Delivering the benefits of agricultural biotechnology to smallholder farmers requires that resources be directed towards staple food crops. To achieve effect at scale, beneficial traits must be integrated into multiple, elite farmer‐preferred varieties with relevance across geographical regions. The staple root crop cassava (Manihot esculenta) is consumed for dietary calories by more than 800 million people, but its tuberous roots provide insufficient iron and zinc to meet nutritional needs. In Africa, cassava yields are furthermore limited by the virus diseases, cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). In this study, we strove to develop cassava displaying high‐level resistance to CBSD and CMD to attain food and economic security for cassava farmers, along with biofortified levels of iron and zinc to enhance consumer health. RNAi‐mediated technology was used to achieve resistance to CBSD in two East African and one Nigerian farmer‐preferred cultivars that harboured resistance to CMD. The Nigerian cvs. TMS 95/0505 and TMS 91/02324 were modified with T‐DNA imparting resistance to CBSD, along with AtIRT1 (major iron transporter) and AtFER1 (ferritin) transgenes to achieve nutritionally significant levels of iron and zinc in cassava storage roots (145 and 40 µg/g dry weight, respectively). The inherent resistance to CMD was maintained in all four disease resistant and mineral enhanced cassava cultivars described here, demonstrating that this technique could be deployed across multiple farmer‐preferred varieties to benefit the food and nutritional security of consumers in Africa.

中文翻译：

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在木薯品种中增加抗病能力和矿物质生物强化作用，以提高产量和消费者健康

为了向小农户提供农业生物技术的利益，需要将资源用于主粮作物。为了实现大规模的效果，必须将有益的性状整合到多个农民首选的，与各个地理区域相关的优良品种中。主食作物木薯（Manihot esculenta）被八亿多人用于饮食中的卡路里，但其块根却无法提供足够的铁和锌，无法满足其营养需求。在非洲，木薯的单产还受到病毒病，木薯花叶病（CMD）和木薯褐条病（CBSD）的限制。在这项研究中，我们力求开发出对CBSD和CMD具有高水平抵抗力的木薯，以实现木薯农民的粮食和经济安全，并通过生物强化铁和锌来增强消费者的健康。RNAi介导的技术被用于实现对CMD抗性的两个东非和一个尼日利亚农民偏爱的品种对CBSD的抗性。尼日利亚的简历。对TMS 95/0505和TMS 91/02324进行了修饰，使用T‐DNA和AtIRT1赋予了对CBSD的抗性（主要的铁转运蛋白）和AtFER1（铁蛋白）转基因，在木薯贮藏根中分别达到营养上显着的铁和锌水平（分别为干重145和40 µg / g）。本文所述的所有四个抗病和矿物增强的木薯品种都保持了对CMD的固有抗性，这表明该技术可用于多个农民偏爱的品种，从而有利于非洲消费者的食品和营养安全。