Rice germplasm for high grain Zn content and tolerance of Zn deficient soils

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The project is in four work packages corresponding to the above four specific objectives. In WP1 we will use field, controlled environment and laboratory experiments to assess whether the mechanisms we have identified for seedling-stage tolerance of Zn deficiency universally separate tolerant from sensitive genotypes under seedling-stage Zn deficiency in different soils, and whether they continue to enhance uptake and grain filling during reproductive stages. The field experiments will be at four sites in the Philippines and four in Bangladesh, covering the range of soil types in which Zn deficiency occurs. We will use a common set of 12 contrasting genotypes. Methods will include a novel stable-isotope technique for studying uptake processes. In WP2 we will seek to identify loci and genes enhancing Zn uptake during vegetative and reproductive growth stages, leading to high grain Zn concentrations. Two methods will be used: (a) conventional QTL mapping based on a bi-parental cross, and (b) genome wide association mapping (GWAM) based on a panel of 178 genebank accessions. We will use the results for fine mapping and candidate gene identification. In WP3, we will develop and experimentally test mathematical models of Zn uptake processes in rice paddies, allowing for the biogeochemistry of Zn in submerged soils over the growing season and longer term, and the mechanisms of root-soil interactions. We will use the models and parameter values from the field and other experiments to assess strategies for increasing uptake in different environments and to predict the long-term sustainability of growing high Zn rices in Zn-deficient environments. In WP4 we develop rice breeding and management options and feed them into existing technology-transfer programmes at IRRI. This will include introgression of markers identified in WP2 into major Bangladeshi and Philippine rice varieties.

see main proposal