Shantel A. Martinez

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Wheat Molecular Genetics | Preharvest Sprouting

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Heritability:
Summary of heritability equations for balanced and unbalanced datasets.
There are more ways to calculated H2 based on if you do spatial correction, gxe, and so on, but this is a start.

You can obtain σ g 2 (genotype variance) and σ e 2 (residual variance) in R using the lme4 package with VarCorr(model) after you’ve defined your model, but Dan Sweeney shared with me his function to calculate vBLUP:

  
library(lme4)
model1 <- lmer(Pheno~(1|genotypes)+Env+HD, data = EliteProgramData) 
S_1 <- as.data.frame(VarCorr(model1)); 
sigma2_g <- S_1[1,4]
sigma2_e <- S_1[2,4] #Assuming your model only has 1 random effect. If more than one, [2,4] becomes [n,4] where n = number of random effects + 1 

#Balanced H2
FalMac_H2 <- sigma2_g / (sigma2_g + sigma2_e)

m <- length(unique(EliteProgramData$Env))
MultiEnv_H2 <- sigma2_g / (sigma2_g + (sigma2_e/m))

#Unbalanced H2
Cullis_H2=function(model){
  library(arm)
  ses<- se.ranef(model)$'genotypes' #where 'm' is your model object from 'lmer' (replace 'genotypes' with whatever you call your individuals in the data)
  v_BLUP<- ses^2
  sigma2_g=VarCorr(model, comp="Variance")$'genotypes'[1]
  Reliability<- 1- v_BLUP/ (2\*sigma2_g)  #where sigma2_g is the genetic variance estimated with the model saved in 'm'
  H2<- round(mean(Reliability),3) #This is equivalent to broad-sense heritability on the line-mean (or family-mean, if your individuals are non-inbred families) basis
  H2
}

Cullis_H2(model1)
  

90k Illumina Array SNP Positions

Quite often, as I read a mapping journal article, I want to know if a particular Illumina 90k marker linked to the published QTL. Originally I had to blast the marker one at a time against the wheat genome, but that gets tedious (and you also need to know the marker sequence, fun right). But URGI does have the SNPs aligned to the RefSeqv1.0 JBrowse. So, I downloaded the Infinium 90k track data for every chromosome and compiled them into one 90k position excel file for a quick reference. Feel free to download the quick resource for easy comparison of marker with position.

BUT, another issue I often run into is only knowing the IWB#### index number OR the marker name (ex: BobWhite_c10090_559) when I need the other number/name. So, here is another 90k information combined file that includes alignment of the IWB number, the marker name, flanking SNP sequences, the A allele nucleotide, the B allele nucleotide, and even the original 9k_name if appropriate.

The Falling Numbers Website

PHS/Dormancy Genes Positions
A number of genes in wheat have been cloned and characterized for PHS tolerance or grain dormancy. Since the wheat reference genome is now publically available, we can BLAST the PHS gene sequences (below) against the RefSeqv1.0 alignment and identify the positions on the chromosome. Below are the estimated start and end positions based on the gene sequences available by the authors, in the publication, or public databases. The positions and links to the gene sequences may be useful to cross-reference with future PHS QTL or GWAS analyses.

Gene   Chrm Pos_Start Pos_End RefSeqv1.0_Gene_Name Reference Gene_Seq
TaSdr / Sdr TaSdr-A1 2A 158,452,164 158,453,676 TraesCS2A01G191400 Zhang et al., 2014 KF021988
  TaSdr-B1 2B 200,574,062 200,572,560 TraesCS2B02G215300   KF021990
  TaSdr-D1 2D 142,668,463 142,666,958 TraesCS2D01G196200   KF021992
Tamyb10 / R R-A1 3A 703,906,112 703,904,221 - Himi et al., 2011 AB599721
  R-B1 3B 757,917,663 757,920,399 TraesCS3B01G515900   AB191459
  R-D1 3D 570,799,694 570,803,366 TraesCS3D01G468400   AB191460
TaVp-1 / Vp1 TaVP-1A 3A 659,556,434 659,552,099 TraesCS3A01G417300 Yang et al., 2014 Vp-1A
  TaVP-1B 3B 693,342,691 693,338,300 TraesCS3B01G452200   AJ400713
  TaVP-1D 3D 525,473,897 525,469,502 TraesCS3D01G412800   AJ400714
TaPHS1 / TaMFT TaMFT-3A 3A 7,294,362 7,297,912 TraesCS3A02G006600 Nakamura et al., 2011 G1UE17
TaDOG1 TaDOG1L4 3A 67,123,800 67,124,332 TraesCS3A01G103500 Ashikawa et al., 2013 AB555729
    3B 91,147,446 91,147,986 TraesCS3B01G120900    
    3D 58,107,736 58,108,268 TraesCS3D01G105800    
TaMKK3 / Phs-1 TaMKK3-A 4A 605,019,000 a 605,023,000 TraesCSU01G167000 Torada et al., 2016 LC091368
  TaMKK3-B 5B 710,226,100 710,230,860 TraesCS5B01G565100    
  TaMKK3-D 5D 556,557,389 556,553,063 TraesCS5D01G549600   LC091372
TaQsd1 / Qsd1 b TaA 5A 432,446,370 432,446,370 TraesCS5A01G216200 Onishi et al., 2017 Qsd1
  TaB 5B 387,744,682 387,740,080 TraesCS5B01G214700    
  TaD 5D 332,043,225 332,043,225 TraesCS5D01G224200    

a RefSeqv1.0 maps TaMKK3-A to the unknown chrm, however based on previous research, TaMKK3-A should be between TraesCS4A01G314700 and TraesCS4A01G314800
b the ortholog of the barley dormancy gene HvQsd1. The Onishi et al. 2017 study compared sequence of dormant and non-dormant lines, however further work needs to be published to see if TaQsd1 genes affect seed dormancy