STTR Phase I: Utilizing Natural Variation to Increase the Antioxidant Carotenoid Content in High Yielding Corn Varieties

这项小型企业技术转让（STTR）项目的更广泛影响/商业潜力将是开发和商业化一种新型玉米品种，这种玉米类胡萝卜素含量高，颜色为橙色，产量可与目前的商业杂交品种相竞争。在美国人的饮食中，两种重要的抗氧化类胡萝卜素，叶黄素和玉米黄质，含量很低。这种缺乏与退行性疾病的高风险相关，如年龄相关性黄斑变性，以及潜在的痴呆。这项拟议研究的最终目标是让美国人摄入更多的叶黄素和玉米黄质，这将通过显著提高种植最广泛的主要作物——玉米——中这些抗氧化剂的含量来实现。由于玉米被广泛用于各种受欢迎的加工食品中，提高玉米中类胡萝卜素的含量，可以在不改变消费者饮食习惯的情况下，显著增加美国人摄入的有益健康的抗氧化剂的数量。然而，为了使这一策略在经济上可行，必须开发出富含类胡萝卜素的玉米品种，同时也能提高粮食产量。本STTR一期项目拟开发类胡萝卜素生物合成及其稳定性相关基因有利等位基因的遗传标记。与类胡萝卜素生物合成和稳定性相关的基因存在相当大的遗传变异，然而，在与美国玉米生产有关的商业品种中通常没有发现最有利的等位基因。因此，遗传标记的开发将使有利等位基因从不太适应美国玉米带的低产量种质转移到适合生产具有产量竞争力的商业F1杂交种的优良自交系中，以供美国市场使用。本I期研究的主要目标是创建与类胡萝卜素生物合成和稳定性相关的12个关键基因的有利等位基因相关的用户友好遗传标记。然后，这些标记将通过测试它们产生具有更高类胡萝卜素产量的后代的能力来验证其有效性，特别是叶黄素和玉米黄质。这将产生一套标记和实验育种材料，可用于快速开发固定自交系，用于生产具有产量竞争力的高类胡萝卜素F1杂交种。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) project will be the development and commercialization of a novel variety of corn that is high in carotenoids and orange in color, and with yields that are competitive with today's commercial hybrids. In the diets of Americans, two important antioxidant carotenoids, lutein and zeaxanthin, are in low abundance. This deficiency has been associated with higher risk for degenerative diseases such as Age Related Macular Degeneration, and potentially, dementia. The ultimate goal of the proposed research is to get American's to consume more lutein and zeaxanthin, which will be achieved by increasing significantly the levels of these antioxidants in the most widely grown staple crop: Corn. Since corn is used in a wide variety of popular processed food formats, improving the carotenoid content of corn provides an opportunity to significantly increase the amount of health benefiting antioxidants that Americans consume, without changing consumers eating habits. However, in order for this strategy to be economically feasible, corn varieties that are high in carotenoids must be developed that are also high in grain yield. This STTR Phase I project proposes to develop genetic markers for favorable alleles of genes associated with carotenoid biosynthesis and stability. There is considerable genetic variation in genes associated with carotenoid biosynthesis and stability, however, the most favorable alleles are typically not found in varieties that are commercially relevant to US corn production. Thus, the development of genetic markers will enable favorable alleles to be moved from lower yielding germplasm that is not well adapted to the US Corn Belt into elite inbreds suitable for the production of yield-competitive commercial F1 hybrids for the US market. The primary goal of this Phase I research is to create user-friendly genetic markers associated with favorable alleles for 12 key genes associated with carotenoid biosynthesis and stability. These markers will then be validated for efficacy by testing their ability to create progenies with higher carotenoid production, particularly lutein and zeaxanthin. This will result in a set of markers and experimental breeding materials that can be used to rapidly develop fixed inbreds for use in the production of yield-competitive high carotenoid F1 hybrids.