Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(Pst), is one of the most devastating diseases of wheat throughout the world. H9020-1-6-8-3 is a translocation line originally developed from interspecific hybridization between wheat line 7182 and Psathyrostachys huashanica Keng and is resistant to most Pst races in China. To identify the resistance gene(s) in the translocation line, H9020-1-6-8-3 was crossed with susceptible cultivar Mingxian 169, and seedlings of the parents, F1, F2, F3, and BC1 generations were tested with prevalent Chinese Pst race CYR32 under controlled greenhouse conditions. The results indicated that there is a single dominant gene, temporarily designated as Yr H9020 a, conferring resistance to CYR32. The resistance gene was mapped by the F2 population from Mingxian 169/H9020-1-6-8-3. It was linked to six microsatellite markers, including Xbarc196, Xbarc202, Xbarc96, Xgpw4372, Xbarc21, and Xgdm141, flanked by Xbarc96 and Xbarc202 with at 4.5 and 8.3 c M, respectively. Based on the chromosomal locations of these markers and the test of Chinese Spring(CS) nullitetrasomic and ditelosomic lines, the gene was assigned to chromosome 6D. According to the origin and the chromosomal location, Yr H9020 a might be a new resistance gene to stripe rust. The flanking markers linked to Yr H9020 a could be useful for marker-assisted selection in breeding programs.
LIU Ze-guangYAO Wei-yuanSHEN Xue-xueCHAO Kai-xiangFAN YuLI Min-zhouWANG Bao-tongLI QiangJING Jin-xue
It have proved that wheat translocation line H9020-1-6-8-3 derived from Psathyrostachys huashanica Keng is an important resistant resource to stripe rust.To confirm the existence of resistant genes,it was crossed with susceptible cultivar MingXian 169 as male and female parent,respectively.Seedlings of parents and F2 progeny were tested for resistance to selected CY29 of races of Puccinia striiformis f.sp.tritici from China.H9020-1-6-8-3 had one dominant resistant gene which temporarily named YrHs,whatever it was male or female parent.By using BSA method,two markers,Xgwm261 and Xgwm455 located on 2DL were found.The distance to YrHs were 4.3 and 5.8 cM respectively.The result could be used in molecular-assisted breeding.
