multistagecor {selectiongain} | R Documentation |
Function for calculating correlation matrix in a plant breeding context
Description
This function is used to calculate the (n+1)-dimensional correlation matrix of y and X, where y is the true value (genotypic value in plant breeding) and
are the values of y's observations or selection indices, which are linear combinations of the values of observation from each selection stage.
In a plant breeding context, it is assumed that the genetic structure of the candidates to be selected are genetically fixed, e.g., potential cultivars, clones, inbred lines or testcross progenies of inbred lines with the same or different testers in all stages.
Usage
multistagecor(maseff,VGCAandE,VSCA,VLine,ecoweight,rhop,
T,L,M,Rep,index, indexTrait, covtype, detail,
VGCAandE2, VSCA2, COVgca, COVsca, maseff2, q12, q22)
Arguments
maseff |
is the efficiency of marker-assisted selection (MAS). The default value is NA, which means there is no MAS. If a value between 0 and 1 is assigned to |
VGCAandE |
is the vector of variance components of genetic effect, genotype |
VSCA |
is the vector of variance components for specific combining ability (hybrid breeding). The default value is 0,0,0,0. |
VLine |
Only to be used if parental and testcross selection are performed in a breeding strategy, For an example see the paper "Wegenast, Longin... 2008. Hybrid maize breeding with doubled haploids. IV". If this strategy is implemented, then Vline correspond to the vector of variance components for the parents (line per se). The default value is 0,0,0,0,0. |
ecoweight |
is the vector of economic weight. In the case of simultaneos selection of two traits, this vector contains two elements, each corresponding to economical weigth of each trait |
rhop |
is the genetic correlation between line per se performance and GCA |
T |
is the vector of number of testers at each stage. If there is no tester applied in a certain stage, the value at this stage has to be 1. |
L |
is the vector of number of locations at each stage. |
M |
is the vector of tester type, i.e., number of unrelated inbred lines combined in a single tester in stage j. |
Rep |
is the vector of number of replications at each stage. |
index |
is the control parameter. If it equals TRUE, the optimum selection index of Longin et al. (2007) will be used in the calculation of correlation matrix without MAS. |
indexTrait |
is the control parameter for the simultaneous selection of two traits. Possible options are: "Optimum"(default), "Base" and "Restricted" for the implementation of the well known optimum, base and restricted selection indexes in plant breeding. |
covtype |
is the type of the covariance. Longin's type ( |
detail |
is the control parameter to decide if the correlation matrix, optimal selection index and covariance matrix will be returned ( |
VGCAandE2 |
In the case of simultaneos selection of two traits (index selection) it is the vector of variance components of genetic effect, genotype |
VSCA2 |
In the case of simultaneos selection of two traits (index selection) it is the vector of variance components for specific combining ability for the second trait. The default value is 0,0,0,0. The default value is 0,0,0,0 |
COVgca |
In the case of simultaneos selection of two traits (index selection) is the vector of covariance components of: genetic effect, genotype |
COVsca |
In the case of simultaneos selection of two traits (index selection) is the vector of covariance components of the specific combining ability effects as follows : sca, sca |
maseff2 |
is the efficiency of marker-assisted selection (MAS) for the second trait. The default value is NA, which means there is no MAS and there is not simultaneous selection of two traits. If a value between 0 and 1 is assigned to |
q12 |
is the proportion of genetic variance associated with markers for trait 1 as defined by "Dekkers, JCM. 2007. Prediction of response to marker-assited..."" This parameter is only needed in the case of simultaneos selection of two traits (index selection) |
q22 |
is the proportion of genetic variance associated with markers for trait 2 as defined by "Dekkers, JCM. 2007. Prediction of response to marker-assited..."" This parameter is only needed in the case of simultaneos selection of two traits (index selection) |
Value
The default output is a matrix with dimension n+1 and can be used as input parameter of function multistagegain. When value of detail=TRUE, the correlation matrix, optimal selection index and covariance matrix will be given. If covtype are set to: "2traits_PS" , "2traits_GS" , "2traits_GS-PS" , "2traits_PS-PS" , or "2traits_GS-PS-PS" , the output will be a list of seven matrices as follows: (1) correlation matrix for the index, (2) estimates of the relative index weights B (betas) for each trait in each stage, (3) covariance matrix for the index (4) correlation matrix for trait 1, (5) correlation matrix for trair 2, (6) matrix of genotypic covariances and (7) matrix of phenotypic covariances
Note
no further comment
Author(s)
Xuefei Mi
References
C. Longin, H.F. Utz., J. Reif, T. Wegenast, W. Schipprack and A.E. Melchinger. Hybrid maize breeding with doubled haploids: III. Efficiency of early testing prior to doubled haploid production in two-stage selection for testcross performance. Theor. Appl. Genet. 115: 519-527, 2007.
E.L. Heffner, A.J. Lorenz, J.L. Jannink, and M.E. Sorrells. Plant breeding with genomic selection: gain per unit time and cost. Crop Sci. 50: 1681-1690, 2010.
See Also
selectiongain()
Examples
# example for calculating correlation matrix without MAS
multistagecor(VGCAandE=c(1,0.5,0.5,1,2),L=c(2,10),T=c(1,1),Rep=c(1,1))
multistagecor(VGCAandE="VC2",L=c(2,10),T=c(1,1),Rep=c(1,1),index=TRUE)
# example for calculating correlation matrix with MAS in the first stage
VCgca=c(0.40,0.20,0.20,0.40,2.00)
VCsca=c(0.20,0.10,0.10,0.20)
corr.matrix = multistagecor (maseff=0.40, VGCAandE=VCgca,
VSCA=VCsca, T=c(1,1,5), L=c(1,3,8), Rep=c(1,1,1))