Developing a Cereal Fertility Pipeline (CerFip) for wheat and barley.

全球越来越多地认识到农业和粮食安全的重要性。到2050年人口增长50%的预测强调了对可持续、有效的农业系统的迫切需要。在不增加环境影响的情况下提高作物生产率的战略至关重要。对关键性状的选择性育种，结合杂交品系的使用，有可能实现这些目标。杂交种是由两个不同个体杂交而成的后代。杂交种往往表现出“杂交种的活力”，这可以从提高生长速度方面看出，但总产量也有所提高。杂交优势是杂交种优于双亲的结果，例如，杂交水稻比自交系增产20-30%，因为这样的杂交稻非常有价值，在中国，杂交水稻占所有水稻种植的50%。然而，杂交后代的产生既困难又昂贵，而且在小麦和大麦等温带谷物中也不容易实现。通常需要去势才能产生杂交后代，因为植物在交叉受精之前经常自交受精，这是劳动密集型的，需要特定的种质，或者对环境有很高的影响。温带杂交种的缓慢发展反映了种质的可获得性和对控制男性生育能力的性状的理解方面的瓶颈。最近有报道称，Hystar杂交小麦(先正达)增产约0.5t/ha，杂交大麦(先正达)增产10%。然而，由于缺乏对谷物生殖的分子理解，这些报告受到限制。还需要随后挽救雄性不育系，因此需要涉及可诱导基因系统的方法，或基于环境敏感性的育性转换。环境变化，如低温/高温，似乎也可能影响花粉的活力，从而降低产量。更好地了解谷类花粉的发育，有助于有效地控制雄性育性，将有助于提高产量潜力。关于花粉发育的分子过程的大部分知识已经/正在拟南芥和水稻的模式系统中发展起来。这项建议将利用这一知识，并利用小麦和大麦基因组分析方面的最新技术来开发谷物育性管道(CerFip)，用于将性状从模式系统转移到温带谷物，以控制男性育性。它将产生种质和遗传资源，用于选择性育种、最大受精/结实率和杂交生产的肥力操纵，这些都是提高产量和粮食安全所必需的。它将利用不同基因组之间的比较来识别大麦和小麦中的相应基因。这些新发现的基因将被测试，以确认它们在花粉发育中的作用，并为温带谷物中的雄性生殖提供更多的洞察力。将开发种质来测试选定的基因，用于在男性可育和不育之间切换的系统中应用。这种材料在未来开发控制杂交生育的系统方面可能非常有价值。

There is increasing global awareness of the importance of agriculture and food security. Predictions of a 50% population increase by 2050 emphasise the urgent need for sustainable, effective agricultural systems. Strategies for improved crop productivity without increasing environmental impact are critical. Selective breeding for key traits, combined with the use of hybrid lines has the potential to realise these goals. Hybrids are the progeny derived by crossing two distinct individual together. Hybrids tend to show "hybrid vigour", this can be seen in terms of increased growth, but also overall yield. Hybrid vigour results in the superiority of a hybrid over its parents, for example hybrid rice has 20-30% increased yield compared to inbreds as such hybrids are extremely valuable and in China hybrid rice constitutes >50% of all rice grown. However, the generation of hybrids is difficult and expensive, and has not been easy to achieve in temperate cereals, such as wheat and barley. Emasculation is often needed to generate hybrids, because plants frequently self-fertilise before cross-fertilising, this is labour intensive, requires specific germplasm, or has high environmental impact. The slow development of hybrid temperate cereals is a reflection of the bottleneck in the availability of germplasm and understanding of traits controlling male fertility. Recently there have been reports of Hystar hybrid wheat (Syngenta) with yield increases of ~0.5t/ha and hybrid barley (Syngenta) showing >10% increased yield. However, these reports are restricted by a lack of molecular understanding of cereal reproduction. There is also a need for subsequent rescue of male sterile lines, therefore approaches involving inducible gene systems, or switches in fertility based on environmental sensitivity are needed. It also seems likely that environmental changes, such as low/high temperature may be impacting on pollen viability and therefore reducing yield.A better molecular understanding of cereal pollen development that would facilitate effective control of male fertility would aid in increasing yield potential. Much of this knowledge of the molecular processes of pollen development has/is being developed in the model systems of Arabidopsis and Rice. This proposal will exploit this knowledge and utilise newly available techniques in wheat and barley genomic analysis to develop a Cereal Fertility Pipeline (CerFip) for trait transfer from model systems into temperate cereals for the control of male fertility. It will generate germplasm and genetic resources for the manipulation of fertility for selective breeding, maximal fertilization/seed set, and hybrid production, which are essential for yield improvement and food security. It will use comparisons between the different genomes to identify the corresponding genes in barley and wheat. These newly identified genes will be tested to confirm their role in pollen development and provide greater insight into male reproduction in temperate cereals. Germplasm will be developed to test selected genes for their application in switchable systems between male fertility and sterility. Such material will be potentially very valuable in the future development of systems to control fertility for hybrid development.