CIRAD(Montpellier,France) develops research activities centered on tropical and sub-tropical agricultural systems.Among others crops,cotton is the focus of a series of research programs in different disciplines from e...CIRAD(Montpellier,France) develops research activities centered on tropical and sub-tropical agricultural systems.Among others crops,cotton is the focus of a series of research programs in different disciplines from economics to breeding.Major areas in genetics and breeding relate to(1) genetic diversity,(2) cultivar development through classical and molecular breeding,and(3)展开更多
The Cotton Programme of CIRAD undertakesdifferent research programs aiming at utilizingDNA molecular markers for an applied molecularbreeding of cotton.These programs cover areasfrom marker-assisted selection for fibe...The Cotton Programme of CIRAD undertakesdifferent research programs aiming at utilizingDNA molecular markers for an applied molecularbreeding of cotton.These programs cover areasfrom marker-assisted selection for fiber qualityto functional genomic study of cotton fiberdevelopment.The present communication willgive an overview of major achievements in thesea reas.展开更多
Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's ...Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's Central Highlands.To identify key factors driving soilborne diseases and threatening sustainable production,a soil and root survey was conducted across three provinces:Gia Lai,Dak Lak,and Dak Nong.Soils were characterised by high clay content(51.2-62.0%),moderate silt(35.5-46.0%),and low sand(2.5-2.8%),with a notably low cation exchange capacity(7.72-8.04 cmol_(c) kg^(−1)).The soils were strongly acidic,with average pH values of 4.51 in coffee farms and 5.45 in pepper farms.Despite sufficient levels of nitrogen(N),phosphorus(P),and potassium(K),soilborne pathogens were widespread.Fusarium spp.were detected in all samples,Phytophthora spp.in 64-76%of black pepper farms,and plant-parasitic nematodes in 67-84%of farms,with Meloidogyne spp.predominant.Fusarium density increased with soil acidity in coffee plantations.In coffee,nematode density was positively correlated with N input,while in black pepper,N was negatively correlated with Phytophthora.Organic matter and available K were negatively associated with Fusarium in coffee but positively with Phytophthora in black pepper.These findings underscore the need for integrated management of nutrients and pathogens to sustain perennial crop production in the region.展开更多
Bemisia tabaci is a complex of cryptic agro-economically important pest species characterized by diverse clades,substantial genetic diversity along with strong phylogeographic associations.However,a comprehensive phyl...Bemisia tabaci is a complex of cryptic agro-economically important pest species characterized by diverse clades,substantial genetic diversity along with strong phylogeographic associations.However,a comprehensive phylogenomic analysis across the entire complex has been lacking,we thus conducted phylogenomic analyses and explored biogeographic patterns using 680 single-copy nuclear genes(SCNs)obtained from whole-genome sequencing data of 58 globally sourced B.tabaci specimens.We constructed both concatenation and coalescent trees using 680 SCNs,which produced highly supported bootstrap values and nearly identical topologies for all major clades.When comparing these concatenation trees with those constructed using mitochondrial cytochrome oxidase I(mtCOI)and mitochondrial genome,we found conflicting phylogenetic relationships,with the later trees recovering fewer major clades.In a separate comparison between concatenation and coalescent trees,particularly those generated using IQ-TREE,they were found to delineate population relationships more effectively than RaxML.In contrast,coalescent phylogenies were proficient in elucidating geographical dispersal patterns and the reorganization of biological species.Furthermore,we provided a strict consensus tree that clearly defines relationships within most clades,laying a solid foundation for future research on the evolution and taxonomy of B.tabaci.Ancestral range estimates suggested that the ancestral region of the complex is likely situated in equatorial Africa,the Middle East,and Mediterranean regions.Subsequently,the expansion occurred into part of the Palearctic and further into the Nearctic,Neotropical,Indomalayan,and Australasian regions.These findings challenge both previous classifications and origin hypotheses,offering a notably more comprehensive understanding of the global distribution,evolutionary history,diversification,and biogeography of B.tabaci.展开更多
The use of agricultural residues in biocomposite production has gained increasing attention,driven by several benefits.Converting agricultural by-products into bio-based materials within a circular economy represents ...The use of agricultural residues in biocomposite production has gained increasing attention,driven by several benefits.Converting agricultural by-products into bio-based materials within a circular economy represents a sustainable strategy to mitigate lignocellulosic waste,reduce reliance on fossil resources,and lower environmental pollution.This approach also creates economic opportunities for rural African communities by generating diverse income sources for workers in collection,processing,and manufacturing.As a result,the integration of agricultural residues into biocomposites production not only addresses environmental concerns but also fosters economic growth and supports rural development.In this review,five biomasses from West Africa are examined,focusing on their production,chemical composition,physical and mechanical properties,and potential applications in biocomposites.The five biomasses listed are cocoa pod husks,oil palm empty fruit bunches,rice husks,millet stalks,and typha stalks.Key parameters,such as the type of binder,fiber dimensions,fiber-to-binder ratio,and the strength of fiber-binder adhesion,are systematically studied to assess their influence on the overall performance of the resulting composites.Special attention is given to understanding how these factors affect mechanical properties(e.g.,strength and flexibility),thermal behavior(e.g.,insulation capacity and heat resistance),and physico-chemical characteristics(e.g.,moisture absorption,density,and chemical stability).This comprehensive analysis provides insights into optimizing composite formulations for enhanced functionality and sustainability.This study is essential to optimize the use of agricultural residues inWest Africa for biocomposites,tackling waste issues,promoting sustainability,and filling research gaps on their properties.展开更多
The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance...The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance of low-durable wood species.Wacapou(Vouacapoua americana.,Fabaceae)is a well-known Guianese wood spe-cies commonly used in local wood construction due to its outstanding natural durability,which results from the presence of a large panel of extractives compounds.In addition,its industrial processing generates large amounts of residues.Wacapou residues were extracted by maceration using four different solvents(water/ethanol,ethyl acetate,hexane and dichloromethane/methanol),separately and successively.The yield of each extractive fraction was determined,and their chemical compositions were analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS).Ethyl acetate led to the highest extraction yield,and the active compounds were identified in the obtained extractive fraction.In this sense,the fungicidal and termite-repellent properties of these extractives were then tested using a screening laboratory(with temperate and tropical microorganisms),according to the solution concentration(1%,2.5%,5%,8%and 10%).Finally,Virola michelii Heckel wood samples(low durable species)were impregnated with the 8%concentration solution.The impregnated wood samples were then exposed to a soil bed test.The results highlighted that the nature of the solvent used during wood maceration affects the con-tent of the obtained extractive fractions.Ultra-Performance Liquid Chromatography–High-Resolution Mass Spectrometry(UHPLC-HRMS)analyses showed the influence of extraction parameters on the nature of the extracted molecules.Wacapou extracts(from ethyl acetate maceration)showed good anti-fungal and anti-termite activities.Additionally,the concentration in extractives had an impact on the anti-termite activity level for Reti-culitermesflavipes and Cryptotermes sp.Formulations based on Wacapou extractives showed a good potential for valorization in eco-friendly preservatives,aiming to confer better durability to local low-durability wood species.展开更多
The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geogra...The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geographical origins. The identification and quantification of fatty acids and the polyphenolic profile were carried out by GC-MS and HPLC-UV, respectively. Analysis of fatty acid methyl esters allowed the identification and quantification of 18 fatty acids. Oils from unwashed seeds were richer in palmitic (C16:0), stearic (C18:0), oleic (C18:1) and arachidic (C20:0) acids. In addition, HPLC-UV analysis at 279 nm shows that oils from unwashed seeds are richer in tyrosol, hydroxytyrosol and caffeic acid. With regard to the polyphenolic profile, gallic acid and quercetin were not detected in these baobab oils. Principal component analysis of fatty acid and phenolic compound content showed that oils from unwashed seeds would best preserve their chemical and associated potential bioactive characteristics.展开更多
Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertili...Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass(PTI), conservation agriculture with strip tillage(CA_ST), and conservation agriculture with no tillage(CA_NT) were compared with the reference plough-based tillage(PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model(CSM) of CROPGRO-Cotton to evaluate the effects of genotype(G) × environment(E) × management(M) interactions on seed cotton yield(SCY).Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.展开更多
How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the ...How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.展开更多
Granier sap flow system is one of the most commonly used techniques for measurements of whole-tree water use in ecophysiological and forest hydrological studies.However,in the literature there is not one paper that ex...Granier sap flow system is one of the most commonly used techniques for measurements of whole-tree water use in ecophysiological and forest hydrological studies.However,in the literature there is not one paper that exclusively reviews the Granier method.In this paper,we recapitulate the theoretical basis of the Granier sap flow system and review recent developments in calibration and modification of the sensor probes.Practical issues,such as the determination of the non-flow signal values,natural thermal gradient,wounding effect,reversed sap flow pattern and extrapolation of individual measurement of sap flux density to whole-tree sap flow.are discussed in detail.In the perspectives,new approaches are put forward to use the strong coupling between photosynthesis and transpiration or canopy conductance,via the measurement of 13C discrimination,to estimate whole-canopy carbon assimilation.展开更多
In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to g...In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction（GGE） biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley（YaRV）, China. Four traits（cotton lint yield, fiber length, lint breaking tenacity, micronaire） and two composite selection indices were considered. It was found that the assumption of a single mega-environment in the YaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments： a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identification of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, Sichuan Province, China, was found to be desirable for none.展开更多
文摘CIRAD(Montpellier,France) develops research activities centered on tropical and sub-tropical agricultural systems.Among others crops,cotton is the focus of a series of research programs in different disciplines from economics to breeding.Major areas in genetics and breeding relate to(1) genetic diversity,(2) cultivar development through classical and molecular breeding,and(3)
文摘The Cotton Programme of CIRAD undertakesdifferent research programs aiming at utilizingDNA molecular markers for an applied molecularbreeding of cotton.These programs cover areasfrom marker-assisted selection for fiber qualityto functional genomic study of cotton fiberdevelopment.The present communication willgive an overview of major achievements in thesea reas.
基金funded by the Australian Centre for International Agricultural Research(ACIAR)project“AGB-2018-175:Enhancing smallholder livelihoods in the Central Highlands of Viet Nam through improving the sustainability of coffee and black pepper farming systems and value chains”and Deakin University.
文摘Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's Central Highlands.To identify key factors driving soilborne diseases and threatening sustainable production,a soil and root survey was conducted across three provinces:Gia Lai,Dak Lak,and Dak Nong.Soils were characterised by high clay content(51.2-62.0%),moderate silt(35.5-46.0%),and low sand(2.5-2.8%),with a notably low cation exchange capacity(7.72-8.04 cmol_(c) kg^(−1)).The soils were strongly acidic,with average pH values of 4.51 in coffee farms and 5.45 in pepper farms.Despite sufficient levels of nitrogen(N),phosphorus(P),and potassium(K),soilborne pathogens were widespread.Fusarium spp.were detected in all samples,Phytophthora spp.in 64-76%of black pepper farms,and plant-parasitic nematodes in 67-84%of farms,with Meloidogyne spp.predominant.Fusarium density increased with soil acidity in coffee plantations.In coffee,nematode density was positively correlated with N input,while in black pepper,N was negatively correlated with Phytophthora.Organic matter and available K were negatively associated with Fusarium in coffee but positively with Phytophthora in black pepper.These findings underscore the need for integrated management of nutrients and pathogens to sustain perennial crop production in the region.
基金supported by the Bill&Melinda Gates Foundation(African cassava whitefly project,OPP1058938)the National Natural Science Foundation of China(Grant numbers 31501878).
文摘Bemisia tabaci is a complex of cryptic agro-economically important pest species characterized by diverse clades,substantial genetic diversity along with strong phylogeographic associations.However,a comprehensive phylogenomic analysis across the entire complex has been lacking,we thus conducted phylogenomic analyses and explored biogeographic patterns using 680 single-copy nuclear genes(SCNs)obtained from whole-genome sequencing data of 58 globally sourced B.tabaci specimens.We constructed both concatenation and coalescent trees using 680 SCNs,which produced highly supported bootstrap values and nearly identical topologies for all major clades.When comparing these concatenation trees with those constructed using mitochondrial cytochrome oxidase I(mtCOI)and mitochondrial genome,we found conflicting phylogenetic relationships,with the later trees recovering fewer major clades.In a separate comparison between concatenation and coalescent trees,particularly those generated using IQ-TREE,they were found to delineate population relationships more effectively than RaxML.In contrast,coalescent phylogenies were proficient in elucidating geographical dispersal patterns and the reorganization of biological species.Furthermore,we provided a strict consensus tree that clearly defines relationships within most clades,laying a solid foundation for future research on the evolution and taxonomy of B.tabaci.Ancestral range estimates suggested that the ancestral region of the complex is likely situated in equatorial Africa,the Middle East,and Mediterranean regions.Subsequently,the expansion occurred into part of the Palearctic and further into the Nearctic,Neotropical,Indomalayan,and Australasian regions.These findings challenge both previous classifications and origin hypotheses,offering a notably more comprehensive understanding of the global distribution,evolutionary history,diversification,and biogeography of B.tabaci.
基金BIO4Africa Project which is funded by the European Union(Horizon 2020-No.101000762).
文摘The use of agricultural residues in biocomposite production has gained increasing attention,driven by several benefits.Converting agricultural by-products into bio-based materials within a circular economy represents a sustainable strategy to mitigate lignocellulosic waste,reduce reliance on fossil resources,and lower environmental pollution.This approach also creates economic opportunities for rural African communities by generating diverse income sources for workers in collection,processing,and manufacturing.As a result,the integration of agricultural residues into biocomposites production not only addresses environmental concerns but also fosters economic growth and supports rural development.In this review,five biomasses from West Africa are examined,focusing on their production,chemical composition,physical and mechanical properties,and potential applications in biocomposites.The five biomasses listed are cocoa pod husks,oil palm empty fruit bunches,rice husks,millet stalks,and typha stalks.Key parameters,such as the type of binder,fiber dimensions,fiber-to-binder ratio,and the strength of fiber-binder adhesion,are systematically studied to assess their influence on the overall performance of the resulting composites.Special attention is given to understanding how these factors affect mechanical properties(e.g.,strength and flexibility),thermal behavior(e.g.,insulation capacity and heat resistance),and physico-chemical characteristics(e.g.,moisture absorption,density,and chemical stability).This comprehensive analysis provides insights into optimizing composite formulations for enhanced functionality and sustainability.This study is essential to optimize the use of agricultural residues inWest Africa for biocomposites,tackling waste issues,promoting sustainability,and filling research gaps on their properties.
基金PROTEXTWOOD (ID 2202-102) funded through LabEx AGRO ANR-10-LABX-0001-01 (under ISiteUniversité de Montpellier framework)the project PANTHER2-Guyane funded through AgenceNationale de la Recherche (ANR-22-CE43-0019)+2 种基金“Investissement d’Avenir” grant managed by Agence Nationale de la Recherche (CEBA, ref. ANR-10-LABX-25-01)supported by the FEDER (European Regional Development Fund)research project “EcovaloBois” (Project number: GY0015430)by the CNRS peps INSIS2018 research project “GuyavaloFibres”.
文摘The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance of low-durable wood species.Wacapou(Vouacapoua americana.,Fabaceae)is a well-known Guianese wood spe-cies commonly used in local wood construction due to its outstanding natural durability,which results from the presence of a large panel of extractives compounds.In addition,its industrial processing generates large amounts of residues.Wacapou residues were extracted by maceration using four different solvents(water/ethanol,ethyl acetate,hexane and dichloromethane/methanol),separately and successively.The yield of each extractive fraction was determined,and their chemical compositions were analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS).Ethyl acetate led to the highest extraction yield,and the active compounds were identified in the obtained extractive fraction.In this sense,the fungicidal and termite-repellent properties of these extractives were then tested using a screening laboratory(with temperate and tropical microorganisms),according to the solution concentration(1%,2.5%,5%,8%and 10%).Finally,Virola michelii Heckel wood samples(low durable species)were impregnated with the 8%concentration solution.The impregnated wood samples were then exposed to a soil bed test.The results highlighted that the nature of the solvent used during wood maceration affects the con-tent of the obtained extractive fractions.Ultra-Performance Liquid Chromatography–High-Resolution Mass Spectrometry(UHPLC-HRMS)analyses showed the influence of extraction parameters on the nature of the extracted molecules.Wacapou extracts(from ethyl acetate maceration)showed good anti-fungal and anti-termite activities.Additionally,the concentration in extractives had an impact on the anti-termite activity level for Reti-culitermesflavipes and Cryptotermes sp.Formulations based on Wacapou extractives showed a good potential for valorization in eco-friendly preservatives,aiming to confer better durability to local low-durability wood species.
文摘The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geographical origins. The identification and quantification of fatty acids and the polyphenolic profile were carried out by GC-MS and HPLC-UV, respectively. Analysis of fatty acid methyl esters allowed the identification and quantification of 18 fatty acids. Oils from unwashed seeds were richer in palmitic (C16:0), stearic (C18:0), oleic (C18:1) and arachidic (C20:0) acids. In addition, HPLC-UV analysis at 279 nm shows that oils from unwashed seeds are richer in tyrosol, hydroxytyrosol and caffeic acid. With regard to the polyphenolic profile, gallic acid and quercetin were not detected in these baobab oils. Principal component analysis of fatty acid and phenolic compound content showed that oils from unwashed seeds would best preserve their chemical and associated potential bioactive characteristics.
基金supported by the Benin Cotton Research Institute (IRC)the Cotton Interprofessional Association (AIC)+1 种基金the French Agricultural Research Centre for International Development (CIRAD)the TAZCO_(2) project (Transition Agroécologique des Zones Cotonnières du Bénin),which is funded by the Republic of Benin and the French Development Agency (AFD)。
文摘Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass(PTI), conservation agriculture with strip tillage(CA_ST), and conservation agriculture with no tillage(CA_NT) were compared with the reference plough-based tillage(PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model(CSM) of CROPGRO-Cotton to evaluate the effects of genotype(G) × environment(E) × management(M) interactions on seed cotton yield(SCY).Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.
基金supported by grants from the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk0205 to Lin Xia,No.2021xjkk0604 to Jilong Cheng)the National Natural Science Foundation of China(32170416 to Qisen Yang,31900325 to Jilong Cheng)+1 种基金the Joint Fund of National Natural Science Foundation of China(U2003203 to Lin Xia)the Key Laboratory of Zoological Systematics and Evolution of the Chinese Academy of Sciences(Y229YX5105 to Qisen Yang).
文摘How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.
文摘Granier sap flow system is one of the most commonly used techniques for measurements of whole-tree water use in ecophysiological and forest hydrological studies.However,in the literature there is not one paper that exclusively reviews the Granier method.In this paper,we recapitulate the theoretical basis of the Granier sap flow system and review recent developments in calibration and modification of the sensor probes.Practical issues,such as the determination of the non-flow signal values,natural thermal gradient,wounding effect,reversed sap flow pattern and extrapolation of individual measurement of sap flux density to whole-tree sap flow.are discussed in detail.In the perspectives,new approaches are put forward to use the strong coupling between photosynthesis and transpiration or canopy conductance,via the measurement of 13C discrimination,to estimate whole-canopy carbon assimilation.
基金funded by the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(12)5035)the National Natural Science Foundation of China(30971735)+1 种基金the China Agriculture Research System(CARS-18-20)the Special Fund for Agro-Scientific Research in the Public Interest of China(Impact of Climate Change on Agriculture Production of China,200903003)
文摘In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction（GGE） biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley（YaRV）, China. Four traits（cotton lint yield, fiber length, lint breaking tenacity, micronaire） and two composite selection indices were considered. It was found that the assumption of a single mega-environment in the YaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments： a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identification of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, Sichuan Province, China, was found to be desirable for none.
