QTL mapping for the resistance to yellow rust race CYR34 in triticale

Yellow rust is an important destructive fungal disease caused by Puccinia stritformis in small grain cereals, and the prevalent Chinese yellow race CYR34 has recently become widespread in China. To detect quantitative trait loci (QUA) responsible for resistance to CYR34 in triticale (xTriticosecale Wittm.), 520 F-2 plants derived from the cross between cv. Gannong No. 1 (susceptible parent) and cv. Gannong No. 2 (resistant parent) were used as mapping population. Fourteen inter-simple sequence repeat (ISSR) markers were used for constructing the linkage map. The obtained results indicated that 92 loci have been mapped on seven linkage groups (LG1-LG7). The total map length was 542.9 cM with an average of 6.95 cM per marker. Six QTLs (qdr1, qdr3, qdr4, qdr5-1, qdr5-2, and qdr6) related to the resistance to CYR34 have been detected. The contribution of these QTLs varied from 5.1% to 11.2%. Moreover, qdr5-I was the main QTL responsible for CYR34 resistance.