BaseWPDist: Distribution of base seed water potential

In HTSeedGLM: Hydro Thermal Time Analysis of Seed Germination Using Generalised Linear Model

Distribution of base seed water potential

Description

This function provides the estimates of stress and uniformity parameters along with respective variances using generalised linear model fitted to observed germination percentage of seed. The model can be fitted under logit, probit and cloglog transformations.

Usage

BaseWPDist(model)

Arguments

model

Fitted model

Value

• Degrees of freedom

• p_value: For testing significance of water potential

• stress: Location parameter of the base seed water potential

• uniformity: Scale parameter of the base seed water potential

• var_stress: Variance of estimator of the location parameter

• var_uniformity: Variance of estimator of the scale parameter

References

• Bradford, K. J. (2002). Applications of Hydrothermal Time to Quantifying and Modeling Seed Germination and Dormancy. Weed Science, 50(2), 248–260. http://www.jstor.org/stable/4046371

• Kebreab, E., & Murdoch, A. J. (1999). Modelling the effects of water stress and temperature on germination rate of Orobanche aegyptiaca seeds. Journal of Experimental Botany, 50(334), 655-664. doi:10.1093/jxb/50.334.655

• Dobson, A. J., & Barnett, A. G. (2018). An introduction to generalized linear models. Chapman and Hall/CRC.

Examples

X <- c(0,-0.3,-0.6,-0.9) # Various water potentials
y <- c(44,10,10,4) # Number of germinated seeds
n <- c(100,100,100,100) # Total number of viable seeds
n_y <- n-y
sg.mat <- cbind(y,n_y)
res.glm1 <- glm(sg.mat~ X,family=binomial(link=logit)) # Using logit transformation
my.bdl<- BaseWPDist(res.glm1)
res.glm2 <- glm(sg.mat~ X,family=binomial(link=probit)) # Using probit transformation
my.bdp<- BaseWPDist(res.glm2)
res.glm3 <- glm(sg.mat~ X,family=binomial(link=cloglog))# Using cloglog transformation
my.bdcl<- BaseWPDist(res.glm3)

HTSeedGLM documentation built on April 12, 2025, 9:13 a.m.