Modelling tiller growth and mortality as a sink-driven process using Ecomeristem: implications for biomass sorghum...

Area of Science:

• Agricultural science
• Plant physiology
• Computational biology

Background:

• Plant modeling aids ideotype design, especially for biomass sorghum requiring multi-trait consideration.
• Biomass production and quality traits are crucial for sorghum ideotype conception.

Purpose of the Study:

• Evaluate three modeling approaches for predicting tiller growth, mortality, and their impact on biomass sorghum ideotype prediction.
• Determine if tillering cessation and mortality are source or sink-driven.

Main Methods:

• Compared three Ecomeristem model versions using field data from two sorghum genotypes at two planting densities.
• Validated the best model with an eight-genotype dataset for predicting genotypic and environmental control of biomass production.
• Performed sensitivity analysis on key genotypic parameters for optimal combinations.

Main Results:

• Sink-driven control of tillering cessation and mortality accurately represented phenotypic variability in biomass production and carbohydrate partitioning.
• Light conversion efficiency and stem diameter were identified as key traits for enhancing sorghum biomass.
• Tillering's contribution to biomass is highly genotype and environment-dependent, posing challenges for ideotype design.

Conclusions:

• The Ecomeristem model, by simulating sink-driven tiller processes, effectively predicts biomass sorghum production variability.
• This modeling approach can assist in ideotyping for current and future climate scenarios, especially when integrated with genetic models and considering water deficit.