Molecular Mapping of Two Novel Stripe Rust Resistant Genes YrTp1 and YrTp2 in A-3 Derived from Triticum aestivum × Thinopyrum ponticum

Loss of variety resistance to stripe rust （Puccinia striiformis Westend f. sp.tritici） is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources. Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance （immune） to currently epidemic yellow rust races （CY29, 31, 32） was screened out in offspring of Triticum aestivura x Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes： one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F2 and BC1 populations. A marker WMC477-167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-2os bp located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTpl and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.

Fine mapping and transcriptome sequencing reveal candidate genes conferring all-stage resistance to stripe rust on chromosome arm 1AL in Chinese wheat landrace AS1676

Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.

Molecular mapping of stripe rust resistance gene YrH9017 in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3

Several new stripe rust pathogen races emerged in the wheat growing regions of China in recent years.These races were virulent to most of the designated wheat seedling resistance genes.Thus,it is necessary and worthwhile to identify new valuable resistant materials for the sake of diversifying resistant sources,pyramiding different resistance genes and achieving durable resistance.Here,we identified the resistance gene,temporarily designated as YrH9017,in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3.A total of 146 F2 plants and their derived F2:3 families in a cross of Mingxian 169 and H9017-14-16-5-3 were used to evaluate seedling stripe rust response and as a mapping population.Finally,we constructed a genetic map including eight simple sequence repeat(SSR) markers and expressed sequence tag(EST) markers.YrH9017 was located on the long arm of chromosome 2A and closely linked with two EST-sequence tagged site(EST-STS) markers BG604577 and BE471201 at 1.3 and 1.8 cM distance,respectively.The two closest markers could be used for marker-assisted selection of YrH9017 in breeding.

Postulation of Seedlings Resistance Genes to Yellow Rust in Commercial Wheat Cultivars from Yunnan Province in China

The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.

小麦条锈病抗性基因定位及分子标记技术研究进展

条锈病流行对小麦生产造成巨大损失,选育和种植持久抗性品种是防治小麦条锈病最经济有效的策略。为达到多基因聚合培育持久抗病品种的目标,必须不断发掘抗病种质、解析其抗病遗传机制并开发分子标记。基于文献,对条锈病抗性基因发掘涉及的抗病性、分子标记、基因定位方法和定位进展及其在育种中的应用进行了综述,明确了小麦条锈病基因定位涉及技术的现状、局限性及优势,从而为后续的条锈病抗性基因发掘、多基因聚合和持久抗性小麦品种的选育与生产布局提供技术指导,以降低西北麦区和小麦主产区条锈病流行的频率,进一步促进国家粮食安全。

国内外153份小麦种质条锈病抗性鉴定与评价

【目的】条锈病是威胁小麦安全生产的重要真菌病害,了解国内外育种材料抗性水平和抗病基因的分布,发掘新的抗性资源,为提高抗病基因利用效率提供依据。【方法】利用中国当前条锈菌优势生理小种CYR33和CYR34对153份国内外小麦育种材料进行苗期抗性鉴定,于2018—2019、2019—2020和2020—2021年,在湖北鄂州,利用这两个小种对供试材料进行成株期抗性鉴定;结合已知抗性基因Yr5、Yr9、Yr10、Yr15、Yr17、Yr18、Yr26、Yr29和YrSP等功能标记或紧密连锁分子标记进行基因型检测。【结果】苗期结果显示,10份材料对CYR33表现免疫(反应型IT为0),包括7份国内材料(即山农28、漯麦163、石麦13、中意6号、郯麦98-2、中麦175和泰山21)和3份国际玉米小麦改良中心(CIMMYT)材料(CIM-53、CIM-60和CIM-71);仅2份国内材料在苗期对CYR34小种表现免疫(郯麦98-1和山农102)。此外,成株期条锈病田间鉴定显示,64份材料在田间3年均表现出稳定抗性(最终严重度≤5%),包括7份国内材料和57份CIMMYT材料。利用抗病基因功能标记或紧密连锁分子标记检测显示,153份材料中携带Yr9、Yr10、Yr17、Yr18、Yr26、Yr29和YrSP抗性基因的材料分别有31、23、73、2、4、50和2份,未检测到含有Yr5和Yr15的材料。综合苗期和成株期表型,仅CIM-53对2个生理小种在苗期和成株期均表现为免疫(IT=0,严重度为0),分子标记检测显示,该材料可能含有已知抗病基因Yr17和Yr29。【结论】国内外153份小麦种质对当前条锈菌流行生理小种的抗性主要以成株抗性为主,其中国内小麦品种主要携带Yr9、Yr10和Yr26抗性基因,而CIMMYT小麦品系则携带Yr17、Yr18和Yr29为主,表明通过聚合1—2个非免疫苗期抗性基因和2—3个成株抗性基因,在成株期多个环境条件下均表现出近免疫抗性水平,是CIMMYT小麦品系保持持久抗性的主要原因。亟待广泛挖掘抗源,发掘新的抗病基因,充分利用现代生物技术手段快速培育具有持久抗性且农艺性状优良的小麦新品种,进一步提高中国麦区条锈病整体抗性水平。

长江中下游小麦新品系条锈病抗性评估与抗病基因分析

由小麦条锈菌(Puccinia striiformis West. f. sp.tritici Eriks.&Henn.)引起的条锈病是世界范围内小麦的重要病害。长江中下游麦区是中国小麦主产区之一和重要的小麦商品粮基地,也是中国小麦条锈病流行的重点防控地区。准确评价该地区小麦品种(系)对当前小麦条锈病流行小种的抗性,了解抗条锈基因在各个品种及所处麦区内的分布状况,对及时调整抗病育种目标、指导抗病品种及抗病基因的合理布局与应用具有重要意义。本研究收集了2019-2021年间苏、皖、鄂等长江中下游麦区103份小麦材料,包括34份当地主栽品种和69份参加新品种区域审定试验的高代品系,于2021年分别在陕西杨凌混合小种(CYR32、V26-lab)人工病圃及四川江油自然诱发病圃进行成株期抗条锈性鉴定;以当前流行条锈菌小种条中32(CYR32)和G22致病类群(V26-lab)对参鉴品系进行苗期分小种鉴定,利用16个已知抗条锈基因的19个SNP标记进行分子检测,其中包括11个全生育期抗病基因[Yr5a、Yr5b (YrSP)、Yr6、Yr7、Yr9、Yr15、Yr26、Yr28、Yr81、YrZH84和YrAS1676]和5个成株期抗病基因(Yr18、Yr30、Yr78、Yr86和YrLT26),推测小麦品系可能携带的抗病基因。结果表明,34份主栽品种中,23份表现成株期抗病。在69份高代品系中,苗期对CYR32和V26-lab小种表现抗病的品系分别有11份和13份,对CYR32和V26-lab均表现免疫或者近免疫的品系仅有2份。根据品系成株期抗病DS值的聚类热图结果表明,在杨凌表现抗病的品系有44份,在江油表现抗病的品系有25份,在两地均表现环境稳定抗病的品系有17份。分子检测表明,参鉴品系中可能携带Yr5b、Yr6、Yr7、Yr9、Yr30、Yr78、Yr81、Yr86、YrZH84、YrLT26和YrAS1676,其中只有Yr6、Yr81和YrLT26显著影响抗病性,没有发现可能携带Yr5a、Yr15、Yr18、Yr26和Yr28的品系。此外,Yr78、Yr81、Yr86和YrAS1676组合表现可有效抗条锈病。长江中下游麦区小麦品系对小麦条锈菌当前流行小种的抗性整体水平较2010年前明显提高,抗病基因的使用呈多样化趋势。

小麦农家种成株期条锈病抗性QTL定位及其育种效应解析

条锈病是世界范围内严重影响小麦产量的重要病害。遗传和育种利用效应不清,加之不良性状连锁累赘是限制绝大多数已发掘小麦条锈病抗性基因在育种及生产中难以广泛应用的关键。前期研究发现,小麦农家种红芒麦子对我国当前小麦生产上流行的主要条锈菌生理小种及致病类群具有稳定的成株期抗性。本研究通过构建Avocet S×红芒麦子F1及F2和F2:3家系,利用分离群体分组分析法(bulked segregation analysis, BSA)并结合小麦55K SNP芯片及外显子测序技术,在7A和7D染色体上鉴定到2个来自红芒麦子的成株期条锈病抗性主效QTL(QYr.HM-7AL和QYr.HM-7DS),分别解释了11.64%~15.25%和24.33%~40.58%的表型变异。标记连锁分析、遗传和物理图谱综合分析发现,QYr.HM-7DS与已知成株期条锈病抗性基因Yr18呈高度共线性,表明该位点抗性效应来源于Yr18;而QYr.HM-7AL是一个控制小麦成株期条锈病抗性潜在新位点,并进一步开发了可用于跟踪选择该位点的KASP(kompetitive allele-specific PCR,竞争性等位基因特异性PCR)分子标记。利用绵麦1618×红芒麦子BC_1F_2遗传改良群体对来自红芒麦子成株期条锈病抗性主效QTL遗传效应及其与产量相关性状协同改良效应进行解析。结果发现,在绵麦1618遗传背景下,Yr18和QYr.HM-7AL的转育或聚合可显著降低条锈病危害,且对小麦穗长和分蘖数呈正向效应。上述研究结果表明,在小麦产量育种中可利用农家种红芒麦子进行成株期条锈病遗传改良。

四川小麦新品种的条锈病抗性基因分布

条锈病是四川小麦重要病害。为了解四川近年来审定小麦品种的条锈病抗性水平和抗病基因利用情况,对2017年以来审定的63个小麦新品种进行条锈病抗性鉴定,利用抗病基因Yr5、Yr7、Yr15、Yr18、Yr27、Yr28、Yr36、Yr46、YrU1、YrSP的功能标记和Yr17、Yr26、Yr29的紧密连锁标记进行检测。结果表明,57个品种在苗期对条锈菌小种CYR34的抗性水平达到中抗以上(IT=0~6)。所有品种的田间成株期抗性均达到中抗及以上(IT=1~4)。未检测到Yr5、Yr27、Yr46和YrU1的功能位点,其余9个基因均存在于四川小麦品种中。Yr7、Yr17、Yr26和Yr29在供试品种的分布频率超过50%。综上所述,四川小麦新品种条锈病抗性水平整体较高,条锈病抗性基因丰富;小麦祖先物种抗条锈病基因Yr15、Yr28和Yr36已成功应用于四川小麦育种。

442份小麦苗期抗条锈病鉴定

为了解442份小麦材料苗期的抗病性,利用当前条锈菌优势流行生理小种CYR32、CYR33和CYR34对其进行苗期抗性鉴定,并利用基因芯片检测了其中241份春小麦所携带的抗条锈基因。结合苗期抗条锈病鉴定和基因芯片检测结果,共筛选出151个抗性品种,其中四川材料和CIMMYT材料中的抗条锈病基因较为丰富,且分布频率高。研究结果为筛选国内抗病性小麦种质资源以及国外优异种质的引进提供了参考,也为挖掘小麦抗条锈病基因及后续小麦抗条锈病分子育种研究奠定基础。

玉米南方锈病研究进展

综述了玉米南方锈病(southern corn rust,SCR)的发生分布、病原特征、病原遗传结构、玉米抗病基因、防控措施方面的综合进展,分析了目前SCR研究中存在的问题,指出了今后应重视建立和优化综合防控体系,注重挖掘抗病基因、开发快速检测工具和筛选高效农药,以期为SCR的有效防治提供指导性策略。

基于BSR-Seq分析筛选Y1499条锈病抗性相关基因

条锈病是危害小麦生产安全的重要病害之一,而携带不同抗病基因小麦品种的利用与合理布局是降低病害威胁最经济可靠的途径。为挖掘和丰富小麦条锈病抗性相关基因资源,本研究以筛选到的抗条锈病硬粒小麦种质Y1499和感病材料Gaza为亲本构建遗传群体,在室内对其进行苗期抗性鉴定和统计分析;利用衍生后代中选择的F 3∶4群体构建混池,进行RNA测序,对测序数据进行相关分析。结果表明,Y1499对CYR32的抗性由两个主效基因互补遗传控制。利用BSR-Seq关联分析在鉴定到3个小麦材料Y1499中条锈病抗性基因候选区间。GO富集结果显示,F 3∶4抗感池间差异表达基因涉及多个过氧化物酶等抗氧化反应相关基因。KEGG富集结果表明,显著差异表达基因主要富集于谷胱甘肽代谢和苯丙烷类生物合成等代谢通路。

基于BSA-seq技术对乌拉尔图小麦条锈病抗病基因的初步定位

【目的】发掘和克隆小麦条锈病抗病基因,为小麦条锈病抗病育种提供遗传基因资源。【方法】以乌拉尔图小麦为材料,通过接种鉴定筛选具有条锈病抗性的材料,利用正向遗传学和混合分组测序分析法(BSA-seq)在乌拉尔图小麦材料中鉴定新的条锈病抗病基因位点。【结果】通过接种鉴定筛选到6个具有小麦条锈病抗性的乌拉尔图小麦材料,通过构建杂交群体结合BSA-seq技术在其中1个抗病材料TuW1中鉴定出1个新的条锈病抗病基因位点,定位于7AS染色体的0~35.2 Mb区间。【结论】通过正向遗传学结合BSA-seq技术在乌拉尔图小麦中鉴定到1个新的条锈病抗病基因位点,为小麦条锈病抗病育种提供了基因资源。

小麦骨干亲本周8425B抗条锈病优异基因在其衍生品种中的遗传解析

周8425B是黄淮海麦区应用较广泛的矮秆大穗、抗病抗逆小麦骨干亲本,解析周8425B衍生品种的条锈病抗性遗传表现及其携带的抗条锈病基因遗传传递信息对新品种选用具有重要价值。本研究以条锈病强毒力生理小种条中34(CYR34)单一菌种对收集的222份周8425B衍生品种进行苗期条锈病抗性鉴定,以CYR34为主的混合菌种对衍生品种进行成株期条锈病抗性鉴定,利用周8425B携带的抗条锈病基因YrZH84、YrZH84.2、Yr30、YrZH22和Yr9紧密连锁的分子标记对衍生品种进行基因型检测。研究结果表明,周8425B苗期和成株期对目前强毒力优势菌种CYR34均表现高抗条锈病。在222份周8425B的衍生品种中,2年表现稳定成株期抗病的衍生品种有昌麦9号、济研麦10、百农4199、赛德麦7号和郑麦103等14份,占比6.3%;表现稳定全生育期抗病的衍生品种有周麦11、周麦22、周麦26、周麦36、兰天36、存麦16和郑品麦8号等52份,占比23.4%。周8425B衍生品种主要通过周麦11、周麦12、周麦13、周麦15、周麦16和周麦17等6个子一代再次衍生到子二代。子一代中周麦16和周麦13由于具有较好的农艺性状直接衍生出较多品种,周麦12与周麦13培育出子二代周麦22衍生出45个子三代,周麦11培育出矮抗58衍生出54个子三代。周8425B携带的YrZH84、YrZH84.2、YrZH22、Yr30和Yr9在衍生后代中的频率分别为34.7%、14.9%、41.9%、66.2%和67.1%。仅携带其中1个抗病基因的衍生品种以携带YrZH84的平均严重度最低,为15.4%;聚合2个抗病基因的衍生品种中,以携带YrZH84+YrZH22的平均严重度最低,为20.0%;聚合3个抗病基因的衍生品种中,以携带YrZH84+YrZH22+Yr9的平均严重度最低,为17.2%;聚合4个抗病基因的衍生品种中,携带YrZH84+YrZH22+Yr30+Yr9的平均严重度为16.9%,携带YrZH84.2+YrZH22+Yr30+Yr9的平均严重度为38.4%。苗期以携带全生育期抗性基因YrZH84或含有YrZH84的基因组合的衍生品种的抗病性较好。研究结果为中国小麦骨干种质周8425B的持续改良利用提供了条锈病基因信息,鉴定出对强毒力生理小种CYR34表现抗病的衍生新种质,为我国小麦抗条锈病遗传育种提供了参考。

Pathogenesis-related protein genes involved in race-specific allstage resistance and non-race specific high-temperature adultplant resistance to Puccinia striiformis f. sp. tritici in wheat

Interactions of the stripe rust pathogen （Puccinia striiformis f. sp responses. Among various genes involved in the plant-pathogen related （PR） protein genes determine different defense responses tritici） with wheat plants activate a w^ae range OT nost nteractions, the expressions of particular pathogenesis-Different types of resistance have been recognized and utilized for developing wheat cultivars for resistance to stripe rust. All-stage resistance can be detected in seedling stage and remains at high levels throughout the plant growth stages. This type of resistance is race-specific and not durable. In contrast, plants with only high-temperature adult-plant （HTAP） resistance are susceptible in seedling stage, but become resistant when plants grow older and the weather becomes warmer. HTAP resistance controlled by a single gene is partial, but usually non-race specific and durable. The objective of this study was to analyze the expression of PR protein genes involved in different types of wheat resistance to stripe rust. The expression levels of 8 PR protein genes （PR1, PRI.2, PR2, PR3, PR4, PR5, PR9 and PRIO） were quantitatively evaluated at 0, 1, 2, 7 and 14 days after inoculation in single resistance gene lines of wheat with all-stage resistance genes YrTrl, Yr76, YrSP and YrExp2 and lines carrying HTAP resistance genes Yr52, Yr59, Yr62 and Yr7B. Races PSTv-4 and PSTv-37 for compatible and incompatible interactions were used in evaluation of PR protein gene expression in wheat lines carrying all-stage resistance genes in the seedling- stage experiment while PSTv-37 was used in the HTAP experiment. Analysis of quantitative real-time polymerase chain reaction （qRT-PCR） revealed that all of the PR protein genes were involved in the different types of resistance controlled by different Yr genes. However, these genes were upregulated at different time points and at different levels during the infection process among the wheat lines with different Yr genes for either all-stage resistance or HTAP resistance. Some of the genes were also induced in compatible interactions, but the levels were almost always higher in the incompatible interaction than in the compatible interaction at the same time point for each Yr gene. These results indicate that both salicylic acid and jasmonate signaling pathways are involved in both race-specific all-stage resistance and non-race specific HTAP resistance. Although expressing at different stages of infection and at different levels, these PR protein genes work in concert for contribution to different types of resistance controlled by different Yr genes.

四川省育成小麦品种和高代品系对条锈病的抗病性评价

四川省不仅是条锈菌冬繁区,也是我国东部麦区重要的春季初侵染菌源地和毒性变异地。准确评价四川小麦新育成品种和高代品系对条锈病的抗性水平,能为合理培育和使用抗病品种提供重要依据。利用当前条锈菌优势小种和4个地点的成株期鉴定圃对来自四川省的115份小麦育成品种和299份高代品系进行苗期和成株期抗病性鉴定。结果表明,新育成品种苗期对优势小种的高抗CYR32、CYR33和CYR34的比例发生不同程度的变化,对CYR32的高抗比例为40.9%、对CYR34的高抗比例为17.4%,而供试高代品系高抗比例从52.3%降至46.2%;中抗类型育成品种从20.0%增加到40.9%,高代品系从19.6%增加至33.2%。表明条锈菌优势小种更替后一些材料仍保留了部分抗性,后期选育的高代品系兼顾对新小种的抗病性。育成品种在四川成都和甘肃清水成株期鉴定,高抗品种所占比例较低,分别为13.9%和3.5%,但高代品系高抗类型比例较高,分别为42.2%和8.5%,表明甘肃和四川条锈菌的致病类型和发病环境条件存在较大差异,近年来四川小麦成株抗条锈病育种取得显著进展。

220份四川小麦条锈病抗性鉴定与评价

【目的】了解四川小麦条锈病抗性水平及抗性基因本底,为实现小麦生产抗性多基因布局、可持续利用抗病基因提供依据。【方法】利用条锈病流行生理小种对220份四川小麦进行条锈病抗性表型鉴定并结合已知Yr基因进行分子检测。【结果】29份育成品种和27份农家种对CYR34表现苗期抗性;40份农家种和53份育成品种表现出稳定成株期抗性。2、35、66、72、37和20份种质分别携带Yr10、Yr17、Yr18、Yr24/26、Yr41和Yr48;41份种质携带2个及以上Yr基因。【结论】四川农家种对我国优势条锈菌具有较高比例抗性;农家种以携带Yr18为主,育成品种主要携带Yr17、Yr24/26和Yr41;推测4个具有全生育期抗性的育成种质可能携带其他已知或未知Yr基因或组合,可供进一步Yr基因遗传解析和育种利用。

南阳麦区小麦品种(系)条锈抗性及抗病基因分析

南阳是小麦条锈病重要的冬繁与流行区,了解南阳麦区小麦品种(系)对条锈菌主流小种抗性表现及抗条锈病基因分布情况,为主产区小麦安全生产、品种布局及抗条锈病育种提供参考。利用流行小种混合菌种(条中32、条中33、条中34)及自然诱发发病,以南阳麦区22个主栽品种和146个高代品系为材料,在南阳进行自然诱发鉴定,在杨凌进行人工接种鉴定,使用Yr2、Yr10、Yr18、Yr32相关分子标记进行检测。结果表明,22个主栽品种在自然鉴定表现中抗及以上的有12个、中抗到中感有4个、中感及以上的有6个,接种鉴定表现中抗及以上的有14个、中感及以上的有8个,21个品种检测到含有Yr2,15个含有Yr10,0个含有Yr18,4个含有Yr32,11个检出含有Yr2+Yr10,1个检出含有Yr2+Yr32,3个检出含有Yr2+Yr10+Yr32。146个高代品系自然诱发鉴定表现中抗及以上的有126个、中感18个、高感2个,接种鉴定表现中抗及以上的有99个、中感20个、高感27个,141个检测到含有Yr2,87个含有Yr10,0个含有Yr18,35个含有Yr32,61个检出含有Yr2+Yr10,8个检出含有Yr2+Yr32,4个检出含有Yr10+Yr32,22个检出含有Yr2+Yr10+Yr32。南阳主栽品种西农979、郑麦9023、兰考198、百农207等对条锈病丧失抗性,郑麦7698、南阳996、西农501条锈抗性较好,聚合Yr2+Yr10+Yr32的西农511、矮抗58、西农509等品种推广利用价值较大,主栽品种与高代品系聚合Yr2+Yr10+Yr32和Yr32利用率均不高。立足南阳麦区新品种的选育、推广,要加强Yr32及条锈病多抗基因聚合品种(系)的利用。

The Stripe Rust Resistance Gene Yr10 Encodes an Evolutionary-Conserved and Unique CC-NBS-LRR Sequence in Wheat

The first seedling or all-stage resistance （R） R gene against stripe rust isolated from Moro wheat （Triticum aes- tivum L.） using a map-based cloning approach was identified as Yr10. Clone 4B of this gene encodes a highly evolutionary- conserved and unique CC-NBS-LRR sequence. Clone 4E, a homolog of Yr10, but lacking transcription start site （TSS） and putative TATA-box and CAAT-box, is likely a non-expressed pseudogene. Clones 4B and 4E are 84% identical and divergent in the intron and the LRR domain. Gene silencing and transgenesis were used in conjunction with inoculation with differen- tially avirulent and virulent stripe rust strains to demonstrate Yr10 functionality. The Yr10 CC-NBS-LRR sequence is unique among known CC-NBS-LRR R genes in wheat but highly conserved homologs （E = 0.0） were identified in Aegilops tauschii and other monocots including Hordeum vulgare and Brachypodium distachyon. Related sequences were also identified in genomic databases of maize, rice, and in sorghum. This is the first report of a CC-NBS-LRR resistance gene in plants with limited homologies in its native host, but with numerous homologous R genes in related monocots that are either host or non-hosts for stripe rust. These results represent a unique example of gene evolution and dispersion across species.

Identification of an AFLP marker linked to the stripe rust resistance gene Yr10 in wheat

AFLP analysis of near-isogenic lines of the stripe rust resistance gene Yr10 was carried out with 6 Pst I -primers and 10 Taq I -primers with the donor parent of Yr1O gene as the check. A total of about 4200 distinguishable bands were amplified, of which 5 were stable. The genetic linkage of the 5 polymorphic DNA fragments with the target gene were tested preliminarily on a segregating F2 population derived from a cross between the gene donor parent 'Moro' and susceptible cultivar 'Mingxian 169'. The DNA fragment PT0502 was found closely linked to the Yr10 gene and cloned and sequenced. Based on the sequence specific primers for PCR were designed and synthesized. Genetic linkage analysis with 195 segregating F2 plants indicated that the genetic distance was 0.5 cM between the main product SC200 fragment produced by PCR with the primers and the Yr10 gene. The primers can be used to detect the Yr10 gene quickly, effectively and exactly.