Enhancing initial growth of transplanted rice under phosphorus deficiency: combined effects of tillering quantitative trait locus and P-dipping technique

Phosphorus (P) deficiency severely constrains rice production in sub-Saharan Africa. Previous studies showed that P-dipping, involving localized application of P near the root zone, and MP3, a natural allele of OsTB1/FC1 that enhances rice tillering, effectively improve rice growth and productivity in P-deficient soils in Madagascar. In the present study, we investigated the combined impact of these two technologies on the initial growth of transplanted rice in P-deficient soils using potted plants. Our experiments revealed that near-isogenic lines for MP3 and fc1 (the loss-of-function allele of OsTB1/FC1) promoted tillering and increased initial shoot biomass compared with the parental cultivar ‘Takanari’ when combined with P-dipping. The rise in shoot biomass would be attributed to increased P-uptake in the shoots, which were brought about by a continuous P-supply from the root zone due to P-dipping. Consequently, these combinations have the potential to enhance rice productivity in P-deficient paddy fields in sub-Saharan Africa.