Department of Agroforestry, Environmental Biology and Chemistry, Section of Genetics and Plant Breeding, University of Bari, Via Amendola 165/A, 70126 Bari, Italy.
Theor Appl Genet. 2011 Dec;123(8):1425-31. doi: 10.1007/s00122-011-1677-6. Epub 2011 Aug 18.
The powdery mildew disease affects several crop species and is also one of the major threats for pea (Pisum sativum L.) cultivation all over the world. The recessive gene er1, first described over 60 years ago, is well known in pea breeding, as it still maintains its efficiency as a powdery mildew resistance source. Genetic and phytopathological features of er1 resistance are similar to those of barley, Arabidopsis, and tomato mlo powdery mildew resistance, which is caused by the loss of function of specific members of the MLO gene family. Here, we describe the obtainment of a novel er1 resistant line by experimental mutagenesis with the alkylating agent diethyl sulfate. This line was found to carry a single nucleotide polymorphism in the PsMLO1 gene sequence, predicted to result in premature termination of translation and a non-functional protein. A cleaved amplified polymorphic sequence (CAPS) marker was developed on the mutation site and shown to be fully co-segregating with resistance in F(2) individuals. Sequencing of PsMLO1 from three powdery mildew resistant cultivars also revealed the presence of loss-of-function mutations. Taken together, results reported in this study strongly indicate the identity between er1 and mlo resistances and are expected to be of great breeding importance for the development of resistant cultivars via marker-assisted selection.
白粉病影响多种作物，也是全世界豌豆（Pisum sativum L.）种植的主要威胁之一。隐性基因 er1 早在 60 多年前就已被描述，在豌豆育种中广为人知，因为它作为白粉病抗性来源仍然保持其效率。er1 抗性的遗传和植物病理学特征与大麦、拟南芥和番茄 mlo 白粉病抗性相似，这是由 MLO 基因家族特定成员功能丧失引起的。在这里，我们描述了通过使用烷基化剂硫酸二乙酯进行实验诱变获得一种新的 er1 抗性系。该系在 PsMLO1 基因序列中发现了一个单核苷酸多态性，预计会导致翻译提前终止和无功能蛋白。在突变位点上开发了一个切割扩增多态性序列 (CAPS) 标记，并显示在 F2 个体中与抗性完全共分离。对来自三个白粉病抗性品种的 PsMLO1 进行测序也揭示了功能丧失突变的存在。总之，本研究报告的结果强烈表明 er1 和 mlo 抗性之间的同一性，预计通过标记辅助选择开发抗性品种具有重要的育种意义。
