Identification of Co-Segregating RAPD Marker Linked to Powdery Mildew Resistance Gene Pm18 in Wheat

The Pm18 gene of wheat confers resistance to the powdery mildew which is one of the mostserious diseases in many regions of the world. In this study, bulked segregant analysis(BSA) was used to develop randomly amplified polymorphic DNA (RAPD) markers linked toPm18 gene. Three hundred and twenty decamer primers were screened and one of them wasidentified as RAPD marker (S411600) linked to Pm18. Using the F2 mapping population fromthe cross Pm18Chancellor, the marker S411600 was shown to co-segregate with the genePm18. This marker can be conveniently used for marker-assisted selection in wheatbreeding programs for the identification or pyramiding of Pm18 with other resistancegenes.

Molecular and Physical Mapping of Powdery Mildew Resistance Genes and QTLs in Wheat: A Review

Wheat powdery mildew(Pm) is a major disease of wheat worldwide. During the past years, numerous studies have been published on molecular mapping of Pm resistance gene(s) in wheat. We summarized the relevant findings of 89 major resistance gene mapping studies and 25 quantitative trait loci(QTL) mapping studies. Major Pm resistance genes and QTLs were found on all wheat chromosomes, but the Pm resistance genes/QTLs were not randomly distributed on each chromosome of wheat. The summarized data showed that the A or B genome has more major Pm resistance genes than the D genome and chromosomes 1A, 2A, 2B, 5B, 5D, 6B, 7A and 7B harbor more major Pm resistance genes than the other chromosomes. For adult plant resistance(APR) genes/QTLs, B genome of wheat harbors more APR genes than A and D genomes, and chromosomes 2A, 4A, 5A, 1B, 2B, 3B, 5B, 6B, 7B, 2D, 5D and 7D harbor more Pm resistance QTLs than the other chromosomes,suggesting that A genome except 1A, 3A and 6A, B genome except 4B, D genome except 1D, 3D, 4D, and 6D play an important role in wheat combating against powdery mildew. Furthermore, Pm resistance genes are derived from wheat and its relatives, which suggested that the resistance sources are diverse and Pm resistance genes are diverse and useful in combating against the powdery mildew isolates. In this review, four APR genes, Pm38/Lr34/Yr18/Sr57, Pm46/Lr67/Yr46/Sr55, Pm?/Lr27/Yr30/Sr2 and Pm39/Lr46/Yr29, are not only resistant to powdery mildew but also effective for rust diseases in the field, indicating that such genes are stable and useful in wheat breeding programmes. The summarized data also provide chromosome locations or linked markers for Pm resistance genes/QTLs. Markers linked to these genes can also be utilized to pyramid diverse Pm resistance genes/QTLs more efficiently by marker-assisted selection.

IDENTIFICATION OF RAPD MARKER LINKED TO POWDERY MILDEW RESISTANCE GENE Pm12 IN WHEAT

Powdery mildew is one of the most serious diseases of wheat in China. In this paper,bulked segregant analysis (BSA) was used to search for randomly amplified polymorphic DNA (RAPD) markers linked to the Pm12 gene,which confers resistance to the powdery mildew in wheat. 200 decamer primers were screened and one RAPD marker (S107 1900 ) was identified to be linked to Pm12 in coupling phase,and their genetic distance is 11.98± 4.00cM. This marker can be used for marker-assisted selection in wheat breeding for the identification or pyramiding of Pm12 with other resistance genes.

Resistance Analysis of Wheat Cultivars against Powdery Mildew in Anhui Province of China

[ Objective ] The paper was to determine the resistance level of the tried and pre-examination wheat cultivars against powdery mildew in Anhui Province of China. [ Method ] By using artificial inoculation and identification method in fields, the resistance of wheat cultivars was identified in consecutive three years from 2010 to 2012. [ Result] The highly susceptible （HS） cultivar accounted for 30%, 42% and 11% of total tested cultivars in the years of 2010, 2011 and 2012, respectively; moderately susceptible （MS） cultivar accounted for 53% of total tested cuhivars in 2010, which accounted for 47% and 57% in 2011 and 2012, respectively; moderately resistant （MR） cuhivar accounted for 17% of total tested cultivars in 2010, which accounted for 11% and 32% in 2011 and 2012, respectively. [ Conclusion] The paper can guide breeding direction, and also provide scientific basis for variety approval.

Identification of Resistance of Powdery Mildew and Stripe Rust of Winter Wheat Strains in Xinjiang

Wheat powdery mildew and stripe rust are the major diseases in wheat producing area in Xinjiang.To obtain wheat germplasm resources and varieties resistant to powdery mildew and rust,36 high-generation stable strains of Xinjiang winter wheat were evaluated using the method of natural inducement from 2018 to 2020.A total of 5 strains with high resistance to powdery mildew,4 strains with slow stripe rust and 1 strain with resistance to powdery mildew and adult plant slow stripe rust were obtained.And the parental combination of disease-resistant varieties was analyzed.These studies will provide theoretical basis for the breeding of resistant wheat varieties in Xinjiang.

Characterization of Three Novel Wheat LThinopyrum intermedium Addition Lines with Novel Storage Protein Subunits and Resistance to Both Powdery Mildew and Stripe Rust

Wide hybridization is an effective approach for enhancing the resistance of bread wheat （Triticum aestivum L.） to biotic and abiotic stresses by introducing favorable alien genes （Sepsi et al., 2008）. Wheatgrass, Thinopyrum intermedium （Host） Barkworth ＆ D.R. Dewey or Agropyron intermedium （Host） Beauvoir （2n = 42; genome formula JJjSjSstst）, is a perennial species in the tribe Triticeae and an important source of wheat improvement for biotic and abiotic stress resistance and quality-related traits, such as high grain protein concentration （Chen et al., 1998; 2001; 2003; Han et al., 2004; Li and Wang, 2009）. In addition, the ready crossing ability of wheatgrass with various Triticum species has made it popular in germ- plasm development.

RFLP Tagging of a Gene Pm12 for Powdery Mildew Resistance in Wheat (Triticum aestivum L. )

A dominant gene, Pml2, conferring the resistance to powdery mildew (Erysiphe graminis) has been transferred to wheat from Aegilops speltoides. Sixteen RFLP probes were used to test Line 31 and its parents, showing that Line 31 is a 6B/6S translocation lines. The linkage analysis by five probes indicates that Pm12 is located on the chromosome 6B/6S, and tightly flanked by an RFLP marker α-Amy-1 (1.1 cM), identified by RFLP and isozyme analysis. This approach is equally applicable to the identification of other transferred alien genes and the segments of alien chromosome introgressed into wheat.

Introgression of Resistance to Powdery Mildew Conferred by Chromosome 2R by Crossing Wheat Nullisomic 2D with Rye

Using the nulUsomic back-cross procedure, four wheat-rye chromosome substitution 2R （2D） lines with different agronomic performance, designated WR02-145-1, WR01-145-2, WR02-145-3, and WR02-145-4, were produced from a cross between 2D nullisomic wheat （Triticum aestivum L. cv. ＂Xiaoyan 6＂） and rye （Secale cereale L. cv. ＂German White＂）. The chromosomal constitution of 2n=42=21 in WR02-145 lines was confirmed by cytological and molecular cytogenetic methods. Using genomic in situ hybridization on root tip chromosome preparations, a pair of intact rye chromosomes was detected in the WR02-145 lines. PCR using chromosome-specific primers confirmed the presence of 2R chromosomes of rye in these wheat-rye lines, indicating that WR02o145 lines are disomic chromosome substitution lines 2R （2D）. The WR02-145 lines are resistant to the powdery mildew （Erysiphe graminis DC. f. sp. tritici E. Marchal） isolates prevalent in northern China and may possess gene（s） for resistance to powdery mildew, which differ from the previously identified Pm7gene located on chromosome 2RL. The newly developed ＂Xiaoyan 6＂- ＂German White＂ 2R （2D） chromosome substitution lines are genetically stable, show desirable agronomic traits, and are expected to be useful in wheat improvement.

Gene expression profiling related to powdery mildew resistance in wheat with the method of suppression subtractive hybridization

'Bainong 3217 × Mardler' BC5F4 wheat line at the initial stage of inoculation with powdery mildew pathogen (Erysiphe graminis DC) was used to construct a suppression subtractive hybridization (SSH) cDNA library. Totally 760 ESTs were obtained through sequencing. Similarity analysis of ESTs based on BLASTn and BLASTx with the sequences in GenBank, in combination with macroarray differential screening, revealed that 199 ESTs of 65 kinds were known to be functionally disease resistance related. Based on the gene expression profiling in the present study, it is postulated that salicylic acid (SA) and MAP-related signal transduction pathways were involved in powdery mildew resistance in wheat. System acquired resistance genes were predominant in terms of kinds and quantity. With the initiation of cell defense reaction, the genes conferring anti-oxidation substances were largely expressed and thus cell protection mechanism was activated. Much evidence revealed that phenylpropanes metabolic pathway was

腥掷孢酵母17wy1的分离、鉴定及对小麦白粉病防效初探

采用26S rDNA序列对分离自异常生长小麦白粉菌分生孢子上的菌株17wy1进行鉴定,明确其分类地位;通过孢子萌发抑制试验、室内盆栽和田间小麦白粉病防治试验测定17wy1发酵液对小麦白粉菌分生孢子萌发的影响及对小麦白粉病的生防效果,并通过定量PCR技术分析小麦病程相关蛋白基因PR1、PR2、PR5、TaPAL的表达模式,解析17wy1的拮抗机制,为小麦白粉病的生物防治提供依据。结果表明,菌株17wy1为腥掷孢酵母(Golubevia albescens),其发酵液(5×107个/mL)对小麦白粉菌分生孢子萌发抑制率为85.1%,对室内盆栽麦苗和田间小麦白粉病的防效分别为58.5%和69.8%;喷施酵母17wy1发酵液后,室内显症麦苗体内的病程相关蛋白基因PR1、PR5被诱导显著上调表达。可见,酵母菌17wy1可抑制小麦白粉菌分生孢子萌发,对室内盆栽麦苗和田间小麦白粉病具有较好的防治作用,是小麦白粉病的潜在生防菌。

小麦四个抗白粉病基因的KASP标记检测

为提高Pm13的检测效率,了解Pm21、PmV、Pm12和Pm13共4个小麦抗白粉病基因在山东小麦育种中的利用情况,本研究通过测序和引物设计成功转化了Pm13的KASP标记,并采用4个基因的KASP标记对2022—2023年山东省小麦高产区试组和强筋区试组的140份参试品系和2份区试对照品种进行检测,结果显示140份材料均不含上述4个基因,表明它们在山东小麦育种中应用较少。本研究可为利用KASP标记开展小麦抗白粉病基因的分子标记辅助选择提供参考,促进其育种应用。

俄罗斯春小麦抗白粉病基因检测及其组成分析

为了解俄罗斯春小麦抗白粉病基因的组成及分布规律,利用已开发的Pm2、Pm3b、Pm4、Pm8、Pm13和Pm21标记对外引俄罗斯251份春小麦品种进行了检测和分析。结果表明,在251份小麦品种中,分布5种抗白粉病基因,其中Pm2和Pm3分布频率较高,均为90.44%;Pm13为57.77%,抗病基因Pm4分布频率为10.36%,Pm8基因的分布频率为5.58%,抗病基因Pm21在引入的俄罗斯春小麦中没有分布,有6份材料没有检测出含有上述基因标记。俄罗斯251份春小麦品种中小麦抗白粉病基因组合共有15种类型,其中116份小麦品种以Pm2/Pm3/Pm13类型所占比例为46.22%;其他14种类型所占比例依次为,Pm2/Pm3类型比例为23.90%;Pm2/Pm3/Pm4类型比例为4.78%;Pm2/Pm3/Pm4/Pm13类型比例为4.38%;Pm2类型比例为3.58%;Pm3和Pm2/Pm13类型比例均为2.79%;Pm3/Pm13和Pm2/Pm3/Pm8类型比例均为2.39%;Pm2/Pm3/Pm4/Pm8和Pm2/Pm3/Pm8/Pm13类型比例均为1.20%;Pm13类型比例为0.79%;Pm2/Pm8、Pm3/Pm4/Pm13和Pm3/Pm8/Pm13比例为0.40%;本研究明确了俄罗斯春小麦品种抗白粉病基因的组成和分布频率,可进一步利用外引材料开展抗白粉病育种。

Transcriptome Comparison of Susceptible and Resistant Wheat in Response to Powdery Mildew Infection

Powdery mildew （Pro） caused by the infection of Blumeria graminis f. sp. tritici （Bgt） is a worldwide crop disease resulting in significant loss of wheat yield. To profile the genes and pathways responding to the Bgt infection, here, using Affymetrix wheat microarrays, we compared the leaf transcriptomes before and after Bgt inoculation in two wheat genotypes, a Pm-susceptible cultivar Jingdong 8 （S） and its near-isogenic line （R） carrying a single Pm resistant gene Pm30. Our analysis showed that the original gene expression status in the S and R genotypes of wheat was almost identical before Bgt inoculation, since only 60 genes exhibited differential expression by P = 0.01 cutoff. However, 12 h after Bgt inoculation, 3014 and 2800 genes in the S and R genotype, respectively, responded to infec- tion. A wide range of pathways were involved, including cell wall fortification, flavonoid biosynthesis and metabolic processes. Further- more, for the first time, we show that sense-antisense pair genes might be participants in wheat-powdery mildew interaction. In addition, the results of qRT-PCR analysis on several candidate genes were consistent with the microarray data in their expression patterns. In summary, this study reveals leaf transcriptome changes before and after powdery mildew infection in wheat near-isogenic lines, suggest- ing that powdery mildew resistance is a highly complex systematic response involving a large amount of gene regulation.

127份甘肃农家小麦品种兼抗条锈病与白粉病鉴定与评价

小麦条锈病、白粉病是发生于甘肃陇南乃至全国小麦生产上的最主要病害之一,种植抗病品种是防治病害最经济有效且绿色环保的措施。兼抗种质资源材料的匮乏是制约甘肃陇南小麦条锈病和白粉病品种选育和病害有效防控的主要因素。农家品种是小麦抗病种质资源重要的基因库,开展兼抗病害材料鉴定是准确评价供试材料抗病性的基础性工作。2021年和2022年,在甘肃省农业科学院植物保护研究所兰州温室和甘谷试验站,对127份小麦农家品种进行了苗期、成株期抗条锈病和白粉病性鉴定,结果发现:供试材料中苗期对条锈菌和白粉菌混合菌表现抗病的分别有36份和24份,占28.35%和18.90%;兼抗材料15份,占11.81%。成株期在接种及自然诱发条锈菌和白粉菌条件下,表现抗病的分别有39份和72份,占30.71%和56.69%;兼抗材料有27份,占21.26%。全生育期兼抗材料有11份,占8.66%。抗白粉病基因分子检测结果发现,含有抗病基因Pm2、Pm4a、Pm8、Pm21的分别占30.71%、86.61%、25.20%、3.15%;含有2个及以上基因组合品种有60个,占47.24%。结合前期抗条锈病研究结果,将会为筛选出的优异材料利用和持续解决甘肃陇南兼抗品种匮乏难题提供材料支撑。

波斯小麦Cypa35-3成株期抗白粉病基因定位

源自苏联的波斯小麦Cypa35-3对陕西关中地区白粉菌优势小种表现为成株期高抗白粉病。为明确Cypa35-3抗白粉病基因所在染色体位置及其抗白粉病基因的遗传规律,利用Cypa35-3与高感白粉病的加拿大二粒小麦Flavescens进行杂交,在成株期自然发病条件下对亲本及其杂交F_(1)、F_(2)、F_(2)∶3群体进行白粉病抗性评价与遗传分析;选用分布于A、B染色体组14对染色体上共计601对SSR标记,利用分离群体分组分析法(BSA)对Cypa35-3的F_(2)群体进行多态性标记筛选。结果表明,Cypa35-3的成株期白粉病抗性受1对显性基因控制,暂命名为PmCypa35-3。通过群体筛选,获得4对位于1B染色体上的SSR标记,分别为Xbarc81、Xcfd48、Xbarc61、Xbarc302,其中Xbarc81、Xcfd48位于PmCypa35-3两侧,遗传距离分别为25.2 cM、8.6 cM。由此将成株期抗白粉病基因PmCypa35-3初步定位于1B染色体。通过与1B染色体上及波斯小麦中正式命名的抗白粉病基因的基因来源和标记位置进行对比,发现PmCypa35-3与它们均不相同,推测PmCypa35-3可能是一个新的小麦成株期抗白粉病基因,可作为小麦抗病育种的新抗源。

四倍体小麦成株抗白粉病基因定位

四倍体小麦是普通小麦的祖先种,也是重要的粮食作物。发掘四倍体小麦抗病种质并鉴定其携带的抗病基因,旨在为小麦新品种选育提供新抗源。TDI-1是栽培二粒小麦,在多年的田间种植过程中表现出对白粉病免疫的表型。为了确定TDI-1携带的抗病基因,为小麦白粉病抗性遗传提供理论依据,首先将其与表现为感白粉病表型的硬粒小麦TDU-1进行杂交并构建了遗传群体,然后对亲本及其杂交F_(1)、F_(2)、F_(2:3)群体进行了白粉菌小种E09接种试验和抗病性分析,最后利用混合分离群体分析法(BSA)对抗白粉病基因进行了定位。结果表明,TDI-1在苗期对E09表现为感病,在成株期对E09表现为抗病;TDI-1和TDU-1的F_(1)植株在成株期对E09表现为抗病;F_(2)群体中,表现为抗病的单株数和感病的单株数的比例符合3∶1(χ^(2)_(3∶1)=0.11,P=0.74);F_(2∶3)家系中,纯合抗病、抗病性分离、纯合感病的家系数目之比符合1∶2∶1(χ^(2)_(1∶2∶1)=0.47,P=0.79),表明TDI-1成株期白粉病抗性由1个显性基因控制,暂将其命名为PmTDI-1。对TDI-1和TDU-1及其杂交后代F_(2)群体进行分子标记筛选,发现4个位于2A染色体短臂上的分子标记Xwmc407、NRM-2AS29、NRM-2AS45和NRM-2AS84与PmTDI-1紧密连锁,其中,NRM-2AS45和NRM-2AS84位于两侧,遗传距离分别为1.8,4.6 cM。由此,将成株期抗白粉病基因PmTDI-1初步定位于2A染色体短臂上。研究结果显示,从四倍体小麦TDI-1中鉴定到1个新的显性成株抗白粉病基因PmTDI-1。

小麦白粉病抗性的全基因组关联分析

对我国华北、华东、华中等多个地区的215份小麦种质资源进行成株期白粉病抗性表型鉴定,结合小麦16 K高密度芯片进行全基因组关联分析(GWAS)。结果表明,有25个SNP位点与小麦白粉病抗性显著相关,其中位于2 B染色体上的1个区段及位于3 B染色体上的1个位点在多个环境中被检测到;位于2 B染色体上的区段与已命名的小麦白粉病抗性基因Pm51距离相近,推测为同一位点;位于3 B染色体上的位点推测是一个新位点。

新麦系列小麦品种(系)白粉病抗性研究

为小麦品种(系)推广应用提供理论依据,研究新麦系列不同小麦品种(系)白粉病抗性,利用多个生理小种混合诱发行接种,检测20个新麦系列小麦品种(系)。结果表明,新麦系列小麦品种(系)白粉病抗性欠佳,抗病表现与系谱相关。筛选出近免疫品种1个,为新麦20,中抗品种3个,为新麦9319、新麦12、新麦40。筛选出的近免疫品种新麦20可以作为小麦抗病育种的亲本材料加以应用;新麦9319、新麦12、新麦40这3个中抗品种可以作为绿色种植基地小麦品种;新麦18、新麦19、新麦29这3个高感品种在推广应用中应注意白粉病防治。

栽培小麦Brock中抗白粉病相关基因TaRPP13-1B的克隆及功能分析

白粉病是小麦生产中的主要病害之一,发掘抗病基因并实现抗病基因转育是提高作物抗病性的最经济有效的方法。本研究克隆了一个位于小麦染色体1B上、具有典型CC、NBS和LRR结构域的基因TaRPP13-1B。接种白粉菌后,TaRPP13-1B基因在抗病小麦Brock和BJ-1中表达量虽然出现上下调波动,但平均表达水平一直高于感病小麦品种京411。采用病毒诱导的基因沉默和转基因过表达技术进行功能分析,发现抑制目标基因表达,抗病小麦品种Brock对白粉菌的抗性显著降低;过表达TaRPP13-1B的转基因小麦津强5号对白粉菌抗性明显提高。说明TaRPP13-1B基因参与小麦抗白粉病的防御反应过程。该研究为小麦抗病品种的选育提供了有价值的备选基因。