'Smart' cereals for management of stemborer pests in staple cereals in Africa

天牛是撒哈拉以南非洲重要粮食作物玉米和高粱的毁灭性害虫。它们通过在茎内挖洞来破坏这些作物，导致植物倒塌和死亡。Stemper害虫破坏了小农户的谷物种植，并威胁到粮食安全，因为它们造成了很高的作物损失。在之前的研究中，我们证明了通过改变作物周围的植物气味可以防止这些损失。我们使用伴生植物来释放气味，以驱赶害虫，并吸引攻击害虫的天敌昆虫。斯瓦希里语的配套种植制度被称为“推拉”或“苏库马-瓦塔”，在小农中很受欢迎，但如果作物本身在虫害肆虐时能释放出适当的气味，这种种植制度就会得到改善。最近，我们发现某些农民选择的玉米品种具有商业杂交玉米所没有的有价值的防御特性。这种特征涉及到气味的释放，这种气味被称为信号化学物质，在昆虫产卵后，这种气味对害虫的天敌具有吸引力。释放的信号化学物质与推拉系统中的伴生植物释放的信号化学物质是相同的。然而，具有这一特性的作物品种缺乏其他重要的农艺性状，特别是产量和品质。为了将这种天然的抗虫性传递给农民，需要进行育种计划，将这种特性转化为改良的作物品种。这是一个困难的过程，但如果能找到与葡萄球菌抗性性状紧密连锁的遗传标记，将会大大便利这一过程。该项目的目标是定义与信号化学生产特性相关的遗传标记。我们将通过一项全面的实验计划来实现这一点，在这些实验中，将识别不同作物品种在昆虫产卵后释放的信号化学物质，测量昆虫对它们的反应，并绘制与诱导信号化学物质发射相关的基础基因图。我们将使用Rothamsted Research(英国)提供的最先进的信号化学鉴定平台和东非和中非生物科学中心(肯尼亚贝卡)的遗传分析资源，并连接到康奈尔大学的测序设施。作物将在国际昆虫生理和生态中心(CIPE，肯尼亚)种植和试验，该中心在进行与非洲小农需求相关的研究并对他们的生计产生影响方面有着良好的记录。

Stemborers are devastating insect pests of important food crops, maize and sorghum, in sub-Saharan Africa. They damage these crops by burrowing inside the stem causing the plants to collapse and die. Stemborer pests undermine smallholder cereal cultivation and threaten food security of the very high crop losses they cause. In previous research, we demonstrated that these losses can be prevented by changing the plant odours surrounding the crop. We used companion plants to release smells that repel the pest and attract natural enemy insects that attack the pest. The companion cropping system known as "push-pull" or "Sukuma-Vuta" in Swahili is very popular with smallholder farmers but this would be improved if the crop itself could release the appropriate odours when infested with pest insects. Recently we have found that certain farmer selected varieties of maize have a valuable defence trait not present in commercial hybrid maize. The trait involves release of odours, called semiochemicals, which are attractive to natural enemies of the pest after the stemborer lays her eggs on the plant. The semiochemicals released are the same ones released by companion plants in the push-pull system. The crop varieties with this trait, however, are lacking in other important agronomic traits, particularly yield and quality. To deliver this natural pest resistance to the farmer, breeding programmes are needed to move the trait from into improved crop varieties. This is a difficult process but would be greatly facilitated if genetic markers linked closely to the stemborer resistance trait could be identified. The goal of this project is to define genetic markers associated with the semiochemical production trait. We will achieve this by a comprehensive programme of experiments in which the semiochemicals emitted by different crop varieties after insect egg laying will be identified, insect responses to them measured and the underpinning genes associated with induced semiochemical emission mapped. We will use a state-of-the-art semiochemical identification platform available at Rothamsted Research (UK) and resources for genetic analyses at the Biosciences Eastern and Central Africa hub (BECA, Kenya) with a link to the Cornell University sequencing facility. Crops will be grown and trialled at the International Centre for Insect Physiology and Ecology (icipe, Kenya) which has a proven track record of doing research that is relevant to the needs of smallholder farmers in Africa and makes a difference to their livelihoods.