米苦荞易脱壳性的遗传特性和分子标记研究

Low hulling rate and high broken rate affecting the processing quality and appearance quality of buckwheat which plays an important role in determining the deep processing and utilization potential of buckwheat products are the key issues urgently needed to solvein buckwheat production. Rice tartary buckwheat is the only one species of Fagopyrum with excellent characteristics of non-adhering hull and thus it is rare and valueless resource for improving the grain quality of hulling rate and broken rate of buckwheat. In this study, the inheritance and molecular markers of non-adhering hull in buckwheat will be investigated. The common tartary buckwheat will be cross to rice tartary buckwheat to study the inheritance and genotype of non-adhering hull of rice tartary buckwheat according to the proportion of non-adhering hull in hybrid offspring. Furthermore, specific RAPD markers closely linked with the characteristics of non-adhering hull of rice tartary buckwheat will be identified using RAPD technology. The specific RAPD markers will be converted to stable SCAR markers for the screen of non-adhering hull-using molecular marker assisted selection. The results will provide guidance for breeding new high-yield varieties with non-adhering hull of tartary buckwheat. The outputs of the project are expected to have predictable scientific significance and potential application in buckwheat production.

荞麦的脱壳率低、脱碎率高是荞麦籽粒加工中急待解决的问题，它严重影响着荞麦产品的加工质量和外观品质，进而影响着荞麦产品的深加工和开发利用前景。米苦荞是荞麦属中唯一具有"易脱壳性"这一优异特性的极为珍贵的资源，所以本项目拟开展米苦荞易脱壳性的遗传特性及分子标记探索研究，即通过普通苦荞与米苦荞的杂交，根据杂交后代中易脱壳性状的表现型出现的比例，推测出米苦荞易脱壳性状的基因型和遗传特性，同时，利用RAPD技术检测出与米苦荞易脱壳性连锁的特异RAPD标记，并将特异的RAPD标记转换成稳定的SCAR标记，为培育具有易脱壳性的优质高产苦荞新品种提供指导。预期研究成果具有可预见的科学意义和潜在应用前景。

荞麦的脱壳率低、脱碎率高是荞麦籽粒加工中急待解决问题，它严重影响着荞麦产品加工质量和外观品质，进而影响着荞麦产品的深加工和开发利用前景。米苦荞是荞麦属中唯一具有“易脱壳性”这一优异特性的极为珍贵资源，所以本项目选择易脱壳的米苦荞品种作为父本，高产优质的云荞1号、云荞2号、晋苦6号、K12、YZ13等5个难脱壳的苦荞品种作为母本，配置了5个组群杂交组合，采用人工去雄授粉、套袋隔离的方式进行杂交，①根据普通苦荞（难脱壳）与米苦荞（易脱壳）杂交的F1、F2、BC1F1群体中易脱壳性状和难脱壳性状分离比例，明确了苦荞脱壳性状是质量性状，且难脱壳性状是受一对显性基因控制，易脱壳性状是受一对隐性基因控制；同时，分析了米苦荞易脱壳性与其他农艺性状的遗传相关性；建立了苦荞人工去雄授粉的杂交育种技术；另外，利用苦荞种壳转录组测序结果，初步分析出米苦荞易脱壳性状形成的原因主要是由于籽粒成熟前期木质素积累少造成的；利用扫描电镜观察到苦荞易脱壳与难脱壳品种的种壳厚度变化规律及其种壳表面的不同典型特征。②建立了苦荞DNA最佳提取方案和稳定的RAPD、SSR、SCAR最佳分子标记反应转化体系和反应程序。③筛选出了与米苦荞易脱壳性连锁的特异的3个RAPD分子标记、30个SSR分子标记。④利用已建立的SCA R标记的转化体系，把与米苦荞易脱壳性状连锁的特异RAPD标记转化成SCAR标记。⑤从普通苦荞（难脱壳）与米苦荞（易脱壳）杂交不同世代中，筛选出结实率高、早熟、矮杆、易脱壳等各种类型的优异苦荞新种质751份；同时，鉴评筛选出了适应范围广、生育期短、产量高等综合性状优且具有易脱壳性的稳定的F6苦荞新品系4份。⑥发表学术论文7篇。该项目获得的优异苦荞新种质已用于苦荞新品种的选育；选育出的综合性状优具有易脱壳性苦荞新品系已在云南荞麦的主产区进行了小范围的示范推广和转化。