Molecular mapping of greenbug resistance loci Gb6 and Gb2 in 1AL.1RS wheat-rye translocations

Authors: LU, HUANGJUN - Texas Agrilife Research; RUDD, JACKIE - Texas Agrilife Research; Burd, John; Weng, Yiqun

Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2008
Publication Date: 1/12/2009
Citation: Lu, H., Rudd, J.C., Burd, J.D., Weng, Y. 2009. Molecular mapping of greenbug resistance loci Gb6 and Gb2 in 1AL.1RS wheat-rye translocations [abstract]. In: Proceedings of the XVII Annual International Plant & Animal Genome Conference, January 10-14, 2009, San Diego, California. p. 282.

Interpretive Summary:

Technical Abstract: The greenbug, Schizaphis graminum (Rondani), is an economically important aphid pest of wheat worldwide. The greenbug resistance genes Gb2 and Gb6, derived from the same donor rye line 'Insave', are presented in wheat germplasm lines 'Amigo' and 'GRS1201' respectively as 1AL.1RS wheat-rye translocations. Gb2 was defeated due to the appearance of greenbug biotype E in the 1980's, but Gb6 has a wider spectrum of resistance to different biotypes as compared with the currently deployed resistance gene Gb3. In the present study, an F2:3 families mapping population was developed from the cross N96L9970 (gb2gb2Gb6Gb6) X TAM107 (Gb2Gb2gb6gb6) for molecular mapping of the two greenbug resistance genes. Segregating among F2:3 families of host responses to infestation of two greenbug biotypes E and KS1 revealed that Gb2 and Gb6 were two independent loci in rye chromosome arm 1RS which were 18.0 cM apart from each other. Molecular mapping identified 5 markers which were linked with Gb2 and Gb6. The closest marker was XIA294 mapped 14.8 cM from Gb2. Physically, Gb2 is located near rye Sec1 locus (for secalin grain protein) and Gb6 is distal to Gb2 in the satellite region of 1RS. Searching for more closely linked markers for Gb6 is underway.