Modeling vegetative vigour in grapevine: unraveling underlying mechanisms

Abstract

Mechanistic modeling constitutes a powerful tool to unravel complex biological phenomena. This study describesthe construction of a mechanistic, dynamic model for grapevine plant growth and canopy biomass (vigor). Toparametrize and validate the model, the progeny from a cross of Ramsey (Vitis champinii) Riparia Gloire (V. riparia) was evaluated. Plants with different vigor were grown in a greenhouse during the summer of 2014 and2015. One set of plants was grafted with Cabernet Sauvignon. Shoot growth rate (b), leaf area (LA), dry biomass,whole plant and root specific hydraulic conductance (kHand Lpr), stomatal conductance (gs), and water potential(Ψ) were measured. Partitioning indices and specific leaf area (SLA) were calculated. The model includes anempiricalfit of a purported seasonal pattern of bioactive GAs based on published seasonal evolutionary levels andreference values. The model provided a goodfit of the experimental data, with R¼0.85. Simulation of single traitvariations defined the individual effect of each variable on vigor determination. The model predicts, withacceptable accuracy, the vigor of a young plant through the measurement of Lprand SLA. The model also permitsfurther understanding of the functional traits that govern vigor, and, ultimately, could be considered useful forgrowers, breeders and those studying climate change.