CIMMYT小麦种质C615抗叶锈病QTL分析

由Puccinia triticina引起的叶锈病是小麦主要病害之一, 引进种质C615具有叶锈病成株期抗性, 但其抗病性遗传机制尚不清楚。本研究以抗病亲本C615与高感叶锈病亲本宁麦18构建的F_2:7代重组自交系群体为材料, 利用337对多态性SSR标记构建遗传连锁图谱, 结合2016、2017连续两年的叶锈病鉴定结果进行复合区间作图, 结果在1BL、2DS、3BS、4DL和6BS染色体上共发现了5个抗性QTL, 暂命名为QLr.njau-1BL、QLr.njau-2DS、QLr.njau-3BS、QLr.njau-4DL和QLr.njau-6BS。其中, QLr.njau-1BL、QLr.njau-3BS和QLr.njau-4DL在两年均被检测到, 分别解释10.1%~15.7%、10.9%~13.5%和8.2%~9.0%的表型变异; 另2个QTL只在一年被检测到, 解释6.2%和9.2%的表型变异。除QLr.njau-2DS外的4个抗性QTL均来源于抗病亲本C615。QLr.njau-1BL和QLr.njau-4DL分别与已报道的慢病性基因Lr46、Lr67在同一区域, QLr.njau-3B可能为一个新的抗叶锈病QTL。此外, 本研究在C615/扬麦13 (轮回亲本)BC₄F₅回交群体中选出了15个农艺性状优良且抗叶锈病的株系, 利用与C615所含抗性QTL紧密连锁的7个SSR标记对其进行基因型检测, 结果显示所有这15个株系均含有来自C615的抗性QTL, 且有3个株系聚合了全部抗性位点, 表明C615可作为抗源亲本用于高产、抗病育种。本研究结果将为分子标记选育抗叶锈品种提供材料和技术支撑。     

12个主产区历史小麦品种抗叶锈病基因分析

近年来,小麦叶锈病发生有加重趋势,培育抗病品种是减轻小麦叶锈病危害的环保有效途径。用12个小麦品种及35个含已知抗叶锈病基因的载体品系在苗期接种19个不同毒性的叶锈菌生理小种,通过基因推导和系谱分析发掘待测品种中的抗叶锈病基因,并通过分子标记检测进一步验证;在田间接种强毒性混合生理小种,进行成株期病情严重度与普遍率调查,筛选慢锈性品种。结果表明,在石新828、百农3217、济南2号、泰山1号、石特14、晋麦2148、烟农15、小偃6号、温麦6号共9个品种中检测到Lr1、Lr26、Lr34、Lr37和Lr46共5个抗叶锈病基因,其中部分品种中发现多个抗性基因。成株期筛选出百农3217、平阳27、济南2号、泰山1号、石特14、晋麦2148、碧蚂4号、烟农15、小偃6号、温麦6号共10个慢叶锈性品种,其中碧蚂4号和小偃6号等品种是我国小麦育种的骨干亲本,探究这些品种中的抗病基因对培育小麦抗叶锈病品种具有重要意义。     

宁夏春小麦品种宁春27号成株期抗条锈性遗传分析

为明确宁夏春小麦品种宁春27号成株期抗条锈性的遗传基础,以宁春4号和宁春27号杂交重组自交系为材料,应用植物数量性状主基因+多基因混合遗传模型分析方法,解析宁春27号条锈病抗性的遗传特点.结果表明,宁春27号对小麦条锈病抗性属于成株期抗性,RILs群体成株抗性连续分布,且为数量性状.以反应型和严重度数据进行遗传分析,宁...     

兼抗型成株抗性小麦品系的培育、鉴定与分子检测

小麦条锈病、叶锈病和白粉病是我国小麦的重要真菌病害,培育兼抗型成株抗性品种是控制病害最为经济有效和持久安全的方法。本研究选用由成株抗性育种方法培育的21份冬小麦高代品系和96份春小麦高代品系,在多个环境下进行这3种病害的成株期抗性鉴定,并利用紧密连锁的分子标记检测了兼抗型基因Lr34/Yr18/Pm38、Lr46/Yr29/Pm39和Sr2/Yr30的分布。田间鉴定表明,21份冬小麦品系中有17份兼抗3种病害,占80.9%;96份春小麦品系中有85份兼抗3种病害,占88.5%。分子标记检测发现,21份冬小麦品系均含QPm.caas-4DL,其中7份还含QPm.caas-2BS,9份还含QPm.caas-2BL;96份春小麦品系中,18份含Lr34/Yr18/Pm38,37份含Lr46/Yr29/Pm39,29份含Sr2/Yr30。以上结果表明,分子标记与常规育种相结合,可有效培育兼抗型成株抗性品种,为我国小麦抗病育种提供了新思路。     

青海春小麦品种高原363成株期抗条锈病基因遗传模型分析

为明确青海春小麦品种高原363成株期抗条锈性遗传基础,分别以成株期抗条锈性青海春小麦品种高原363与感病春小麦品种Taichung 29(T29)杂交并自交创建F_(2∶3)分离群体,通过在青海省西宁市和海东市互助县2个试验地点各2 a的田间病圃抗病性鉴定,使用单个分离世代分析法用植物数量性状主基因+多基因混合遗传模型分析高原363/T29 F_2群体的抗性遗传效应。F_(2∶3)群体的反应型和严重度的频率分布结果表明,高原363/T29 F_(2∶3)群体的病害严重度和反应型在西宁和互助共2个环境2 a测试下呈现双峰分布,没有出现连续性分布现象,但是又出现了不同区段内连续性变化,初步分析认为,高原363对小麦条锈病的成株期抗性是一种复杂遗传,这种遗传不仅仅由主效基因控制,同时还受到微效多基因控制,遗传模型分析结果表明,在2个不同地点测试下的高原363,无论是采用严重度数据得出的最优遗传模型还是使用反应型数据得出的最优遗传模型,都是被微效基因影响的2对主基因遗传,并且主基因的作用方式(C-1:2MG-ADI加性-显性-上位性,C-5:2MG-AED完全显性,C-6:2MG-EEAD等显性)是不同的。     

70份国外小麦品种(系)的苗期和成株期抗叶锈病鉴定

小麦叶锈病是小麦生产中的重要病害之一,培育持久抗病品种是最经济、有效和环保的方法。本研究用19个不同毒力的叶锈菌小种苗期接种70份国外引进小麦品种(系)及36个已知抗叶锈病基因的载体品种进行抗性鉴定,同时在2016—2017年度分别于河北保定和河南周口对70份国外引进品种进行田间抗叶锈性鉴定。为进一步检测材料中所携带的苗期和成株抗叶锈病基因,利用12个与已知基因紧密连锁的分子标记进行检测,综合基因推导、系谱分析和分子标记检测的结果,在33份材料中鉴定出15个抗叶锈病基因,包括Lr1、Lr2a、Lr26、Lr3ka、Lr11、Lr17、Lr30、Lr10、Lr14a、Lr2b、Lr13、Lr15、Lr21、Lr44和Lr45,田间鉴定筛选出39份品种表现慢锈性。苗期和田间表现表明,国外品种中含有丰富的对我国叶锈菌小种有效的苗期和成株期抗叶锈病基因,可作为小麦抗叶锈病抗源在抗病育种中加以利用。     

小麦品种贵农21,贵农22抗病性研究

采用温室苗期测定和成株期人工诱发接种鉴定方法研究了簇毛麦——硬粒小麦杂种后代贵农21、22的抗病性。苗期抗性测定表明,贵农21、22对国外15个小麦条锈菌生理小种表现为免疫至近免疫反应,仅对具有毒性基因Yr10的菌系82E16表现出中度感病,对供试的国内14个主要条锈菌菌系呈观免疫至近免疫反应。田间成株期抗性试验结果显示,贵农21、22对小麦条锈病、白粉病免疫,高抗秆锈病,中抗叶锈病。小麦品种贵农21、22可作为抗病资源和生产品种加以推广应用。     

河北省又取得一批农药植保类科研成果

<正>(接上期)6.小麦持久抗病品种兰天9号成珠抗叶锈基因的QTL作图单位名称:河北农业大学评价单位名称:河北省教育厅用分子标记技术发掘中国小麦品种兰天9号的成株抗叶锈基因位点及其紧密连锁的分子标记,为持久多抗品种的选育和成株抗叶锈基因的克隆奠定基础。本研究在兰天9号和感病品种辉县红杂交获得的F2∶3群体中共检测     

利用永久F2群体定位小麦株高的QTL

为研究小麦株高的遗传机制,利用DH群体构建了一套包含168个杂交组合的小麦永久F₂群体, 并于2007年种植于山东泰安和山东聊城。构建了一套覆盖小麦21条染色体的遗传连锁图谱并利用该图谱的324个SSR标记对小麦株高进行QTL定位研究,使用基于混合线性模型的QTLNetwork 2.0软件进行QTL分析。在永久F₂群体中定位了7个株高QTL,包括4个加性QTL,一个显性QTL,一对上位性QTL,共解释株高变异的20%,其中位于4D染色体的qPh4D,具有最大的遗传效应,贡献率为7.5%;位于2D 染色体显性效应位点qPh2D,可解释1.6%的表型变异;位于5B~6D染色体上位效应位点,可解释1.7%的表型变异。还发现加性效应、显性效应和上位效应对小麦株高的遗传起重要作用,并且基因与环境具有互作效应,结果表明利用永久F₂群体进行QTL定位研究的方法有助于分子标记辅助育种。     

小麦慢白粉病QTL对条锈病和叶锈病的兼抗性

聚合兼抗白粉病、条锈病和叶锈病的慢病性基因,是培育持久多抗小麦品种的重要措施。百农64和鲁麦21均为慢白粉病品种,分别含有4个和3个慢白粉病抗性QTL。将百农64与鲁麦21杂交,获得21个聚合2~5个慢白粉病抗性QTL的F₆株系,于2012-2013年度分别在四川郫县和甘肃天水进行条锈病田间抗性鉴定,在河北保定和河南周口进行叶锈病田间抗性鉴定。分析21个株系条锈和叶锈病的最大严重度和病程曲线下面积,检测单个QTL和QTL聚合体对条锈病和叶锈病的抗性效应。结果表明,QPm.caas-4DL、QPm.caas-6BS和QPm.caas-2BL对条锈病均有显著的抗性,分别解释表型变异的16.9%、14.1%和17.3%;QPm.caas-4DL对叶锈病也有显著抗性,可解释表型变异的35.3%;QPm.caas-1A/QPm.caas-4DL/ QPm.caas-2DL/QPm.caas-2BS/QPm.caas-2BL和QPm.caas-1A/QPm.caas-4DL/QPm.caas-2BS/QPm.caas-2BL聚合体对条锈病和叶锈病的抗性显著高于两亲本,它们均含有来自百农64的QPm.caas-4DL以及来自鲁麦21的QPm.caas-2BL和QPm.caas-2BS,表明这些QTL具有明显的兼抗性效应。在小麦抗病育种中,聚合慢病性QTL越多,慢病性越强,聚合4~5个慢病性QTL时,株系可达到高抗甚至接近免疫的水平,是选育持久抗性小麦品种的重要手段。     

Adult plant leaf rust resistance derived from the wheat landrace cultivar Americano 44d is conditioned by interaction of three QTL

Americano 44 is a landrace derived wheat cultivar from Uruguay that has had long lasting resistance to the leaf rust pathogen Puccinia triticina. A population of 92 recombinant inbred lines derived from the cross ‘Thatcher*3/Americano 44d’ was evaluated for segregation of adult plant leaf rust resistance in four field plot tests and two greenhouse tests. A genetic map was constructed with 381 Diversity Array Technology markers, five simple sequence repeat markers, and seven kompetitive allele specific PCR markers. Significant effects for reduction of leaf rust severity were found for quantitative trait loci (QTL) on chromosomes 3AS, 3DS and 6DS. Individually the 3AS and 3DS regions did not decrease leaf rust severity in any of the tests compared to the susceptible parent, yet strongly interacted when present in the same genotype to decrease leaf rust severity equal to the resistant parent. Genotypes with only the 6DS region had significantly lower leaf rust severity compared to the susceptible parent in three of the field plot tests. The 6DS QTL also interacted with the 3DS QTL to decrease leaf rust severity. Major QTLs on chromosome 3AS and 3DS are both located in the distal region and may be encoded by homoeoalleles.     

Inheritance and QTL mapping of leaf rust resistance in the European winter wheat cultivar ‘Beaver’

Genetic studies were conducted on an European winter wheat cultivar, Beaver, to determine the mode of inheritance of leaf rust resistance at seedling and adult plant growth stages using a recombinant doubled haploid population, Beaver/Soissons. Greenhouse studies indicated the involvement of genes Lr13 and Lr26 in governing leaf rust resistance at seedling growth stages, whereas, adult plant resistance (APR) in the field with pathotypes carrying virulence individually for Lr13 and Lr26 showed trigenic inheritance for the population. Marker regression analysis of adult plant field data indicated the involvement of six significant QTLs (chromosomes 1B, 3B, 3D, 4B, 4D and 5A) in year 2005, four QTLs (1B, 3B, 4B and 5A) in 2006, and six QTLs (1A, 1B, 3B, 4A, 4B and 5A) in 2007 for reducing leaf rust severity. QTLs on chromosomes 1B, 4B and 5A were considered the most important because of their detection across years, whereas QTLs on chromosomes 1A, 3B, 3D and 4A were either inconsistent or non-significant and unexplained. Based on an association of closely linked markers with phenotypic data, putative single gene stocks were identified for each consistent QTL and crossing was initiated to develop populations segregating for each to permit fine mapping of the identified regions.     

普通小麦‘Holdfast’条锈病成株抗性QTL定位

Holdfast是来自英国的小麦品种,多年来一直保持良好的条锈病持久抗性。本研究目的是发掘Holdfast的条锈病成株抗性基因及其紧密连锁的分子标记,为小麦持久抗性品种选育提供材料和方法。利用铭贤169和Holdfast杂交后代重组自交系(recombinant inbred lines, RIL)群体,于2014—2015和2015—2016年度在甘肃甘谷、甘肃中梁和四川成都进行条锈病成株抗性鉴定,并统计最大严重度(maximum disease severity, MDS)。基于小麦660K SNP芯片和BSA(bulkedsegregantanalysis)技术初步确定抗病基因所在的染色体后,将目标区域的SNP标记转化为KASP(KompetitiveallelespecificPCR)标记,检测整个RIL群体,进行基因型分析。最后进行RIL群体条锈病成株抗性的QTL分析,在5AL和7AL染色体上发现了2个成株抗性QTL。5A染色体长臂上1个条锈病成株抗性QTL QYr.gaas-5AL,在所有环境下均存在,可解释6.5%～9.3%的表型变异; QYr.gaas-5AL位于标记Ax-109948955和Ax-108798241之间,连锁距离分别为0.5 cM和1.1 cM。在7A染色体长臂上定位到1个条锈病成株抗性QTL QYr.gaas-7AL,在2015年和2016年甘谷环境中均稳定存在,分别解释6.2%和7.3%的表型变异;QYr.gaas-7AL位于标记Ax-110361069和Ax-108759561之间,连锁距离分别为0.5 cM和0.7 cM。携带QYr.gaas-5AL和QYr.gaas-7AL抗病等位基因家系的MDS显著低于感病等位基因家系的MDS,表明QYr.gaas-5AL和QYr.gaas-7AL可有效降低条锈病严重度,可应用于小麦抗条锈育种。     

Detection of quantitative trait loci for leaf rust resistance in wheat––T. timopheevii/T. tauschii introgression lines

Advanced backcross QTL analysis was used to identify QTLs for seedling and adult plant resistance to leaf rust in introgression lines derived from a cross between the spring wheat cultivar ‘Saratovskaya 29’ and a synthetic allopolyploid wheat (T. timopheevii/T. tauschii). F₂ mapping populations involving two backcross selections (‘BC5’ and ‘BC9’ lines) were genotyped with microsatellite markers. Two significant QTL for adult plant resistance were identified in line ‘BC5’: one on chromosome 2B, but originating from chromosome 2G, explained 31% of the trait variance. The other, derived from T. tauschii and mapped to the short arm of chromosome 2D explained 19% of the trait variance. In the second line, one major seedling and adult plant resistance QTL was identified on chromosome 2B. Both QTL co-located to the same marker interval. Such introgression lines, resulting from the reconstruction of common wheat genome, are of interest both as initial material for breeding and improvement of current cultivars, and as a resource for the study of the interaction and transformation of genomes.     

Detection of molecular markers linked to the durable adult plant stripe rust resistance gene Yr18 in bread wheat (Triticum aestivum L.)

Stripe rust of wheat caused by Puccinia striiformis West. f. sp. tritici presents a serious problem for wheat production worldwide, and identification and deployment of resistance sources to it are key objectives for many wheat breeders. Here we report the detection of simple sequence repeat (SSR) markers linked to the durable adult plant resistance of cv. ‘Otane’, which has conferred this resistance since its release in New Zealand in 1984. A double haploid population from a cross between ‘Otane’ and the susceptible cv. Tiritea’ was visually assessed for adult plant infection types (IT) in the glasshouse and field, and for final disease severity in the field against stripe rust pathotype 106E139A⁺. At least three resistance loci controlled adult plant resistance to stripe rust in this population. Quantitative trait loci (QTL) mapping results revealed that two of these, one on chromosome 7DS corresponds to the durable adult plant resistance gene Yr18 and other on chromosome 5DL were contributed from ‘Otane’; while the remaining one on chromosome 7BL, was contributed from the susceptible ‘Tiritea’. Interval mapping placed the ‘Otane’‐resistant segment near the centromere of chromosome 7DS at a distance of 7 cM from the SSR marker gwm44. The stability of QTL in the two environments is discussed. SSR gwm44 is potentially a candidate marker for identifying the durable resistance gene Yr18 in breeding programmes.     

QTL analysis of crown rust resistance in perennial ryegrass under conditions of natural and artificial infection

Crown rust is an economically devastating disease of perennial ryegrass. Both artificial crown rust inoculations, with the possibility of several selection cycles in one year, as well as marker-assisted selection can be used for more efficient breeding of new resistant cultivars. The objective of this study was to map quantitative trait loci (QTL) for response to crown rust infection in perennial ryegrass. In order to identify relevant markers for response to crown rust infection, QTL mapping was performed on a ryegrass mapping population which was evaluated for resistance in the field for two years as well as by artificial pathogen inoculations using a detached leaf assessment. The broad sense heritability values for the field, detached leaf and combined assays were 0.42, 0.56, and 0.64, respectively, indicating a good potential for selection for crown rust resistance. A total of six QTLs were identified and mapped to linkage groups (LG) LG1, LG4 and LG5, explaining between 6.8% and 16.4% of the total phenotypic variation.     

小麦品种扬麦16赤霉病抗扩展QTL定位及分析

扬麦系列品种赤霉病抗性在世界范围内得到重视,但其抗性遗传机制尚不清楚。扬麦16是近年来大面积推广的抗赤霉病品种,本研究以扬麦16与中麦895杂交构建的174个双单倍体(doublehaploidlines,DH)系为材料,于2017—2019年连续3年对该群体采用单花滴注进行赤霉病抗扩展鉴定。利用660KSNP芯片构建高密度遗传图谱,共检测到6个抗性QTL,分别位于2DL、3BL、4BS、4DS、5BL和6AS染色体上。除4BS位点外,其他5个抗性等位基因均来源于扬麦16。QFhb.yaas-4DS和QFhb.yaas-6AS均在多年被检测到,可解释8.8%～15.0%的表型变异;QFhb.yaas-2DL、QFhb.yaas-3BL仅在1年被检测到,分别解释10.5%和14.7%的表型变异;QFhb.yaas-5BL和来源于中麦895的QFhb.yaas-4BS仅在1年被检测到且效应仅为6.4%和8.3%。QTL效应分析结果表明,相较于单个位点,多个抗性QTL的聚合可显著降低赤霉病严重度。扬麦16抗赤霉病QTL将为揭示扬麦品种抗性遗传机制及开发相应分子标记奠定基础。