期刊文献+
共找到62篇文章
< 1 2 4 >
每页显示 20 50 100
STRUCTURE AND EXPRESSION OF EPSTEIN-BARR VIRUS MEMBRANE ANTIGEN IN RECOMBINANT VACCINIA VIRUS
1
作者 谷淑燕 江民康 +4 位作者 赵文平 曾毅 侯云德 朱既明 Hans Wolf 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1989年第1期44-49,共6页
The Epstein-Barr virus membrane antigen was constructed and inserted into vaccinia virus, Tian-tan strain in order to study the effect of this virus on EB infection and tumorogenesis. The EBV-derived membrane antigen ... The Epstein-Barr virus membrane antigen was constructed and inserted into vaccinia virus, Tian-tan strain in order to study the effect of this virus on EB infection and tumorogenesis. The EBV-derived membrane antigen was expressed under the control of a 7.5 K promoter of vaccinia virus. The antibody against the membrane antigen of EB virus was produced on rabbits vaccinated with recombinant vaccinia virus. 展开更多
关键词 EBV MA STRUCTURE AND EXPRESSION OF EPSTEIN-BARR VIRUS MEMBRANE ANTIGEN IN RECOMBINANT VACCINIA VIRUS GENE
暂未订购
Depicting the battle between nectarine and Monilinia laxa:the fruit developmental stage dictates the effectiveness of the host defenses and the pathogen’s infection strategies 被引量:3
2
作者 Marta Balsells-Llauradó Christian J.Silva +7 位作者 Josep Usall Núria Vall-llaura Sandra Serrano-Prieto Neus Teixidó Saskia D.Mesquida-Pesci Antonieta de Cal Barbara Blanco-Ulate Rosario Torres 《Horticulture Research》 SCIE 2020年第1期619-633,共15页
Infections by the fungus Monilinia laxa,the main cause of brown rot in Europe,result in considerable losses of stone fruit.Herein,we present a comprehensive transcriptomic approach to unravel strategies deployed by ne... Infections by the fungus Monilinia laxa,the main cause of brown rot in Europe,result in considerable losses of stone fruit.Herein,we present a comprehensive transcriptomic approach to unravel strategies deployed by nectarine fruit and M.laxa during their interaction.We used M.laxa-inoculated immature and mature fruit,which was resistant and susceptible to brown rot,respectively,to perform a dual RNA-Seq analysis.In immature fruit,host responses,pathogen biomass,and pathogen transcriptional activity peaked at 14–24 h post inoculation(hpi),at which point M.laxa appeared to switch its transcriptional response to either quiescence or death.Mature fruit experienced an exponential increase in host and pathogen activity beginning at 6 hpi.Functional analyses in both host and pathogen highlighted differences in stage-dependent strategies.For example,in immature fruit,M.laxa unsuccessfully employed carbohydrate-active enzymes(CAZymes)for penetration,which the fruit was able to combat with tightly regulated hormone responses and an oxidative burst that challenged the pathogen’s survival at later time points.In contrast,in mature fruit,M.laxa was more dependent on proteolytic effectors than CAZymes,and was able to invest in filamentous growth early during the interaction.Hormone analyses of mature fruit infected with M.laxa indicated that,while jasmonic acid activity was likely useful for defense,high ethylene activity may have promoted susceptibility through the induction of ripening processes.Lastly,we identified M.laxa genes that were highly induced in both quiescent and active infections and may serve as targets for control of brown rot. 展开更多
关键词 FRUIT PATHOGEN STRATEGIES
原文传递
Effects of ratios of yak to cattle inocula on methane production and fiber digestion in rumen in vitro cultures 被引量:1
3
作者 Weiwei Wang Wei Guo +7 位作者 Jianxin Jiao Emilio M Ungerfeld Xiaoping Jing Xiaodan Huang Allan A Degen Yu Li Sisi Bi Ruijun Long 《Journal of Integrative Agriculture》 2025年第4期1270-1284,共15页
Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitig... Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitigate CH_(4)production and improve digestibility in cattle,we incubated substrate with rumen inoculum from yak(YRI)and cattle(CRI)in vitro in five ratios(YRI:CRI):(1)0:100(control),(2)25:75,(3)50:50,(4)75:25 and(5)100:0 for 72 h.The YRI:CRI ratios of 50:50,75:25 and 100:0 produced less total gas and CH_(4)and accumulated less hydrogen(H_(2))than0:100(control)at most time points.From 12 h onwards,there was a linear decrease(P<0.05)in carbon dioxide(CO_(2))production with increasing YRI:CRI ratio.At 72 h,the ratios of 50:50 and 75:25 had higher dry matter(+7.71%and+4.11%,respectively),as well as higher acid detergent fiber digestibility(+15.5%and+7.61%,respectively),when compared to the 0:100 ratio(P<0.05).Increasing the proportion of YRI generally increased total VFA concentrations,and,concomitantly,decreased the proportion of metabolic hydrogen([2H])incorporated into CH_(4),and decreased the recovery of[2H].The lower[2H]recovery indicates unknown[2H]sinks in the culture.Estimated Gibbs free energy changes(ΔG)for reductive acetogenesis were negative,indicating the thermodynamic feasibility of this process.It would be beneficial to identify:1)the alternative[2H]sinks,which could help mitigate CH_(4)emission,and 2)core microbes involved in fiber digestion.This experiment supported lower CH_(4)emission and greater nutrient digestibility of yaks compared to cattle.Multi-omics combined with microbial culture technologies developed in recent years could help to better understand fermentation differences among species. 展开更多
关键词 yak rumen fluid methane DIGESTIBILITY metabolic hydrogen
在线阅读 下载PDF
极干旱胁迫对雀麦、多年生黑麦草生长和体内水分的影响 被引量:2
4
作者 张咏梅 胡海英 +3 位作者 白小明 Matthew Cory García-Favre Javier Ordóez Iván P 《草地学报》 CAS CSCD 北大核心 2024年第12期3807-3818,共12页
为研究极端干旱对牧草生长的影响,选择多年生黑麦草(Lolium perenne,Lp)和雀麦(Bromus valdivianus,Bv)给予80%~85%植物有效水(Plant available water,PAW)和20%~25%PAW 2种水分处理,分析两种牧草生长及体内水分状况对干旱胁迫的响应。... 为研究极端干旱对牧草生长的影响,选择多年生黑麦草(Lolium perenne,Lp)和雀麦(Bromus valdivianus,Bv)给予80%~85%植物有效水(Plant available water,PAW)和20%~25%PAW 2种水分处理,分析两种牧草生长及体内水分状况对干旱胁迫的响应。研究表明:80%~85%PAW充足水分下,两种牧草生物量积累、水势(Water potential,WP)、相对含水量(Relative water content,RWC)和净光合速率(Net photosynthetic rate,Pn)无明显种间差异。Bv叶片宽而重,蒸腾速率(Transpiration rate,Tr)、CO_(2)总导度(Total conductance to CO_(2),CndCO_(2))和气孔导度(Conductance to H 2O,Gs)显著高于Lp。而Lp分蘗多、叶多汁,瞬时水分利用效率是Bv的1.63倍。20%~25%PAW对两种牧草生长影响不完全一致,叶饱和重、干重和叶面积有相反变化趋势,但与充足水分相比差异不显著;Pn,Tr,CndCO_(2),Gs和RWC则极显著降低,WP极显著降低了1.60 MPa,致使枯叶占比和叶温差显著升高。总之,雀麦和多年生黑麦草生长相近,水分利用模式不同;遭受极端干旱,不同种的两种牧草耐旱机制具有一定的共性,通过增强叶片持水力、降低水分循环、减少蒸腾失水以提高牧草抗旱性。 展开更多
关键词 干旱胁迫 光合作用 蒸腾作用 生物量积累 瞬时水分利用效率 水势
在线阅读 下载PDF
Litterfall production modeling based on climatic variables and nutrient return from stands of Eucalyptus grandis Hill ex Maiden and Pinus taeda L.
5
作者 Andrés Baietto Andrés Hirigoyen +1 位作者 Jorge Hernández Amabelia del Pino 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期26-36,共11页
Native grasslands in the Pampas of South America are increasingly being replaced by Eucalyptus and Pinus stands.The short rotation regimes used for the stands require high nutrient levels,with litterfall being a major... Native grasslands in the Pampas of South America are increasingly being replaced by Eucalyptus and Pinus stands.The short rotation regimes used for the stands require high nutrient levels,with litterfall being a major source of nutrient return.To model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptus grandis and Pinus taeda stands,we measured litter production over 2 years,using conical litter traps,and monitored climatic variables.Mean temperature,accumulated precipitation,and mean maximum vapor pres-sure deficit at the seasonal level influenced litterfall produc-tion by E.grandis;seasonal accumulated precipitation and mean maximum temperature affected litterfall by P.taeda.The regression tree modeling based on these climatic vari-ables had great accuracy and predictive power for E.grandis(N=33;MAE(mean absolute error)=0.65;RMSE(root mean square error)=0.91;R^(2)=0.71)and P.taeda(N=108;MAE=1.50;RMSE=1.59;R^(2)=0.72).The nutrient return followed a similar pattern to litterfall deposition,as well as the order of importance of macronutrients(E.grandis:Ca>N>K>Mg>P;P.taeda:N>Ca>K>Mg>P)and micronutrients(E.grandis and P.taeda:Mn>Fe>Zn>Cu)in both species.This study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems. 展开更多
关键词 AFFORESTATION LITTERFALL Nutrient recycling Climate modeling MYRTACEAE PINACEAE
在线阅读 下载PDF
Deciphering the fiber quality of Gossypium barbadense L.var.brasiliensis in La Convención,Cusco,Perú
6
作者 MORALES-ARANIBAR Luis SAENZ Manuel Canto +5 位作者 MORALES-ARANIBAR Carlos Genaro RIVERA Marite Yulisa Nieves AGUILERA Jorge González STEINER Fábio BARDIVIESSO Diógenes Martins ZUFFO Alan Mario 《Journal of Cotton Research》 CAS 2024年第3期231-242,共12页
Background The quality of cotton fiber determines its value in the textile market,influencing agricultural profitability and the efficiency of textile processing.The selection of genotypes with superior fibers is a ke... Background The quality of cotton fiber determines its value in the textile market,influencing agricultural profitability and the efficiency of textile processing.The selection of genotypes with superior fibers is a key factor for genetic improvement programs seeking adaptability and sustainability in the face of climate change.This demonstrates the strategic importance of this plant for sustainable agriculture and the global textile industry.The objective of this research was to decipher the fiber quality of Gossypium barbadense var.brasiliensis in the native Amazonian communities of La Convención,Cusco-Perú,and to evaluate other critical aspects of native cotton that have not yet been identified.The methodology included non-probability sampling for accessibility,qualitative and quantitative analyses,and multivariate analyses.The fiber length(mm),micronaire index(maturity/fineness),fiber strength(gf/tex),length uniformity index(%),fiber elongation(%),maturation index(%),and short fiber index(%)were the fiber characteristics evaluated using the HVI method in cotton genotypes.Results Cotton accessions collected from Koribeni(Gossypium spp.)and Shivankoreni(Gossypium barbadense var.brasiliensis)stood out for their fiber quality properties,especially length,strength,and uniformity,which highlights their relevance for advanced textile applications and potential for use in plant genetic improvement programs.Conclusion These findings reinforce the need to conserve and study these native cotton accessions from the Peruvian Amazon region,which can offer promising perspectives for the textile industry and agricultural biodiversity. 展开更多
关键词 COTTON Sustainability Amazonian communities Cotton fiber quality
在线阅读 下载PDF
Optimization of fungicidal and acaricidal metabolite production by endophytic fungus Aspergillus sp. SPH2
7
作者 Nicolas Reyes Castillo Carmen E.Díaz +3 位作者 M.Fe Andres Juan Imperial Félix Valcárcel Ana Azucena González Coloma 《Bioresources and Bioprocessing》 2024年第1期395-406,共12页
The endophytic fungus Aspergillus sp.SPH2 was isolated from the stems of the endemic plant Bethencourtia palmensis and its extracts were found to have strong fungicidal effects against Botrytis cinerea and ixodicidal ... The endophytic fungus Aspergillus sp.SPH2 was isolated from the stems of the endemic plant Bethencourtia palmensis and its extracts were found to have strong fungicidal effects against Botrytis cinerea and ixodicidal effects against Hya-lomma lusitanicum at different fermentation times.In this study,the fungus was grown using three different culture media and two methodologies,Microparticulate Enhancement Cultivation(MPEC)and Semi-Solid-State Fermentation(Semi-SSF),to increase the production of secondary metabolites during submerged fermentation.The addition of an inert support to the culture medium(Semi-SSF)resulted in a significant increase in the extract production.However,when talcum powder was added to different culture media,unexpected results were observed,with a decrease in the production of the biocompounds of interest.Metabolomic analyses showed that the production of aspergillic,neoaspergillic,and neohydroxyaspergillic acids peaked in the first few days of fermentation,with notable differences observed among the methodologies and culture media.Mellein production was particularly affected by the addition of an inert support to the culture medium.These results highlight the importance of surface properties and morphology of spores and mycelia during fermentation by this fungal species. 展开更多
关键词 ENDOPHYTE ASPERGILLUS ANTIFUNGAL Ixodicidal FERMENTATION Mellein
在线阅读 下载PDF
多年生黑麦草、雀麦根系形态和生长对土壤干旱的适应性 被引量:8
8
作者 张咏梅 胡海英 +3 位作者 白小明 Matthew Cory García-Favre Javier Ordóñez Iván P 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2022年第11期1784-1794,共11页
为了研究牧草根系对干旱环境的适应性,选择多年生黑麦草(Lolium perenne)和雀麦(Bromus valdivianus)进行盆栽试验,给予80%~85%有效水(PAW)充分供水和20%~25%PAW极端干旱两种水分模式,通过对两种牧草的根系外形、干物质积累和根系形态... 为了研究牧草根系对干旱环境的适应性,选择多年生黑麦草(Lolium perenne)和雀麦(Bromus valdivianus)进行盆栽试验,给予80%~85%有效水(PAW)充分供水和20%~25%PAW极端干旱两种水分模式,通过对两种牧草的根系外形、干物质积累和根系形态学分析,探求两牧草在极干旱胁迫下的有效生产策略。研究表明,两种牧草的根尖外形略有不同。雀麦根毛长而密,分生区细胞致密,伸长区较长;多年生黑麦草根毛稀疏,伸长区短。20%~25%PAW极干旱胁迫使黑麦草根系粗细不匀,出现畸形;而雀麦根系未见明显受害。两种牧草生物量在茎叶和根的积累无显著的种间差异和水分处理间的组间差异。雀麦和多年生黑麦草单株根系的总长度、根面积、根平均直径、根尖数和分叉数存在极显著差异。多年生黑麦草根量显著高于雀麦(至少P≤0.01),根长和面积是雀麦的1.5倍左右,根尖数和分叉数是雀麦的2倍以上。雀麦根系末端侧根分枝密度高,短且粗;多年生黑麦草侧根细而长。干旱胁迫显著减少了两种牧草的总根长度,促进了雀麦根的径向生长。总之,雀麦根毛区较多年生黑麦草发达,多年生黑麦草根量显著多于雀麦。黑麦草主要以根数量(量)取胜,采取广泛吸水的适应策略;雀麦以根毛发达,侧根分枝密度高(质)为主,采用确保有效吸水的适应策略。 展开更多
关键词 多年生牧草 极干旱胁迫 适应策略 根尖 根系生物量 根系形态
在线阅读 下载PDF
Grain yield losses in yellow-rusted durum wheat estimated using digital and conventional parameters under field conditions 被引量:3
9
作者 Omar Vergara-Diaz Shawn C.Kefauver +2 位作者 Abdelhalim Elazab Maria Teresa Nieto-Taladriz Jose Luis Araus 《The Crop Journal》 CSCD 2015年第3期200-210,共11页
The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen(Warrior/Ambition),against which the present cultiva... The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen(Warrior/Ambition),against which the present cultivated wheat varieties have no resistance, appeared and spread rapidly. It threatens cereal production in most of Europe. The search for sources of resistance to this strain is proposed as the most efficient and safe solution to ensure high grain production. This will be helped by the development of high performance and low cost techniques for field phenotyping. In this study we analyzed vegetation indices in the Red,Green, Blue(RGB) images of crop canopies under field conditions. We evaluated their accuracy in predicting grain yield and assessing disease severity in comparison to other field measurements including the Normalized Difference Vegetation Index(NDVI), leaf chlorophyll content, stomatal conductance, and canopy temperature. We also discuss yield components and agronomic parameters in relation to grain yield and disease severity.RGB-based indices proved to be accurate predictors of grain yield and grain yield losses associated with yellow rust(R2= 0.581 and R2= 0.536, respectively), far surpassing the predictive ability of NDVI(R2= 0.118 and R2= 0.128, respectively). In comparison to potential yield, we found the presence of disease to be correlated with reductions in the number of grains per spike, grains per square meter, kernel weight and harvest index. Grain yield losses in the presence of yellow rust were also greater in later heading varieties. The combination of RGB-based indices and days to heading together explained 70.9% of the variability in grain yield and 62.7% of the yield losses. 展开更多
关键词 Wheat yellow rust Field phenotyping NDVI Phenology Puccinia striiformis RGB-based indices Triticum durum
在线阅读 下载PDF
Stand-level biomass models for predicting C stock for the main Spanish pine species 被引量:5
10
作者 Ana Aguirre Miren del Río +1 位作者 Ricardo Ruiz-Peinado Sonia Condés 《Forest Ecosystems》 SCIE CSCD 2021年第2期387-402,共16页
Background:National and international institutions periodically demand information on forest indicators that are used for global reporting.Among other aspects,the carbon accumulated in the biomass of forest species mu... Background:National and international institutions periodically demand information on forest indicators that are used for global reporting.Among other aspects,the carbon accumulated in the biomass of forest species must be reported.For this purpose,one of the main sources of data is the National Forest Inventory(NFI),which together with statistical empirical approaches and updating procedures can even allow annual estimates of the requested indicators.Methods:Stand level biomass models,relating the dry weight of the biomass with the stand volume were developed for the five main pine species in the Iberian Peninsula(Pinus sylvestris,Pinus pinea,Pinus halepensis,Pinus nigra and Pinus pinaster).The dependence of the model on aridity and/or mean tree size was explored,as well as the importance of including the stand form factor to correct model bias.Furthermore,the capability of the models to estimate forest carbon stocks,updated for a given year,was also analysed.Results:The strong relationship between stand dry weight biomass and stand volume was modulated by the mean tree size,although the effect varied among the five pine species.Site humidity,measured using the Martonne aridity index,increased the biomass for a given volume in the cases of Pinus sylvestris,Pinus halepensis and Pinus nigra.Models that consider both mean tree size and stand form factor were more accurate and less biased than those that do not.The models developed allow carbon stocks in the main Iberian Peninsula pine forests to be estimated at stand level with biases of less than 0.2 Mg·ha^(-1).Conclusions:The results of this study reveal the importance of considering variables related with environmental conditions and stand structure when developing stand dry weight biomass models.The described methodology together with the models developed provide a precise tool that can be used for quantifying biomass and carbon stored in the Spanish pine forests in specific years when no field data are available. 展开更多
关键词 Martonne aridity index Dry weight biomass Carbon stock National Forest Inventory Peninsular pine forest Biomass expansion factor
在线阅读 下载PDF
Effect of genistein supplementation of thawing medium on characteristics of frozen human spermatozoa 被引量:5
11
作者 Juan Carlos Martinez-Soto Juan de DiosHourcade +2 位作者 Alfonso Gutierrez-Adan Jose Lorenzo Landeras Joaquin Gadea 《Asian Journal of Andrology》 SCIE CAS CSCD 2010年第3期431-441,I0012,共12页
In this study, we evaluated the effects of genistein supplementation of the thawing extender on frozen-thawed human semen parameters. We analyzed the effect of supplementation on sperm motility, capacitation (membran... In this study, we evaluated the effects of genistein supplementation of the thawing extender on frozen-thawed human semen parameters. We analyzed the effect of supplementation on sperm motility, capacitation (membrane lipid disorder), reactive oxygen species (ROS) generation, chromatin condensation and DNA damage. Using this preliminary information, it maybe possible to improve the cryopreservation process and reduce the cellular damage. We have confirmed that the isoflavone genistein (10 μmol L-1) has antioxidant properties on the frozen-thawed spermatozoa. This results in a decreased ROS production that shows a slight improvement in the sperm motility, and decreases the membrane lipid disorder and DNA damage caused by cryopreservation. These results suggest an effect of genistein on sperm functionality that could be of interest for assisted reproduction treatments using frozen- thawed human spermatozoa, but further studies will be necessary to confirm our findings and to evaluate the possible clinical applications. 展开更多
关键词 ANTIOXIDANTS CRYOPRESERVATION DNA damage GENISTEIN ISOFLAVONES sperm motility
暂未订购
Recent advances in bird sperm morphometric analysis and its role in male gamete characterization and reproduction technologies 被引量:4
12
作者 Julian Santiago-Moreno Milagros Cristina Esteso +6 位作者 Silvia Villaverde-Morcillo Adolfo Toledano-Diaz Cristina Castafio Rosario Velazquez Antonio Lopez-Sebastian Agustin Lopez Goya Javier Gimeno Martinez 《Asian Journal of Andrology》 SCIE CAS CSCD 2016年第6期882-888,共7页
Postcopulatory sexual selection through sperm competition may be an important evolutionary force affecting many reproductive traits, including sperm morphometrics. Environmental factors such as pollutants, pesticides,... Postcopulatory sexual selection through sperm competition may be an important evolutionary force affecting many reproductive traits, including sperm morphometrics. Environmental factors such as pollutants, pesticides, and climate change may affect different sperm traits, and thus reproduction, in sensitive bird species. Many sperm-handling processes used in assisted reproductive techniques may also affect the size of sperm cells. The accurately measured dimensions of sperm cell structures (especially the head) can thus be used as indicators of environmental influences, in improving our understanding of reproductive and evolutionary strategies, and for optimizing assisted reproductive techniques (e.g., sperm cryopreservation) for use with birds. Computer-assisted sperm morphometry analysis (CASA-Morph) provides an accurate and reliable method for assessing sperm morphometry, reducing the problem of subjectivity associated with human visual assessment. Computerized systems have been standardized for use with semen from different mammalian species. Avian spermatozoa, however, are filiform, limiting their analysis with such systems, which were developed to examine the approximately spherical heads of mammalian sperm cells. To help overcome this, the standardization of staining techniques to be used in compute^-assessed light microscopical methods is a priority. The present review discusses these points and describes the sperm morphometric characteristics of several wild and domestic bird species. 展开更多
关键词 AVIAN computer-assisted assay MORPHOMETRY SPERMATOZOA
原文传递
Development of cork oak (Quercus suber L.) seedlings in response to tree shelters and mulching in northwestern Tunisia 被引量:5
13
作者 Taher Mechergui Marta Pardos +2 位作者 Naceur Boussaidi Brahim Hasnaoui Douglass F. Jacobs 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第2期193-204,共12页
The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings.... The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments (non-vented, vented, and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk (organic mulches), gravel (inorganic mulch) and no mulch). At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass (from samples extracted after two years) were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth. 展开更多
关键词 Quercus suber L. AFFORESTATION tree shelter MULCHING seedling growth polycyclism
在线阅读 下载PDF
Maternal undernutrition and offspring sex determine birth-weight, postnatal development and meat characteristics in traditional swine breeds 被引量:1
14
作者 M.Vázquez-Gómez C.García-Contreras +4 位作者 L.Torres-Rovira S.Astiz C.óvilo A.González-Bulnes B.Isabel 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2018年第3期674-688,共15页
Background: The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to con... Background: The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to consequences in its meat and carcass quality. The current study involved a total of 80 litters from Iberian sows fed a diet fulfilling daily requirements(n = 47; control) or providing 70% daily requirements(n = 33; underfed) from d 38 to d 90 of gestation when fetal tissue development begins. After birth, piglets born live were classified as low birthweight(LBW; < 1 kg) and normal birth-weight(NBW; ≥1 kg). During the growing phase, 240 control and 230 underfed pigs(50% males and females) distributed by BW category and sex were studied until the slaughter.Results: At birth and weaning, there were significant differences in all morphological measures and weight between NBW and LBW piglets as expected(P < 0.0005), but few effects of the gestational feed restriction. During the growing phase, NBW pigs continued with higher weight than LBW pigs on all the days of evaluation(P < 0.05),even though control-LBW-females and LBW-males showed a catch-up growth. However, underfed pigs showed slower growth and higher feed conversion ratio than control pigs(P < 0.0001) at 215 days old. Moreover, the average daily weight gain(ADWG) for the overall period was greater for NBW, male and control pigs than for their LBW, female and underfed pigs(P < 0.0001, P< 0.0005 and P< 0.05, respectively) and NBW pigs were slaughtered at a younger age than LBW pigs(P < 0.0001). After slaughtering, control pigs also had higher carcass yield and backfat depth than underfed pigs(P < 0.0005) and the maternal nutritional effect caused main changes in the polar lipid fraction of liver and loin. The fatty acid composition of loin in control pigs had higher C18:1 n-9 and n-3 FA concentrations, as well as lower ∑n-6/∑n-3 ratio, than in underfed pigs(P < 0.005).Conclusions: In brief, results showed that the effects of maternal nutritional restriction appeared and increased with offspring age, causing worse developmental patterns for underfed pigs than for control pigs. 展开更多
关键词 CARCASS quality FATTY acids Feed RESTRICTION Growth Iberian pigs Low BIRTH-WEIGHT MALNUTRITION
在线阅读 下载PDF
Development of ecoregion-based merchantable volume systems for Pinus brutia Ten. and Pinus nigra Arnold. in southern Turkey 被引量:4
15
作者 Ramazan Ozcelik Yasin Karatepe +2 位作者 Nevzat Gurlevik Isabel Canellas Felipe Crecente-Campo 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第1期101-117,共17页
Estimating individual tree volume is one of the essential building blocks in forest growth and yield models. Ecologically based taper equations provide accurate vol- ume predictions and allow classification by mer- ch... Estimating individual tree volume is one of the essential building blocks in forest growth and yield models. Ecologically based taper equations provide accurate vol- ume predictions and allow classification by mer- chantable sizes, assisting in sustainable forest management. In the present study, ecoregion-based compatible volume systems for brutian pine and black pine in the three ecoregions of southern Turkey were developed. Several well-known taper functions were evaluated. A second- order continuous-time autoregressive error structure was used to correct the inherent autocorrelation in the hierar- chical data, allowing the model to be applied to irregularly spaced and unbalanced data. The compatible segmented model of Fang et al. (For Sci 46:1-12, 2000) best described the experimental data. It is therefore recommended for estimating diameter at a specific height, height to a specific diameter, merchantable volume, and total volume for the three ecoregions and two species analyzed. The nonlinearextra sum of squares method indicated differences in ecoregion and tree-specific taper functions. A different taper function should therefore be used for each pine spe- cies and ecoregion in southern Turkey. Using ecoregion- specific taper equations allows making more robust esti- mations and, therefore, will enhance the accuracy of diameter at different heights and volume predictions. 展开更多
关键词 Taper function Segmented model Brutianpine Black pine. Ecoregion PINACEAE
在线阅读 下载PDF
Influence of mulching and tree shelters on 4-year survival and growth of zeen oak (Quercus canariensis) seedlings 被引量:1
16
作者 Taher Mechergui Marta Pardos Douglass F.Jacobs 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第1期129-141,共13页
We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Ital... We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Italian Stone Pine(Pinus pinea L.), Lentisk(Pistacia lentiscus L.),and a combination of Italian Stone Pine and Lentisk(organic mulches), gravel(inorganic mulch) and control), and three tree shelter types(non-vented and vented tree shelters, and control) were tested. An increase in the number of internodes occurred under the gravel mulch, while a reduction in survival was found for the lentisk mulch. Tree shelters had no effect on survival, but increased mean height growth and reduced mean diameter growth during the 4 years(excepting a non-significant effect for vented tree shelter at year four). Comparison of the annual shoots and growth units(GU) between sheltered and unsheltered plants according to year of formation revealed two growth phases. In first phase, shoots were totally or partially inside the shelters; mean length of annual shoots and GU were greater for sheltered plants. The second phase was characterized by shoots emerging from shelters; mean length of annual shoots and GU were similar for all plants, with or without tree shelters. Results suggest that the use of tree shelters, particularly vented shelters, could contribute to the improvement of the artificial regeneration of zeen oak.The use of mulching alone or in combination with tree shelters did not improve zeen oak performance in the field. 展开更多
关键词 Zeen OAK MULCHING Tree SHELTERS Plantation SURVIVAL rate GROWTH
在线阅读 下载PDF
Runner Bean (Phaseolus coccineus L.) Production in Chile 被引量:1
17
作者 J. Tay A. Pedreros and A. France 《Journal of Agricultural Science and Technology(B)》 2011年第3期360-362,共3页
Runner bean is usually grown in Chile as household plantings, in small surfaces with trellis support. Several studies were made to grow runner beans extensively without trellis support, like common beans are grown. Th... Runner bean is usually grown in Chile as household plantings, in small surfaces with trellis support. Several studies were made to grow runner beans extensively without trellis support, like common beans are grown. Three runner bean ecotypes were evaluated, with and without trellis support. Although the highest yield was obtained with trellis support, significant yields were obtained without trellis. Thus, this specie can be established without support like the common bean, allowing a great economic advantage especially at large scale plantings. The ecotype named "Quilapallar" was selected by its white and large grains and excellent cooking quality. Then, seed rates and dry grain yield were compared with commercial varieties of common bean. There was not statistical difference in yield among row distances, except when this was 25 cm apart. Besides, there was not statistical difference among Quilapallar and Torcaza INIA, although the later is a common bean variety with a high yield potential. 展开更多
关键词 Runner bean Phaseolus coccineus common bean agronomic trials.
在线阅读 下载PDF
A QTL associated with leaf trichome traits has a major influence on the abundance of the predatory mite Typhlodromus pyri in a hybrid grapevine population 被引量:2
18
作者 Paola Barba Rebecca Loughner +3 位作者 Karen Wentworth Jan Peter Nyrop Gregory M.Loeb Bruce I.Reisch 《Horticulture Research》 SCIE 2019年第1期639-650,共12页
The abundance of predatory phytoseiid mites,Typhlodromus pyri,important biological control agents of spider mite pests in numerous crops,is positively influenced by the density of leaf trichomes and tuft-form domatia ... The abundance of predatory phytoseiid mites,Typhlodromus pyri,important biological control agents of spider mite pests in numerous crops,is positively influenced by the density of leaf trichomes and tuft-form domatia in vein axils.Identification of the genetic regions controlling both trophic levels could facilitate the improvement of predatory mite habitat in breeding programs.The abundance of T.pyri and non-glandular trichomes was measured in a segregating F1 family derived from the cross of the complex Vitis hybrid,‘Horizon’,with Illinois 547-1(V.rupestris B38×V.cinerea B9),finding positive correlation among traits.High density genetic maps were used to localize one major quantitative trait locus(QTL)on chromosome 1 of Illinois 547-1 associated with both predatory mite abundance and leaf trichomes.This QTL explained 23%of the variation in phytoseiid abundance and similar amounts of variance in domatia rating(21%),domatia size(16%),leaf bristle density(37%in veins and 33%in blades),and leaf hair density(20%in veins and 15%in blades).Another nine QTL distributed among chromosomes 1,2,5,8,and 15 were associated solely with trichome density,and explained 7–17%of the phenotypic variation.Combined,our results provide evidence of the genetic architecture of non-glandular trichomes in Vitis,with a major locus influencing trichome densities,domatia size and predatory mite abundance.This information is relevant for breeding grapevines with a more favorable habitat for biological control agents. 展开更多
关键词 breeding CROPS PREDATOR
原文传递
Exploring the factors affecting carbon and nutrient concentrations in tree biomass components in natural forests,forest plantations and short rotation forestry 被引量:5
19
作者 Roque Rodriguez-Soalleiro Cristina Eimil-Fraga +6 位作者 Esteban Gomez-Garda Juan Daniel Garcia-Villabrille Alberto Rojo-Alboreca Fernando Munoz Nerea Oliveira Hortensia Sixto Cesar Perez-Cruzado 《Forest Ecosystems》 SCIE CSCD 2018年第4期498-515,共18页
Background: Coupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nu... Background: Coupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nutrient concentrations are often assumed to be constant for some species and specific tree components, at least in mature stands,the concentrations usually vary with age, site index and even with tree density. The main objective of this study was to evaluate the sources of variation in nutrient concentrations in biomass compartments usually removed during harvesting operations, covering a range of species and management conditions: semi-natural forest, conventional forest plantations and short rotation forestry(SRF). Five species(Betula pubescens, Quercus robur, Eucalyptus globulus, Eucalyptus nitens and Populus spp.) and 14 genotypes were considered. A total of 430 trees were sampled in 61 plots to obtain 6 biomass components:leaves, twigs, thin branches, thick branches, bark and wood. Aboveground leafless biomass was pooled together forpoplar.The concentrations of C, N, K, P, Ca, Mg, S, Fe, Mn, Cu, Zn and B were measured and the total biomass of each sampled tree and plot were determined. The data were analysed using boosted regression trees and conventional techniques.Results: The main sources of variation in nutrient concentrations were biomass component > > genotype(species) ≈ age >tree diameter. The concentrations of Ca, Mg and K were most strongly affected by genotype and age. The concentrations of P, K, Ca, Mg, S and Cu in the wood component decreased with age, whereas C concentrations increased, with a trend to reach 50% in the older trees. In the SRF, interamerican poplar and P. trichocarpa genotypes were comparatively more efficient in terms of Ca and K nutrient assimilation index(NAI)(+65-85%) than eucalypts, mainly because leafless biomass can be removed. In the conventional eucalypt plantations(rotation 15 years), debarking the wood at logging(savings of225% of Ca and 254% of Mg for E. globulus) or the use of selected genotypes(savings of 45% of P and 35% of Ca) will provide wood at a relatively lower nutrient cost. Considering all the E. globulus genotypes together, the management for pulp with removal of debarked wood shows NAI values well above(x 1.7-x 3.9) the ones found for poplar or eucalypt SRF and also higher(x 1.6-x4.0) than the ones found for oak and birch managed in medium or long rotations.The annual rates of nutrient removal were low in the native broadleaved species but the rates of available soil nutrients removed were high as compared to poplar or eucalypts. Management of native broadleaved species should consider nutrient stability through selection of the biomass compartments removed.(Continued on next page)(Continued from previous page)Conclusions: The nutrient assimilation index is higher in poplar grown under short rotation forestry management than in the other systems considered. Nutrient management of fast growing eucalyptus plantations could be improved by selecting efficient genotypes and limiting removal of wood. The values of the nutrient assimilation index are lower in the natural stands of native broadleaved species than in the other systems considered. 展开更多
关键词 Nutrient removal Biomass crops Poplar genotypes Eucolyptus OAK BIRCH Plantation sustainability
在线阅读 下载PDF
Environmental Assessment of Tetracycline’s Residues Detected in Pig Slurry and Poultry Manure 被引量:2
20
作者 Matilde Carballo Sonia Aguayo +2 位作者 Miguel González Fernando Esperon Ana de la Torre 《Journal of Environmental Protection》 2016年第1期82-92,共11页
The widespread use of antimicrobials in animal husbandry has led to an increase in concentrations of antibiotics in animal faeces. Furthermore, the spreading of this waste as fertilizer on agricultural land indirectly... The widespread use of antimicrobials in animal husbandry has led to an increase in concentrations of antibiotics in animal faeces. Furthermore, the spreading of this waste as fertilizer on agricultural land indirectly introduces antimicrobial residues into the environment. This study examined samples of pig slurry and poultry manure for three tetracyclines—oxytetracycline (OTC), chlortetracycline (CTC) and doxycycline (DOC) and conducted an environmental evaluation of soils. The samples were taken from manure heaps on eight broiler chicken farms and from slurry ponds on eight pig farms. The tetracycline analysis was conducted using high-performance liquid chromatography combined with tandem mass spectrometry (HPLC/MS). The risk assessment was carried out on the basis of the estimated PECsoil value and the ecotoxicological information available for terrestrial organisms. TC concentrations were between >0.01 and 1.38 mg/kg. OCT was detected in 37% of the poultry manure and in 20% of the pig slurry samples. DOC was present in 50% of pig slurry samples with an average concentration of 1.2 mg/kg, while CTC was only found in one slurry sample at a concentration of 0.56 mg/kg. Compared with published values for these two farm animals from other countries, the TC concentrations obtained in this study were low. The environmental importance of the data generated was also discussed. 展开更多
关键词 TETRACYCLINES Pig Slurry Poultry Manure Risk Evaluation
在线阅读 下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部