水稻铁生物强化育种中稻米加工与铁浓度的快速测定方法

铁对人体的健康十分重要,缺铁已对人类健康和世界经济造成巨大影响。针对我国水稻生物强化育种工作中存在的样品加工过程铁污染严重,以及缺少适合育种群体大规模简便、快速的铁浓度检测手段,本研究发展了一种振荡研磨加工方法和基于邻二氮菲染色的比色测定方法。在研磨程度相同的情况下,经铁制精米机械加工的18个样品中有一半样品的铁浓度显著高于振荡研磨加工的,表明铁制精米加工机械对水稻精米加工存在明显的铁污染。本研究发明的精米振荡研磨加工方法,可以消除加工机械对样品加工过程中的铁污染。尽管对59个铁生物强化后代的测定平均铁浓度邻二氮菲比色法要比ICP-MS高出2.98mgkg-1,但两者的相关系数高达0.87,表明该测定方法适用于大批量育种群体精米铁浓度的初步筛选。与ICP-MS相比,邻二氮菲比色法具有简便、快速和低成本的特点。以铁浓度高的水稻种质为供体,导入广西本地高产品种背景,对分离后代采用上述加工和检测方法进行筛选,育成新品系精米的铁浓度比原品种提高了3倍。

A Robust and Cost-Effective SGOC Method for Testing Rice Iron Concentration in Biofortified Breeding

Iron is an important micro-nutrient to human health. Malnutrition of iron is a serious problem associated with resource poor population of many developing countries. Development and consumption of iron-rich rice varieties are considered one of the ways to solve the problem. To facilitate large-scale screening of breeding materials for iron concentration in the rice iron-biofortified breeding program of China, we developed a new method “surging and grind-milling of orthophenanthroline colorimetry testing” (SGOC). Based on the testing results of 3 sets of 84 diverse rice genotypes that differ greatly in grain iron concentration, the correlation coefficient was as high as 0.87 between the SGOC method and the standard ICP-MS testing method. The per sample cost of the SGOC method was about 0.1$, or 50 times less the ICP-MS method, indicating that the SGOC method is a robust, fast and cost-effective, particularly useful for preliminary screening of the iron concentration of large numbers of early generation breeding materials. Our results demonstrated that milling and polishing with iron-made equipment tended to significantly increase the iron concentration of processed rice, which was also eliminated in the SGOC method. Finally, our results on the 59 BC progeny indicate that introgression of genes/ QTLs for high iron concentration from high iron rice germsperm into elite local rice varieties is an efficient way to develop high yielding rice varieties with significantly improved rice iron concentration in future rice biofortified breeding.