摘要：Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO
2 assimilation rate (
A) of two elite rice (
Oryza sativa) cultivars and 76 inbred lines across the whole growing season. The integrated
A value after heading was positively associated with crop growth rate (CGR) from heading to harvest, but that before heading was not. A curve-smoothing analysis of
A after heading showed that accumulated
A at > 80% of its maximum (
A
80) was positively correlated with CGR in analyses of all lines mixed and of lines grouped by genetic background, while the maximum
A and accumulated
A at ≤ 80% were less strongly correlated with CGR. We also found a genomic region (~ 12.2 Mb) that may enhance both
A
80 and aboveground biomass at harvest. We propose that maintaining a high
A after heading, rather than having high maximum
A, is a potential target for enhancing rice biomass accumulation.
