Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a devastating wheat disease worldwide. The Chinese wheat cultivar Chuanmai 32 has shown stable resistance to stripe rust for 10 yr in Sichuan Province, a hotspot for stripe rust epidemics. The objective of the present study was to map quantitative trait loci （QTL） for adult-plant resistance （APR） to stripe rust in a population of 140 recombinant inbred lines （RILs） derived from Chuanmai 32/Chuanyu 12. Field trials were conducted in Chengdu and Yaan, Sichuan, from 2005 to 2008, providing stripe rust reaction data for 6 environments. 797 simple sequence repeat （SSR） markers were screened for association with stripe rust reaction, initially through bulked segregant analysis （BSA）. Based on the mean disease values averaged across environments, the broad-sense heritability of maximum disease severity （MDS） was 0.75. Two QTLs for stripe rust resistance were detected by composite interval mapping （CIM）. They were designated QYr.caas-3BL and QYr.caas-3BS and explained from 6.6 to 20.1%, respectively, of the phenotypic variance across environments. QYr.caas-3BL came from Chuanmai 32; QYr.caas-3BS with lower effect was from the susceptible parent Chuanyu 12. Both QTLs appear to be new.
为明确小麦地方品种和生产主栽品种间的亲缘关系以及MFLP分子标记技术在小麦品种遗传多样性研究中的有效性,利用MFLP标记技术对24个地方品种和12个来自河北、山东和河南的生产主栽品种基因组DNA进行遗传多样性分析,并利用NTSYS pc 2.10软件对试验数据进行非加权组法（UPGMA）聚类研究。结果表明,5对MFLP引物共扩增出279条具有特异性的多态性谱带。主栽品种间遗传相似系数为0.6989~0.8746,其遗传距离比较近;而地方品种间及地方品种与生产品种间遗传多样性差异较大。利用34个MFLP指纹图谱标记位点编制了分子检索表,能成功区分36个小麦品种。研究结果还表明,MFLP分子标记技术可有效地应用于小麦品种间的亲缘关系和遗传多样性研究中。
The German wheat cultivar Ibis has excellent adult plant resistance（APR） to stripe rust in Gansu,a hotspot for stripe rust in China.To elucidate the genetic basis of APR to stripe rust in Ibis,237 F3 lines derived from the cross Ibis/Huixianhong were evaluated at Tianshui,Gansu,in the 2008-2009 and 2009-2010 cropping seasons,and at Chengdu,Sichuan Province,China,in the 2009-2010 cropping season.Inoculations were conducted with a mixture of several prevalent Pst races in both locations.Maximum disease severity（MDS） data showed a continuous distribution of response,indicating quantitative nature of resistance to stripe rust in Ibis.The broad-sense heritability of MDS was 0.75 based on the mean values averaged across three environments.A total of 723 simple sequence repeat（SSR） markers were used to map the QTL for APR by inclusive composite interval mapping（ICIM）.QTLs mapping to chromosomes 2BS and 6BS,designated as QYr.caas-2BS.1 and QYr.caas-6BS.1,respectively,explained 4.1-40.7% of the phenotypic variance in MDS across environments.The major effect QTL QYr.caas-2BS.1,flanked by Xgwm148 and Xwmc360,was consistently detected at all three sites as well as the averaged data over three environments,accounting for 40.7,24.2,5.2 and 29.9% of phenotypic variance,respectively.The molecular markers closely linked to this QTL have potential for use in marker-assisted selection and gene pyramiding to improve the durability of stripe rust resistance in wheat breeding.
BAI BinREN YanXIA Xian-chunDUJiu-yuanZHOU GangWU LingZHU Hua-zhongHE Zhong-huWANG Cheng-she
