A coordination model captures the dynamics of organ extension in contrasted maize phenotypes

The development of plant FSPMs requires to define how phytomers extend and reach their mature size. Both the rate and duration of organ extension are impacted by environmental conditions. However, the second point is rarely considered in plant growth models. Our work relied on an existing model based on the formalisation of coordination rules for maize, which allows flexibility in plant growth timing. However, the validation of this model was based up to now on a single experiment with one genotype, and did not include a direct evaluation of the coordination rules. The objective of the present work was to get a deeper view of the ability of modelling approaches based on coordination rules to simulate shoot development in maize. First we assessed the validity of coordination rules for two genotypes with contrasted number of leaves and grown in contrasted environments. Second we adjusted the model on both genotypes. Some formalisms were adapted to best represent both genotypes. Finally, our results show that a same set of coordination rules could represent precisely the development of maize genotypes of contrasted architectures. This bring support to the idea that coordination rules could be used in FSPM models as an alternative to a fixed thermal time schedule.