title: Pm55, a developmental-stage and tissue-specific powdery mildew resistance gene introgressed from Dasypyrum villosum into common wheat.
abstract: Powdery mildew resistance gene Pm55 was physically mapped to chromosome arm 5VS FL 0.60-0.80 of Dasypyrum villosum . Pm55 is present in T5VS·5AL and T5VS·5DL translocations, which should be valuable resources for wheat improvement. Powdery mildew caused by Blumeria graminis f. sp. tritici is a major wheat disease worldwide. Exploiting novel genes effective against powdery mildew from wild relatives of wheat is a promising strategy for controlling this disease. To identify novel resistance genes for powdery mildew from Dasypyrum villosum, a wild wheat relative, we evaluated a set of Chinese Spring-D. villosum disomic addition and whole-arm translocation lines for reactions to powdery mildew. Based on the evaluation data, we concluded that the D. villosum chromosome 5V controls post-seedling resistance to powdery mildew. Subsequently, three introgression lines were developed and confirmed by molecular and cytogenetic analysis following ionizing radiation of the pollen of a Chinese Spring-D. villosum 5V disomic addition line. A homozygous T5VS·5AL translocation line (NAU421) with good plant vigor and full fertility was further characterized using sequential genomic in situ hybridization, C-banding, and EST-STS marker analysis. A dominant gene permanently named Pm55 was located in chromosome bin 5VS 0.60-0.80 based on the responses to powdery mildew of all wheat-D. villosum 5V introgression lines evaluated at both seeding and adult stages. This study demonstrated that Pm55 conferred growth-stage and tissue-specific dependent resistance; therefore, it provides a novel resistance type for powdery mildew. The T5VS·5AL translocation line with additional softness loci Dina/Dinb of D. villosum provides a possibility of extending the range of grain textures to a super-soft category. Accordingly, this stock is a new source of resistance to powdery mildew and may be useful in both resistance mechanism studies and soft wheat improvement.
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China. zrq@njau.edu.cn.
authors.forename: Ruiqi
authors.initials: R
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Bingxiao
authors.initials: B
authors.lastname: Sun
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Aizhong
authors.initials: A
authors.lastname: Cao
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Xing
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Yigao
authors.initials: Y
authors.lastname: Feng
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), 06600, Mexico, DF, Mexico.
authors.forename: Caixia
authors.initials: C
authors.lastname: Lan
authors.affiliation: College of Agronomy, Nanjing Agricultural University/National Key Laboratory of Crop Genetics and Germplasm Enhancement/JCIC-MCP, Nanjing, 210095, China.
authors.forename: Peidu
authors.initials: P
authors.lastname: Chen
mesh_terms: D001203:Ascomycota; D032461:Chromosomes, Plant; D060467:Disease Resistance / Q000235:genetics*; D005799:Genes, Dominant; D017343:Genes, Plant; D005819:Genetic Markers; D020161:Physical Chromosome Mapping; D000069600:Plant Breeding; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D006109:Poaceae / Q000235:genetics*; D014178:Translocation, Genetic; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
chemical_list: D005819:Genetic Markers