油菜苗期抗旱性的表达谱分析与QTL定位

Drought is the most severe factor limiting agriculture production. In China, drought frequently occurs in autumn and stunts rapeseed seeding growth, leading to >25% yield penalty.Therefore, it is of great important to initiate research on drought-tolerance improvement in rapeseed to achieve a stable yield under adverse conditions and thus guarantee safe oil supply in our country. In this proposal, we focuse on screening and identifying drought tolerant candidate genes as a start point. Firstly, gene expression profile of rapeseed seedlings under stress conditions is analyzed by RNA-Seq technique in order to obtain candidate drought responded genes. Then, special PCR markers (i.e. functional markers) are designed according to above gene sequences and used for QTL mapping in a RIL population to confirm their usefulness. These results will be important in predictive breeding of drought tolerant rapeseed variety. To our knowledge, this is the first study of drought tolerance in rapeseed by RNA-Seq technique. One unique feature of this project is the adopted route "from genes to markers". According to this idea, we first isolate drought candidate genes and then convert them into functional markers. This technical route will ensure our outputs to be original and creative. As global worming being more serious, the issue of agriculture drought is now more pressing. Thus, initiation of study on genetic improvement of rapeseed drought tolerance is of great urgency.

干旱是农业生产的最大限制性因素，我国频繁发生的秋旱严重影响油菜苗期生长，每年可造成25%以上的产量损失。开展油菜抗旱性的遗传改良研究，提高其抗旱减灾能力，对于确保我国油料安全供给具有十分重要的意义。 本项目以转录组测序技术（RNA-seq）为手段，以抗旱相关基因为切入点，首先分析油菜干旱胁迫下的基因表达谱特征，获得抗旱性差异表达基因，然后根据基因序列开发SNP标记并在RIL群体中进行QTL作图验证，从而获得抗旱性的功能标记，为油菜抗旱育种提供技术和材料保障。本项目首次将RNA-seq技术应用到油菜抗旱性的遗传研究领域，通过"先找基因，后找标记"的思路，在获得分子标记的同时，也验证了相应抗旱基因的功能，研究结果将具有原创性。随着全球气候变暖，农业干旱问题更加突出，开展油菜抗旱性遗传改良研究已经刻不容缓。

油菜是我国最重要的冬季油料作物，随着全球气候变暖，秋旱频繁发生，严重影响油菜出苗质量和后期产量。为此，我们系统开展了油菜抗旱性的遗传机理研究及品种改良，建立了油菜抗旱鉴定技术平台，制定了《油菜抗旱性鉴定技术规范》农业行业标准，鉴定出3份高度抗旱的油菜新品种；通过远缘杂交创制出2个抗旱的株系材料。通过转录组测序技术获得了6000余个抗旱差异表达基因，并对其中的3个基因（WRKY40、WRKY60和ALAAT1）进行了转基因验证。首次应用转录组关联分析技术解析了油菜苗期抗旱性，获得与抗旱指标显著关联的功能标记274个，可追溯到177个已知基因。开发具有实用价值的功能标记1个，建立了抗旱性遗传改良的分子标记辅助选择技术体系，培育新品种1个，其推广应用前景广阔。