This pilot study aimed to calibrate a scientific protocol by assessing the effect of a demethylation agent on plant phenotype. Seeds were treated with six different doses of the agent, including a zero-dose control, and then sown in trays, with each tray containing seeds treated at the same dose. Each dose was replicated across four trays: two containing 60 plants and two containing 100 plants. The experiment was arranged in a completely randomized design. For each tray, the number of plants exhibiting a normal phenotype (Normal) and the total number of plants (Total) were recorded, with each tray identified by a unique index (DTray). The dataset allows investigation of the relationship between agent dose and the binomially distributed probability of plants showing a normal phenotype.
Format
A data frame with 4 variables: DTray, Dose, Total, Normal.
- DTray
Factor. Unique identifier for each tray in the experiment.
- Dose
Numeric. Dose of demethylation agent applied to the seeds (including zero for controls).
- Total
Integer. Total number of plants in each tray.
- Normal
Integer. Number of plants in each tray exhibiting a normal phenotype.
Source
Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression
Examples
glm(cbind(Normal, Total - Normal) ~ Dose,
family = binomial(),
data = demethylation)
#>
#> Call: glm(formula = cbind(Normal, Total - Normal) ~ Dose, family = binomial(),
#> data = demethylation)
#>
#> Coefficients:
#> (Intercept) Dose
#> 2.793 -7.623
#>
#> Degrees of Freedom: 23 Total (i.e. Null); 22 Residual
#> Null Deviance: 1901
#> Residual Deviance: 160.6 AIC: 235.6
glm(cbind(Normal, Total - Normal) ~ log(Dose + 0.1),
family = binomial(),
data = demethylation)
#>
#> Call: glm(formula = cbind(Normal, Total - Normal) ~ log(Dose + 0.1),
#> family = binomial(), data = demethylation)
#>
#> Coefficients:
#> (Intercept) log(Dose + 0.1)
#> -3.188 -3.148
#>
#> Degrees of Freedom: 23 Total (i.e. Null); 22 Residual
#> Null Deviance: 1901
#> Residual Deviance: 26.62 AIC: 101.6