title: Virulence and Molecular Characterization of Experimental Isolates of the Stripe Rust Pathogen (Puccinia striiformis) Indicate Somatic Recombination.
abstract: Puccinia striiformis causes stripe rust on wheat, barley, and grasses. Natural population studies have indicated that somatic recombination plays a possible role in P. striiformis variation. To determine whether somatic recombination can occur, susceptible wheat or barley plants were inoculated with mixed urediniospores of paired isolates of P. striiformis. Progeny isolates were selected by passing through a series of inoculations of wheat or barley genotypes. Potential recombinant isolates were compared with the parental isolates on the set of 18 wheat or 12 barley genotypes that are used to differentiate races of P. striiformis f. sp. tritici (the wheat stripe rust pathogen) and P. striiformis f. sp. hordei (the barley stripe rust pathogen), respectively, for virulence changes. They were also tested with 51 simple-sequence repeat and 90 single-nucleotide polymorphism markers for genotype changes. From 68 possible recombinant isolates obtained from nine combinations of isolates based on virulence tests, 66 were proven to be recombinant isolates by molecular markers. Various types of recombinants were determined, including lost virulence from both virulent parental isolates, gained virulence from both avirulent isolates, combined virulences from both parents, and inherited virulence from one parent and avirulence from another. Marker data indicate that most of the recombinants were produced through chromosome reassortment and crossover after the hybridization of two parental isolates. The results demonstrate that somatic recombination is a mechanism by which new variants can be generated in P. striiformis.
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Yu
authors: Y
authors: Lei
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Meinan
authors: M
authors: Wang
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Anmin
authors: A
authors: Wan
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Chongjing
authors: C
authors: Xia
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Deven R
authors: DR
authors: See
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Min
authors: M
authors: Zhang
authors: First and sixth authors: Agricultural College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; first, second, third, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman 99164-6430; and fifth and seventh: United States Department of Agriculture-Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430.
authors: Xianming
authors: X
authors: Chen
mesh_terms: D001487:Basidiomycota / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D005838:Genotype; D001467:Hordeum / Q000382:microbiology*; D018895:Microsatellite Repeats / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D013172:Spores, Fungal; D014908:Triticum / Q000382:microbiology*
keywords: somatic hybridization; yellow rust