鲁豫皖交界地区四个小麦禾谷孢囊线虫群体致病型鉴定

为了明确鲁豫皖交界地区小麦禾谷孢囊线虫的致病类型,利用23个国际鉴别寄主品种和1个当地小麦品种温麦19对采自山东菏泽、安徽颍上、河南商丘和淮阳的4个小麦禾谷孢囊线虫群体致病型进行了鉴定。4个群体的致病型不同于国际上已命名的16个小麦禾谷孢囊线虫致病型。13个A组鉴别寄主对山东菏泽与安徽颍上群体具有相同的抗性反应,这2个线虫群体属于同一致病型;河南商丘群体与上述2个群体的毒性相似,但大麦寄主KVL191对山东菏泽群体和安徽颍上群体表现为抗病,而对河南商丘群体表现感病;河南淮阳群体的致病谱较宽,明显不同于其它3个群体。对照小麦品种温麦19对4个小麦禾谷孢囊线虫群体均表现感病。     

Disease severity and pathotype dynamics of Puccinia striiformis f.sp. tritici in Denmark

Disease severity of wheat yellow rust, Puccinia striiformis f.sp. tritici , was analysed in Denmark from 1985 to 1999 in relation to the effects of weather on winter survival, distribution of host cultivars and pathotype dynamics. Below-average temperatures in January and February (midwinter) reduced yellow rust on the susceptible cv. Anja, and in three of four growth seasons following cold winters no yellow rust was observed on any cultivar under natural conditions. The agronomic consequences of dispersal of yellow rust urediniospores from external sources to Denmark, in a period during which large areas were planted with relatively few wheat cultivars, were demonstrated in several cases, most evidently when the Yr9 and Yr17 resistance genes became ineffective. Yr9 was overcome by the pathogen in a period with severe yellow rust epidemics on commercial cultivars, while virulence for Yr17 was first observed in a year with almost no yellow rust. In contrast, the resistance in cv. Kraka ( Yr1, CV ) was increasingly effective in controlling yellow rust, because pathotypes with the matching combination of virulence declined in the pathogen population. Pathotype frequency dynamics were thus influenced by selection forces within the country, and by selection forces in areas where spores were spread to Denmark from outside. The importance of a sufficient level of partial resistance in the wheat germplasm to prevent too much damage by yellow rust epidemics, in the event that the resistance genes are overcome by the pathogen population, is emphasized.     

我国40个小麦品种抗叶锈性研究

 选用11个具不同毒性基因组合的叶锈菌致病类型推导分析了1998~1999年度国家小麦区域试验40个品种所携带的抗叶锈病基因状况。在供试的39个已知抗叶锈基因(或基因组合)中,推导出Lr1、Lr2c、Lr3bg、Lr10、Lr13、Lr14a、Lr16、Lr23、Lr26、Lr32等10个抗叶锈基因,分布在24个品种中,有11个品种携带未知抗叶锈基因,5个品种不具有苗期抗叶锈基因。选用BBB、DHS、PGT和PHT等4个叶锈菌致病类型并设置5/10℃、15/20℃、25/30℃(黑暗/光照)3种不同的温度条件,研究了40个供试品种的抗性稳定性。结果表明,在这些品种中有15个品种的侵染型表现稳定或较稳定,3个品种表现为高温抗性,2个品种表现低温抗性,其余20个品种存在明显的品种、菌系和温度三者的相互作用;利用6个叶锈菌混合优势小种在田间进行成株期抗叶锈性鉴定结果表明,在40个供试品种中有21个品种具有良好的抗性,其中,至少有6个品种表现为慢锈性,有4个品种表现为明显的成株抗性,有4个品种可能携带成株抗性基因Lr34。文中还对几个主要抗叶锈基因的抗性特点及其利用价值等进行了讨论。     

中国条锈菌新小种条中30、31号的研究

本文报道了1991年以来对新小种条中30、31号鉴定与致病性的研究。继1991年发现对绵阳系成株小麦有致病力的、对Hybrid46有毒的新致病类型91—1,1993年又发现了新的致病类型93—1。根据它们对我国鉴别寄主的反应,命名为条中30、31号。与条中28、29号相比,新小种具有更宽毒性基因组成和更高的相对寄生适合度值,它们对我国生产品种、高代品系和重要抗源有更广的致病范围。证实两个新小种的出现和发展是绵阳系小麦抗条锈变异的主要因素,建议加强对新小种抗病育种和流行预测的研究。     

Is virulence phenotype evolution driven exclusively by Lr gene deployment in French Puccinia triticina populations?

Puccinia triticina is a highly damaging wheat pathogen. The efficacy of leaf rust control by genetic resistance is mitigated by the adaptive capacity of the pathogen, expressed as changes in its virulence combinations (pathotypes). An extensive P. triticina population survey has been carried out in France over the last 30 years, describing the evolutionary dynamics of this pathogen in response to cultivar deployment. We analysed the data set for the 2006–2016 period to determine the relationship between the Lr genes in the cultivars and virulence in the pathotypes. Rust populations were dominated by a small number of pathotypes, with variations in most of the virulence frequencies related to the corresponding Lr gene frequencies in the cultivated landscape. Furthermore, the emergence and spread of a new virulence matched the introduction and use of the corresponding Lr gene (Lr28), confirming that the deployment of qualitative resistance genes is an essential driver of evolution in P. triticina populations. However, principal component analysis (PCA) revealed that certain pathotype–cultivar associations cannot be explained solely by the distribution of Lr genes in the landscape. This conclusion is supported by the predominance of a few pathotypes on some cultivars, with the persistence of several other compatible pathotypes at low frequencies. Specific interactions are not, therefore, sufficient to explain the distribution of virulence in rust populations. The hypothesis that quantitative interactions between P. triticina populations and bread wheat cultivars—based on differences in aggressiveness—is also a driver of changes in pathotype frequencies deserves further investigation.     

春小麦品种沈免2063抗叶锈性遗传分析

为明确春小麦品种沈免2063所含抗叶锈病基因的对数、身份、显隐性和互作关系,以沈免2063为父本,分别与感病品种Thatcher及小麦抗叶锈病近等基因系Lr9、Lr19、Lr24、Lr25、Lr28、Lr42和Lr43的载体品系杂交,获得F1、F2和F3代群体后,分别在苗期和成株期进行抗病性测定。结果表明:沈免2063含有3对显性遗传且相互独立作用的抗叶锈病基因Lr9、Lr19和Lr25,在苗期,沈免2063对致病类型CBG/QQ的抗病性由Lr9和Lr25控制,对PHT/RP的抗病性由上述3对抗叶锈病基因控制;在成株期,沈免2063对优势致病类型PHT/RP和THT/TP等比混合菌种的抗病性由上述3对抗叶锈病基因控制。Lr9、Lr19和Lr25在育成品种中出现频率很低,目前尚很有效,但这3个基因均为典型的垂直抗病性基因,应进行基因布局、基因轮换等科学组配,才能延长其使用寿命。     

Low diversity and fast evolution in the population of Puccinia triticina causing durum wheat leaf rust in France from 1999 to 2009, as revealed by an adapted differential set

No internationally agreed differential set is available for characterization of virulences in populations of Puccinia triticina causing wheat leaf rust on durum wheat. In a first step, 73 potentially differential host genotypes were tested with 96 durum leaf rust isolates collected in France. A differential set, adapted to the local epidemiological context and useful for comparison with international studies was selected, including French commercial cultivars, Thatcher lines with Lr genes, and international cultivars. In the second step, a sample of 310 isolates collected in France from 1999 to 2009 was characterized on this set. Diversity was very low, as only five pathotypes were distinguished. Genotyping of a subset of 76 isolates according to 20 SSR markers confirmed this low diversity, with 73 isolates belonging to a single dominant genotype. Population was strongly shaped by cultivars, and the findings explain the successive breakdown of resistance sources deployed in French durum wheat cultivars. The gene Lr14a, suggested to be an efficient source of resistance in several European and American countries, was overcome by pathotypes frequent in France since 2000. Postulation of resistance genes in the commercial cultivars led to a proposed simplified version of the differential set. This study, providing new information about leaf rust resistance genes present in the French durum wheat germplasm, highlights the need to diversify sources of resistance to P. triticina in this germplasm. The results are also discussed in terms of relatedness and intercontinental migration of P. triticina on durum wheat.     

1992~1996年我国小麦叶锈菌毒性动态

 利用已知抗叶锈病基因的小麦近等基因系(或单基因系)作鉴别寄主,监测来自我国12个省(市、区)的499份叶锈标样。结果表明:(1)在发现的诸多致病类型(毒性基因组合)中,PHT出现频率较高(26.6%),为优势类型,其余类型的出现频率均在7.4%以下;(2)毒性基因V2a、V9、V15、V19、V20、V24、V28、V29、V37、V38和V13+3Ka的出现频率小于30%,V2b、V18、V25、V27+31和V33+34的出现频率在30%~60%之间,其对应的抗性基因可视为我国小麦叶锈菌的有效抗病基因;(3)不同生态区的叶锈菌株,毒性基因(或基因组合)的组成特点、出现频率及多样性等差异较大。文中建议采用"固定鉴别基因+辅助鉴别基因"的复合鉴定系统,并对小麦抗叶锈病生态育种及抗锈基因分区部署等问题进行了讨论。     

Diversity,spatial variation,and temporal dynamics of virulences in the German leaf rust (<Emphasis Type="Italic">Puccinia recondita</Emphasis> f. sp. <Emphasis Type="Italic">secalis</Emphasis>) population in winter rye

A large collection of German rye leaf rust isolates was analysed to characterize the diversity, spatial variation and temporal dynamics of virulences. Virulence-avirulence phenotypes (=pathotypes) were determined on 23 host differentials. We found 93 pathotypes among 177 single-uredinial isolates in 2000, 201 pathotypes among 437 isolates in 2001, and 125 pathotypes among 213 isolates in 2002. In total, the 827 analyzed isolates represented 317 pathotypes. Frequency of virulences on the individual differentials varied from 2% to 97%. Eight of the differentials showed a high resistance level with virulence frequencies <10%. Virulence complexity of the isolates ranged from 3 to 21 with a mean of nine. The percentages of highly virulent isolates (>14 virulences) increased from 4 to 15% during the sampling period. A high level of virulence diversity was observed within and between individual sampling sites with Simpson indices around 0.9. Evenness indices ranged from 0.88 to 0.92. Four of the five most frequent pathotypes were found in each year but their frequency never exceeded 10%. Isolates with unusual virulence combinations could be clearly separated by principal component analysis. Location-specific pathotype frequencies were revealed in each year, but the frequency patterns varied across years. On four fields a considerable increase of highly virulent pathotypes occurred within 6 weeks during the epidemic. The high diversity of pathotypes as well as the fast accumulation of highly virulent pathotypes favour the adaptation of the pathogen to race-specific host resistances. More durable resistance might be achievable by combining new effective race-specific resistances with adult-plant and/or race-non-specific quantitative resistances.     

1999年我国小麦叶锈菌毒性监测

采用国际通用的小麦叶锈菌鉴别寄主和辅助鉴别寄主分析了来自1999年我国不同地区小麦叶锈菌的毒性基因,479个叶锈菌株共划分为162个毒性类型,其中23个为主要毒性类型.毒性类型中出现频率最高的为FHB、PHT、FHG、THT,它们对抗叶锈基因Lr2a、Lr2b、Lr3、Lr10、Lr14b、Lr16、 Lr26的平均毒性频率高于80%,而对Lr3ka、Lr25、Lr19、Lr24、Lr30、Lr15、Lr35的平均毒性频率低于30%;发现对Lr35有毒力的菌株,出现频率为1.04%;至今尚未发现对Lr38、Lr45抗性基因有毒力的菌株.研究同时发现,不同地区小麦叶锈菌的毒性类型不同,毒性频率存在一定的差异.Lr9、Lr15、Lr19、Lr24、Lr35、Lr38、Lr45为小麦抗叶锈育种可利用的有效抗病基因.     

A high virulence and pathotype diversity of Puccinia striiformis f.sp. tritici at its centre of diversity,the Himalayan region of Pakistan

Information on the pathogen virulence profile and diversity across locations is crucial for host germplasm improvement and deployment. The rapid acquisition of virulence to host resistance by the wheat yellow/stripe rust pathogen (Puccinia striiformis f.sp. tritici: PST), makes it crucial to know about its virulence and pathotype diversity. Recent studies have shown the plausible centre of origin of the pathogen in the Himalayan region, with Pakistan being the most ancestral to all other worldwide populations. To assess the status of virulence and pathotype diversity in the Himalayan region of Pakistan, a set of 127 PST infected wheat samples from eight locations were collected, multiplied and pathotyped using a set of 36 differential lines from the world set, European and Chinese sets, and 9 Avocet Yr isolines. Virulence (Vr) was recorded to 18 out of 24 tested yellow rust resistance (Yr) genes, while a total of 53 pathotypes were detected out of 127 isolates tested. Virulence was found to the resistance genes rarely deployed in Pakistan (Vr8) or even worldwide level (Vr5), while virulence to Vilmorin 23 (Yr3+) was absent in Pakistan, which is common in Europe. None of the pathotypes was dominant across all locations, however, no clear spatial structuring was observed for the studied locations. Our results suggested a high virulence and pathotype diversity in line with the previously proposed potential role of sexual recombination in the temporal maintenance of PST in the Himalayan region of Pakistan. This information should be useful in host resistance gene improvement and deployment.     

Virulence Phenotypes of a Worldwide Collection of Puccinia triticina from Durum Wheat

ABSTRACT A total of 78 isolates of Puccinia triticina from durum wheat from Argentina, Chile, Ethiopia, France, Mexico, Spain and the United States and 10 representative isolates of P. triticina from common wheat from the United States were tested for virulence phenotypes on seedling plants of 35 near-isogenic lines of Thatcher wheat. Isolates with virulence on lines with leaf rust resistance genes Lr10, Lr14b, Lr20, Lr22a, Lr23, Lr33, Lr34, Lr41, and Lr44 represented the most frequent phenotype. Cluster analysis showed that P. triticina from durum wheat from South America, North America, and Europe had an average similarity in virulence of 90%, whereas isolates from Ethiopia were <70% similar to the other leaf rust isolates collected from durum wheat. Of the 11 isolates from Ethiopia, 7 were avirulent to Thatcher and all near-isogenic lines of Thatcher. The isolates from common wheat had an average similarity in virulence of 60% to all leaf rust isolates from durum wheat. P. triticina from durum wheat was avirulent to many Lr genes frequently found in common wheat. It is possible that P. triticina currently found on durum wheat worldwide had a single origin, and then spread to cultivated durum wheat in North America, South America, and Europe, whereas P. triticina from Ethiopia evolved on landraces of durum wheat genetically distinct from the cultivated durum lines grown in Europe and the Americas.     

Comparative Analysis of Indices in the Study of Virulence Diversity Between and Within Populations of Puccinia recondita f. sp. tritici in Israel

ABSTRACT Isolates of Puccinia recondita f. sp. tritici (n = 260) obtained from bread, durum, and wild emmer wheat leaf collections throughout Israel during 1993 to 1997 were analyzed for virulence on a set of wheat differentials. The overall frequency of virulence increased on differentials possessing resistance genes Lr1, Lr2a, Lr3, and Lr26 and decreased on Lr17, Lr21, and Lr30. Genes Lr9 and Lr24 were resistant, while Lr18 was susceptible (98% in 1996) to all tested leaf rust isolates and Lr10 and Lr23 were susceptible to more than 78% of the isolates. Diversity between populations (years) was assessed using Kosman's H(KB) (based on degrees of similarity among distinct phenotypes) and H(KDis) (based on frequencies of individual virulences) and Nei's and Rogers' distances. The greatest difference occurred between the 1993 and 1994 populations. Phenotypic diversity within each population (year) was analyzed using the Shannon's, Simpson's, and Kosman's indices. The highest diversity within years was recorded in 1994 and significantly increased from 1993 to 1994 for all indices. The variance in the diversity between populations can be only partially explained by differences between corresponding diversities within population. The comparative analysis of diversity between and within populations over the 5 years enabled a detailed study of changes in the pathogen population. The results show that the different measures do not yield the same rank order of diversity.     

偃麦草属E染色体组特异SCAR标记对Lr19的特异性和稳定性研究

 小麦抗叶锈基因Lr19来源于长穗偃麦草,表现优良的抗叶锈性,国内外发现对Lr19有毒性的小麦叶锈菌菌株的报道较少。本研究以TcLr19和Thatcher亲本以及TcLr19×Thatcher F₂代单株构建的分离群体为材料,建立了与Lr19共分离的稳定的SCAR分子标记,命名为Y₁₉SCAR₉₈₂。对49个小麦抗叶锈近等基因系材料的稳定性检测结果表明,其重复性好且为Lr19特异的分子标记。对120个小麦品种检测的结果表明,该标记可有效应用于小麦抗叶锈分子辅助选择育种。     

Physiological specialization and pathotype distribution of Puccinia recondita in western Europe, 1995

A pathogenicity survey of Puccinia recondita f.sp. tritici ( Prt ) was conducted in western Europe in 1995. Random urediospore isolates (850) of Prt were collected from the air by means of a jet spore sampler in wheat-growing regions of Austria, Belgium, France, Germany, northern Italy, Switzerland and the UK. Pathogenicity of the isolates was determined in tests of detached primary leaf segments maintained on water agar supplemented with benzimidazole (35 p.p.m.). The differential genotypes used were Thatcher, 20 near-isogenic Thatcher lines each with a single leaf rust resistance gene, and five cultivars/lines with additional resistance genes. All isolates were avirulent for the genes Lr9, Lr19, Lr21, Lr24, Lr25 and Lr29 , and both virulence and avirulence were detected for the remaining 19 genes. Fifty-three pathotypes were identified, four of which predominated (64% of isolates) and were widespread throughout western Europe. Three of the four predominant pathotypes were also identified in collections of wheat leaf rust collected in Poland, Hungary, Estonia and Finland. One pathotype, which comprised 35% of isolates in the south of France, was not detected in any other region. This pathotype was indistinguishable from several isolates obtained from Morocco, which suggested that it may have originated from northern Africa. Comparisons with previously published data suggested that the four predominant pathotypes were very similar and possibly the same as pathotypes present in the former Czechoslovakia for up to 20 years. The results obtained provide evidence of migration of Prt over considerable distances in western Europe, stressing the need for a co-ordinated approach for genetical control of the disease in this region.     

Virulence of Puccinia triticina in Turkey and leaf rust resistance in Turkish wheat cultivars

Leaf rust caused by Puccinia triticina is a common disease on wheat in the coastal regions of Turkey. Collections of P. triticina from infected wheat leaves were obtained from the main wheat production zones of Turkey in 2009 and 2010. A total of 104 single uredinial isolates were tested for virulence on 20 lines of Thatcher wheat that differ for single leaf rust resistance genes. Forty-four different virulence phenotypes were identified over both years. Four phenotypes were found in both years. Phenotype FHPTQ found in 2009, with virulence to genes Lr2c, Lr3, Lr16, Lr26, Lr3ka, Lr17a, Lr30, LrB, Lr10, Lr14a, Lr18, Lr3bg, and Lr14b, was the most common phenotype at 15.4 % of the total isolates. Forty-three winter and spring wheat cultivars from Turkey were tested as seedlings with 13 different P. triticina virulence phenotypes from Canada, the US and Turkey. The infection types on the cultivars were compared with infection types on the Thatcher near isogenic lines to postulate the presence of seedling leaf rust resistance genes in the cultivars. Resistance genes Lr1, Lr3a, Lr10, Lr14a, Lr17a, Lr20, Lr23, and Lr26 were postulated to be present in the Turkish wheat cultivars. DNA of the wheat cultivars was tested with PCR markers to determine the presence of the adult plant resistance genes Lr34 and Lr37. Marker data indicated the presence of Lr34 in 20 cultivars and Lr37 in three cultivars. Field plot evaluations of the wheat cultivars indicated that no single Lr gene conditioned highly effective leaf rust resistance. Resistant cultivars varied for combinations of seedling and adult plant resistance genes.     

Diversity and distribution of pathotypes of the soybean rust fungus Phakopsora pachyrhizi in East Africa

Phakopsora pachyrhizi is a biotrophic fungus that causes rust on soybean, leading to devastating yield losses. Development of resistant cultivars for deployment in different geographic regions requires a comprehensive understanding of the prevalent P. pachyrhizi pathotypes. To determine the pathotypes existing in four East African countries, 65 isolates were tested on 11 soybean host differentials. In addition, the virulence spectrum of isolates collected from the same region over multiple years was compared. The majority of the isolates (54%) belonged to pathotype 1000, which was found in all countries. The pathotypes with the most complex virulence spectrum, which comprised isolates from Kenya and Malawi, were virulent on four differentials. All pathotypes were virulent on soybean genotypes carrying the Rpp1 resistance gene to P. pachyrhizi, but they were avirulent on cultivars carrying the Rpp1b, Rpp2, or Rpp3 gene, as well as on cultivar No6-12-1 that carries Rpp2, Rpp4, and Rpp5. Two of the pathotypes were virulent on cultivar UG 5 that carries Rpp1 and Rpp3 and on Hyuuga that carries Rpp3 and Rpp5. The isolates collected from different countries differed in their virulence spectrum across the years. Shannon's index (H) and Simpson's index (S) of diversity indicated that the isolates from Malawi were more diverse (H = 1.55, S = 0.90) while those from Uganda had lower diversity (H = 0.78, S = 0.46 ). The Rpp genes that were found to provide resistance to all pathotypes of P. pachyrhizi can be employed for soybean breeding aimed at durable rust resistance.     

Genetics of leaf rust resistance in spring wheat cultivars alsen and norm

ABSTRACT Alsen is a recently released spring wheat cultivar that has been widely grown in the United States because it has resistance to Fusarium head blight and leaf rust caused by Puccinia triticina. Norm is a high yielding wheat cultivar that has been very resistant to leaf rust since it was released. Alsen and Norm were genetically examined to determine the number and identity of the leaf rust resistance genes present in both wheats. The two cultivars were crossed with leaf rust susceptible cv. Thatcher and F(1) plants were backcrossed to Thatcher. Eighty one and seventy three BCF(1) of Thatcher times; Alsen and Thatcher x Norm respectively, were selfed to obtain BCF(2) families. The BCF(2) families were tested as seedlings with different isolates of P. triticina that differed for virulence to specific leaf rust resistance genes. The BCF(2) families that lacked seedling resistance were also tested as adult plants in greenhouse tests and in a field rust nursery plot. Segregation of BCF(2) families indicated that Alsen had seedling genes Lr2a, Lr10, and Lr23 and adult plant genes Lr13 and Lr34. Norm was determined to have seedling genes Lr1, Lr10, Lr16, and Lr23 and adult plant genes Lr13 and Lr34. The characterization of Lr23 in the segregating populations was complicated by the presence of a suppressor gene in Thatcher and the high temperature sensitivity of resistance expression for this gene. The effective leaf rust resistance in Alsen is due to the interaction of Lr13 and Lr23, with Lr34; and the effective leaf rust resistance in Norm is due to the interaction of Lr13, Lr16, and Lr23, with Lr34.     

小麦条锈菌生理小种条中32号及水源14致病类型在甘肃的流行与发展趋势

小麦条锈菌新毒性小种的产生与发展是造成条锈病大流行及品种抗锈性丧失的主导因素。1999～2004年采用条锈菌生理小种变异监测、致病性及寄生适合度测定、毒谱分析、哺育品种调查等方法,对条中32号及水源14致病类型的流行预测进行了系统研究。结果表明,条中32号及水源14致病类型已经成为甘肃省第一、二位优势小种,两小种毒性谱宽、致病力强、寄生适合度高、哺育品种面积大,其流行趋势已超过条中31号,将继31号后成为危害甘肃省小麦生产的流行小种。小麦条锈菌毒性群体结构已进入以条中32号和水源14致病类型为代表的Hybrid46和水源11致病类群占优势的新时期,这也对全国小麦条锈菌群体组成产生重要影响。     

Diversity of virulence phenotypes among annual populations of wheat leaf rust in Israel from 1993 to 2008

Leaf rust, caused by the fungus Puccinia triticina, is the most common rust disease of wheat in wheat‐producing areas worldwide. The Israeli population of wheat leaf rust has been consistently monitored since 1993. A total of 840 single urediniospore isolates from Triticum aestivum (567), T. dicoccoides (119) and T. durum (154) were analysed during 1993–2008. The structure of the pathogen population has changed to a large extent since 1993. The annual populations of P. triticina were separated into two distinct groups: 1993–1999 and 2000–2008. Differentiation among the annual pathogen populations, as well as between the overall populations of the 1990s and 2000s, could be mainly attributed to the following forces: (i) migration of leaf rust urediniospores from neighbouring regions; and (ii) selection pressure of new yellow rust‐resistant wheat cultivars that have been introduced into Israel since 1997. Genetic multiplicity of wild emmer contributes to P. triticina variability in Israel. Leaf rust populations collected from common wheat, wild emmer and durum wheat differed. The population that originated from T. durum was rather stable during the years of the survey, whereas that from T. aestivum changed significantly from the 1990s to the 2000s. Diversity within the annual populations of P. triticina was highest in 1994 when many new pathotypes and associations between virulences were observed. Single‐step derivatives of the new pathotypes became dominant after 2000. Significant changes in virulence frequency to a number of Lr genes (e.g. Lr2a, Lr15, Lr17, Lr21, Lr26) were also registered in 2000–2008.