GENETICS OF STEM RUST RESISTANCE IN WHEAT CULTIVARS ROMANY, Es.P 518/9, BONNY AND TAMA

Abstract

The genetics of resistance to stem rust (Puccinia grurninis tritici) was investigated in wheat (Triticurn aestivum L.) cultivars Romany, Es.P 5 1819, Bonny and Tama that are resistant to many races in both Canada and Kenya. Seedling resistance in the four cultivars to 12 Canadian races is controlled griinarily by previously identified genes. The results indicate that the cultivars have the following genes: Romany -Sr.5, Sr6, Sr7a, SrYb and SriV; Es.P 51819 -Sr5, Sr6, Sr7a, Sr8, Sr9b, SriV and possibly Sr17; Bonny -Sr6 and S r l l ; and Tama -Sr6 and Sr8. Gene SrW confers moderate resistance and is also present in the cultivar Webster.

Genetics of Resistance to Rust in Cereals from a Canadian Perspective

“…Intensive world-wide searches for new Sr genes in hexaploid wheats (Dyck & Green 1975, Shang et al 1988, Claude et al 1986 indicate that this genetic pool may be completely exhausted. Repeatedly, "unknown" resistance genotypes, when analyzed, are identified as having combinations of already known genes such as Sr6, SV7a, Sr8a, Sr9b, and particularly Sr30.…”