc.,which displays herringbone branching.All three topological indices were significantly lower for monocots(TI=0.700±0.130,qa=0.191±0.149 and qb=0.086±0.236)than eudicots(TI=0.752±0.206,qa=0.405±0.569 and qb=0.229±0.393),indicating that the roots of monocots are typi-cally more dichotomous-like than those of eudicots.Among the four life forms,the three topological indices for emergent plants(TI=0.832±0.006,qa=0.616±0.018 and qb=0.381±0.014)were significantly higher than those of the other three life forms.Overall,there was no difference between the topological indices of introduced and native aquatic plants,but the introduced species M.aquaticum and Alternanthera philoxeroides(Mart.)Griseb.had both aquatic and edaphic roots as well as unusual functions,which may help explain their strong viability.展开更多
文摘被子植物是现存高等植物最为繁盛的类群,约30万种,是陆地植被的主要组成成分。搞清科、属和种的数量和范畴对认识全球和区域生物多样性有重要价值。分子系统学的快速发展,使很多被子植物的科和属的范畴发生了变化。本文结合APGⅢ系统和一些新的系统发育研究动态,对中国原产和引入的被子植物科属名单进行了整理,确认被子植物在中国原产258科,引入55科(其中6科归化),中国原产2,872属,引入1,605属(含归化152属),并简要介绍了中国被子植物科属范畴的历史沿革和新变化。新的名录与《中国植物志》相比,新增115科1,729属,与Flora of China相比,新增85科1,531属。
文摘This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertiliz
基金supported by the National High Technology Development Project of China under contract No. 2012AA10A404the Recommended International Advanced Agricultural Science and Technology Project of China under contract No. 2012-S5
文摘Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.
基金supported by the National Natural Science Foundation of China(Nos.32220103010,32192431,31722013)the National Key R&D Program of China(Nos.2023YFF1304201,2020YFA0608100)+1 种基金the Major Program of Institute of Applied EcologyChinese Academy of Sciences(No.IAEMP202201)。
文摘Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patterns in species-specific responses to extreme droughts.Here,we conducted a study integrating dendrochronology and remote sensing methods to investigate the mosaic-distributed maple-oak(native)natural forests and poplar plantations(introduced)in the Horqin Sandy Land,Northeast China.We assessed the impacts of extreme droughts on tree performances by measuring interannual variations in radial growth and vegetation index.The results showed that precipitation and self-calibrated palmer drought severity index(scPDSI)are the major factors influencing tree-ring width index(RWI)and normalized difference vegetation index(NDVI).The severe droughts between 2000 and 2004 resulted in reduced RWI in the three studied tree species as well as led to NDVI reductions in both the maple-oak natural forests and the poplar plantations.The RWI reached the nadir during the2000-2004 severe droughts and remained at low levels two years after the severe drought,creating a legacy effect.In contrast to the lack of significant correlation between RWI and scPDSI,NDVI exhibited a significant positive correlation with scPDSI indicating the greater sensitivity of canopy performance to droughts than radial growth.Furthermore,interspecific differences in RWI and NDVI responses were observed,with the fast-growing poplar species experiencing a more significant RWI decrease and more negative NDVI anomaly during severe droughts than native species,highlighting the species-specific trade-offs between drought resilience and growth rate.This study emphasizes the importance of combining tree-level radial growth with landscape-scale canopy remote sensing to understand forest resilience and response.Our study improves our understanding of forest responses to extreme drought and highlights species differences in climate responses,offering crucial
基金Sponsored by the Innovation and Entrepreneurship Training Planning Project for University Students in Anhui Province(S202212216129)Key Research Project of Natural Science in Universities of Anhui Province(2023AH051816)General Teaching Research Project of Anhui Province(2022jyxm665).
文摘The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factors such as plant type,resistance and drought tolerance of introduced flowering shrubs.The results show that the application effect of grade-I introduced flowering shrubs(including 12 kinds,e.g.Lantanacamara)was the best(j≥2.6),and that of grade-II introduced flowering shrubs(including 14 kinds,e.g.Abelia×grandiflora‘Francis Mason’)was better(2.2≤j<2.6),while that of grade-III introduced flowering shrubs(including 4 kinds,e.g.Ligustrum×vicaryi)was moderate(j<2.2).The evaluation results can provide reference for the application effect of introduced flowering shrubs in landscape in Hefei City.
基金Special Foundation of National Science and Technology Basic Research(2013FY112300).
文摘Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aquatic plants.In this study,we divided 21 aquatic plants(including five introduced plants)into multiple plant groups(different life forms,monocot/eudicot and introduced/native)with the goal of addressing two questions:(i)what root structures do aquatic plants exhibit,and(ii)are there differences among these plant groups?Methods Twenty-one aquatic plants belonging to four life forms(free-float-ing,emergent,floating-leaved and submerged)were collected at the near flowering stage from a typical macrophyte-dominated lake in the yangtze River Basin,China.The following root topological parameters were quantified:altitude(a),path length(pe),magnitude(M),mean topological length(b),topological index(TI)and normed indices qa and qb.Important Findings The root topological indices TI,qa and qb for the 21 aquatic plants were 0.724±0.013,0.290±0.031 and 0.152±0.024(means±S.E.),respectively,revealing a general pattern of dichotomous branching,except for the aquatic root of Myriophyllum aquati-cum(Vell.)Verdc.,which displays herringbone branching.All three topological indices were significantly lower for monocots(TI=0.700±0.130,qa=0.191±0.149 and qb=0.086±0.236)than eudicots(TI=0.752±0.206,qa=0.405±0.569 and qb=0.229±0.393),indicating that the roots of monocots are typi-cally more dichotomous-like than those of eudicots.Among the four life forms,the three topological indices for emergent plants(TI=0.832±0.006,qa=0.616±0.018 and qb=0.381±0.014)were significantly higher than those of the other three life forms.Overall,there was no difference between the topological indices of introduced and native aquatic plants,but the introduced species M.aquaticum and Alternanthera philoxeroides(Mart.)Griseb.had both aquatic and edaphic roots as well as unusual functions,which may help explain their strong viability.
