Year: 2016
Type: conference-paper
Abstract: Introduction Plant adaptation to variable resources depends on phenotypic plasticity, enabling adjustment of organ deployment and growth to balance source-sink relationships. Plasticity in rice is mostly compensatory and stabilizes harvest index (HI). Since Donald (1968) proposed the concept of ideotype, breeders sought modifying morphology to increase yield, e.g., in green revolution semidwarfs, IRRI’s New Plant Type or China’s Super Hybrid Rice (Dingkuhn et al., 2015). But effects of modified morphology and partitioning can be absorbed by compensatory plasticity resulting in unchanged yield. Crop models unable to simulate plasticity are not suited to predict ideotype performance. We sought to model compensatory plasticity with the new crop model SAMARA using IR72 rice. Plasticity in organ number and size is driven by an internal competition index (Ic) relating fresh assimilate supply (S) to aggregate demand (D) in growing organs [Ic=S/D]. Low S triggers reserve mobilization, reduced organ size and mortality of leaves or tillers. Ic>1 promotes storage. The objectives were to (1) study experimentally effects of population and environment on morphology and yield, (2) calibrate and validate SAMARA, and (3) evaluate observed and simulated plasticity.
Source: Agritrop (Cirad)
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2338566195