Estimation of sink capacity of rice grains: A comparison of calculation methods based on 1000-grain weight and grain projected area

Accurate estimation of sink capacity in rice (grain number × potential grain size), independent filling, is necessary for considering source – interactions. However, how to measure size still a matter debate. Here, we investigated the effect modifying grain-filling environment on 1000-grain weight grains screened by specific gravity or brown thickness, projected area (‘grain area’), husk as candidate indicators using japonica cultivar Koshihikari and its near-isogenic line with greater spikelet number. We found be best, followed weight. developed novel method calculate from area; was based relationship between individual area. Comparison conventional showed that although more accurate, useful enough, because screening thickness selected filled well, limited.