Technical aspects of zinc and iron analysis in biofortification of the staple food crops, wheat and rice
A major priority for any breeding initiative is to have in place effective tools for assessing the genetic variation of the trait of interest. Ideally, these technologies should be relatively low in cost and also rapid in their analysis to allow for high throughput. In its early years, the HarvestPlus program has relied heavily on ICP-OES for its micronutrient analysis as it has very good sensitivity, can have a throughput of around 500 samples per day and is able to detect Al and Ti which are seen as indicators of soil contamination in plant tissue samples. The down-side to the technology is the high cost of analysis and the degree of specialization needed to run the equipment. Colorimetric techniques such as Dithizone (for Zn) and Perl’s Prussian Blue (for Fe) have been developed for high throughput screening and are currently in use within some breeding programs. Newer technologies are also being explored and they include NIRS and both hand-held and bench-top XRF. Results are promising and research in this area is continuing. Research into ways of minimizing harvest and post-harvest soil contamination of plant tissues has also lead to more robust protocols and development of “contaminant-free” equipment for use by all research disciplines working in biofortification.
19th World Congress of Soil Science, Soil Solutions for a Changing World. 1-6 August 2010, Brisbane, Australia. p. 42-44.