草害是影响作物高产、稳产、优质的重要因素之一,培育及推广抗除草剂水稻品种是最为经济有效的解决杂草问题的方式,目前江苏抗除草剂粳稻品种非常紧缺,无法适应农业生产中的用种需求.本研究综合评价了抗除草剂基因ALS627N在江苏粳稻育种实践中的育种应用潜力.通过连续回交结合分子标记辅助选择将金粳818中的ALS627N基因导入江苏省2个优良食味粳稻品种南粳5718和南粳505中,在每个遗传背景下选择3个背景与受体亲本基本一致、携带ALS627N的BC5 F5世代稳定改良品系,与受体亲本相比,ALS627N高世代回交改良系均表现出对咪唑啉酮类除草剂咪唑乙烟酸的完全抗性,表明在江苏省粳稻背景中导入ALS627N可以实现对除草剂的抗性.与受体亲本相比,ALS627N高世代回交改良系的农艺性状、产量及品质相关性状未发生一致变化,表明导入ALS627N对水稻重要经济性状没有带来不利影响.稻瘟病和白叶枯病抗性鉴定结果发现,ALS627N高世代回交改良系的穗颈瘟和白叶枯病抗性水平与受体亲本一致,表明导入ALS627N也不会影响稻瘟病和白叶枯病抗性.上述结果表明ALS627N基因在培育抗除草剂粳稻品种上具有很高的育种利用价值,得到的抗除草剂新品系不仅有望迅速服务于农业生产,还可以作为新的供体,加快江苏及其周边地区抗除草剂粳稻品种的开发.

Selenium (Se) is a nutritionally important micronutrient for humans. The use of Se fertilizers is often the most feasible approach to precisely increase Se contents in rice grains, but the effects of common commercial Se fertilizers on producing Se-rich rice remain to be investigated. In this study, we compared the effects of liquid and granular Se fertilizers on the accumulation of Se and heavy metals in rice grains of four different varieties in field. Results showed that Se accumulation in rice grains was affected by the form of fertilizers, applied concentrations of Se fertilizers, and rice varieties. Liquid fertilizer displayed significantly higher Se transfer efficiency than granular fertilizer, whereas the granular fertilizer had a slightly higher effect on organic Se accumulation. More than 95.5% Se in grains were organic Se, with selenomethionine (SeMet) being the dominant one. The proportion of organic selenocysteine (SeCys2) in grains was significantly higher in treatments with liquid fertilizer. Both forms of fertilizers significantly reduced the accumulation of cadmium, lead, and arsenic. Collectively, our study provides a reference for producing Se-rich rice in a more competitive manner in practice.

[目的]培育抗除草剂品种是水稻育种中的一个重要方向,开发高效的功能标记可以加快抗除草剂性状的筛选工作.[方法]利用开发的dCAPS和KASP分子标记对试验材料的基因型分型,另结合除草剂喷施试验进行表型鉴定.[结果]测序结果验证了前人发现的金粳818中乙酰乳酸合成酶(acetolactate synthase,ALS)基因第627位氨基酸由丝氨酸(serine,S)突变为天冬酰胺(asparagine,N)是其抗咪唑啉酮类除草剂的主要原因,本文将其命名为ALS627N.根据此变异位点的DNA序列差异,开发了两个新的功能标记dC-ALS-627和K-ALS-627,可有效区分ALS627N纯合型、杂合型及非突变纯合型.[结论]两个标记均可以广泛用于ALS627N基因的标记辅助选择育种,有助于加快培育抗咪唑啉酮类除草剂新品种,具有重要的实际应用价值.