Replication data: Shallow rooting as a means of increased Zn-uptake by Zn-deficiency tolerant rice genotypes

Increased root numbers of rice genotypes have been attributed to its tolerance to Zn deficiency. However, its role in soil Zn uptake by plants and productivity in Zn deficient soils remains unclear. Here, we examined the root numbers of rice genotypes (Zn-efficient, Zn-inefficient and popular variety) at different soil depths (soil surface, 0-2, 2-4 and 4 cm below) including their role in soil Zn uptake , yield or productivity and grain Zn biofortification grown under Zn deficient soil at the IRRI experimental station. The root numbers at each soil depth [soil surface (P<0.05), 0-2 (P<0.01), 2-4 (P<0.0001) and below 4cm (P<0.001)] were significantly different among genotypes and the Zn-efficient (IR55179) genotype showed the highest root numbers among genotypes on the soil surface and at 0-2cm soil depth. Results showed that root numbers present on the soil surface (P <0.001) and at 0-2 cm soil depth (P <0.001) revealed significant correlations with grain Zn concentration/uptake. Moreover, root numbers from all soil depths were significantly correlated with the mean soil DTPA-extractable Zn, while root numbers from 0-2 and 2-4 cm were significantly correlated with plant parts biomass during flowering and maturity. Overall, the increased root numbers of Zn-efficient genotypes at the top layer of soils play a pivotal role in soil Zn availability, plant Zn uptake and productivity, highlighting that increased root numbers are good indicator of Zn deficiency tolerance in rice. Location: IRRI Demoplot Years: 2015-2016