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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #368069
Research Project: Genetic Mechanisms and Improvement of Insect Resistance in Wheat, Barley, and Sorghum

Location: Peanut and Small Grains Research Unit

Title: Pest resistance - discovery and introgression

Author
item Xu, Xiangyang

Submitted to: Agricultural Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: 11/30/2018
Publication Date: 2/1/2019
Citation: Xu, X. 2019. Pest resistance - discovery and introgression. In: Partners and Progress - Wheat Research at OSU, 2018. Oklahoma Agric. Exp. Station. P-1053, p. 13-15.

Interpretive Summary: Wheat, a worldwide staple crop, has been inflicted by biotic stresses caused by greenbug, bird cherry oat aphid (BCOA), leaf rust and powdery mildew in the Great Plains of the USA. Identification and characterization of germplasm resistant to these pests and diseases are of agronomic importance. A large set of wheat accessions were screened for BCOA resistance, and two wheat accessions exhibiting resistance to barley yellow dwarf diseases in previous studies, Utah No. 101 A149 and Harvest Queen 2433, showed BCOA resistance. The greenbug resistance gene in wheat reselection line PI 595379-1, designated Gb595379, was mapped to the terminal region of chromosome 7D. Two novel powdery mildew resistance genes, Pm63 in PI628024 and Pm223899 in PI 623899, were also characterized using molecular markers. Pm63 and Pm223899 were mapped to the terminal bin of the long arm of chromosome 2B and the short arm of chromosome 1A, respectively. In addition, a new leaf rust resistance gene in PI 470121, designated Lr470121, was delimited to a genomic region of approximately 4.8 Mb on the short arm of chromosome 2A. Gb595379, Pm63, Pm223899, and Lr470121 can be used in wheat breeding to enhance resistance to biotic stresses, and molecular markers closely linked to these genes were developed to facilitate their introgression into elite cultivars.

Technical Abstract: Wheat, a worldwide staple crop, has been inflicted by biotic stresses caused by greenbug, bird cherry oat aphid (BCOA), leaf rust and powdery mildew in the Great Plains of the USA. Identification and characterization of germplasm resistant to these pests and diseases are of agronomic importance. A large set of wheat accessions were screened for BCOA resistance, and two wheat accessions exhibiting resistance to barley yellow dwarf diseases in previous studies, Utah No. 101 A149 and Harvest Queen 2433, may feature novel BCOA resistance. The greenbug resistance gene in wheat reselection line PI 595379-1, designated Gb595379, was mapped to the terminal region of chromosome 7D. Two novel powdery mildew resistance genes, Pm63 in PI628024 and Pm223899 in PI 623899, were also characterized using molecular markers. Pm63 was mapped to the terminal bin of the long arm of chromosome 2B (2BL 0.89-1.0), while Pm223899 was mapped to an interval of about 831 Kb in the terminal region of the short arm of chromosome 1A, spanning from 4,504,697 to 5,336,062 bp of the Chinese Spring reference sequence. Candidate genes were identified for Pm223899. In addition, a new leaf rust resistance gene in PI 470121, designated Lr470121, was delimited to a genomic region of approximately 4.8 Mb, spanning from 60.80 Mb to 65.65 Mb on the short arm of chromosome 2A of Chinese Spring reference sequence. Gb595379, Pm63, Pm223899, and Lr470121 can be used in wheat breeding to enhance resistance to biotic stresses, and molecular markers closely linked to these genes were developed to facilitate their introgression into elite cultivars.