Association Between Grain Filling Rate and Duration and Yield Components in Rice¹

Abstract

The identification of readily measured traits that are associated with higher yields of field crops is important to plant breeders. The objective of this research was to determine if differences in grain filling rate and duration existed in rice ( Oryza sativa L.) and if so, were these grain filling parameters correlated with other yield related components of the rice plant. Fifteen genotypes of rice were selected to represent a sample having diverse agronomic characteristics. Samples of panicles of the 15 genotypes were taken at weekly intervals for approximately 6 weeks during the grain filling period. The cubic polynomial model was found to closely fit the dry weight data (r 2 ≥ 0.95 for all genotypes). Grain filling rate and duration as well as other grain filling parameters were determined from the model. Correlation between the grain filling parameters with yield components indicated that grain firing rate was more important than duration in this study. Grain filling rate, in turn, was positively and highly significantly correlated with actual panicle weight and 100‐grain weight and negatively correlated with panicles m ‐2 .