Scientists at Rothamsted Research have developed a new mathematical model for seed germination.
Current germination models use water and temperature as the main drivers of seed activity. These are based largely on water potential, which is the energy that drives water to move from one system to another.
Researchers said that this is challenging to measure accurately in the field, and that the new model uses water content which is much easier to measure.
The field experiments were conducted during the 2018/2019 growing season at Shangqiu Station of the National Agroecological Monitoring Network in China.
These germination models are essential to the seed industry, as it is important to develop lines where each individual seed germinates at roughly the same time and grows uniformly.
This is particularly important for crops like carrots or onions where having similarly sized plants makes them more profitable.
Seed suppliers must therefore test seed samples to ensure a certain germination rate is met, a process that can be difficult and time-consuming. As a result, modelling is used to assess each batch based on a given sample.
However, current models do not always accurately reflect field conditions, and this is where the new model comes in.
The researchers have said that water content is much easier to measure accurately in situ, than the drivers of water potential. That makes the new model far more likely to accurately predict germination times in field situations.
The research team created a new model by viewing seed germination as a dynamic process.
To validate the model, they conducted field experiments by drilling wheat seeds at different dates to establish a temperature gradient and in different plots to create a soil water content gradient.
Comparisons between the experimental data over a period of seven years and calculated results show that the model accurately reproduces all germination patterns and the subsequent seedling tillering with a 95% fit.
“This is the first time a germination model has been able to be developed using field data,” said Dr Xiaoxian Zhang, corresponding author of the new study.
“Seed germination is a crucial stage in plant development, intricately regulated by various environmental stimuli.”
“We believe this new approach offers a genuinely new approach to germination modelling and for the first time takes on tiller number,” he added.
The study described how seed germination has received less attention compared to other topics in plant science.
However, the advances in molecular technologies over the past few decades have substantially improved understanding of the genes and interlocked hormone networks that regulate seed germination.
