A new greenbug resistance gene Gb8 conferring broad resistance to US greenbug biotypes was identified in hard red winter wheat line PI 595379-1 and was mapped to the terminal region of chromosome 7DL. 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 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 version 1.0 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 and the estimated genetic distance between Gb8 and Gb3 was 15.35 ± 1.35 cM. Gb8 can be directly used in wheat breeding to enhance greenbug resistance.

中文翻译：

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Gb8，一种新基因，赋予小麦对经济上重要的绿虫生物型的抗性。

在硬红冬小麦品系 PI 595379-1 中鉴定出一种新的绿虫抗性基因 Gb8，该基因赋予对美国绿虫生物型的广泛抗性，并定位到染色体 7DL 的末端区域。青虫 [Schizaphis graminum (Rondani)] 是一种世界性害虫，对小麦生产构成严重威胁。迫切需要可以方便地用于小麦育种的新的青虫抗性基因。本研究的目的是表征 PI 595379-1 中的绿虫抗性基因，PI 595379 的单一植物选择。对来自 PI 595379-1 和 PI 595379-1 和PI 243735 表明单个基因，称为 Gb8，条件抗性。连锁分析将 Gb8 置于染色体 7DL (7DL3-082-1​​.0) 的末端 bin 中的 2.7 Mb 间隔中，跨越 595。中文 Spring IWGSC RefSeq 1.0 版参考序列中的 6 到 598.3 Mb。Gb8 与新开发的 SSR 标记 Xstars508 共分离，位于参考序列中的 596.4 Mb。等位性检验表明，Gb8 与同一染色体臂上的三个永久命名基因不同，估计 Gb8 和 Gb3 之间的遗传距离为 15.35 ± 1.35 cM。Gb8可直接用于小麦育种以增强抗青虫性。