A grammar-based model of barley including virtual breeding, genetic control and a hormonal metabolic network


  • G. Buck-Sorlin
  • O. Kniemeyer
  • W. Kurth


The incorporation of some genetic and physiological processes in a developmental model of Hordeum vulgare L. (barley) is presented. The model exhibits different hierarchical scales and has been conceived as a Relational Growth Grammar (RGG). RGG is a new formalism that has been developed as an extension of L-Systems and implemented using a new modelling language, eXtended Lsystems (XL). Models written in XL can be executed using the interactive, Java-based modelling platform GroIMP, which has been developed for this purpose. The barley model proper is a set of morphogenetic rules. These are combined with a set of rules representing a metabolic network simulating some key steps of the biosynthesis of gibberellic acid (GA1). The transport of GA1 and GA19 (a metabolic precursor of GA1) along the developing simulated structure has also been foreseen. In the model, the local concentrations of GA1 in a module induce the elongation of internodes. In an extension of this base model, called "BarleyBreeder", individual virtual specimens are chosen interactively from a population, followed by the simulation of reproduction. Both genotype and phenotype of the population are visualized. So far, the model is restricted to a few Mendelian genes, one of which (the dwarfing gene Zeocrithon) is directly interacting with the biosynthesis of GA1.