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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 #366449
Research Project: Genetic Mechanisms and Improvement of Insect Resistance in Wheat, Barley, and Sorghum

Location: Peanut and Small Grains Research Unit

Title: Gb8, a new gene conferring resistance to economically important greenbug biotypes in wheat

Author
item Xu, Xiangyang
item Li, Genqiao
item CARVER, BRETT - Oklahoma State University
item Armstrong, John

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2019
Publication Date: 1/27/2020
Citation: Xu, X., Li, G., Carver, B.F., Armstrong, J.S. 2020. Gb8, a new gene conferring resistance to economically important greenbug biotypes in wheat. Theoretical and Applied Genetics. 133:615-622. https://doi.org/10.1007/s00122-019-03491-1.
DOI: https://doi.org/10.1007/s00122-019-03491-1

Interpretive Summary: Greenbug [Schizaphis graminum (Rondani)] is a worldwide insect pest that poses a serious threat to wheat production. Greenbug resistance sources are very limited, and only Gb3 has been used in wheat breeding. Given that Gb3 only confers resistance to a few greenbug biotypes, new greenbug resistance genes that can be readily used in wheat breeding are urgently needed. We screened over 10,000 germplasm for resistance to greenbug biotype E, leading to the identification of a few resistant plants in PI 595379. A single plant selection line PI 595379-1 was subsequently developed. The objective of this study was to characterize the greenbug resistance gene in PI 595379-1. Genetic analysis of response to greenbug biotype E in an F2:3 population derived from a cross between PI 595379-1 and PI 243735 indicated that a single dominant gene, designated Gb8, conditioned resistance. Linkage analysis placed Gb8 in a 2.7 Mb interval in the terminal region of the long arm of chromosome 7D, spanning 595.6 to 598.3 Mb in the Chinese Spring IWGSC RefSeq v1.0 reference sequence. Gb8 co-segregated with a newly developed SSR marker Xstars508, positioned at 596.4 Mb in the reference sequence. Allelism tests showed that Gb8 is a new gene. Gb8 conferred a broader range of resistance than other known genes such as Gb3, Gb4, and Gb7 and can be directly used in wheat breeding to enhance resistance to economically important greenbug biotypes B, C, E, H, I, and FL.

Technical Abstract: Greenbug [Schizaphis graminum (Rondani)] is a worldwide insect pest that poses a serious threat to wheat production. New greenbug resistance genes that can be readily used in wheat breeding are urgently needed. The objective of this study was to characterize a greenbug resistance gene in PI 595379-1, a single plant selection from PI 595379. Genetic analysis of response to greenbug biotype E in an F2:3 population derived from a cross between PI 595379-1 and PI 243735 indicated that a single dominant gene, designated Gb8, conditioned resistance. Linkage analysis placed Gb8 in a 2.7 Mb interval in the terminal bin of chromosome 7DL (7DL3-082-1.0), spanning 595.6 to 598.3 Mb in the Chinese Spring IWGSC RefSeq v1.0 reference sequence. Gb8 co-segregated with a newly developed SSR marker Xstars508, positioned at 596.4 Mb in the reference sequence. Allelism tests showed that Gb8 was different from three permanently named genes on the same chromosome arm. Gb8 conferred a broader range of resistance than other known genes such as Gb3, Gb4, and Gb7 and can be directly used in wheat breeding to enhance resistance to greenbug biotypes B, C, E, H, I, and FL.