The Experimental And Model-assisted Analysis Of Rice Growth And Development Case Studies Of Tillering Inhibition: Toward Shortening The Gap Between Genotype And Phenotype With Plant Growth Models

Phenotype is the result of the interaction of genotype and environment, a given genotype can be expressed as different phenotypes in different environments, which is known as plant inherent phenotypic plasticity. The plasticity helps plant to be adapted to adverse environment, nevertheless, but we have to admit that plasticity make it difficult to uncover genetic action from many phenotypic forms. Nowadays genomics rapid evolving allows decoding the genome more easily, and even discovering massive genes, therefore the expanding phenotype requires to be explored. Within the context, it will be essential to further understand the genetic profiles from plastic process and understand the contributions of gene and environment to phenotypes.The gap exists between genotype and phenotype as the non-linear process from gene to protein, and phenotype, efficient approaches or tools are expected to span the gap between genotype and phenotype. Plant growth models have been developed to simulate plant growth kinetics response to environment, parameters and environmental conditions have been incorporated into modeling approaches. Thus, plant growth models were reckoned to play one important role to unravel plant real genetic action from complex plasticity. Rice is one typical model plant widely used in genomics or functional genomics, rice tillering is genotype dependant and environment sensitive. In the paper, we will study rice plastic development responding to tillering inhibition towards understanding genotype-phenotype and plasticity, and examine the ability of plant growth models to address plastic modeling within G×E.Two experiments were successively carried out in an automatic controlled growth chamber at CIRAD (Montpellier, France). The experiments were designed with a reference (wild type) genotype Nippon Bare (1) grown under optimal conditions; (2) with a systematic (manual) pruning of tillers; and (3) one of its TDNA organogenesis-deficient mutant (phyllo, a knock out mutant based on Nippon bare genetic background). Plants were cultivated until 50 days (vegetative stage) after germination with a hydroponics system. A set of three to four plants per treatment were destructively measured to achieve fresh weight, dry weight and dimensions of individual organs.Two plant growth models were attempted to interpret and simulate rice phenotypic development in response to tillering inhibition. GreenLab, one mathematical plant architectural model, was developed to simulate plant architectural dynamics and feedback of architecture and physiological function. Plant 3D architecture determines the radiation capture and thus biomass production, whereafter biomass is allocated to new organs designated as thermal time, the morphological architecture (e.g. geometric dimension & leaf angle) of organs will change as biomass accumulation, thus biomass production will be renewed in new growth cycle. Parameters optimization was achieved with least square method by CornerFit software. The other model EcoMeristem, one crop model basis with morphogenesis concept, was introduced here to simulate...