Biomass-based rapeseed (Brassica napus L.) stem and rachis geometric parameter model

To quantify the relationships between rapeseed stem and rachis geometric parameters and the corresponding organ biomass, we presents a biomass-based model of stem and rachis geometric parameters of rapeseed (Brassica napus L.), including biomass-based total length model for ramification, maximum diameter model for ramification, length model for main stem, maximum diameter model for main stem, and length model for main rachis, designed to explain effects of cultivars and environmental conditions on rapeseed stem and rachis morphogenesis at the individual stem level. Various model variables, including organ length, maximum diameter, and corresponding organ biomass, were parameterized for rapeseed based on data derived from an outdoor experiment with rapeseed cv. Ningyou18, Ningyou16, and Ningza19. The organ dimensions of rapeseed were modelled taking corresponding organ biomass as an independent variable. Various variables in rapeseed showed marked consistency in observation and simulation, suggesting possibilities for a general rapeseed stem and rachis geometric parameter models. Our descriptive models were validated with the independent experiment data, and the results showed that these models paid a good performance and reliability for predicting length and maximum diameter for stem and rachis, which can set the stage for connection to physiological model via biomass and development of Functional Structural Rapeseed Models (FSRMs), and start with the localized production and partitioning of assimilates as affected by abiotic growth factors.