On April 6, the research results of the joint cooperation between the South Asian Institute of the Chinese Academy of Thermal Sciences and the Kansas State University Department of Agronomy, etc. were published online in the TOP journal”Crop Journal” in the first area of agricultural and forestry sciences, with the title of the article”Development of diagnostic markers” for a wheat leaf rust resistance gene Lr42 using RNA-sequencing”. The study found an important candidate gene for wheat leaf rust resistance LR42, and developed two molecular markers that can be used for leaf rust diagnosis, which greatly improves the diagnostic efficiency of leaf rust.
Figure 1 TaRPM1 allele structure map
Leaf rust is a kind of wheat leaf disease that is popular all over the world. Planting disease-resistant varieties is an effective measure to reduce the impact of leaf rust on yield and quality. Lr42 is a leaf rust resistance gene identified from Aegilops, and it has a good disease resistance effect against leaf rust that is now prevalent in the United States and many other countries. In this study, RNA-seq analysis was performed on the near isogenic lines of two Lr42 alleles, and then the sequence polymorphism of a differentially expressed gene encoding NB-ARC protein (TaRPM1) located in the candidate region of Lr42 was used to develop The diagnostic marker of Lr42. According to a deletion mutation site and a single nucleotide mutation site of the TaRPM1 gene, two types of markers were obtained. Haplotype analysis shows that these markers have better diagnostic properties for Lr42 and are better than previous markers in selection accuracy. The newly developed marker has the advantages of low cost and easy detection. It is suitable for high-throughput or low-throughput marker screening, and provides strong support for molecular-assisted breeding of wheat resistance to leaf rust.
Figure 2 LR42 mark detection results
Dr. Yang Liu from the Institute of South Asia of the Chinese Academy of Thermal Sciences is the first author of the paper, and Professor Bai Guihua from the Department of Agronomy, Kansas State University is the corresponding author. This research was funded by the National Research Program Competition Funding Project of the United States Department of Agriculture (2017-67007-25939) and the China Scholarship Council Project (201708460028).