Cyto genetic studies in wheat 11. sr 9g for reaction to puccinia graminis tritici
Mcintosh, R.A.; Luig, N.H.; Johnson, R.; Hare, R.A.
Zeitschrift fuer Pflanzenzuechtung 87(4): 274-289
An allele at the Sr9 locus in chromosome 2B is described. Sr9g is present in the Stakman differentials 'Acme' and 'Kubanka'. It was transferred to the hexaploid wheats [T. aestivum] 'Marquillo', 'Double Cross' and 'Thatcher' from the stem rust resistant T. durum ' Iumillo'. In 'Iumillo' and many hexaploid derivatives, Sr9g is closely associated with Yr7 for resistance to P. striiformis, Sr9g is important to the study of variation in P. graminis tritici in Australia and Africa, but appears unimportant in North America. Its presence in wheat cultivars selected for resistance in North America is difficult to explain. Sr9g showed genetic linkage of 35.4 .+-. 2.3% with Sr16.