Implementing effective marker technologies into disease resistance wheat breeding programmes within Africa

在面临全球粮食不安全的世界经济中，对增加农业生产的需求从未像现在这样大。这一需求是在自然资源减少、土地边缘化加剧和气候变化不确定性的背景下提出的。因此，发展低化学品投入、可持续的农业系统至关重要。小麦与水稻和玉米一起，为人类提供了相当大比例的热量摄入。生物胁迫是农作物生产的主要制约因素，小麦的真菌锈病是一个重大的全球性问题。虽然疾病造成的破坏是世界上所有小麦种植区的一个问题，但在那些小麦产量低和一般经济气候禁止使用杀菌剂的国家，问题却很复杂。这一点在非洲资源贫乏的小规模农民身上表现得最为明显。1999年，乌干达出现了一种新的茎锈病，克服了70%的小麦品种的抗性。这种通常被称为Ug99的新品种导致了2007年和2008年全球小麦价格的上涨，东非一条面包的价格上涨了70%。2000年，在美国发现了一种新的更具侵略性的条锈病，它能够在更高的温度下生长。该品种于2001年在欧洲被发现，2002年在西澳大利亚被发现，那里以前温暖的气候不利于条锈病的感染。这代表了一种新的病原体传播速度最快的报道。因此，建立可持续的小麦生产系统至关重要。要实现这一目标，开发高产、抗病的小麦品种还有很长的路要走。在这个项目中，我们对茎锈病和条锈病的一些新抗性来源进行了遗传和生物学表征，这些抗性已被证明在非洲南部和东部对这两种疾病有效。将利用DNA标记来确定产生抗性的基因的位置，并测量每个基因对总体抗性的贡献。生物学研究将告诉我们这种基因所赋予的抗性机制，从而告诉小麦育种者应该将哪些基因积累到新的小麦品种中以获得加性效应。将利用最新的标记技术为每个抗性基因开发DNA标记。DNA标记为小麦育种者提供了一种工具，通过这种工具，小麦育种者可以将一些抗性基因金字塔化，从而在更短的时间内培育出优质的小麦品种。为了确保非洲的国家小麦育种计划能够使用这些DNA标记，将在南非和肯尼亚的研究和育种机构中建立两个标记平台。因此，该项目包含一个大型能力建设方案，提供有形基础设施和训练有素的人员。将建立一条从英国到非洲的知识技术转移管道，以RSA和肯尼亚为切入点，这条管道将在本赠款的整个生命周期内及以后发挥作用。

In a world economy faced with global food insecurity the demand for increased agricultural production has never been greater. This demand is set against a background of declining natural resources, increasing land marginalisation and the uncertainties of climate change. The development of low-chemical input, sustainable agricultural systems is therefore critical. Along with rice and maize, wheat provides a substantial proportion of the calorific intake of the human population. Biotic stresses present a major constraint to crop production, with the fungal rusts of wheat being a significant, global problem. While the devastation caused by disease is an issue for all wheat growing regions of the world the problem is confounded in those countries where low wheat yields and the general economic climate prohibit the use of fungicides. This is never more apparent than for resource poor, small scale farmers in Africa.In 1999 a new race of stem rust appeared in Uganda, overcoming the resistance present in 70% of wheat varieties. This new race, commonly known as Ug99 contributed to the global wheat price increases seen in 2007 and 2008, with the price of a loaf of bread in east Africa increasing by 70%. In 2000 a new, more aggressive race of stripe rust was detected in the US which was able to grow at higher temperatures. This race was found in Europe in 2001 and Western Australia in 2002, where previously the warmer climate was not conducive to stripe rust infection. This represented the fastest reported spread of a new pathogen race. It is therefore vital that sustainable wheat production systems are put in place. The development of high-yielding, disease resistant wheat varieties will go a long way to achieve this.In this project we undertake a genetic and biological characterisation of a number of sources of novel resistance to stem and stripe rust, which has proven effective against these two diseases in southern and eastern Africa. The genes responsible for the resistance will be genetically defined using DNA markers to locate the position of the genes and measure the contribution of each to the overall resistance. Biological studies will inform as to the mechanisms of resistance such gene confers, thereby informing wheat breeders which genes to accumulate into new wheat varieties to obtain additive effects.DNA markers will be developed for each resistance gene using the latest marker technologies. DNA markers provide tools by which wheat breeders can pyramid a number of resistance genes, allow for the development of superior wheat varieties in a much reduced time frame.To ensure that these DNA markers can be used by national wheat breeding programmes within Africa two marker platforms will be established within research and breeding institutes in South Africa and Kenya. The project therefore contains a large capacity building programme, providing physical infrastructure and trained personnel. A knowledge-technology transfer pipeline will be established from the UK into Africa, using RSA and Kenya as the entry points, which will function both during the lifetime of this grant and beyond.