Plant Growth, Biomass and Yield Component Measurements
At maturity stage, plant shoots were harvested. The panicles were counted, and the total stem and leaf dry matter per plant (Tot.shoot dry matter) were measured after drying at 70°C for 48 h and adding DM from organs used for biochemical analyses. Maximum tiller number was determined at vegetative stage.
Grain yield and yield components were calculated according to (Liuet al. , 2008): grains were sorted by using a densiometric column. The dry weight of ripened grains was determined after oven-drying at 80°C for 72 h. The 1,000-grain dry weight was then calculated.
In both experiments, local C source–sink ratio (LSSR) was estimated for each plant by dividing flag leaf blade area and fertile spikelet number on the main stem.