Rice production is a particularly important crop for the half-world population. Therefore, knowledge about which genes are implicated in the functionality of the Photosystem II, that are still poorly explored could collaborate in the assisted selection of rice improving. In the present study, we applied Genome wide Association Studies of PSII chlorophyll fluorescence under two contrasting environmental conditions in 283 rice accessions highly diverse. A total of 110 significant association SNP-phenotype were observed, and 69 quantitative trait loci identified with a total of 157 genes, of which 38 were highly significant, mapped spread out through rice genome. These underlying regions are enriched in genes related to biotic and abiotic stresses, transcription factors, Calvin cycle, senescence, and grain characters. The correlations analyses PSII chlorophyll fluorescence parameters and some panicle characteristics found here suggest the possibility of developing molecular markers to assist the breeding programs that improve photosynthesis and yield in rice.HighlightThe genetic structure of the Photosystem II functionality in rice was studied by using genome-wide association through chlorophyll fluorescence.