Molecular approaches in identifying leaf rust resistance genes in Russian wheat varieties

Russian soft wheat varieties are screened with the use of molecular markers of Lr genes. A low genetic diversity is found among leaf rust resistant varieties, in which genes Lr9 and Lr19 dominate. There are no highly effective genes Lr25, Lr29, and Lr39(41) and adult plant resistance genes Lr37 and Lr21 in the studied varieties. Among genes with limited effectiveness, the most prevalent are genes Lr10 and Lr26, respectively in 45 and 10% of the varieties.     

Identification of leaf rust resistance genes in common wheat varieties from China and foreign countries

Wheat leaf rust, triggered by Puccinia triticina Eriks(Pt), is among the most important diseases of wheat worldwide. Deploying resistant varieties against leaf rust is the most effective, environmentally-friendly and economic way to control the disease. In the present study, 66 wheat varieties form China and foreign countries were tested with 17 Pt races for gene postulation during the seedling stage in the greenhouse. All the varieties were also planted to identify slow rusting responses to leaf rust at the adult plant stage in Baoding and Zhoukou field trials during the 2016/2017 to 2017/2018 cropping seasons. Moreover, 12 closely linked molecular markers to known leaf rust resistance(Lr) genes were used for assessing all the varieties. The results of both gene postulation and molecular marker identification showed that a total of eight Lr genes, Lr1, Lr10, Lr17, Lr20, Lr26, Lr34, Lr37 and Lr46, either singly or in combination were detected in 32 varieties. Known Lr genes were not identified in the remaining 34 varieties. Seventeen varieties were found to have slow rusting resistance. The resistance sources identified in this study can be used as resources for resistance against leaf rust in wheat breeding programs in China and the respective foreign countries.     

Phytopathological characteristics of leaf rust resistance of new winter wheat varieties

The characteristics of types of leaf rust resistance of 14 winter wheat varieties under artificial climate chamber and field conditions as well as recommendations on their effective use are given.     

Triticale diversity in leaf rust resistance

An evaluation of 416 triticale accessions from the Vavilov All-Russian Research Institute of Plant Industry (VIR) collection reveals a great diversity of forms in the character of leaf rust resistance. A nonuniform distribution of resistant phenotypes is noted in groups differing in ploidy level and geographic origin. The identified 17 varieties and lines not infected by geographically distant aggressive populations of this pathogen are especially valuable for use in breeding.     

Genetic control of triticale leaf rust resistance

Genetic control of leaf rust resistance is studied by the hybridological analysis method in hexaploid triticale cultivars Matyrskoe, PRAG 140/1, BG 13, Tal’va 100, Kartli 6, Kolor, AD-52, PRAG 72, and PCHL Tel 216. Mono-or digenic inheritance of resistance is shown as a result of crossing with susceptible cultivars Viktor and Slavyanin. Susceptible plants are found in all F₂ hybrid populations obtained from crossing resistant cultivars, which indicates nonidentity of resistance genes and their high diversity.     

不同抗性小麦品种受叶锈菌侵染前后防卫酶活性变化研究

对小麦叶锈菌侵染前后2个不同抗性小麦品种叶片中的POD、PPO、PAL、β-1,3-葡聚糖酶4种防卫酶的活性变化进行了研究。结果表明:在接种前,抗病品种的POD和PPO活性均高于感病品种,而抗、感品种间PAL和β-1,3-葡聚糖酶的活性差异不大;接种叶锈菌后抗病品种和感病品种小麦叶片中的4种防御酶活性均高于未接种处理,并且抗病品种接种后PPO活性变化幅度明显高于感病品种;抗病、感病的小麦接种叶锈菌处理与未接种处理的POD、PPO、PAL、β-1,3-葡聚糖酶4种防卫酶的活性均升高,POD、PPO、PAL 3种酶活性在接种后3 d达到峰值,β-1,3-葡聚糖酶在接种后4 d达到峰值;相对于其他防御酶,PAL在测定期内活性变化程度不高,表现平稳。     

Monitoring the development of leaf rust pathogen on common wheat specimens

During 1995–2005 the leaf rust pathogen was monitored on common wheat specimens with identified Lr resistance genes. The number of pustules on the flag leaf surface of the host plant, pustule area, number of spores in it, and type of reaction are used as the main indices of pathogenesis of the pathogen. A number of regression models reflecting the main quantitative regularities of variables of the pathogen’s state are proposed.     

Agrobiological characteristics of leaf rust resistance in wheat under conditions of the northwestern region of the Russian Federation

The effect of the level of nitrogen nutrition of spring wheat breeding varieties and lines of various geographic provenance, their morphoagronomic characteristics, and expression of Lr genes on wheat leaf rust pathogenesis is studied. The dependence of changes in the intensity of disease development, number of pustules on flag and preflag leaves, area of pustule, number of spores in it, and type of wheat reaction on a set of agrobiological factors is shown.     

普通小麦抗条锈新种质--WT212的抗性及遗传分析

对普通小麦抗条锈新种质——WT212的抗锈性及遗传学特性进行了分析。结果表明,WT212具有多小种抗性,参试的4个条锈菌生理小种的抗性受1对显性基因控制;细胞遗传学分析表明,WT212所携带的抗源不同于以1BL/1RS易位系为基础的"洛类"抗源,而是一种来自黑麦染色体组的抗条锈新抗源。初步断定WT212为可能只涉及1对染色体的小麦—黑麦易位系。     

6个小麦抗叶锈病近等基因系的cDNA-AFLP差异表达分析

应用cDNA-AFLP技术对小麦抗叶锈病近等基因系TcLr9、TcLr15、TcLr19、TcLr25、TcLr38、TcLr45和感病亲本Thatcher间的表达差异进行分析,共选用226对引物组合对其进行筛选,检测出7 554条条带,平均每对引物可获得33条扩增条带。筛选出68对引物能够在小麦抗叶锈病近等基因系TcLr9、TcLr15、TcLr19、TcLr25、TcLr38、TcLr45和感病亲本Thatcher之间扩增出特异表达条带,特异表达检出率为30.1%。68对引物共扩增出84条特异表达条带,并根据基因表达与否及表达量划分为9种不同的特异表达类型(I~IX)。其中,I、V和VII型特异表达类型为组成型表达,共49条;II、IV、VI和VIII型特异表达类型表达上调,共21条;III和IX型特异表达类型表达下调,共14条。有5种特异表达类型(IV、V、VI、VII、VIII型)可能与小麦的抗病反应相关,并且这5种特异表达类型又分为两类亚型,第一类亚型是小麦抗叶锈病近等基因系与小麦叶锈菌互作时特异表达(I V型)或者表达量明显增加(VI、VIII型),为诱导性特异表达类型;第二类亚型为组成型特异表达类型(V、VII型)。     

小麦抗叶锈基因Lr34的RAPD分析

在建立了适合本实验室的RAPD反应体系基础上,用120个随机引物对含抗病基因Lr34小麦品种和感病品种Thatcher进行了RAPD分析.68个引物均能扩增出可辨条带,其中S22扩增出1条660 bp特异性条带,S130扩增出1条2 000 bp特异性条带,S503扩增出1条500 bp特异性条带.S22和S503在实验中获得较好的重复性,并将其产物命名为S22-660和S503-500.     

17个粗山羊草品种(系)抗叶锈基因的鉴定

为鉴定17个粗山羊草品种(系)中可能含有的抗叶锈病基因,用10株具有不同毒力的小麦叶锈菌混合菌对17个粗山羊草品种进行成株期抗叶锈性鉴定,筛选出7个在田间对叶锈菌有抗性的材料。用抗叶锈基因Lr1、Lr9、Lr19、Lr21、Lr24、Lr28、Lr29和Lr34的STS、SCAR或CAPS标记对这些品种进行分子辅助鉴定。初步明确粗山羊草CN40033和CN30823中可能含有Lr1基因;CN42471中可能含有Lr9基因;CN30942中可能含有Lr21;供试的17个粗山羊草品种中都不含有Lr19、Lr24、Lr28、Lr29和Lr34。     

小麦品种辽春10抗叶锈病基因LrLC10的比较基因组学定位

为明确小麦品种辽春10对叶锈菌小种PHT抗病的遗传基础,利用感病小麦材料87-1与抗病小麦材料辽春10构建的F_(2:3)群体,对其进行成株期抗病性鉴定和遗传分析。结果表明,辽春10中含有1个显性抗叶锈病基因,暂命名为LrLC10。利用BSA法和比较基因组学策略对该抗病基因进行分子标记分析,将LrLC10定位于小麦2BS染色体上。共构建了含有8个分子标记的LrLC10基因的连锁图,其中:CAUT253位于LrLC10的远着丝粒侧,距离为0.1cM;CAUT163和CAUT131与LrLC10共分离;CAUT239位于LrLC10的近着丝粒侧,遗传距离为0.5cM。     

10 个川麦系列小麦品种在绵阳田间抗条锈病鉴定

选用2006—2010年通过四川省农作物品种审定的10个川麦系列小麦品种,通过大田自然诱发,对其成株期不同生育期的抗锈性进行鉴定分析,旨在筛选出具有免疫及高抗的品种。方差分析结果表明,不同品种普遍率以及严重度的差异显著,部分川麦系列品种病情指数有显著差异。综合分析表明,川麦53、川麦48、川麦54表现为近免疫,川麦55、川麦58表现为高抗,川麦56表现为中抗,其余表现为中感。相关性分析表明,不同抗性组分之间均表现为极显著相关。表明在生产中不能忽视任何一个因素,一旦发现条锈病,应立即进行防治,防止条锈病的加重与蔓延。     

小麦抗叶锈病基因LrAlt的比较基因组学分析

斯卑尔脱小麦材料Altgold含有小麦抗叶锈病基因LrAlt。该基因被定位于小麦2A染色体短臂末端。本研究基于小麦与短柄草和水稻基因组良好的共线性关系,对小麦抗叶锈病基因LrAlt进行比较基因组学分析,发现该基因所在基因组区域对应于短柄草第5染色体和水稻第4染色体的直系同源基因组区域,据此开发出与LrAlt连锁的EST-STS标记BE498683、BE471132.1、BG605273和CD454629,并构建了LrAlt的遗传连锁图谱,这4个EST-STS标记与Xbarc212共分离,位于LrAlt近着丝粒侧,距离LrAlt 1.9cM。同时,通过筛选Graingenes 2.0公布的位于LrAlt附近的SSR标记,发现Xbarc124、Xgwm614与LrAlt紧密连锁,均与Xbarc212共分离。本研究通过比较基因组学的策略和筛选Graingenes 2.0公布的SSR标记,共得到与LrAlt紧密连锁的9个新的分子标记,为构建LrAlt的高密度精细遗传连锁图谱、分子标记辅助选择和基因聚合奠定了基础。     

Postulation of seedling leaf rust resistance genes in 84 Chinese winter wheat cultivars

Wheat leaf rust(caused by Puccinia triticina) is one of the most important fungal diseases in China. There are tens of winter wheat cultivars which are approved to be released by the government at a national level and more than 100 wheat cultivars at the provincial level. But there is no information about leaf rust(Lr) genes in these cultivars, which makes it difficult for farmers and breeders to select which cultivars they should plant in their fields and use in their breeding programs. The objective of this paper was to identify the leaf rust resistant genes at seedling stage present in the 84 commercial wheat cultivars from China that have been released in the past few years. A set of 20 near isogenic lines with Thatcher background and 6 lines with known Lr genes were used to test the virulence of 12 races of P. triticina(Pt). By comparing the infection types(ITs) produced on the 84 cultivars by the 12 Pt races with the ITs on the differential sets, the Lr genes were postulated. In addition, 8 molecular markers of Lr genes such as Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26 and Lr29, which are closely linked to or co-segregated with the Lr gene, were used for further validation of the genes in the 84 Chinese winter wheat cultivars. Twelve Lr genes, including Lr1, Lr3,(Lr3bg),(Lr3ka), Lr11, Lr13, Lr14 a, Lr16, Lr26, Lr27, Lr30 and Lr31 were postulated to be present either singly or in combinations in these Chinese wheat cultivars. Lr3 and Lr26 were detected most often in the tested cultivars, with frequencies of 51.2 and 38.1%, respectively. No wheat Lr genes were detected in 16 cultivars, and 4 cultivars may carry unknown Lr genes other than those used in this study. Lr9, Lr20, Lr21, Lr24, Lr25 and Lr29 were not present in any of the 84 tested accessions.     

‘中梁22号’小麦抗条锈基因的遗传分析

采用常规杂交方法,以陇南重要小麦生产品种‘中梁22号’作母本,感病品种‘铭贤169’作父本进行杂交,在F2代材料苗期分别接种条锈菌单孢菌系‘条中32号’、‘水14’、‘水7’和‘水4’.抗性遗传结果表明:对‘条中32号’,F2代植株抗感分离比为24∶390,符合理论比1∶15;对‘水14’,F2代植株抗感分离比为46∶341,符合理论比9∶55;对‘水7’,F2代植株抗感分离比为190∶225,符合理论比7∶9;对‘水4’,F2代植株抗感分离比为212∶151,符合理论比9∶7,经卡方测验上述结果均符合理论结果.据此推知‘中梁22号’对‘条中32号’的抗性由2对隐性抗性基因控制,‘水14’由2对显性抗性基因和1对隐性抗性基因控制,‘水7’由2对隐性互补抗性基因控制,‘水4’由2对显性累加抗性基因控制.     

小麦抗叶锈基因Lr37 ISSR分子标记的初步研究

利用ISSR(内部简单重复序列)技术对感病品种Thatcher及20个以Thatcher为轮回亲本的小麦抗叶锈病近等基因系进行分析,找到1个与Lr37基因连锁的ISSR标记。经过多次重复发现,在一套ISSR引物中,引物UBC812在小麦抗叶锈基因Lr37近等基因系间表现多态性。当用这个引物对已知含Lr37基因的3个抗病材料及其它不含Lr37基因的感病材料进行检测时,多态性标记UBC812-1200可以从3个含Lr37基因的抗病材料中检测到1条1200bp的多态性带,而在其它感病材料中均未出现。     

基于支持向量机的小麦条锈病和叶锈病图像识别

为了解决生产中小麦条锈病和叶锈病症状难以区分的问题,提高识别率和精度,提出了一种基于支持向量机和多特征参数的小麦条锈病和叶锈病图像分类识别方法。利用图像裁剪方法获取典型症状的子图像,采用中值滤波算法对图像进行去噪,利用K_means硬聚类算法实现病斑分割,提取病斑区域的形状、颜色和纹理特征空间的50个特征参数,设计支持向量机分类器进行分类识别。根据优选的26个特征参数,利用以径向基函数作为核函数的支持向量机对这2种小麦锈病图像进行识别。结果表明:训练样本识别率均为96.67%,测试样本识别率均为100%;与其他核函数相比,径向基核函数最适合于这2种小麦锈病的识别。所提出的基于支持向量机的方法可有效地进行小麦条锈病和叶锈病的图像识别。     

四川省22 个小麦品种田间抗条锈病鉴定及聚类分析

选用2010—2017年四川省农作物品种审定的22个四川地区栽培的小麦品种,对其抗条锈病能力进行鉴定并筛选出高抗品种,然后设置自然诱发产生条锈病的大田鉴定试验。对小麦生育期抗条锈病能力的鉴定结果包括反应型、病叶率和病情指数进行相关性分析,结果成显著正相关。针对反应型、病叶率和病情指数进行聚类分析。综合分析结果将22个小麦品种分为三大类,6个品种为高抗条锈病,7个品种为中抗条锈病,9个品种为中感条锈病,其中高抗品种为资阳1号、国豪麦15、绵麦1501、西科麦7号、西科麦10号和川育24号。结果表明,由于CYR34的出现使得部分新培育的小麦品种快速丧失抗病性。