Association mapping of yield and its components in rice 2007
Association mapping of yield and its components in rice cultivars
H.A.Agrama ?G.C.Eizenga ?W.Yan
Received:23April 2006/Accepted:29October 2006/Published online:11February 2007óSpringer Science+Business Media B.V.2007
Abstract To make advances in rice breeding it is important to understand the relatedness and ancestry of introduced rice accessions,and iden-tify SSR markers associated with agronomically important phenotypic traits,for example yield.Ninety-two rice germplasm accessions recently introduced from seven geographic regions of Africa,Asia,and Latin America,and eleven US cultivars,included as checks,were evaluated for yield and kernel characteristics,and genotyped with 123SSR markers.The SSR markers were highly polymorphic across all accessions.Popu-lation structure analysis identi?ed eight main clusters for the accessions which corresponded to the major geographic regions,indicating agree-ment between genetic and prede?ned popula-tions.Linkage disequilibrium (LD)patterns and distributions are of fundamental importance for genome-wide mapping association.LD between linked markers decreased with distance and with a substantial drop in LD decay values between
20and 30cM,suggesting it should be possible to achieve resolution down to the 25cM level.For the 103cultivars,the complex traits yield,kernel width,kernel length,kernel width/length ratio,and 1000-kernel weight,were estimated by analysis of variety trial data.The mixed linear model method was used to disclose marker-trait associations.Many of the associated markers were located in regions where QTL had previ-ously been identi?ed.In conclusion,association mapping in rice is a viable alternative to QTL mapping based on crosses between different lines.
Keywords Linkage disequilibrium áUni?ed mixed-model method áPopulation structure áKinship coef?cient áRelatedness Abbreviations
SSR Simple sequence repeat QTL Quantitative trait loci cM CentiMorgan
Introduction
Rice (Oryza sativa L.)genetic mapping often involves the development,genotyping,and phe-notyping of doubled haploid (Li et al.2003;
H.A.Agrama (&)
University of Arkansas Rice Research and Extension Center,Stuttgart,AR 72160,USA e-mail:hagrama@https://www.sodocs.net/doc/182775097.html,
G.C.Eizenga áW.Yan
United States Department of Agriculture –Agricultural Research Service,Dale Bumpers
National Rice Research Center,Stuttgart,AR 72160-1090,USA
Mol Breeding (2007)19:341–356DOI 10.1007/s11032-006-9066-6
Hittalmani et al.2002),recombinant inbred(Ge et al.2005;Guo et al.2005),or advanced backcross(Li et al.2004;Jing et al.2005)lines derived from an F1cross between different cultivars.For these mapping populations there is extreme disequilibrium between linked loci (Mather et al.2004)and there should be no population structure,because of the random sampling,or disequilibrium between non-linked loci favoring the detection and approximate mapping of quantitative trait loci(QTL).In contrast,genetic mapping in humans relies on analysis of genotypic and phenotypic data sam-pled non-randomly from existing populations of complex but often unknown structure.In these populations,linkage disequilibrium(LD)may decline over relatively short or long distances in the genome,making?ne mapping possible.In sugar beet(Beta vulgaris L.),LD extended to 3cM(Kraft et al.2000)and LD in some Arabidopsis populations exceeded50cM(Nord-borg et al.2002).LD as a function of genetic distance is very common for distances<10cM (Kraakman et al.2004)in barley(Hordeum vulgare L.),in contrast with maize(Zea mays L.),for which the LD diminished after2000bp (Remington et al.2001).LD decay between all pairs of SNP(single nucleotide polymorphism) loci in the region around the rice xa5locus approached0.1after only100kb(Garris et al. 2003)and in Arabidopsis the pattern of polymor-phism LD decayed rapidly,within50kb(Nord-borg et al.2005),in contrast with one human population for which the LD extended over3cM (Eaves et al.1998).Most studies of species variation begin by sampling from populations de?ned on the basis of culture or geography and might not re?ect underlying genetic relationships (Rosenberg et al.2002;Foster and Sharp2002).If a whole-genome scan is to be undertaken,trait mapping by allele association requires high marker density(Lander and Schork1994;Jorde 1995;Jorde2000;Risch2000).SSRs are particu-larly useful for studying the population structure and demographic history of domesticated species such as rice(Garris et al.2005),and are being extensively used to genotype rice germplasm collections(Yang et al.1994;McCouch et al. 1997;Ishii and McCouch2000;Ishii et al.2001;Ni et al.2002;Lu et al.2005).Use of SSR markers to interpret population structure results in much greater resolution than use of other types of marker,because of the high level of polymor-phism at SSR loci(Akkaya et al.1992;Cho et al. 2000).In rice the highly polymorphic nature of SSR motifs is coupled with a low level of homoplasy observed in O.sativa cultivars(Chen et al.2002),providing an appropriate tool for population genetic studies.Although polymor-phic SSRs are excellent molecular markers, because of their multi-allelism and the resulting high informativeness(Weber and May1989),they may not be frequent enough for association studies(Ching et al.2002).Size homoplasy of SSR alleles and allele reversion could also be a problem in some populations(Estoup et al.1995; Viard et al.1998).Rice has the smallest genome size(estimated as approx.430Mb)among cereal crops,which makes it most manageable at the whole-genome level.
The potential of LD and regression methods to identify and characterize loci/genes associated with different complex traits in true breeding lines has been demonstrated in barley and maize(Kraakman et al.2004;Wilson et al.2004).In contrast with calculating associations between pairs of loci or genes by the traditional LD technique,or using a single marker-trait regression scheme,a multivar-iate approach,known as discriminant analysis,has been used for whole-genome scans of microsatellite markers associated with economic traits in unre-lated inbred lines of rice(Zhang et al.2005).Of particular interest to rice breeders is the possibility of using existing germplasm resources for gene and allele discovery on the basis of association mapping strategies(Kruglyak1999;Jorde2000;Farnir et al. 2000).Understanding population structure is important to avoid identifying spurious associa-tions between phenotype and genotype in associ-ation mapping(Pritchard and Rosenberg1999; Pritchard et al.2000;Pritchard and Donnelly2001).
Detection of marker-trait associations in breeding germplasm has potential advantages over classical linkage analysis and QTL mapping (Jannink and Walsh2002).For example,broader genetic variation in a more representative genetic background can be included in the analysis,LD mapping may achieve higher resolution,and
multi-trait phenotypic data stored in databases can be linked to marker characterizations of the cultivars involved.The last advantage is espe-cially important when evaluation of the trait is time-consuming and expensive,as it is for yield, adaptability,and stability(Kraakman et al.2004). This approach may,however,be limited by the structure of the population,eventually leading to spurious,inappropriate levels of LD for QTL mapping,and insuf?cient phenotypic or genetic diversity available within the gene pool(Condon and Smith2005).The number of markers needed for genome-wide LD scanning depends on the level of LD,however;to be effective,LD-map-ping requires a marker density compatible with the distances across which LD extends in the population of interest.Association mapping could complement and enhance previous QTL infor-mation for marker-assisted selection in wheat (Breseghello and Sorrells,2006),barley(Kraak-man et al.2006),and maize(Yu and Buckler 2006).Within different sets of barley germplasm there was frequent disequilibrium among non-linked SSR markers,suggesting that association mapping without consideration of population structure would result in a high rate of false positive Type I errors(Mather et al.2004).Use of auni?ed mixed-model approach to account for multiple levels of relatedness simultaneously,as detected by use of genetic markers,has improved control of both type I and type II error rates(Yu et al.2006).
Multi-allelic markers,for example SSRs,have been used to characterize population structure in maize(Flint-Garcia et al.2005;Remington et al. 2001)and rice(Garris et al.2003);and LD-based associations in wheat,(Kruger et al.2004),barley (Maccaferri et al.2005),and Lolium(Sk?t et al. 2005).The objective of this research was to use a large collection of blast(Magnaporthe oryzae B. Couch)resistant rice accessions to determine the utility of population structure analysis,linkage disequilibrium(LD),and association mapping of yield traits in evaluating rice germplasm accessions. Materials and methods
Included in this study were92blast-resistant rice germplasm accessions from seven different regions of Africa,Asia,and Latin America (Table1).The91accessions were recently added to the USDA-ARS National Plant Germplasm System.The eleven US cultivars were Bengal (PI561535),Cocodrie(PI606331),Drew (PI596758),Katy(PI527707),Kaybonnet (PI583278),LaGrue(PI568891),Lemont (PI475833),Newbonnet(PI474580),Wells(Mold-enhauer et al.2000),Saber(PI633624),and Zenith(CIor7787).TeQing(PI536047)is an older cultivar from Guangdong,China.Further infor-mation on the accessions and cultivars is available from the USDA-ARS National Plant Germplasm System(https://www.sodocs.net/doc/182775097.html,/npgs/).
The test was seeded in April2000and April 2001in a split-block design(group as main block)with four replications at the University of Arkansas Rice Research and Extension Center in Stuttgart,AR,USA.The plots were 4.5m long and six rows wide with20cm spacing between rows.At maturity, 3.6m from the center,two rows in each plot were harvested for grain yield(GY).Other aspects of?eld management and measures of grain quality were as described by Dilday et al.(2001)and Yan et al.(2003).Seed(30g)of each accession was dehulled to determine the kernel length(KL), kernel width(KW)and kernel length/width ratio (LWR)with the GrainCheck312video image system(FOSS Food Technology).Thousand kernel weight(TKW)was determined by weigh-ing1000rice kernels.
Genomic DNA was extracted from leaf tissue by the methods described in Eizenga et al.(2006). One-hundred and twenty-three microsatellite markers located on the twelve chromosomes were selected from the core set developed and mapped by McCouch et al.(2002).The forward primers were labeled with FAM,TET,NED,or HEX ?uorescent dyes and the reverse primers were unlabeled.DNA ampli?cation was performed using an MJ Research PTC-10096Plus thermal cycler.PCRs were conducted in a10-l L reaction mix containing37.5ng template DNA,1·PCR buffer,0.025units Taq DNA polymerase(Qia-gen,Valencia,CA,USA),0.2mmol dNTPs,and 0.8pmol forward and reverse https://www.sodocs.net/doc/182775097.html,rma-tion on primer sequences and PCR ampli?cation conditions for each set of primers are available at
Table1Rice germplasm accessions included in this study and their country of origin a
No.Accession name Country of origin b 1Bhujon Kolpo Bangladesh
2Bogra Bangladesh
3Khoia Bangladesh
4Iac47Brazil
5IRGA409Brazil
6Guang-6ai-4China
702428China-CD
8Chunzhi No.11China-CD
9Fu No83China-CD
10Kechengnuo No.4China-CD
11Sheng10China-CD
12Shufeng117China-CD
13Shufeng122China-CD
14Tie90-1China-CD
15Tiejing No.4China-CD
16Zhang32China-CD
17Xiangzaoxian No.1China-HN 1871198China-HZ
19Aijiaonante China-HZ
20Zanuo No.1China-HZ
21Zhongyu No.1China-HZ
22Zhongyu No.6China-HZ
23Zhongzao No.1China-HZ
24460China-JT 252410China-JT 264484China-JT 274593China-JT 284594China-JT 294596China-JT 304597China-JT 314607China-JT 324611China-JT 334612China-JT 344632China-JT 354633China-JT 364642China-JT 374641(1)China-JT
38GP-2China-JT
39Gui99China-JT
40R147China-JT
41R312China-JT
42Dian No.1China-KM
43Egyptian Jasmine Egypt
44GZ-1368-5-4Egypt
45GZ-5578-2-1-2Egypt
46GZ-5594-23-1-2Egypt
47GZ-5830-48-2-2Egypt
48Ad9246Ivory Coast
49Fkr19(Tox728-8)Ivory Coast
50Fkr48Ivory Coast
5132Xan Sc Ivory Coast
52Ita406Ivory Coast
53Ita416Ivory Coast Table1Continued
No.Accession name Country of origin b 54Let3137Ivory Coast
55S992-F4-2-5-1-B Ivory Coast
56Tnau7893Ivory Coast
57Tox3093-35-2-3-3-1Ivory Coast
58Tox3211-49-1-1-3-2Ivory Coast
59Tox3241-21-2-2-3-2Ivory Coast
60Tox3241-22-3-3-3Ivory Coast
61Tox3241-31-2-1-3-1Ivory Coast
62Tox3441-123-2-3-2-2-2Ivory Coast
63Tox3553-34-3-2-3-2-2Ivory Coast
64Tox3706-60-3-3-3Ivory Coast
65Tox3706-6-3-3-2Ivory Coast
66Tox3716-4-3-2-2-2-2Ivory Coast
67Tox3717-25-3-1-3Ivory Coast
68Tox3717-25-3-3-1Ivory Coast
69Tox3717-25-3-3-2Ivory Coast
70Tox3717-76-2-2-3Ivory Coast
71Tox3717-81-1-1-3Ivory Coast
72Tox3770-17-2-2-1Ivory Coast
73Tox3771-144-2-1-1Ivory Coast
74Tox3772-38-2-2-3Ivory Coast
75Tox3772-40-3-2-2Ivory Coast
76Tox3772-94-1-1-1Ivory Coast
77Tox3779-51-2-2-2Ivory Coast
78Tox3867-19-1-1-3-1-1-1Ivory Coast
79Tox3869-34-1-3-1-1-3-3Ivory Coast
80Tox3872-61-3-3-3-2-1Ivory Coast
81Tox3894-41-2-3-1Ivory Coast
82Tox4136-38-2Ivory Coast
83Tox4251-313-3Ivory Coast
84Tox3749-71-1-1-3-2-2Ivory Coast
85Wab450-24-3-2-P18-hb Ivory Coast
86Wab450-I-B-P-62-hb Ivory Coast
87Pyongyang23Korea,N.
88IR56450-28-2-21Philippines
89Nj7050717578Philippines
90RP2199-16-2-2-1Philippines
91S972B-22-1-3-1-1Philippines
92Bengal USA
93Cocodrie USA
94Drew USA
95Katy USA
96Kaybonnet USA
97LaGrue USA
98Lemont USA
99Newbonnet USA
100Saber USA
101Te Qing China/USA
102Wells USA
103Zenith USA
a Adapted from Eizenga et al.(2006)
b Source of Chinese germplasm:CD-Chengdu,HN-Hunan,HZ-Hangzhou,KM-Kunming,JT-Joshua Tao
https://www.sodocs.net/doc/182775097.html,/(veri?ed3July2006). PCR products were separated by size using an ABI3700DNA analyzer(Applied Biosystems (ABI),Foster City,CA,USA).SSR fragment sizing was performed with Gene Scan software (ABI)using the local Southern method and default analysis settings after which alleles were identi?ed with Genotyper software(ABI)and binned manually.For most markers fractional numbers were rounded to the nearest integer and alleles differing by1bp were declared different. SSR data,obtained from genotyping US cultivars with the same ABI3700DNA analyzer(Lu et al. 2005),was included for comparison.The map position of most of the SSR loci was inferred from McCouch et al.(2002).
The model-based software Structure(Pritchard et al.2000)was used to infer population structure using a burn-in of10,000,run length of100,000, and a model allowing for admixture and corre-lated allele frequencies.Ten independent runs yielded consistent results.A model-based cluster-ing algorithm was applied that identi?ed sub-groups with distinctive allele frequencies.This procedure,implemented in computer structure, places individuals into K clusters,where K is chosen in advance but can be varied for indepen-dent runs of the algorithm.The degree of admix-ture,alpha,was inferred from the data.When alpha is close to zero,most individuals are essentially from one population or another whereas alpha>1means that most individuals are admixed(Falush et al.2003).The range of possible tested K s was from2to10.
Distance-based analysis of the accessions using Euclidean inferred ancestry for each accession and the key for identifying the accessions was shown in the neighbor-joining tree using the unweighted pair group method using arithmetic averages(UPGMA).This is a hierarchical algo-rithm for clustering accessions into similar groups. The output of this clustering procedure is a dendrogram or tree with distance along the horizontal(top)axis and the accessions lines listed vertically down the side.Levels of genetic variation within and among populations identi?ed by the cluster analysis were estimated from allelic frequencies using analysis of molecular variance, AMOVA(Weir and Cockreham1984;Weir 1996).The software Arlequin 3.0(Excof?er et al.2005)performs the AMOVA procedure using SSR and standard multi-locus frequency data.Wright’s F-statistics are a hierarchical series of?xation indices where F IS represents the deviation from Hardy–Weinberg expectation within populations(approximately equal to the mean F across populations),F ST measures the ?xation of different alleles in different popula-tions,and F IT measures deviations from Hardy–Weinberg expectation across the population sys-tem as a whole.
Decay of LD with distance in cM between SSR loci within the genome was evaluated using PowerMarker 3.23(Liu and Muse2004).The LD decay was calculated using the statistical coef?cient of determination(R2)which is a measurement of correlation between a pair of variables(Hill and Robertson1968).All associ-ation tests were run with the mixed linear model (MLM)method as described by Yu et al.(2006) in TASSEL1.9.4(https://www.sodocs.net/doc/182775097.html,/), a recently developed uni?ed mixed-model meth-od simultaneously taking into account multiple levels of both gross level population structure(Q) and?ner scale relative kinship(K).The popula-tion structure matrix(Q)was identi?ed by run-ning Structure at K=7.The relative kinship matrix(K matrix)was obtained by running SPAGeDi(Hardy and Vekemans2002).Output from SPAGeDi was formatted to a text?le readable by TASSEL.The P-value determines whether a QTL is associated with the marker and the R2-marker evaluates the magnitude of the QTL effects(personal communication,Zhiwu Zhang,Cornell University).
Results
The103accessions had a mean grain yield(GY) of7,301kg ha–1,a mean kernel length(KL)of 6.7mm,a mean kernel width(KW)of2.3mm,a mean kernel length/width ratio(LWR)of2.9,and a mean1000-kernel weight(TKW)of21.2g (Table2).Correlations of TKW with GY and with KW,and of KL with LWR were very signi?cant(P<0.0001).Correlation of KL with TKW was signi?cant(P<0.001)as was the
correlation of GY with KW(P<0.01).There was a positive correlation between GY and KL but it was not signi?cant.Signi?cant negative correla-tions of LWR with KW(P<0.0001)and GY (P<0.01)were found.This indicates that increas-ing KW and KL results in increase kernel weight and,to a lesser extent,improves GY.The correlations also suggest that increased KW has more effect on GY than increased KL.The negative correlation between KW and KL (P<0.001)indicates that as KW increases KL decreases.
All123SSR markers were polymorphic and produced a total of1009alleles among the103 accessions assayed.The average number of alleles per locus was8.2,ranging from2(RM338on chromosome3)to21(RM206on chromosome 11).The average genetic diversity over all SSR loci was0.635,ranging from0.115(RM512on chromosome12)to0.881(RM304on chromo-some10).
Analysis of genetic distance and population structure provided evidence of signi?cant popu-lation structure in these rice accessions and identi?ed the highest likelihood value at K=7 for all ten replicates(Fig.1).Analysis of these data identi?ed the major substructure groups when the number of populations was set at three,however,which was consistent with clustering based on genetic distance.In this worldwide sample,accessions from the same prede?ned population nearly always shared similar membership coef?cients in inferred clus-ters(Fig.2).At K=3,most accessions were classi?ed into one of the three groups,which corresponded to the traditional rice sub-species indica(29accessions),temperate japonica(32), and tropical japonica(17)separated by relatively large genetic distance.In addition to these78 accessions that were clearly assigned to a single population,where more than85%of their inferred ancestry is derived from one of the model-based populations,25accessions in the sample were categorized as having a mixed ancestry,de?ned as an‘‘admix’’(Fig.2). Although most of these were identi?ed as admix-ture between indica and temperate japonica groups,other admixture combinations were also present.
Divergence among the accessions was found using all measures of population structure.The Structure model-based analysis for several theo-retical population sizes(de?ned in this study as ancestral backgrounds)with the highest posterior probability was for a model with seven different backgrounds(Fig.3,center).For these ancestral backgrounds,a burn of10,000runs followed by data collection on100,000runs seemed to be suf?cient,giving reasonably consistent values of ln prop data(X|K)across replicates.At K=7,the backgrounds largely corresponded to major geo-graphic regions with one background being US accessions.Several accessions,for example ‘‘Tox3717-25-3-3-2’’and‘‘Shufeng-122’’,had
par-
Table2Descriptive statistics for yield(GY),dehulled kernel length(KL),kernel width(KW),kernel length/ width ratio(LWR),and1000-kernel weight(TKW)
GY(kg ha–1)KL
(mm)
KW
(mm)
LWR TKW
(g)
Average7301 6.7 2.3 2.921.2 Range8822 2.4 1.1 3.011.2 Minimum2897 5.4 1.8 1.016.2 Maximum117197.8 2.9 4.027.4 Std.Dev.19500.60.20.5 2.1 Correlations
GY
KL0.019
KW0.186*–0.481**
LWR–0.162*0.846***–0.748***
TKW0.348***0.395**0.496***–0.064
*P<0.01,**P<0.001,***P<0.0001
tial membership in multiple backgrounds.At K=7,the cluster that included tropical japonica populations split into two clusters,of which one includes all US genotypes(Fig.3).
Distance-based analysis of the103accessions with Euclidean distance detected eight major clusters(Fig.3,left and right sides).The acces-sions were classi?ed into eight clusters by the UPGMA and algorithm neighbor joining tree based on the genetic similarity matrix.These clusters usually agreed with the origin of the accessions and the clustering previously de?ned by Eizenga et al.(2006).All US accessions were grouped in cluster1;cluster3contained Chinese lines from J.Tao,cluster4contained the breeding lines obtained from the Africa Rice Center (WARDA),Bouake,Ivory Coast,cluster7 mainly included Chinese lines from Chengdu, and cluster8contained the Chinese lines from Hangzhou(Fig.3).Clusters2,5,and6had more than one ancestral background,de?ned as an admixture,and these clusters included accessions from Bangladesh,Brazil,Egypt,North Korea,the Philippines,and China.
The distribution of molecular genetic variation among and within the eight clusters of accessions was estimated by AMOVA,which revealed41% of total variation was among the clusters whereas 51%of the variation was within the clusters (Table3).Calculation of Wright’s F statistics for all SSR loci revealed F IS was0.66,suggesting there was deviation from Hardy–Weinberg expec-tation for molecular variation within the clusters, F IT was0.71,signifying non-equilibrium condi-tions across clusters and a de?ciency of heterozy-gous SSR loci,and F ST was0.312indicating31.2% of the total genetic variation was among the clusters.
Determination of F ST for the polymorphic SSR loci across all accessions revealed F ST ranged from0.06for RM120on chromosome11to0.94 for RM124on chromosome4with an average of 0.381,indicating38.1%of the total variation in allele frequency of the103accessions was because of genetic differences among clusters.Determi-nation of the pair-wise F ST values between the eight clusters(Table4)indicated that genetic differentiation among clusters was highest for the combination of clusters1and3(F ST=0.719). The F ST values for cluster1paired with clusters4, 5,6,7,and8ranged from0.649to0.533and F ST=0.381for clusters1and 2.These values con?rm that the US accessions were quite differ-ent from most other accessions except those in cluster2.The combination of clusters7and8had the lowest F ST value(0.110),because of the shared ancestry of these clusters.The average F ST value for all eight cluster combinations was0.391.
The distribution of data points in the plot of LD (R2)decay against distance(cM)within the twelve chromosomes(Fig.4)showed that LD was not a simple monotonic function of the distance between markers.LD was very common for distances <30cM and occasionally,LD occurred between SSR loci that were further apart.The R2between unlinked markers on different chromosomes was mainly<0.4.Some unlinked SSR markers associ-ated with blast resistance were identi?ed using these accessions by Eizenga et al.(2006)and had higher R2.For example,R2values were1.0(RM206 on chromosome11,OSM89on chromosome12), 0.96(RM208on chromosome2,RM5963on chromosome6),and0.91(RM3431-ch6,RM144-ch11).In contrast with a-priori expectation,some marker pairs that were close together on the Gramene map were not correlated across the genotypes and so were in linkage equilibrium.
Association analysis(Table5)identi?ed mar-ker-trait associations(P<0.05)for all the traits evaluated,these included GY,KW,and LWR, associated?ve markers each,KL,with six mark-ers,and TKW,with four markers.A total of25 marker-trait associations were identi?ed with21 different SSR markers.Four markers were asso-ciated with two traits:RM85on chromosome3 was associated with KW and TKW,RM122on chromosome5was associated with KL and TKW, RM459also on chromosome5was associated with KL and TKW,and RM228on chromosome 10was associated with GY and LWR.Seventeen of the25associations were in regions where QTL associated with the given trait had previously
Fig.2Estimated population structure(K=3)for the103 accessions as rice subgroups tropical japonica(TRJ), temperate japonica(TEJ),and indica(IND).Each accession is represented by row,which is partitioned into K colored segments according to the individual’s esti-mated membership fractions in each of the K clusters
b
been identi?ed(https://www.sodocs.net/doc/182775097.html,/).Of the
25marker-trait associations,seven were identi?ed as explaining20%or more of the total variation (R2,Table5)for GY(RM261,RM228),KL (RM284),LWR(RM7,RM228),and TKW (RM440,RM122).Only RM284associated with KL was not in the region of a previously identi?ed QTL for the associated trait.
Discussion
The genetic structure of rice has previously been documented(Glaszmann1987;Parsons et al. 1999;Ni et al.2002;Garris et al.2005)but this analysis uses accessions recently introduced into the USA that have blast resistance(Eizenga et al. 2006).By use of Structure software with K=3, the O.sativa rice accessions were signi?cantly differentiated into three subgroups,temperate japonica,tropical japonica,and indica.The anal-ysis revealed that several accessions had partial ancestry in more than one backgrounds.These accessions probably had a complex breeding history involving intercrossing and introgression between germplasm from diverse backgrounds, overlaid with strong selection pressure for agro-nomic and quality characteristics(Mather et al. 2004).Population structure analysis identi?ed eight main clusters for the accessions that corre-sponded to major geographic regions.General agreement between the genetic and prede?ned clusters suggests that knowledge of the ancestral background can facilitate choices of parental lines in rice-breeding programs(Rosenberg et al. 2002).Although both rice-breeding efforts and domestication have had large effects on structur-ing the diversity of rice,the independent popula-tion histories of the groups have also shaped the gene pools(Garris et al.2005).
Values of F ST were high when the eight clusters were considered,thus identifying large differ-ences between the accessions.It has been dem-onstrated that markers with higher F ST values have greater resolving power and produce more consistent genetic distance estimates(Watkins et al.2003).The signi?cant F ST among the clusters suggests a real difference between these clusters,and heterosis might be observed for crosses between the accessions made to improve yield(N’Goran et al.2000).
Linkage disequilibrium(LD)studies have now been conducted for more than a dozen plant systems,both at the individual gene level and at the level of whole genome.In individual species, these studies included:
Fig.3Population structure and distance-based analysis of the103rice accessions using Euclidean-inferred ancestry for each accession.Initially,the accessions were divided into clusters based on UPGMA and neighbor joining(left and right sides).Next,the accessions were divided into seven ancestral backgrounds de?ned as K(center)based on analysis in Structure.Accessions were assigned to a single background or to two or more backgrounds if the genotype indicated the accession was admixed with membership in two or more different backgrounds and estimated on a scale from1.0(accession is from one K only)to0.0(accession is not from this K)
b
Table3Analysis of molecular variance (AMOVA)for the eight clusters of rice accessions identi?ed in Fig.3 Fixation indices:
F IS=0.663,F ST=0.312, F IT=0.710Source of variation d.f.Sum of
squares
Variance
components
Percentage
variation
P-
value Among clusters71193.29 6.1441.37<0.001 Among accessions within
clusters
951707.258.3250.71<0.001 Within accessions103136.50 1.327.92<0.001 Total2053037.0415.79
Table4Pair-wise F ST values between eight clusters as
identi?ed using Euclidean distance in Fig.3
Popu-
lation
12345678
1–
20.381–
30.7190.601–
40.6090.4850.496–
50.5610.4180.3920.169–
60.6490.4670.4790.3620.198–
70.5890.4120.3600.2910.1680.142–
80.5330.4000.3010.2910.1570.2080.110–
(i)estimation of the extent of LD in different
plant genomes or in different parts of the
genome of an individual species,
(ii)measure of nucleotide diversity/haplotype structure,(iii)assessment of the effect of selection/domes-tication,
(iv)identi?cation of marker-trait associations, Gupta et al.(2005).
Table5Association(R2)of SSR markers with yield(GY),dehulled kernel length(KL)and width(KW),length/width ratio (LWR),and1000dehulled kernels weight(TKW),as described in Table2
Trait SSR Marker a Chromosome no.Position(cM)P R2b GY RM4163191.6c0.05150.1244 GY RM261435.4c0.00160.2032 GY RM4478124.60.03700.1950 GY RM2711059.4c0.01110.1909 GY RM2281096.3c0.01180.2542 KL RM259154.2c0.02370.1016 KL RM163131.5c0.03170.1155 KL RM12250.0c0.01670.1226 KL RM284883.70.01970.3258 KL RM2021154.00.01050.1012 KL RM2871168.60.04910.1994 KW RM4683202.30.00600.1351 KW RM853231.00.01030.1451 KW RM459593.6c0.00410.1305 KW RM2487116.60.01060.1867 KW RM15289.4c0.00220.1318 LWR RM10920.00.00090.1287 LWR RM7364.0c0.01710.2359 LWR RM2459112.30.00060.1748 LWR RM2281096.3c0.02030.3213 LWR RM1471099.8c0.01390.1330 TKW RM449178.4c0.01180.2199 TKW RM853231.0c0.04290.1914 TKW RM12250.0c0.00390.2661 TKW RM459593.6c0.05090.1750
a Only SSR markers with a signi?cant marker-trait association are reported(P<0.05)
b R2indicates the percentage of the total variation explained
c QTL for the given trait previously reporte
d in th
e same region(https://www.sodocs.net/doc/182775097.html,/)
The LD between unlinked loci,for example RM208and RM224on chromosomes2and11, and RM3431and RM144on chromosomes6and 11,was occasionally signi?cant.These markers are linked with three blast-resistance(Pi-)genes located on these chromosomes(Fjellstrom et al. 2004).LD was high among unlinked SSR markers around Pi that were associated with blast resis-tance in these accessions.Our results suggest that mapping strategies exploiting LD around the region of Pi-loci may be particularly effective in rice,as it was in exploiting the haplotype diversity and LD surrounding the xa5locus(Garris et al. 2003).Further research will be conducted to describe the diversity and decay of linkage disequilibrium in this region of the rice genome, to characterize the extent of LD in resistant accessions,to determine if it is possible to reduce the number of candidate genes,and to analyze haplotype diversity in the context of population structure to determine the distribution of the resistance allele among ecotypes and to make predictions about the allelic diversity underlying the Pi phenotype.In contrast with the situation in the human,genome-wide LD mapping of which may require a marker density two times of magnitude higher than that required for conven-tional linkage mapping,the available150micro-satellites could be suf?cient for?rst-pass LD screening in rice genotypes(Kruglyak1999).The corollary of this observation,however,is that the mapping resolution to be gained from LD is likely to be limited in these populations also.In this work we still observed a substantial drop in LD values between20and30cM,suggesting it should,nevertheless,be possible to achieve res-olution down to the25cM level.The same observation on LD at larger distances was found in Arabidopsis(Nordborg et al.2002)and barley (Kraakman et al.2004).In sugar beet lines, however,LD was<3cM(Kraft et al.2000),in Lolium perenne,LD was<3.4cM(Sk?t et al. 2005),and in maize LD diminished over a distance of2000bp(Remington et al.2001). Signi?cant LD between pairs of unlinked markers was observed(McRae et al.2002;Sk?t et al. 2005),emphasizing the advantage of both linkage and LD testing.Many factors affect LD(Ardlie et al.2002),but the most probable cause of the high level of LD in rice is that it is a self-pollinated species.Selection can also increase LD,for instance,by a hitchhiking effect in which the alleles at?anking loci of a locus under selection can be rapidly swept to high frequency or?xation(Kraakman et al.2004).Further analyses will be required to evaluate the bene?t of LD mapping at the sub-cM level in these populations.
For LD between two multi-allelic loci,r2 (statistical coef?cient of determination)and D￠(absolute ratio of deviation of haplotype frequen-cies from disequilibrium compared with its max-imum value)are the most widely used measure of LD for each pair of alleles,or even for overall LD between all the alleles at two loci(Gupta et al. 2005).Whereas D￠measures only recombination differences,r2summarizes recombination and mutation history.Also,r2is indicative of how markers might be correlated with the QTL of interest,so r2is often preferred for association studies(Abdallah et al.2003).In the sets of cultivated rice examined here,linkage disequilib-rium as r2is present on a scale that could be useful for association mapping.Genome-scale association mapping should be possible,if ade-quate methods are implemented to control the effects of population structure.Model-based analyses of population structure,for example those conducted here,may be helpful for provid-ing information that could be incorporated into association mapping analyses.
Fear of false-positive outcomes arising from population strati?cation has virtually dictated progress in human association study design and analysis methodology(Cardon and Bell2001,Yu et al.2006).Genome-scale association mapping should be possible if adequate methods are implemented to control for the effects of popu-lation structure.Association mapping without consideration of population structure would have a high rate of Type I error(false positive)because of spurious associations between non-linked loci. Model-based analysis of population structure similar to that conducted here has provided information that has been incorporated into association mapping analysis.
In the eight clusters identi?ed in this study,F IS was high,suggesting that most of the populations
deviated from the Hardy–Weinberg expectation within populations.The F IT value,indicating nonequilibrium conditions across populations and de?ciency of heterozygotes,was also high. Testing for association between the SSR multilo-cus genotype data associated with quantitative variation in the presence of population structure (Thornsberry et al.2001;Remington et al.2001) was applied using the MLM procedure in TAS-SEL(Yu et al.2006).The positive results from these studies should encourage the further testing of these methods in different genetic systems,in the same way as we applied these procedures to rice.Association between markers and grain yield,dehulled kernel length,and width,length/ width ratio,and1000-kernel weight was examined in two ways—signi?cance of marker-trait associ-ation(P-values)using TASSEL software and marker-trait associations found in other QTL studies reported in https://www.sodocs.net/doc/182775097.html,/.This indicates that QTL detected in mapping popula-tions from biparental mapping populations were widely presented in this set of accessions,and that they could be detected with LD mapping.Asso-ciation between traits and marker regions that had not been implicated before to affect trait suggest new QTL.The trait markers association was indicative of a rapid decrease in correlation, suggesting LD across a short distance.Within different sets of barley germplasm there was frequent disequilibrium among non-linked SSR loci,suggesting that association mapping without consideration of population structure would have a high rate of false positive Type I error(Mather et al.2004).A uni?ed mixed-model approach to account for multiple levels of relatedness simul-taneously,as detected by genetic markers,has resulted in improved control of both type-I and type-II error rates(Yu et al.2006).
Plant genetics has an important and challeng-ing goal of identifying the genetic variants that underlie complex traits.Two main approaches are available for mapping the relevant genes and identifying the variants that associate with the traits:linkage mapping in families and popula-tion-based genetic association studies.Linkage mapping has been very successful in?nding genes for rare,Mendelian,monogenic disease resis-tance.For complex traits that involve variants at several loci,each of which contribute small amounts to the overall genetic contribution, linkage studies mainly identify only those loci with the strongest in?uence,however.The most signi?cant?nding of this paper is that the LD in this set of germplasm did not decay until20–30cM.These results could have important impli-cations for association testing in rice.There are two previous studies of LD in rice.The?rst is that of Garris et al.(2003)who found LD to decay at 100kb across one region on chromosome5.In a second study Olsen et al.(2006)analyzed a500-kb region on chromosome6and found a250kb selective sweep at the waxy locus that led to elevated LD in that region.This would indicate that LD decay at250kb was unusually high, because of selection on the waxy locus.Although the amount of LD will vary across the genome (because of recombination rates,selective pres-sures,etc.),these studies seem indicative of LD decaying in rice at1cM or less(assuming an average of250kb/cM across the genome).This is in contrast with the LD decaying at20–30cM in the current study.LD in some Arabidopsis populations exceeds50cM(Nordborg et al. 2002),however,and LD as a function of genetic distance is very common for distances<10cM (Kraakman et al.2004)in barley.
In theory,genetic association mapping has greater power than linkage studies to identify variants with weak effects that might contribute risk for common complex traits(Risch and Merikangas1996).Whole-genome association studies have the advantage of enabling the entire genome to be assessed for trait-associated vari-ants,rather than analyzing speci?c candidate genes.The disadvantage of such studies,however, is that a large amount of genotyping is required. This can be reduced by using a subset of markers to report on neighboring linked markers within the genome(Smith and O’Brien2005).Applica-tion of association mapping to plant breeding seems to be a promising means of overcoming the limitations of conventional linkage mapping (Stich et al.2005).Our results have shown that LD studies are an ef?cient means of indicating novel genes for important agronomic characters that subsequently can be validated in speci?c biparental crossing populations,and for con?rm-
ing QTL that have been detected in mapping populations.
Acknowledgement The authors acknowledge the support of H.Raeann Refeld and Dr Hesham A. Agrama from the Arkansas Rice Research and Promotion Board.Technical contributions to this research were made by H.Raeann Refeld and Quynh P. Ho.Contributions of Melissa H.Jia,Gordon https://www.sodocs.net/doc/182775097.html,ler and the late Mark A.Redus of the DB NRRC Genomics Core Facility also are acknowledged.
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猎头服务合同书
编号：_______________ 本资料为word版本，可以直接编辑和打印，感谢您的下载 猎头服务合同书 甲方：___________________ 乙方：___________________ 日期：___________________
委托方____________________以下简称甲方代理方_________人才服务部以下简称乙方甲方因业务发展需要，委托乙方搜索所需人才。 经双方友好协商，达成以下合作条款第一条 主旨本合同目的在于确定乙方代表甲方搜索候选人时双方的权利及义务。 第二条 搜索服务的基本方式1甲方需提供与所需搜索职位有关的详细资料给乙方，其中主要包括--工作环境，如公司背景、现状规模、发展状况、目前和将来的投资等;--职务名称、职位职责，个人发展前景、直属上司情况及汇报路线;--所须具备的条件包括年龄、性别、教育程度、英文程度、专业经验以及个人品性;--工作中所需要的独立性、工作氛围，流动性出差需要和上班地点等;--福利待遇包括基本工资、奖金和津贴、工作时数、生活条件以及合同保险。 2乙方工作程序--搜索可能达到该标准的候选人，对这些候选人进行初次面试筛选并确证其资料的真实性;--将候选人资料提交甲方参考，包括对其经验的评价及对其性格，能力和潜质的看法;--为双方安排面谈时间、地点，并参与其中一些条款的协商，协助聘用合同的最终签署;--协助甲方督促被录用候选人与原工作单位按正常的程序办好离职手续。 3乙方在合同签定之日起天内完成对甲方所需人才的寻访、测评及背景调查，将完整、真实的候选人资料提交甲方，并安排候选人面试。 4甲方应在收到乙方提供的候选人资料后两日内，做出是否与己有人才资料重复的判断，否则视为乙方推荐;甲方应在收到乙方提供的候选人才资料后一周内，做出是否需要复试的判断，甲方应在候选取人面试后两周内将面试意见及审核结果反馈给乙方，在复试后四周内做出是否录用的判断。 第三条 保证期1推荐的候选人被甲方录用，并最终到甲方工作，视为猎头服务成功。 2雇员在保证期三个月内无论因任何原因离职，甲方应五天内向乙方提出书面报告，乙方将免费为甲方推荐另一合适候选人到职;乙方收到甲方书面报告后二个月内没有推荐合格人选到职，乙方应退还该项服务费的_______。
介词from的语法特点与用法习惯
介词?f rom的语法特点与用法习惯 1.不要根据汉语意思在及物动词后误加介词?from。如： 他上个星期离开中国去日本了。 误：?H e left from China for Japan last week. 正：?H e left Chine for Japan last week. 另外，也不要根据汉语意思错用介词?from。如： 太阳从东方升起，从西方落下。 误：?T he sun rises from the east and sets from the west. 正：?T he sun rises in the east and sets in the west. 2.f rom虽然本身是介词，但它有时也可接介词短语作宾语。如： Choose a book from among these. 从这些书中选一本吧。 A man stepped out from behind the wall. 一个人从墙后走出来。 比较： I took it from the bed. 我从床那儿（或床上）拿的。 I took it from under the bed. 我从床下拿的。 注意，下面一句用了?from where（引导非限制性定语从句），而未用?f rom which，其中的where=i n the tree，即?from where=f rom in the tree。如： He hid himself in a tree, from where he could see the enemy in the distance. 他躲在一棵树上，从那儿他可以看到远处的敌人。 3.有时其后可接?w hen, where引导的宾语从句，此时可视为其前省略了?t he time, the place。如： He didn’t speak to me from when we moved in. 从我们迁入之时起，他没和我说过话。
猎头协议(标准范本)
猎头协议 In accordance with the relevant provisions and clear responsibilities and obligations of both parties, the following terms are reached on the principle of voluntariness, equality and mutual benefit. 甲方：__________________ 乙方：__________________ 签订日期：__________________ 本协议书下载后可随意修改
协议编号：YH-FS-825220 猎头协议 说明：本服务协议书根据有关规定，及明确双方责任与义务，同时对当事人进行法律约束，本着 自愿及平等互利的原则达成以下条款。文档格式为docx可任意编辑使用时请仔细阅读。 甲方：_________ 乙方：_________ 1．公司指定 根据本合同协议和条款，乙方委托并指定甲方为乙方提供本合同规定的各项咨询服务。 2．双方关系 甲方和乙方均为独立法人。本合同的签订在甲方和乙方之间并不产生任何雇用、代理、合资或业务伙伴关系。甲方绝非乙方的法律代表，无论是任何目的，甲方均不能以书面或其它明示或隐含方式，以乙方的名义享受权利或承担义务。 3．服务 甲方将根据乙方提供的职位要求向乙方推荐合适的人选。具体职位描述、要求及人数由乙方提供，详细的书面材料作为本协议的附件一，具有同等法律效力；
甲方应确保每一个推荐给乙方的候选人首先经过甲方的面试筛选。若乙方要求，甲方应对候选人简历中包含的信息或候选人提供的其它信息的准确和真实性及在面试过程中发现的问题进行核实。 凡经甲方推荐的人才，从推荐之日起12个月内，如果乙方未通过甲方暗地或通过第三方录用该人才，无论长期或短期，均视为甲方推荐成功，乙方按照本合同相关条例支付咨询费用。如果乙方把甲方推荐的人才中转推荐给第三方，甲方亦按照本合同相关条例向乙方要求支付咨询费用； 4．机密 甲方承诺： 1）对获知的乙方及其分支机构的商业和技术信息保守秘密； 2）对获知的乙方或分支机构的雇员或候选人相关信息保守秘密。 3）甲方推荐的候选人及其身份和职业相关信息只可提供乙方使用，不得向乙方以外的第三方泄露候选人的信息。 乙方接受本合同后，也将承诺所有由甲方推荐的候选人
现代汉语连词意义及用法总结
连词 连词是用来连接词与词、词组与词组、句子与句子，表示某种逻辑关系的虚词。连词可以表并列、承接、转折、因果、选择、假设、比较、让步、递进、条件、目的等关系。一般说来，连词有很多是由副词、介词发展而来的；很多副词、介词又是由动词发展而来。所以动词、介词、连词需要区别。 和 =跟、=与、=及、=同<方>。表示并列关系、联合关系。 车上装的是机器和材料。他的胳膊和大腿都受伤了。工人和农民都是国家的主人。工业与农业。批评与自我批评。我同你一起去。图书、仪器、标本及其他。（注意：用“及”连接的成分多在词义上有主次之分，主要成分放在“及”的前面） 以及 连接并列的词或词组（“以及”前面往往是主要的）：院子里种着大丽花、矢车菊、夹竹桃以及其他的花木。 既=既然 既来之，则安之。既然他不愿意，那就算了吧。既然知道做错了，就应该赶紧纠正。你既然一定要去，我也不便阻拦。既要做，就一定要做好。既然这样，还不去做？用在上半句话里，下半句话里往往用副词就、也、还跟他呼应，表示先提出前提，而后加以推论。 既然。。。就。。。既然。。。也。。。既然。。。还。。。 继而=既而 先是惊叹，既而大家一起欢呼起来。人们先是一惊，继而哄堂大笑。先是一个人领唱，继而全体跟着一起唱。表示紧随在某一情况或动作之后。 而 1、连接动词、形容词、词组、分句。 （1）连接语意相承的成分。伟大而艰巨的任务。战而胜之，取而代之，我们正从事一个伟大的事业，而伟大的事业必须有最广泛的群众的参加和支持。 （2）连接肯定和否定相互补充的成分：此种花香浓而不烈，清而不淡。马克思主义叫我们看问题不要从抽象的定义出发，而要从客观存在的事实出发。有转折的意思。 （3）连接语意相反的成分，表转折：如果能集中生产而不集中，就会影响改进技术、提高生产。 （4）连接事理上前后相因的成分：因困难而畏惧而退却而消极的人，不会有任何成就。 2、有“到”的意思。一而再，再而三。由秋而冬。由南而北。 3、把表示时间、方式、目的、原因、依据等的成分连接到动词上面。匆匆而过、挺身而出、为正义而战、因公而死、视情况而定、三十而立。 而且 表示更进一步，前面往往有“不但、不仅”跟它呼应：性情温和而且心地善良。他不仅会开汽车，而且会修汽车。不但战胜了各种灾害，而且获得了丰收。 因而=因此 表示结果。下游河床狭窄，因而河水容易泛滥。 因为 常跟所以连用，表示因果关系。因为今天事情多，所以没去成。 何况 用反问的语气表示更进一层的意思。这么多事情一个人一天做完是困难的，何况他又是新手。他在生人面前都不习惯讲话，何况要到大庭广众之中呢？（even）
动名词的语法特征及用法
动名词的语法特征及用法 动名词由动词加－ing词尾构成，既有名词的特征，又有动词的特征。了解动名词的语法特征可帮助学习者深入理解动名词的意义，从而正确使用动名词。 一、动名词的名词特征 动名词的名词特征表现在它可在句子中当名词来用，作主语、宾语、表语、定语。例如： Beating a child will do more harm than good．打孩子弊大于利。（作主语） Do you mind answering my question？你不介意回答我的问题吧？（作宾语） To keep money that you have found is stealing．把拾到的钱留起来是偷盗行为。（作表语） No one is allowed to speak aloud in the reading room．阅览室里不许大声说话。（作定语） 在动名词担任这些句子成分时，学习者需注意的是： 1、有些动词后只能用动名词作宾语，构成固定搭配，需特别记忆。常见的这类动词有：admit（承认），advise（建议），allow（允许）， appreciate（感激），avoid（避免），can't help（禁不住），consider（考虑），deny（否认），dislike（不喜欢），enjoy（喜欢），escape（逃脱），excuse（原谅），feel like（想要），finish（结束），give up（放弃），imagine（想象），involve（包含），keep（保持），mind（介意），miss（错过），permit（允许），practise（练习），quit（停止），recollect （记得），recommend（推荐），suggest（建议），stop（停止），resent（对……感到愤恨、怨恨），risk（冒……危险），cannot stand（受不了）等。例如： We do not permit smoking in the office．我们不允许在办公室吸烟。 In fighting the fire，he risked being burnt to death．在救火中，他冒着被烧死的危险。 She denied having stolen anything．她否认偷过任何东西。 I suggest doing it in a different way．我建议换一个方法做这件事。 2、动名词常用于一些固定句型中，常见的有：It is no use ／no good．．．；It is a waste oftime．．．；It is fun ／nice ／good．．．；There isno．．．（不可以／不可能……）等。例如： It is no use asking him．He doesn't know any more than you do． 问他也没用，他并不比你知道得更多。 It's no fun being lost in rain．在雨中迷路可不是好玩的。 It's a waste of time your reasoning with him．你和他讲道理是在浪费时间。
猎头服务合作协议书
猎头服务合作协议书 甲方（委托方）： 地址： 乙方（受托方）： 地址： 甲、乙双方本着互利互惠、平等自愿、有偿服务的原则，就甲方委托乙方代为搜索、甄选、推荐各类种人才等事宜，经充分协商，达成如下协议，以资共同遵守： 一.合同有效期：从______ 年—月—日至__________ 年—月—日。 二.甲方的权利与义务 1. 甲方必须向乙方提供本企业营业执照复印件、公司简介、委托招聘的相关信息。 2. 甲方应按乙方要求提供所需的职位需求信息，并保证寻猎职位信息的真实性，所提要求及待遇 标准，必须按标额执行。如在委托期内，寻猎需求有任何更改应及时通知乙方。 3. 甲方负责对乙方提供的候选人资料进行筛选，对符合初选条件的人，乙方负责协调候选人到甲 方进行面试。 4?如甲方发现乙方提供的人选资料与其他招聘渠道所提供的资料重合时，且甲方从乙 方处获得候选人姓名、联系信息之前，或要求乙方安排候选人面试之前，应在收到乙方人选资 料后5个工作日内提出申明，并出具相关的资料证明，否则即视为认可。 5. 甲方按照公司 的相关面试流程对乙方推荐的候选人进行面试，在面试流程结束后，5 个工作日内告知乙方面试结果。 6. 甲方按时向乙方支付服务费。 7. 在本协议有效期内或本协议终止后十二个月内，甲方聘用乙方推荐的人才的，甲方应于聘用前通知乙方，并按 照本协议第3条规定向乙方支付服务费。甲方聘用乙方推荐的人才但未按前述规定履行通知义务的，甲方除应向乙方一次性支付全额服务费外，应向乙方支付服务费的两倍作为违约金，且甲方聘用的 乙方推荐人才的年薪视为30万元，甲方不得对此提出任何异议。若乙方发现其推荐的人才的年薪高于30 三.乙方的权利与义务 1. 乙方在双方签订委托招聘服务合同后，明确招聘岗位后，寻访和物色工作全面正
猎头合同协议书律师审核版
猎头合同协议书律师审 核版 文稿归稿存档编号：[KKUY-KKIO69-OTM243-OLUI129-G00I-FDQS58-
人才服务协议书 合同编号：XXXXXX 甲方(委托方): 地址： 联系人及电话：传真： 乙方(受托方):XXXX 地址：XXXX 联系人及电话：传真： 甲乙双方经协商一致，就甲方委托乙方在全国范围内代为招聘、甄选、推 荐人才事宜，经充分协商，达成如下协议，以资共同恪守。 一、服务内容 1.甲方委托乙方寻访的职位要求、数量、寻访期、签约年薪（用以约定 寻访委托金）、寻访委托金、寻访服务费等事项，可在由甲方不定时 发出的推荐要求中载明。该推荐要求应以书面形式发出，并作为本协 议的附件。 2.乙方根据甲方提出的人才需求，按甲方要求在约定的时间内为甲方寻 访候选人。经乙方评估认为符合甲方岗位要求后，向甲方推荐，经甲 方面试合格、候选人上岗后，甲方按本合同的规定向乙方支付约定的 服务费用。 二、服务流程 1.在双方签订本协议后，乙方正式启动为甲方提供的猎头服务。 2.在向乙方开放猎头职位的2个工作日内，甲方应当用电子邮件形式向 乙方所需猎头职务的详细职位说明（含工作职责、任职资格、薪金范 围、基本要求、特别需求等），以便乙方搜寻、筛选和向候选人说明
情况等，甲方保证寻访职位信息的真实性；如在委托期内，寻访需求有任何更改均应及时通知乙方。 3.乙方在收到甲方提供的书面职位说明后，应在2个工作日内以电子邮 件形式予以确认，并与甲方进行沟通确认；经双方对职位需求确认一致后，乙方开始进行人才访寻及推荐。 4.自对职位说明书确认后之1个工作日内，乙方指派专人或小组负责为 甲方提供人才寻访推荐服务，以保证按时完成甲方的招聘需求，并在10个工作日内提供第一批候选人至少2-3名，甲方应在收到推荐报告资料3个工作日内向乙方提供对所推荐候选人的反馈意见（如安排面试、暂缓、拒绝），并将同意面试的候选人名单以电子邮件形式提供给乙方，对于需要安排面试的候选人，甲方须在15个工作日内予以面试；乙方根据甲方要求及名单约见面试，甲方在面试后的10个工作日内将面试结果以电子邮件形式通知乙方，如甲方对参加面试的候选人不满意，应以电子邮件形式反馈明确的原因给乙方，乙方应重新搜寻合适的人选，具体工作程序同上。 5.如果乙方向甲方提供的简历已被甲方从其它渠道获取，甲方应当在3 个工作日内以电子邮件形式通知乙方，如乙方提出要求，甲方应提供相应的书面证明。如在上述期限内甲方未提出任何异议的，则该候选人将被视为乙方提供的资源。 6.如甲方对乙方提供的候选人有聘用意向的，应甲方要求及候选人同意 的情况下，乙方应提供候选人背景核查，核查应从公开途径且不侵害候选人隐私。
and的用法及含义
and的用法及含义 And是英语中一个普通的连词，然而and并非只作并列连词用，它还具有一些不太常见的表达方式和意义，应根据上下文的特殊环境，作出判断才能准确理解其用法和意思。 1．and作并列连词，译为“和、并且”等，当连接三个以上的并列成分时，它放在最后一个成分之前，其余用逗号分开，例如： He bought a book and a pen．他买了一本书和一支笔。 Solid，liquid and gas are the three states of matter．固态、液态和气态是物质的三种状态。 2．名词+and+名词，若这种结构表示一个概念时，and+名词相当于介词with+名词，译为“附带、兼”的意思，例如： Noodle and egg is a kind of delicious food．（and egg=with egg）鸡蛋面是一种美味食物。 Whose is this watch and chain？（and chain＝with chain）这块带表链的手表是谁的？ 3．名词复数+and+同一名词的复数，强调连续或众多的含义。例如： There are photos and photos．照片一张接着一张。 They saw film hours and hours last week．上星期他们一小时接一小时地看电影。 4．形容词+and+形容词，这种结构形似并列，实际并非并列结构。例如： This roon is nice and warm（＝nicely warm）． The coffee is nice and hot（=thoroughly hot）． 5．用and连接动词的用法：and+动词作目的状语。动词go（come，stop等）＋and+动词，此时，and+动词相当于in order to+动词，例如： ①I'll go and bring back your boots，（go and bring back=go in order to bringback）我去把你的靴子拿来。 ②and+动词，起现在分词的作用，表示方式或伴随情况。例如： He sat and waited．（and waited=waiting）他坐着等。 ③and+同一动词表示动作长时间地“继续”或“重复”，例如：
法语语法-名词的特点和用法
{1} 1. 名词（le nom, le substantif）的特点 名词是实体词，用以表达人、物或某种概念，如：le chauffeur（司机），le camion（卡车），la beauté（美丽）等。 法语的名词各有性别，有的属阳性，如：le soleil（太阳），le courage（勇敢），有的属阴性，如：la lune（月亮），la vie（生活）。名词还有单数和复数，形式不同，如：un ami（一个朋友），des amis（几个朋友）。 法语名词前面一般要加限定词（le déterminant），限定词可以是数词、主有形容词，批示 形容词或冠词。除数词外，均应和被限定性名词、数一致，如：la révolution（革命），un empire （一个帝国），cermarins（这些水手），mon frère（我的兄弟）。https://www.sodocs.net/doc/182775097.html, 大部分名词具有多义性，在文中的意义要根据上下文才能确定，如： C’est une pluie torrentielle.（这是一场倾盆大雨。） Lorsque rentre la petite fille, c’est sur elle une pluie de baisers.（当小姑娘回家时，大家都拥上去亲吻她）。 第一例, pluie是本义，第二例, pluie是上引申意义。 2. 普通名词和专有名词（le nom commun et le nom propre） 普通名词表示人、物或概念的总类，如：un officier（军官），un pays（国家），une montagne （山），la vaillance（勇敢、正直）。 专有名词指特指的人、物或概念，如：la France（法国）。 专有名词也有单、复数；阴阳性。如：un Chinois（一个中国男人），une Chinoise（一个中国女人），des Chinois（一些中国人）。 3. 普通名词和专有名词的相互转化（le passage d’une catégorie àl’autre） 普通名词可转化为专有名词，如：报刊名：l’Aube（黎明报），l’Humanité（人道报），l’Observateur（观察家报）等报刊名称是专有名词，但它们是从普通名词l’aube（黎明），I’humanité（人道），l’Observateur（观察家）借用来的。 专有名词也可以转化为普通名词，意义有所延伸，其中许多还保持第一个字母大写的形式，如商品名：le champagne（香槟酒），une Renault（雷诺车），le Bourgogne（布尔戈涅洒）。以上三例分别来自专有名词la Champagne（香槟省），Renault（雷诺，姓），la Bourgogne（布尔戈涅地区）。 4. 具体名词和抽象名词（les noms concrèts et les noms abstraits）
猎头服务协议书模板
编号：猎头服务协议书模板 甲方 乙方 签订日期年月日 (本协议书为Word格式，下载后可根据您的需要调整内容及格式，欢迎下载。)
甲方：____________服务有限公司 ____________人才服务中心 乙方：________________________ 甲乙双方就甲方向乙方提供人才猎头服务，达成如下协议： 一、根据中华人民共和国的法律和法规，甲方确认本方有完全的从事本协议所述服务的资格；乙方确认本方是依法成立的组织，符合法律规定的面向社会公开招聘的各项条件和手续，并且向甲方提交的各种书面文件及陈述都是真实有效的。甲乙双方就各自的确认承担相应的法律责任。 二、甲方服务的收费标准是，每成功提供一人，收取________元人民币作为本方的服务佣金。佣金分两次支付，双方签定协议之日，甲方支付________元/人为预付佣金；推荐人选上岗三个月或转正后一个星期内付清余款。 三、甲方收到乙方预付的预付服务佣金后，应按照本协议附件 1的要求为乙方提供人才，并保证所提供人才情况的真实性，同时协助乙方安排有关面试考核的事宜。面试考核应本着方便应聘者及乙方的原则进行。 四、乙方应按照本协议附件1规定的条件考核验收甲方提供的人才。并应于考核之日起________天内将是否聘用（含试用，下同）的意见及理由书面通知甲方。否则，视为同意聘用。 五、甲方应于收到预付服务佣金之日起两个星期至一个月内完
成委托事项，经双方协商同意，上述期限可以改变，但应另以书面文件规定之。 六、乙方同意聘用（接纳为乙方正式员工）甲方提供的人才，甲方服务即告完成。乙方若于聘用后三个月内辞退甲方提供的人才，应于辞退之前通知甲方，并有权要求甲方重新提供服务，甲方应免费为乙方再推荐人选，并得到乙方聘用为止。 七、非因不可抗力，或乙方认可的其他正当理由，甲方在协议规定的期限内未能向乙方提供候选人才的，应全额返还乙方预付佣金；虽提供候选人才而乙方最终未能聘用的，预付佣金应退还甲方。 八、乙方以超出本协议附件1以外的条件拒绝甲方提供的人才，或在本协议规定的有效期限内自行招聘协议附件1规定的人才，从而无需甲方的服务，甲方有权留置乙方全部预付佣金，折抵甲方服务收入。 九、乙方拒绝甲方提供的人才，从而导致甲方服务失败，但在甲方服务终止后的十二个月内聘用曾被乙方拒绝的人才，应于聘用前通知甲方，并向甲方支付全额服务佣金。否则视为违约，乙方应就此向甲方支付________至________倍的服务佣金作为违约金。 十、本协议在乙方委托寻猎的人数超过一人时，对每一个人才的服务分别有效，彼此无法律上的连带责任关系。 十一、本协议的附件作为协议的组成部分，与本协议有同等法
猎头服务合同模板
编号： HT-20214765 甲 方：______________________________ 乙 方：______________________________ 日 期：_________年________月_______日 猎头服务合同模板 The parties may dissolve the contract upon consensus through consultation.
[标签:titlecontent] 甲方(劳务用工单位)： 工商登记号：联系地址：邮政编码：联系电话：传真：联系人：开户行：帐号： 乙方(劳务招聘单位)： 工商登记号：联系地址：邮政编码：联系电话：传真：联系人：开户行：帐号： 甲、乙双方就乙方向甲方提供需求职位人才的寻访推荐服务达成如下合同(以下称“本合同”)： 前言： 甲乙双方保证各自为依据中华人民共和国的相关法律法规合法成立的组织。乙方应确认有从事该项服务的资格，甲方应确认向乙方提供的各种资料的真实性，双方就各自的确认承担各自的法律责任。 甲、乙双方本着自愿和互惠互利的原则，合作签署“本合同”，并愿意自觉遵守“本合同”的各项条款。 第一条服务内容 1、甲方聘请乙方作为其中、高级人才推荐的供应商。
2、甲方如有招聘需求，应向乙方提供委托招聘职位信息，内容包括需求岗位职责描述、胜任条件、薪资福利条件、需求人数和日期等。 3、自甲方正式委托职位寻访之日起，乙方正式启动寻访推荐工作。15个工作日内向甲方推荐每个职位2—3名经过甄选基本符合甲方职位需求的候选人，直到甲方录用乙方所推荐的候选人为止。 4、乙方在推荐候选人时，需要向甲方提供人选的详细简历，说明其以往的工作经历、主要职责、成就以及能说明其工作胜任能力的任何其它必要资料。 5、甲方聘用乙方推荐的人员，在个月(保证期)，自推荐人开始在甲方工作之日起，如发生聘用终止，乙方应为甲方免费提供一次相同职位的人才服务，乙方应保证在甲方通知乙方的15个工作日内为甲方再次提供候选人。 第二条限制 1、甲方不得提供虚假职位需求信息和做出虚假承诺。 2、合作期间甲方不得直接聘用乙方猎头顾问和工作人员，如有发生甲方应付乙方该职位应付猎头佣金的双倍的服务费用。 第三条保密原则 1、乙方应对甲方提供的任何商业、技术资料及员工信息进行保密。 2、甲方应对乙方提供的人选资料、服务费用保密，不得将乙方提供的人选资料用于任何非自己聘用内部员工的目的和提供给甲方
常见系动词的分类及使用特点
常见系动词的分类及使用特点 系动词词义不完整，在句中不能单独使用（除省略句外），后面必须接有表语，系动词和表语一起构成合成谓语。常见的系动词大致可分为三类。 第一类：表示特征或状态的，有 be, look, feel, seem, appear, smell, taste, sound, turn out（结果是、证明是）等。 You'll be all right soon. You don't look very well. I feel rather cold. He seems to be ill. It appears that he is unhappy. The roses smell sweet. The mixture tasted horrible. How sweet the music sounds! The day turned out (to be）a fine one. 第二类：表示从一种状态到另一种状态的变化，有 become, get, grow, turn, fall, go, come, run 等。 He became a world-famous scientist. It is getting warmer and warmer. It grew dark. The food has turned bad. Yesterday he suddenly fell ill. Mary's face went red. His dream has come true. The boy's blood ran cold. 第三类：表示保持状态的，有keep, remain, continue 等。 Keep quiet, children! The weather continued fine for a long time. It remains to be proved. 系动词后的表语可以是名词、代词、数词、形容词、分词、动名词、不定式、副词、介词短语、词组、从句，系动词 be 可用于上述所有情况。如： The people are the real heroes. (名词) That's something we have always to keep in mind. (代词) She is often the first to come here. (数词) She is pretty and wise. (形容词). The news was surprising. (分词) His job is teaching English. (动名词) The only method is to give the child more help. (不定式） I must be off now. (副词) The bridge is under construction. (介词短语) That would be a great weight off my mind. (词组) This is why he was late. (从句) 系动词的使用特点： 1、所有的系动词都可接形容词作表语，此处略举数例。
猎头合同模板
合同编号： 高级人才寻访服务合同 甲方： 地址： 电话： 邮箱： 乙方： 地址： 电话： 传真： 甲、乙双方在平等自愿、协商一致的基础上，就甲方委托乙方寻访和推荐优质人才等事宜，达成如下条款，以共同遵守： 一、服务内容 1.1甲方委托乙方按照甲方提供的职位描述要求寻访人才，接受乙方的推荐，并安排面试。 1.2乙方通过各种渠道搜寻符合甲方职位要求的合适候选人，并推荐给甲方，以满足甲方人 力资源方面的需求。 1.3当乙方所推荐的候选人通过甲方面试，并在甲方所指定的岗位上报到后，该服务主体结 束。但是乙方有义务提供合同所承诺的人员更换服务义务。 二、服务期限 本合同自双方签字起生效，合同有效期为年，自年月日至年月日。 三、甲方的权利和义务 3.1 该职位委托合同甲方委托乙方为其代理招聘服务,。 3.2 甲方须尽可能详细明确的填写《委托猎头登记表》，以及提供委托职位的职位描述。甲方应根据项目进度及乙方服务规程要求，给予乙方项目顾问尽可能详尽的信息支持与配合，以便乙方寻访适合甲方的候选人； 3.3甲方应在乙方推荐人员到职后三个工作日内书面通知乙方。如在聘用通知书约定的上班之日，乙方推荐的人员未能到甲方上班的，甲方应将该情况发生后当日内书面通知乙方；3.4甲方应在与乙方推荐人员签订聘用通知书后五个工作日内将所聘人员职位、到职日期、薪酬、试用期等情况以书面形式通知乙方； 3.5甲方应对乙方提供的人员资料保密，并严格控制内部人员知情范围，不得向外泄露人才资料，或向任何第三方提供人才资料(包括个人和法人)。如有上述情况，一经核实，甲方需无条件给予乙方相应的经济赔偿；
3.6甲方对乙方的任何投诉和建议均可通过发送邮件到邮箱，甲方的投诉和建议将反馈给乙方相关部门。 四、乙方的权利和义务 4.1 甲方填写委托登记表、签订委托招聘服务合同后，乙方开始正式提供合同约定服务； 4.2 乙方应在签订合同后的10个工作日内，向甲方提供书面或电子邮件形式的，与委托职位相适合的有关候选人资料报告； 4.3 乙方自签订本合同起，不得将甲方内的工作人员、商业信息，推荐或泄露给其他可能获得利益的第三方；在本协议到期或终止后，以上保密责任依然存在。 4.4 乙方不得将其推荐给甲方并被成功聘用的人选再次推荐给其它任何客户； 4.5 乙方承诺提供人员更换服务如下：如乙方推荐的候选人在正式报到日起3个月内离职，甲方在被推荐人选离开之日起10个工作天日内以书面形式将该情况通知乙方，乙方应就此职位按甲方要求无偿提供另外人选。新人选入职后，乙方将重新计算保证期并继续承担人员更换服务义务。如果被录用者的工资福利、岗位职位等未能按甲方与候选人事先约定之标准实施，或者遇甲方因办公场所搬迁、重大人事调整所导致的非人选自身原因而导致被录取者离职的，由甲方承担对该被录取者的相关责任，乙方不承担人员更换服务义务； 4.6 任何乙方向甲方所推荐的人员，自被推荐之日起十二个月内，均被视为“乙方推荐人员”，在此期间内，如乙方证实甲方或其子公司与被推荐人发生聘用与被聘用关系，视为乙方已成功推荐，甲方须按本合同支付全额费用； 4.7 自“乙方推荐人员”被推荐予甲方之日起十二个月内，甲方不得就聘用事宜向任何第三方（不包括甲方各分支机构）推荐。 4.8 在合同期内，乙方不得向甲方在职员工推荐任何职位机会。 五、服务费用及付款方式 5.1 成功聘用乙方推荐的候选人后，甲方须向乙方按每人每一职位支付服务费用标准为被雇佣者第一年税前年薪总收入的。被雇佣者年薪总收入包括基本工资、奖金、提成及其他各类现金支付的福利和补贴； 5.2 本合同所称的成功聘用有下述两种情况： 1)甲方与乙方推荐的候选人签订了《劳动合同》或者该候选人员已实际在甲方工作 （含试用期）； 2)包括但不限于甲方与乙方推荐的候选人以顾问或者兼职的形式产生合作关系。 5.3 服务费支付方式如下：乙方推荐的候选人被甲方成功聘用后乙方应向甲方发出付款通知书，甲方应在收到付款通知核实无误后的十个工作日内支付服务费用的。候选人通过三个月试用期之后，乙方应向甲方发出付款通知书，甲方应在收到付款通知核实无误后的十个工作日内支付服务费用的30%。如金额有误，甲方应在收到付款通知后两个工作日内通知乙方；乙方未收到甲方书面的异议通知的，视为甲方确认该付款通知书。 5.4 乙方在提供本合同约定的服务时实际发生的所有费用，如广告费，差旅费等须经甲方事先书面同意，方可由乙方向甲方收取。如甲方延期付款超过天，乙方有权要求甲方及时付清服务费，每天按服务费的加收滞纳金。
统编《语文》二年级下册主要特点及使用建议
统编《语文》二年级下册主要特点及使用建议 原创 2018-03-21 张立霞人教教材培训 导读 2018年春季统编《语文》二年级下册教材网络培训讲义精要。 一、激发儿童学习兴趣，保护儿童天性 1. 选文富有童趣，利于激活儿童的经验、想象。 儿童有自己的世界，有应予尊重的天性。为顺应儿童心理，保护儿童天性，提高教育、教学效果，教科书进行了多方面的尝试与探索。 首先选文富有童趣，利于激活儿童的经验、
想象。生活故事，注意选择儿童凭借有限的生活经验就能理解的文本。童话故事，知识背景相对简单，利于减少阅读障碍。孩童化的表达，贴近儿童的心灵，同时又含了某种诗意和哲理。读起来好玩、有趣，同时内心里会沉淀些有份量的、值得未来去品味的东西。 教材的选文注重借助该年龄段有限的现实经验和相对丰富的想象，激发学习的动力和兴趣。 2. 采用游戏、活动等方式让学生在玩中学。 课后练习：在准确把握习题意图的前提下，尽可能寻找练习中的游戏、活动因素，让学习变得有趣、轻松。 文中泡泡。 字词句运用。
口语交际。 3. 注意练习的趣味性，减少畏难情绪。 写话： （1）精心设计写话内容及呈现方式，尽可能减少畏难情绪。表格的呈现方式，直观提示要写的内容，表格的示例内容也尽量贴近儿童真实生活，利于调动生活积累。 （2）色彩丰富的画面，儿童化的角色选择，有趣的情节设定，可以调动儿童的参与积极性，减少写话障碍。 （3）引导学生不拘形式地写下自己想说的话。 二、注重文化传承，立德树人自然渗透，涵养品格 教科书中的课文，“有意思”与“有意义”兼具，在激发学生学习兴趣的同时，有助于学生的精神成长。教科书统筹安排中华优秀传统文化内容，增强学生的文化认同感和民族自豪感。
猎头合同范本
人才猎头服务协议 甲方： 乙方：尚才荟猎头 甲方因业务发展需要，特委托乙方以猎头服务方式招聘 _____________ 职位人选，甲乙双方 本着“平等合作，互惠互利”的原则，经友好协商达成如下协议： 一、甲方权利与义务 1.甲方应向乙方提供详细、真实的公司背景资料，包括但不限于公司背景、经营状况、发展战略、企业文化等。 2.甲方须负责提供所需招聘岗位的详细资料，真实填写《企业职务需求表》（附件1），并对薪酬、福利、休假等与应聘者利益相关一切信息之真实性负责。 3.收到乙方提交的候选人报告资料后，甲方应在三个工作日内通知乙方是否要求候选人面 试。如果面试，应提前告知时间和地点。面试结束后，甲方应在三个工作日内告知乙方面试结 果。对不合适的候选人，应给出说明。如果不面试，应给出具体的不面试原因。 4.甲方应在面试后积极与乙方沟通、协调，三天内做出上一轮面试的决议（包括安排下一 轮复试或录用）。特殊情况外，每个候选人面试次数最多为四次。 5.甲方对候选人信息、候选人报告、候选人面试过程等一切可能有损于候选人正当利益或 本合同正当履行的信息，负有保密义务。 二、乙方权利与义务 1.乙方对甲方提供的企业、职位等信息负有保密义务。除为完成本合同所必须外，其余未 经甲方授权，不得公开。 2.乙方需在寻访服务期（自—年—月—日至—年—月—日）内利用各种渠道为甲 方寻访、招聘所需人才。乙方在了解候选人的情况，分析其背景资料，并在此基础上进行筛选 后，向甲方提交合适候选人的个人资料。如果在寻访期内，甲方未能对乙方提供的候选人给出明确答
复，乙方有权终止合作。 3.若出现以下任何一种情况，均视为乙方已完成猎头服务全部工作，乙方有权要求甲方按本合同所列的“全职服务费用”，按约定支付周期与方式支付费用。如逾期支付，乙方将保留诉诸法律解决的权利： （1）甲方面试乙方所推荐的候选人后录用其作为甲方员工以全职合作； （2）甲方面试乙方所推荐的候选人后因某种原因不能提供所聘用岗位，但录取该候选人为其他岗位职员。 4.若出现以下任何一种情况，均视为乙方已完成猎头服务全部工作，乙方有权要求甲方按本合同所列的“全职服务费用”，在五个工作日内支付全额猎头服务费。如逾期支付，乙方将保留诉诸法律解决的权利： （1）甲方将乙方所推荐的候选人转荐给其他雇主，并且候选人被他雇主其聘用的； （2）甲方面试乙方所推荐的候选人后表示拒绝聘用，却在面试后一年内聘用乙方曾推荐的人选。 5.若出现以下任何一种情况，均视为乙方已完成猎头服务全部工作，乙方有权要求甲方按本合同所列的“兼职服务费用”，在五个工作日内支付全额猎头服务费。如逾期支付，乙方将保留诉诸法律解决的权利： （1）甲方面试乙方所推荐的候选人后因某种原因不能聘用该候选人，而聘用该候选人做兼职或其他短期服务； （2）甲方面试乙方所推荐的候选人后并没有聘用，而采用咨询、承包等方式与候选人保持合作关系。 三、服务费标准及支付方式 1.全职服务费用标准： □人民币 ____ 万元（大写：________ ）（岗位年薪标准）X ____ % （年薪的百分比）□约定固定金额服务费用人民币 ______ 万元。 说明：支付方式按双方协商约定，二选一。 若甲方提出的岗位薪酬是某一区间的，岗位年薪标准以区间上限为标准。
猎头服务合同word排版格式
猎头服务合同word排版格式 甲方(劳务用工单位)： 工商登记号：联系地址：邮政编码：联系电话：传真：联系人： 开户行：帐号： 乙方(劳务招聘单位)： 工商登记号：联系地址：邮政编码：联系电话：传真：联系人： 开户行：帐号： 甲、乙双方就乙方向甲方提供需求职位人才的寻访推荐服务达成如下合同(以下称“本合同”)：前言： 甲乙双方保证各自为依据中华人民共和国的相关法律法规合法成立的组织。乙方应确认有从事该项服务的资格，甲方应确认向乙方提供的各种资料的真实性，双方就各自的确认承担各自的法律责任。 甲、乙双方本着自愿和互惠互利的原则，合作签署“本合同”，并愿意自觉遵守“本合同”的各项条款。 第一条服务内容
1、甲方聘请乙方作为其中、高级人才推荐的供应商。 2、甲方如有招聘需求，应向乙方提供委托招聘职位信息，内容包括需求岗位职责描述、胜任条件、薪资福利条件、需求人数和日期等。 3、自甲方正式委托职位寻访之日起，乙方正式启动寻访推荐工作。15个工作日内向甲方推荐每个职位2—3名经过甄选基本符合甲方职位需求的候选人，直到甲方录用乙方所推荐的候选人为止。 4、乙方在推荐候选人时，需要向甲方提供人选的详细简历，说明其以往的工作经历、主要职责、成就以及能说明其工作胜任能力的任何其它必要资料。 5、甲方聘用乙方推荐的人员，在个月(保证期)，自推荐人开始在甲方工作之日起，如发生聘用终止，乙方应为甲方免费提供一次相同职位的人才服务，乙方应保证在甲方通知乙方的15个工作日内为甲方再次提供候选人。 第二条限制 1、甲方不得提供虚假职位需求信息和做出虚假承诺。 2、合作期间甲方不得直接聘用乙方猎头顾问和工作人员，如有发生甲方应付乙方该职位应付猎头佣金的双倍的服务费用。 第三条保密原则 1、乙方应对甲方提供的任何商业、技术资料及员工信息进行保密。 2、甲方应对乙方提供的人选资料、服务费用保密，不得将乙方提供的人选资料用于任何非自己聘用内部员工的目的和提供给甲方之外的任何第三方(包括个人和法人)。 3、在未取得到推荐人选的允许，不得向其正在任职的单位(雇主)作背景调查。 第四条人选的推荐、面试 1、甲方在乙方提交候选人资料后的48小时内需将是否面试的决定通知乙方，并在面试后
“之”的意义和用法
“之”的意义和用法 在古代汉语中，“之”字可作实词，也可作虚词，在不同的语境里有不同的意义和用法，同学们在备考时应引起重视。 一、“之”作实词 1、“之”作动词 这时，“之”的意思是“到……去”“往”“到”“至”。 例1 奚以之九万里而南为?(《逍遥游》) 例2项伯乃夜驰之沛公军。(《鸿门宴》) 例3辍耕之垄上。(《陈涉世家》) 2、“之”作代词 “之”作动词的情况在古代汉语中不多见，作代词相对常见一些。“之”作代词时，一般用作宾语，代人、事、处所，所代的对象大多出现在上下文中。作代词时，“之”又分为指示代词和人称代词。 (1)“之”作人称代词，可译为“他(们)”“她(们)”“它(们)”，用作宾语。 例4君为我呼入，吾得兄事之。(《鸿门宴》)
例5生乎吾前，其闻道也固先乎吾，吾从而师之。(《师说》) 例6虽有(通“又”)槁暴，不复挺者，鞣使之然也。(《劝学》) 例7是何异于刺人而杀之，曰“非我也，兵也”?(《寡人之于国也》) 例8盖将自其变者而观之，则天地曾不能以一瞬。(《赤壁赋》) 从上面所举的几个例子我们可以发现，“之”作人称代词时，一般用在动词之后。 “之”所代的人称在上下文中不一定有具体交代，要根据语言环境进行判断，灵活翻译，如“人非生而知之者”中的“之”，其上下文都找不到先行词，它是泛指“知”的对象，即知识、道理等，可略而不译，也可根据上下文之意译为“知识”或“道理”。 (2)“之”作指示代词，译为“此”“这”“那里”“这样”“这个”等，此时，“之”可作定语，也可作宾语。 例9以故其后名之曰“褒禅”。(《游褒禅山记》) 例10由山以上五六里，有穴窈然，入之甚寒。(《游褒禅山记》) 例11均之二策，宁许以负秦曲。(《廉颇蔺相如列传》) 例12之二虫又何知!(《逍遥游》)