期刊文献+
共找到1,834篇文章
< 1 2 92 >
每页显示 20 50 100
Genetic structure of needle morphological and anatomical traits of Pinus yunnanensis 被引量:4
1
作者 Yujie Huang Jianfeng Mao +4 位作者 Zhiqiang Chen Jingxiang Meng Yulan Xu Anan Duan Yue Li 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第1期13-25,共13页
Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and pop... Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/(resin canals area and vascular bundle area), were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future. 展开更多
关键词 Genetic structure NEEDLE Morphologicaland anatomical traits Geographic population Pinusyunnanensis
下载PDF
Responses of Gardenia jasminoides Ellis Leaf Traits and Anatomical Structures to Drought Stress in Purple Soil 被引量:1
2
作者 Yan YANG Lei LI +3 位作者 Jie TANG Yuxi TANG Yongjin LI Mengrong LUO 《Agricultural Biotechnology》 CAS 2021年第5期93-97,共5页
[Objectives]This study was conducted to investigate the response of Gardenia to purple soil drought stress,hoping to provide a reference for the selection of plants for vegetation restoration in purple soil regions.[M... [Objectives]This study was conducted to investigate the response of Gardenia to purple soil drought stress,hoping to provide a reference for the selection of plants for vegetation restoration in purple soil regions.[Methods]The pot-weighing water control method was used to apply different degrees of drought stress to Gardenia seedlings in purple soil,and the effects of drought stress on the electrical conductivity,chlorophyll content,leaf morphology and structure of Gardenia leaves were explored.[Results]The leaf electrical conductivity increased with the increase of drought stress intensity,and the leaf electrical conductivity under severe drought stress increased by 59.93%compared with the control;the chlorophyll content of Gardenia showed a single-peak changing trend that increased and then decreased with the development of drought stress,and it was the highest in each stress stage under severe drought stress;the leaf thickness,palisade tissue thickness and sponge tissue thickness of Gardenia were reduced with the stress degree increasing,and showed the largest decreases under severe stress;the stomatal length,stomatal width and stomatal opening of Gardenia gradually decreased with the increase of stress,while the stomatal density gradually increased.[Conclusions]This study provides a technical and resource basis for vegetation restoration in purple soil. 展开更多
关键词 Purple soil Drought stress Gardenia jasminoides Ellis Anatomical structure Leaf traits
下载PDF
The factorial structure of self-reported androgen-promoted physiological traits
3
作者 Lee Ellis Shyamal Das 《Natural Science》 2010年第10期1164-1170,共7页
Androgens make major contributions to average sex differences in anatomy, physiology, and behavior. Despite having established their crucial role in sexual differentiation, much remains to be learned about how androge... Androgens make major contributions to average sex differences in anatomy, physiology, and behavior. Despite having established their crucial role in sexual differentiation, much remains to be learned about how androgens coordinate their influences. The present study was undertaken to shed light on androgenic effects on the body using self-reported survey data. We analyzed the ratings provided by over 11,000 college students on the magnitude of eleven traits that previous research has shown to be influenced by testosterone or other androgens. Predictably, the average values for all eleven traits were significantly greater in males than in females. Nevertheless, when data were analyzed separately according to sex of the respondents, some of the traits failed to positively correlate with one another, suggesting that not all an-drogen-influenced traits differentiate in a simple fashion. Factor analysis of these eleven traits by sex reinforced this view by identifying four factors. In men, the primary factor loaded most heavily on: masculine body build, masculine mannerisms, overall physical strength, upper body strength, and lower body strength. The primary factor for women was limited to: upper body strength, lower body strength, and overall physical strength. In both sexes, the primary factor was interpreted as reflecting the influence of perinatal and post-pubertal testosterone exposure. The other three factors may reflect the effects of other androgens (e.g., androstenediol), or the influence of female hormones such as estradiol. Findings were discussed in terms of future use of self-reported physiological measures for assessing androgenic effects on the human body. 展开更多
关键词 Androgen-promoted PHYSICAL traits TESTOSTERONE MASCULINIZATION PHYSICAL strength FACTORIAL structure Sex differences
下载PDF
Genetic Diversity,Population Structure,and Genome-Wide Association Study of Seven Agronomic Traits in 273 Diverse Upload Cotton Accessions
4
作者 Yajun Liang Juyun Zheng +8 位作者 Junduo Wang Zhaolong Gong Zhiqiang Li Ling Min Zeliang Zhang Zhiwei Sang Yanying Qu Xueyuan Li Quanjia Chen 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第12期3345-3357,共13页
Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cott... Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cotton accessions in the years 2017 and 2018,which were from 18 geographical regions.We found large variations among the traits in different geographical regions and only half of the traits in either years 2017 or 2018 followed a normal distribution.We then genotyped the collection with 81,612 high quality SNPs.Phylogenetic tree and population structure revealed a diverse genetic structure of the core collection,and geographical diversification was an important factor,but account for part of the variances of genetic diversification.We then performed genome-wide association study for the seven traits in the years 2017 and 2018,and the average values of each trait in the two years,respectively.We identified a total of 19 significant marker-trait associations and found that Pollen Ole e 1 allergen/extension could be the candidate gene associated with the fall-off cotton bolls from the last three branches.In addition,large variations were observed for the heritability of traits in the years 2017 and 2018.These results provide new potential candidate genes for further functional validation,which could be useful for genetic improvement and breeding of new cotton cultivars with better agronomic performances. 展开更多
关键词 Upland cotton agronomic trait genetic diversity population structure genome-wide association study
下载PDF
Assessment of Personality Traits of Physical Education Teachers
5
作者 Erdal Demir Gulsah Sahin 《Journal of Sports Science》 2014年第3期154-160,共7页
The purpose of this study is to examine the relationship between the personality traits of physical education teachers working in secondary schools in Istanbul. The research was conducted in accordance with screening ... The purpose of this study is to examine the relationship between the personality traits of physical education teachers working in secondary schools in Istanbul. The research was conducted in accordance with screening model. The research group is formed by physical education teachers who are working in public and private secondary schools which are connected to the Ministry of National Education in Istanbul in 2012-2013 academic years. Among the participants, 36.8% is formed by female physical education teachers, and 63.2% is formed by male physical education teachers. PERI (personality inventory) short form is used. PERI is formed by five subcomponents: openness to experience, sense of responsibility, extroversion, coherence and emotional stability. Assessment instrument was applied to participants with the face-to-face technique by the researcher. Findings were obtained by using T Test, Kruskal-Wallis Test and Mann-Whitney U Test in the analysis of research data. Consequently, it is understood that physical education teachers had low scores on emotional stability personality traits and so they were not adequate. In openness to experience, extroversion, coherence and sense of responsibility subcomponents, it is understood that they had higher scores and they were adequate. Besides, there is no significant difference found between gender, school type and years of service variables and personality traits (P 〈 0.05). 展开更多
关键词 Physical education teacher PERSONALITY personality traits secondary school.
下载PDF
The Impact of Personality Traits and Problem Structures on Management Decision-Making Outcomes
6
作者 JosefNeuert Christopher A. Hoeckel 《Journal of Modern Accounting and Auditing》 2013年第3期380-391,共12页
Since decision-making behavior has been in the focus both from a scientific and a professional position, there seems to be a dispute whether rational or intuitive decision making leads to better outcomes. By now, scho... Since decision-making behavior has been in the focus both from a scientific and a professional position, there seems to be a dispute whether rational or intuitive decision making leads to better outcomes. By now, scholars have agreed that effective organizations do not have the luxury to choose between the "applications" of intuitive or rational decision making. Instead, they try to understand how different factors like personality traits and problem characteristics influence the decision-making process. Reviewing the literature reveals that personality pre-determination and the structure of problems (e.g., well-structured problems (WSPs) versus ill-structured problems (ISPs)) seem to have a significant impact on the decision-making efficiency. Further, the review also shows that there is a lack of application-oriented empirical studies in this area of research. Therefore, the aim of this research paper is to propose a framework for an empirical study on how personality traits and problem structure influence the decision-making process. First, hypotheses are derived from the literature on how personality pre-determination and behavioral patterns in the decision-making process lead to higher socioeconomic efficiency within certain problem categories. Second, a causal model and a setup for a laboratory experiment are proposed to allow testing the hypotheses. Finally, the conclusions provide an outlook on how this research could support organizations in their decision-making processes. 展开更多
关键词 decision making INTUITION RATIONAL personality traits problem structure efficiency
下载PDF
Study on Underground Stem Tissue Structure and Agronomic Traits of Different Populations of Wild Houttuynia cordata Thumb
7
作者 Can CHEN Huang HUANG +2 位作者 Huabin ZHENG Guangxiang DENG Tianxi WANG 《Medicinal Plant》 2017年第6期51-55,共5页
[Objectives] To study the underground stem tissue structure and agronomic traits of different populations of wild Houttuynia cordata Thumb. [Methods] 8 different populations of wild Houttuynia cordata Thumb. in southe... [Objectives] To study the underground stem tissue structure and agronomic traits of different populations of wild Houttuynia cordata Thumb. [Methods] 8 different populations of wild Houttuynia cordata Thumb. in southern China were selected,the preliminary study was carried out about underground stem tissue structure( stem wall thickness,underground stem cross section diameter,medullary cavity,large vascular bundle area,small vascular bundle area,and number of vascular bundles),and main agronomic traits of aboveground and underground parts. [Results]There were significant differences in the underground stem tissue structure and agronomic traits of some populations of wild Houttuynia cordata Thumb. [Conclusions] From comparison,it reached the conclusion that the populations of wild Houttuynia cordata Thumb. in Kunming of Yunnan,Hechuan of Chongqing,and Nanning of Guangxi showed better underground stem tissue structure and agronomic traits. The results are expected to provide certain guidance for cultivation,reasonable development,and utilization of wild populations of Houttuynia cordata Thumb. 展开更多
关键词 Different populations WILD Houttuynia cordata THUMB UNDERGROUND STEM Tissue structure AGRONOMIC traits Comparison
下载PDF
Population Structure and Marker-Trait Association in Indigenous Aromatic Rice 被引量:2
8
作者 Preeti Rekha TALUKDAR Sunayana RATHI +2 位作者 Khanin PATHAK Sanjay Kumar CHETIA Ramendra Nath SARMA 《Rice science》 SCIE CSCD 2017年第3期145-154,共10页
Joha rice of Assam is a class of rice with aroma, good cooking qualities and excellent palatability, which are grown in different places of Assam with their adaptability to local situations. A total of 143 simple sequ... Joha rice of Assam is a class of rice with aroma, good cooking qualities and excellent palatability, which are grown in different places of Assam with their adaptability to local situations. A total of 143 simple sequence repeat markers were used in this study to reveal sufficient genetic variations among the 40 Joha and 14 non-Joha rice genotypes. Polymorphism information content of these markers were from 0.17 to 0.88, where the average of 3.7 alleles were observed. The model-based population assignment and dendrogram analysis identified three distinct groups in the 54 rice accessions, which established a clear identity of Joha accessions from the Basmati accessions, indicating high diversity and strong population structure in Joha rice. Furthermore, a total of 29 significant marker-trait associations(P < 0.05) for 10 characters were detected. The QTLs related with yield and grain quality can be used effectively in crop improvement programs and for further fine mapping and validation of specific genes to develop gene-based perfect markers in rice breeding and for mining of better alleles of these genes in Joha rice collections. 展开更多
关键词 Joha rice GENETIC diversity ASSOCIATION mapping population structure quantitative trait LOCUS AROMA
下载PDF
Host plant traits play a crucial role in shaping the composition of epiphytic microbiota in the arid desert,Northwest China
9
作者 ZHANG Jun ZHANG Yuanming ZHANG Qi 《Journal of Arid Land》 SCIE CSCD 2024年第5期699-724,共26页
Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and productivity.Nonetheless,the impact of host... Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and productivity.Nonetheless,the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains ambiguous.Utilizing high-throughput sequencing technology,this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms(e.g.,bacteria and fungi)of various plant life forms in the hinterland of the Gurbantunggut Desert,Northwest China.Functional annotation of prokaryotic taxa(FAPROTAX)and fungi function guild(FUNGuild)were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial communities.Result showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants,with Proteobacteria,Cyanobacteria,and Actinobacteriota dominating bacterial community,while Ascomycota and Basidiomycota were prevalent in fungal community.Comparison across different plant life forms highlighted distinct microbial communities,indicating strong filtering effects by plant characteristics.FAPROTAX prediction identified intracellular parasites(accounting for 27.44%of bacterial community abundance),chemoheterotrophy(10.12%),and phototrophy(17.41%)as the main functions of epiphytic bacteria on leaves of different life form plants.FUNGuild prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs(81.77%),Pathotrophs(17.41%),and Symbiotrophs(0.82%).Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial taxa.Raup-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community assembly.Variance partitioning analysis and random forest modeling suggested that plant leaf functional traits significantly impacted both bacterial and fungal community composition,with fungal community composition showing a closer association with leaf nutrients and physiology compared with bacterial community composition.The distinct responses of bacterial and fungal communities to plant traits were attributed to the differing properties of bacteria and fungi,such as bacteria having higher potential dispersal rates and broader ecological niches than fungi.Overall,the results indicate that phyllosphere bacterial and fungal communities undergo similar community assembly processes,with fungi being more influenced by plant characteristics than bacteria.These findings offer novel insights into the ecology of phyllosphere microbial communities of desert plants. 展开更多
关键词 phyllosphere epiphytic bacteria phyllosphere epiphytic fungi community structure community diversity functional diversity plant life form plant functional traits
下载PDF
The haplotype-resolved T2T reference genome highlights structural variation underlying agronomic traits of melon 被引量:1
10
作者 Guoli Li Lingli Tang +5 位作者 Yuhua He Yongyang Xu Abdelhafid Bendahmane Jordi Garcia-Mas Tao Lin Guangwei Zhao 《Horticulture Research》 SCIE CSCD 2023年第10期12-24,共13页
Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet a... Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available.Here we report a chromosome-level T2T genome assembly for 821(C.melo ssp.agrestis var.acidulus),a semi-wild melon with two haplotypes of∼373 Mb and∼364 Mb,respectively.Comparative genome analysis discovered a significant number of structural variants(SVs)between melo(C.melo ssp.melo)and agrestis(C.melo ssp.agrestis)genomes,including a copy number variation located in the ToLCNDV resistance locus on chromosome 11.Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1(CmABA2),encoding a cytoplasmic short chain dehydrogenase/reductase,which controls the biosynthesis of abscisic acid.This study provides valuable genetic resources for future research on melon breeding. 展开更多
关键词 AGRONOMIC traits structural
下载PDF
Structural Traits,Structural Indices and Body Weight Prediction of Arsi Cows
11
作者 Aman Gudeto Tesfaye Alemu Aredo +1 位作者 Tadele Mirkena Sandip Banerjee 《NASS Journal of Agricultural Sciences》 2022年第1期33-40,共8页
Structural measurements are indicators of animal performance,productivity and carcass characteristics.This study was conducted with the objectives of assessing structural measurements,developing body weight prediction... Structural measurements are indicators of animal performance,productivity and carcass characteristics.This study was conducted with the objectives of assessing structural measurements,developing body weight prediction and structural indices for cows of Arsi breed.The cows were purchased from highland and lowland agro-ecologies of Arsi and East Shoa zones of Oromia regional state,Ethiopia and kept in Adami Tulu Agricultural Research Center(ATARC)for the breed development purpose.Totally 222 cows were included in the structural traits measurement.Thirty four young heifers were also considered in the study.Twenty two structural traits were considered during observational survey.The structural index was calculated from the phenotypically correlated linear measurements.Structural traits were analyzed by T-test of SPSS version twenty four.The observed average values of height at wither,chest depth,heart girth,body length,pelvic width,cannon bone circumferences of the cows were 107,55.62,141.06,117.82,31.41 and 13.58cm,respectively.Heart girth(0.82),flank girth(0.73),hook circumferences(0.67),chest depth(0.65)and height at rump(0.64)were highly correlated(P<0.01)to body weight of the cows.Regression analysis indicated that hearth girth had the highest coefficient of determination for body weight of the cows and heifers.Accordingly,the simple linear equations were developed to predict the body weight of cows and heifers.Body weight of Arsi cow(y)=-221.005+3.1(heart girth)and Body weight of Arsi heifer(y)=-188.452+2.75(heart girth).Based on this,the measuring chart tape can be developed to estimate the body weight of Arsi cows and heifers at field condition where there is no access to weighing scales. 展开更多
关键词 Cattle structural traits Arsi cows structural indices Body weight prediction
下载PDF
An Assessment Scale for Evaluating the Experimental Design Ability of Elementary Science Teachers Based on Primary Trait Analysis
12
作者 Saiqi Tian Jinxing Zhu +1 位作者 Chuyin Chen Zhiqing Wang 《Journal of Contemporary Educational Research》 2022年第3期12-20,共9页
In this study,an assessment scale for evaluating the experimental design ability of elementary science teachers was constructed based on primary trait analysis.This assessment scale contains three first-level indexes ... In this study,an assessment scale for evaluating the experimental design ability of elementary science teachers was constructed based on primary trait analysis.This assessment scale contains three first-level indexes and eleven second-level indexes.The corresponding weights of indexes were determined by the objective weighting method.The scores of all the descriptions of the indexes were also assigned.After a trial test,this assessment scale was verified to be reliable and valid for evaluating the experimental design ability of elementary science teachers. 展开更多
关键词 Assessment scale Experimental design ability Elementary science teachers Primary trait analysis
下载PDF
Plant functional trait diversity and structural diversity co-underpin ecosystem multifunctionality in subtropical forests 被引量:3
13
作者 Shuai Ouyang Mengmeng Gou +8 位作者 Pifeng Lei Yue Liu Liang Chen Xiangwen Deng Zhonghui Zhao Yelin Zeng Yanting Hu Changhui Peng Wenhua Xiang 《Forest Ecosystems》 SCIE CSCD 2023年第2期153-161,共9页
Tree species diversity is assumed to be an important component in managing forest ecosystems because of effects on multiple functions or ecosystem multifunctionality.However,the importance of tree diversity in determi... Tree species diversity is assumed to be an important component in managing forest ecosystems because of effects on multiple functions or ecosystem multifunctionality.However,the importance of tree diversity in determining multifunctionality in structurally complex subtropical forests relative to other regulators(e.g.,soil microbial diversity,stand structure,and environmental conditions)remains uncertain.In this study,effects of aboveground(species richness and functional and structural diversity)and belowground(bacterial and fungal diversity)biodiversity,functional composition(community-weighted means of species traits),stand structure(diameter at breast height and stand density),and soil factors(pH and bulk density)on multifunctionality(including biomass production,carbon stock,and nutrient cycling)were examined along a tree diversity gradient in subtropical forests.The community-weighted mean of tree maximum height was the best predictor of ecosystem multifunctionality.Functional diversity explained a higher proportion of the variation in multifunctionality than that of species richness and fungal diversity.Stand structure-played an important role in modulating the effects of tree diversity on multifunctionality.The work highlights that species composition and maximizing forest structural complexity are effective strategies to increase forest multifunctionality while also conserving biodiversity in the management of multifunctional forests under global environmental changes. 展开更多
关键词 Abiotic and biotic factors BIODIVERSITY Functional composition Functional traits Soil microbial diversity Stand structure
下载PDF
Statistical Approaches to Mapping QTL of Dynamic Traits 被引量:1
14
作者 杨润清 田佺 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第S1期103-109,共7页
Quantitative traits whose phenotypic values change with time or other quantitative factor are called dynamic quantitative traits. Genetic analyses of dynamic traits are usually conducted in one of two ways. One is to ... Quantitative traits whose phenotypic values change with time or other quantitative factor are called dynamic quantitative traits. Genetic analyses of dynamic traits are usually conducted in one of two ways. One is to treat phenotypic values collected at different time points as repeated measurements of the same trait, which are analyzed in the framework of multivariate theory. Alternatively, a growth curve may be fit to the phenotypes at multiple time points and inference can be made through the parameters of the growth trajectories. The latter has been used in QTL mapping for developmental traits and resulted in an appearance of the functional mapping strategy. Aiming at the disadvantages of functional mapping strategy, we propose to replace the nonlinear and non-additive model biological meaningful by the orthogonal polynomial or B-Spline model to fit dynamic curves with arbitrary shape and analyze arbitrary complicated data, and the constant residual covariance matrix by the alterable one calculated by using auto-correlation function to deal with discrepancies in measurement schedule of phenotype among progenies. A novel RRM mapping strategy was developed for mapping QTL of dynamic traits, which performs higher detecting efficiency than functional mapping, especially for detection of multiple QTL, has been proved by our simulations and data analysis. Finally, a simplified and effective mapping strategy was further discussed by integrating functional mapping and RRM mapping strategies. 展开更多
关键词 DYNAMIC trait MAPPING QTL functional MAPPING random regression model residual COVARIANCE structure
下载PDF
Deciphering the morpho–physiological traits for high yield potential in nitrogen efficient varieties(NEVs):A japonica rice case study 被引量:3
15
作者 ZHU Kuan-yu YAN Jia-qian +4 位作者 SHEN Yong ZHANG Wei-yang XU Yun-ji WANG Zhi-qin YANG Jian-chang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第4期947-963,共17页
The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defi... The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties. 展开更多
关键词 RICE N-efficient varieties nitrogen use efficiency root morpho–physiological traits nitrogen translocation leaf morphology canopy structure
下载PDF
Genome-wide association of 10 horticultural traits with expressed sequence tag-derived SNP markers in a collection of lettuce lines
16
作者 Soonjae Kwon Ivan Simko +2 位作者 Barbara Hellier Beiquan Mou Jinguo Hu 《The Crop Journal》 SCIE CAS 2013年第1期25-33,共9页
Genetic diversity, population structure, and genome-wide marker-trait association analyses were conducted on a special collection of 298 homozygous lettuce(Lactuca sativa L.) lines. Each of these lines was derived fro... Genetic diversity, population structure, and genome-wide marker-trait association analyses were conducted on a special collection of 298 homozygous lettuce(Lactuca sativa L.) lines. Each of these lines was derived from a single plant that had been genotyped with 384 SNP markers using LSGermOPA. They included 122 butterhead, 53 romaine, 63 crisphead, 53 leaf and 7 stem types. Genetic diversity among these plants was assessed by pairwise comparison based on 322 high-quality SNP markers selected from 384 SNPs. Only 258 unique genotypes were identified among the 298 lines because 26 pairs or small groups(a total of 66 lines) shared identical genotypes. The average genetic similarity coefficient(GS) among these unique genotypes was 63.9% with a range of 40.6% to 99.8%. A phylogenetic tree was constructed based on the genotypic data. The most likely number of populations was estimated to be two or six. Association analysis between the 322 SNP markers and 10 phenotypic traits using the 258 homozygous lines was performed by three different methods: single factor analysis, general linear model analysis, and mixed linear model analysis. Nine significant marker-trait associations(SMTAs) were detected at P < 0.0001 with all three methods and also when considering kinship and/or population structure for this collection, with five SMTAs for seed coat color, one for leaf undulation, two for leaf anthocyanin, and one for stem anthocyanin. These markers will be useful in marker-assisted selection after further validation with segregating populations. 展开更多
关键词 LSGermOPA Genome wide ASSOCIATION study SMTA SIGNIFICANT marker trait ASSOCIATION Genetic diversity Population structure
下载PDF
Research on the Influence Factors and Struction of University Teachers Leader-Member Exchange
17
作者 Cuihua Liu 《International English Education Research》 2014年第3期65-68,共4页
The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college ... The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college teachers. In this paper, the "impact factor structure of university teachers LMX Questionnaire" for four universities 808 subjects was investigated. By exploratory factor analysis and confirmatory factor analysis, it found that the structure of university teachers LMX factors includes five dimensions: values, attitudes up, personality characteristics, switching behavior, objective situations. The questionnaire has good reliability and validity. 展开更多
关键词 University teachers LMX Theory structural Factors
下载PDF
Extremely thin but very robust:Surprising cryptogam trait combinations at the end of the leaf economics spectrum
18
作者 Tana Wuyun Lu Zhang +6 位作者 Tiina Tosens Bin Liu Kristiina Mark JoséÁngel Morales-Sanchez Jesamine Jöneva Rikisahedew Vivian Kuusk Ülo Niinemets 《Plant Diversity》 SCIE CAS CSCD 2024年第5期621-629,共9页
Leaf economics spectrum(LES)describes the fundamental trade-offs between leaf structural,chemical,and physiological investments.Generally,structurally robust thick leaves with high leaf dry mass per unit area(LMA)exhi... Leaf economics spectrum(LES)describes the fundamental trade-offs between leaf structural,chemical,and physiological investments.Generally,structurally robust thick leaves with high leaf dry mass per unit area(LMA)exhibit lower photosynthetic capacity per dry mass(Amass).Paradoxically,“soft and thinleaved”mosses and spikemosses have very low Amass,but due to minute-size foliage elements,their LMA and its components,leaf thickness(LT)and density(LD),have not been systematically estimated.Here,we characterized LES and associated traits in cryptogams in unprecedented details,covering five evolutionarily different lineages.We found that mosses and spikemosses had the lowest LMA and LT values ever measured for terrestrial plants.Across a broad range of species from different lineages,Amass and LD were negatively correlated.In contrast,Amass was only related to LMA when LMA was greater than 14 g cm^(-2).In fact,low Amass reflected high LD and cell wall thickness in the studied cryptogams.We conclude that evolutionarily old plant lineages attained poorly differentiated,ultrathin mesophyll by increasing LD.Across plant lineages,LD,not LMA,is the trait that represents the trade-off between leaf robustness and physiology in the LES. 展开更多
关键词 Investment strategy Leaf density Leaf structural traits LMA estimation bias Non-seed plants trait trade-offs
下载PDF
Vertical stratification of ichneumonid wasp communities: the effects of forest structure and life-history traits
19
作者 Filippo Di Giovanni Pierfilippo Cerretti +2 位作者 Franco Mason Emma Minari Lorenzo Marini 《Insect Science》 SCIE CAS CSCD 2015年第5期688-699,共12页
Parasitoid wasp communities of the canopy of temperate forests are still largely unexplored. Very little is known about the community composition ofparasitoids between canopy and understory and how much of this differ... Parasitoid wasp communities of the canopy of temperate forests are still largely unexplored. Very little is known about the community composition ofparasitoids between canopy and understory and how much of this difference is related to forest structure or parasitoid biological strategies. In this study we investigated upon the difference in the community composition of the parasitic wasps Ichneumonidae between canopy and understory in a lowland temperate forest in northern Italy. We used general linear models to test whether parasitic strategy modifies species vertical stratification and the effect of forest structure. We also tested differences in β-diversity between canopy and understory traps and over time within single forest layers. We found that stand basal area was positively related to species richness, suggesting that the presence of mature trees can influence local wasp diversity, providing a higher number of microhabitats and hosts. The ichneumonid community of the canopy was different from that of the understory, and theβ-diversity analysis showed higher values for the canopy, due to a higher degree of species turnover between traps. In our analyses, the vertical stratification was different between groups of ichneumonids sharing different parasitic strategies. Idiobiont parasitoids of weakly or deeply concealed hosts were more diverse in the understory than in the canopy while parasitoids of spiders were equally distributed between the two layers. Even though the ichneumonid community was not particularly species-rich in the canopy of the temperate forests, the extension of sampling to that habitat significantly increased the number of species recorded. 展开更多
关键词 β-diversity biological traits CANOPY forest structure ICHNEUMONIDAE vertical stratification
原文传递
On the Character Trait of Stephen Dedalus in A Portrait of the Artist as a Young Man
20
作者 胡梦巧 《海外英语》 2017年第4期152-153,共2页
A Portrait of the Artist as a Young Man is the first novel of stream of consciousness in western literature history, it mainly shows the protagonist, Stephen Dedalus' s journeys from childhood to adulthood. This p... A Portrait of the Artist as a Young Man is the first novel of stream of consciousness in western literature history, it mainly shows the protagonist, Stephen Dedalus' s journeys from childhood to adulthood. This paper aims at a better understanding of Stephen Dedalus, and it analyzes his character traits in literature analysis method, textual analysis method and Freud's theory of personality structure and is useful for further study. 展开更多
关键词 stephen character traits POSITIVE NEGATIVE Freud’s theory of personality structure
下载PDF
上一页 1 2 92 下一页 到第
使用帮助 返回顶部