Identification of eight Berberis species from the Yunnan-Guizhou plateau as aecial hosts for Puccinia striiformis f.sp.tritici,the wheat stripe rust pathogen

Puccinia striiformis Westend.f.sp.tritici Erikss.(Pst)infects wheat and causes stripe rust.The rust is heteroecious with wheat as the primary uredinial and telial host and barberry(Berberis spp.)as the alternate pycnial and aecial host.More than 40 Berberis species have been identified as alternate hosts for Pst,and most of these are Chinese Berberis species.However,little is known about Berberis species or their geographic distributions in the Yunnan-Guizhou plateau in southwestern China.The Yunnan-Guizhou plateau is considered to be an important and relatively independent region for the evolution of the wheat stripe rust pathogen in China because the entire disease cycle can be completed within the region.In this study,we conducted a survey of barberry plants in the Yunnan-Guizhou plateau and identified the eight Pst-susceptible Berberis species under controlled conditions,including B.julianae,B.tsienii,B.veitchii,B.wilsonae,B.wilsonae var.guhtzunica,B.franchetiana,B.lepidifolia and B.pruinosa.These species are reported here for the first time to serve as alternate hosts for the wheat stripe rust pathogen under controlled conditions.

Molecular Mapping of a Gene for Resistance to Stripe Rust in Wheat Variety PIW138

Stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is one of the most damaging diseases of common wheat （Triticum aestivum L.）. Wheat variety PIW138 introduced from Pakistan is resistant to the currently prevailing Pst race CYR32 in China. In this study, the bulked segregant analysis （BSA） method and simple sequence repeat （SSR） markers were used to map the stripe rust resistance gene in PIW138. The resistant and susceptible DNA bulks were prepared from the segregating F2 population of the cross between Thatcher, a susceptible variety as the female parent, and PIW138 as the male parent. The segregation of resistant and susceptible F2 plants inoculated with CYR32 indicated that single dominant gene determined the reactions of PIW138 line and temporarily designated as YrP138. Total 200 SSR primers were screened, and 4 SSR markers, Xwmc52, Xbarc61, Xgwm268, and Xgwm153, on chromosome 1B were found to be polymorphic between the resistant and the susceptible DNA bulks as well as their parents. Genetic linkage was tested on the segregating F2 population with 259 plants, including 196 resistant and 63 susceptible plants. All 4 SSR markers were linked to the stripe rust resistance gene in PIW138. The genetic distances of Xwmc52, Xbarc61, Xgwm268, and Xgwm153 to the resistance gene were 29.8, 6.2, 6.8, and 8.2 cM, respectively.

Yr5-virulent races of Puccinia striiformis f.sp.tritici possess relative parasitic fitness higher than current main predominant races and potential risk

Wheat stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most destructive fungal diseases of wheat,and seriously threatens safe production of the crop worldwide.In China,new races historically appeared and rapidly developed to be predominant races and have resulted in ineffectiveness and replacement of wheat resistance cultivars as well as massive reduction in yield.In the present study,the relative parasitic fitness of the two newlyemerged Yr5-virulent races(TSA-6 and TSA-9)were compared with those of four currently predominant Chinese races(CYR31,CYR32,CYR33,and CYR34)based on evaluation on 10 Chinese wheat cultivars.As a result,there were significant differences in the relative parasitic fitness parameters among overall tested races based on multiple comparison(LSD)analysis(P<0.05).The principal component analysis(PCA)of overall parasitic fitness parameters indicated that the sporulation ability,infection and spore survivability,expansion capacity,and potential pathogenicity were the most important parasitic fitness attributes of the tested races.Based on the establishment of extracted three principal components and a comprehensive factor score mathematical models,evaluations of the parasitic fitness attributes of tested races showed that the level of relative parasitic fitness of the tested six races was:CYR32(1.15)>TSA-9(0.95)>TSA-6(0.92)>CYR34(0.29)>CYR31(–1.54)>CYR33(–1.77).The results indicated that two Yr5-virulent races TSA-9 and TSA-6 possessed relative parasitic fitness higher than races CYR34,CYR31,and CYR33,but lower than race CYR32,and have potential risks in developing to be predominant races.Therefore,continual monitoring of both Yr5-virulent races,and their variants is needed.The use of wheat cultivars(lines)with Yr5 resistance gene singly in wheat breeding is essential for being avoided,and is suggested to combine with other effective stripe rust resistance genes.

Characterization of wheat monogenic lines with known Sr genes and wheat cultivars for resistance to three new races of Puccinia graminis f. sp. tritici in China

Wheat stem rust, caused by Puccinia graminis f. sp. tritici(Pgt), is a potentially devastating fungal disease of wheat worldwide. The present study was to evaluate the resistance of 42 wheat monogenic lines with known stem rust resistance(Sr) genes and 69 wheat cultivars to three new Pgt races(34C0MRGQM, 34C3MKGQM, and 34C6MTGSM)identified from aeciospores at the seedling and adult-plant stages. The phenotyping results revealed that monogenic lines harboring resistance genes Sr9e, Sr17, Sr21, Sr22, Sr26, Sr30, Sr31, Sr33, Sr35, Sr36, Sr37, Sr38, Sr47, SrTmp,and SrTt3 were effectively resistant to all three Pgt races at the seedling and adult-plant stages. In contrast, monogenic lines containing Sr5, Sr6, Sr7b, Sr9a, Sr9d, Sr9f, Sr9g, Sr9b, Sr16, Sr24, Sr28, and Sr39 were highly susceptible to these races at both seedling and adult-plant stages. The other lines with Sr8a, Sr10, Sr11, Sr13, Sr14, Sr15, Sr18, Sr20,Sr19, Sr23, Sr25, Sr27, Sr29, Sr32, and Sr34, displayed variable levels of resistance to one or two of the tested races.Seedling infection types(ITs) and adult-plant infection responses(IRs) indicated that 41(59.4%) of the wheat cultivars showed high resistance to all the three races. Molecular marker analysis showed that four wheat culitvars likely carried Sr2, 20 wheat culitvars likely carried Sr31, 9 wheat culitvars likely carried Sr38, and none of the cultivars carried Sr24,Sr25, and Sr26. Our results provide a scientific basis for rational utilization of the tested Sr genes and wheat cultivars against these novel Pgt races.

The TaFIM1 gene mediates wheat resistance against Puccinia striiformis f. sp. tritici and responds to abiotic stress

Fimbrin, a regulator of actin cytoskeletal dynamics that participates in numerous physiological and biochemical processes, controls multiple developmental processes in a variety of tissues and cell types. However, the role of fimbrin in pathogen defense of wheat and the mechanisms have not been well studied. Here, we investigated that the expression of TaFIM1 gene of wheat was significantly induced in response to avirulent race of Puccinia striiformis f. sp. tritici(Pst) and silencing of TaFIM1 by virus-induced gene silencing method. The results show that silencing of TaFIM1 resulted in a reduction of resistance against the stripe rust indicated by both phenotypes and a histological examination of Pst growth. Additionally, the expression level of Ta FIM1 gene was up-regulated under abiotic stresses. These findings suggest that Ta FIM1 functions as a positive regulator of pathogen resistance of wheat plants and response to abiotic stress. Our work may show new light on understanding the roles of fimbrin in wheat.

Association Analysis of SP-SNPs and Avirulence Genes in Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen

Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen due mainly to the nature of obligate biotrophism and the lack of systems for studying its genetics and molecular manipulations. To overcome these limitations, a natural Pst population comprising 352 isolates representative of a diverse virulence spectrum was genotyped using 97 secreted protein-single nucleotide polymorphism (SP-SNP) markers to identify candidate avirulence genes using association analysis. Among avirulence genes corresponding to 19 resistance genes, significantly associated SP-SNP markers were detected for avirulence genes AvYr1, AvYr2, AvYr6, AvYr7, AvYr8, AvYr44, AvYrExp2, AvYrSP, and AvYrTye. These results indicate that association analysis can be used to identify markers for avirulence genes. This study has laid the foundation for developing more SP-SNPs for mapping avirulence genes using segregating populations that can be generated through sexual reproduction on alternate hosts of the pathogen.

Study Genetic Variation Using DNA Molecular Markers and Identification Physiological Races of Wheat Stripe （yellow） Rust Puccinia striiformis f.sp tritici during 2010-2014 in Some Regions of Syria

Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted 70% on wheat variety Mexipak in Syria, and recurrent infection in 2010, caused by a virulent race called Yr27, caused a considerable loss in the production of bread wheat cultivars （Cham 8, Cham 6 particularly） amounted 90%. Recently, 15 races of yellow rust had been addressed in Syria for seasons 2010-2014; 159E256, 166E254, 166E256, 255 E112, 0 E0, 64 E 6, 230 El50, 0 E 18, 198 El30, 166 El50, 102 El60, 128 E0, 126 El50, 214E150, and 6E16. The race 6E16 was the most frequent during the two seasons, while the race 255El12 was the most virulent, followed by the race 230E222 and the race 0E0 was the weakest one. This study revealed the presence of fourteen newly observed races in Syria. Molecular Variance Analysis of Molecular Variance （AMOVA） of 55 yellow rust Puccinia striiformis f.sp tritici isolates examined by Amplify Fragment Length Polymorphism （AFLP） revealed high genetic variation within population, and the dimensional scale analysis （MSD） and tree diagram showed that the Syrian yellow rust isolates were clustered in three groups： the first group contained isolates derived from durum wheat, the second one contained bread wheat isolates, but the third was made of isolates derived from both durum and bread wheat species.

Characterization and Molecular Mapping of a Stripe Rust Resistance Gene in Synthetic Wheat CI110

Stripe rust,caused by Puccinia striiformis f.sp.tritici（Pst）,is one of the most destructive diseases of wheat（Triticum aestivum L.）.To diversify stripe rust-resistant resources for wheat breeding programs,a CIMMYT synthetic wheat line CI110 was identified to be resistant to 28 isolates of Pst,including 6 Chinese prevalent races CYR28-CYR33.Genetic analysis indicated that a single dominant gene was responsible for the stripe rust resistance in CI110,temporarily designated YrC110.A molecular map,harboring YrC110 and 9 linked SSR markers,was constructed through simple sequence repeat（SSR）,and bulked segregant analysis.These linked markers and YrC110 were assigned on the short arm of chromosome 1B using the Chinese Spring nullisomic-tetrasomic and ditelosomic stocks.Gene postulation based on seedling reaction patterns to 30 Pst isolates suggested that the resistance gene YrC110 seemed different from the other known resistance genes tested,such as Yr9,Yr10,Yr15,Yr24,and Yr26/YrCH42.Four SSR markers Xbarc187150,Xgwm18227,Xgwm11223,and Xbarc240292 distinguished YrC110 from Yr10,Yr15,Yr24,and Yr26/YrCH42,and could be used as diagnostic ones for YrC110 in wheat resistant breeding programs against stripe rust.

Genetic Analysis and Molecular Mapping of a Stripe Rust Resistance Gene YrH9014 in Wheat Line H9014-14-4-6-1

Stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is one of the most widespread and destructive wheat diseases in many wheat-growing regions of the world. The winter wheat translocation line H9014-14-4-6-1 has all stage resistance. To identify stripe rust resistance genes, the segregating populations were developed from the cross between H9014-14-4-6-1 and Mingxian 169 （a wheat cultivar susceptible to all Pst races identified in China）. The seedlings of the parents and F1 plants, Fz, F3 and BC1 generations were tested with Pst races under controlled greenhouse conditions. Two genes for resistance to stripe rust were identified, one dominant gene conferred resistance to SUN11-4, temporarily designated YrH9014 and the other recessive gene conferred resistance to CYR33. The bulked segregant analysis and simple sequence repeat （SSR） markers were used to identify polymorphic markers associated with YrH9014. Seven polymorphic SSR markers were used to genotype the F2 population inoculated with SUN11-4. A linkage map was constructed according to the genotypes of seven SSR markers and resistance gene. The molecular map spanned 24.3 cM, and the genetic distance of the two closest markers Xbarc13 and Xbarc55 to gene locus was 1.4 and 3.6 cM, respectively. Based on the position of SSR marker, the resistance gene YrH9014 was located on chromosome arm 2BS. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xbarc13 indicated that YrH9014 was located on chromosome 2B. Based on chromosomal location, the reaction patterns and pedigree analysis, YrH9014 should be a novel resistance gene to stripe rust. This new gene and flanking markers got from this study should be useful for marker-assisted selection （MAS） in breeding programs for stripe rust.

Genetics and Molecular Mapping of Stripe Rust Resistance Gene YrShan515 in Chinese Wheat Cultivar Shan 515

Stripe rust is one of the most important wheat diseases worldwide. To identify new resistance genes is significant in wheat breeding. In this study, stripe rust resistance of a Chinese cultivar Shan 515 was tested with Chinese predominant races of P. striiformis f. sp. tritici in the seedling stage, and genetic analysis and simple sequence repeats （SSR） technique were used to identify the inheritance model of seedling stripe rust resistance in cultivar Shan 515 and to mark the sites of resistance gene（s） on chromosome. The genetic analysis indicated that the resistance of Shan 515 against Su11-4 was conferred by a single dominant gene, which was temporarily designated as YrShan515. Using bulked segregant analysis （BSA） and SSR markers, 12 SSR markers （Xwmc335, Xwmc696, Xwmc476, Xbarc267, Xgwm333, Xwmc653, Xwmc396, Xgwm213, Xgwm112, Xgwm274, Xcfd22, Xgwm131, and Xwmc517） located on wheat chromosome 7BL were linked to YrShan515 with genetic distance ranging from 3 to 24 cM. Based on the previously published genetic map and Chinese Spring nulli-tetrasomic analysis, YrShan515 was located on wheat chromosome 7BL. Polymorphism of wheat cultivars collected from Huanghuai wheat grown regions were screened with two markers, Xwmc653 and Xbarc267, and all of these wheat cultivars tested did not present the polymorphic bands as Shan 515 did. Therefore, it suggested that YrShan515 might be a allele of the available yellow rust resistance gene. The mapping of the new resistance gene in Shan 515 is useful for wheat breeding and diversification of resistance genes against stripe rust in commercial wheat cultivars in China.

Effects of UV-B radiation intensity and timing on epidemiological components of wheat stripe rust

Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation.

Genomic analysis,trajectory tracking,and field surveys reveal sources and long-distance dispersal routes of wheat stripe rust pathogen in China

Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies.Puccinia striiformis f.sp.tritici(Pst),the causal agent of wheat stripe rust,is an airborne fungal pathogen with rapid virulence variation that threatens wheat production through its long-distance migration.Because of wide variation in geographic features,climatic conditions,and wheat production systems,Pst sources and related dispersal routes in China are largely unclear.In the present study,we performed genomic analyses of 154 Pst isolates from all major wheat-growing regions in China to determine Pst population structure and diversity.Through trajectory tracking,historical migration studies,genetic introgression analyses,and field surveys,we investigated Pst sources and their contributions to wheat stripe rust epidemics.We identified Longnan,the Himalayan region,and the Guizhou Plateau,which contain the highest population genetic diversities,as the Pst sources in China.Pst from Longnan disseminates mainly to eastern Liupan Mountain,the Sichuan Basin,and eastern Qinghai;that from the Himalayan region spreads mainly to the Sichuan Basin and eastern Qinghai;and that from the Guizhou Plateau migrates mainly to the Sichuan Basin and the Central Plain.These findings improve our current understanding of wheat stripe rust epidemics in China and emphasize the need for managing stripe rust on a national scale.

Development of automatic counting system for urediospores of wheat stripe rust based on image processing

To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image processing was developed using MATLAB GUIDE platform in combination with Local C Compiler(LCC).The system is independent of the MATLAB environment and can be run on a computer without the MATLAB software.Using this system,automatic counting of Pst urediospores in a microscopic image can be implemented via image processing technologies including image scaling,clustering segmentation,morphological modification,watershed transformation,connected region labeling,etc.Structure design of the automatic counting system,the key algorithms used in the system and realization of the main functions of the system were described in detail.Spore counting tests were conducted using microscopic digital images of Pst urediospores and the high accuracies more than 95%were obtained.The results indicated that it is feasible to count Pst urediospores automatically using the developed system based on image processing.

New insights in the battle between wheat and Puccinia striiformis

Wheat stripe rust caused by Puccinia striiformis f.sp.tritici(Pst)poses a great threat to wheat production worldwide.The rapid change in virulence of Pst leads to a loss of resistance in currently resistant wheat cultivars,which results in frequent disease epidemics.Therefore,a major focus is currently placed on investigating the molecular mechanisms underlying this rapid variation of pathogenicity and coevolving wheat resistance.Limited by the lack of a system for stable transformation of Pst and the difficulties in wheat transformation,it is not easy to generate deeper insights into the wheat-Pst interaction using established genetic methods.Nevertheless,considerable effort has been made to unravel the wheat-Pst interaction and significant progress is being made.Histology and cytology have revealed basic details of infection strategies and defense responses during wheat-Pst interactions,identified cellular components involved in wheat-Pst interactions,and have helped to elucidate their role in the infection process or in plant defense responses.Transcriptome and genome sequencing has revealed the molecular features and dynamics of the wheat-Pst pathosystem.Extensive molecular analyses have led to the identification of major components in the wheat resistance response and in Pst virulence.Studies of wheat-Pst interactions have now entered a new phase in which cellular and molecular approaches are being used.This review focuses on the cellular biology of wheat-Pst interactions and integrates the emerging data from molecular analyses with the histocytological observations.

A secreted catalase contributes to Puccinia striiformis resistance to host-derived oxidative stress

Plants can produce reactive oxygen species(ROS)to counteract pathogen invasion,and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity.Catalases(CATs)have been found to play pivotal roles in detoxifying H_(2)O_(2)formed by superoxide anion catalyzed by superoxide dismutases(SODs).However,few studies have addressed H_(2)O_(2)removing during rust fungi infection of wheat.In this study,we cloned a CAT gene PsCAT1 from Puccinia striiformis f.sp.tritici(Pst),which encodes a monofunctional heme-containing catalase.PsCAT1 exhibited a high degree of tolerance to pH and temperature,and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional.Overexpression of PsCAT1 enhanced S.cerevisiae resistance to H_(2)O_(2).Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death.Knockdown of PsCAT1 using a host-induced gene silencing(HIGS)system led to the reduced virulence of Pst,which was correlated to H_(2)O_(2)accumulation in HIGS plants.These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H_(2)O_(2).

80份国外春小麦种质资源抗条锈性评价

【目的】小麦条锈病是由小麦条锈菌(Puccinia striiformis f.sp.tritici,Pst)引起的世界范围内小麦重要病害之一,培育和种植抗病品种是控制该病害的最有效策略。评价80份国外春小麦种质资源对中国当前小麦条锈菌流行小种的抗条锈性,为中国小麦抗条锈病育种提供依据和抗源。【方法】应用中国流行小麦条锈菌生理小种CYR29、CYR31、CYR32、CYR33以及致病类型PST-HY8和PST-V26对80份国外小麦种质资源进行苗期温室抗病性鉴定,以铭贤169和Av S为感病对照品种;并于2013年和2014年分别在陕西省杨凌和甘肃省天水进行田间成株期抗病性鉴定。根据苗期和田间成株期的抗病性鉴定结果对其进行抗病类型分类和评价。【结果】80份小麦种质资源的抗病类型可分为3类。第1类为全生育期抗病类型,有8份。其中PI660067、PI660119和PI660122在苗期和田间成株期均表现较高水平的抗病性。其余5个品系PI660056、PI607839、PI591045、TA5602和PI660064在苗期则对个别小种表现感病,并且在不同年份和不同测试地点成株期也表现感病。第2类为成株抗病类型,有28份。其苗期对所有测试小种均表现感病,有23份在田间成株期均表现抗病。但PI660075、PI660083、PI660085、PI660097和PI660107在不同年份和不同测试地点成株期表现感病。第3类为兼具成株期和对部分中国小种失去抗性的全生育期抗病类型,有44份,其苗期至少对一个测试小种表现抗病。有37份在田间成株期均表现抗病。但PI660065、PI660076、PI660079、PI660080、PI660095、PI660096和PI610750在不同年份和不同测试地点成株期表现感病。【结论】80份国外小麦种质资源中大部分对中国小麦条锈菌流行小种表现优良的抗病性。这些种质资源可作为抗源在今后抗病育种中加以利用,将丰富中国小麦抗条锈病基因的多样性。可能由于不同年份田间流行小种不同,造成一些成株抗病品系在不同年份和不同测试地点表现感病,由此推测成株抗病性可能也具有小种专化性。

源于硬粒小麦-节节麦人工合成种的小麦新品种川麦38抗条锈性及遗传分析

利用硬粒小麦-节节麦人工合成种与四川小麦杂交、回交,育成高抗条锈小麦新品种川麦38(99-607)。为明确川麦38抗条锈性状的遗传规律,将川麦38与绵阳26、绵阳335、SY95-71、川育12等5个高感条锈小麦品种杂交,获得杂种F1、F2群体;利用条中32对抗×感杂种F1、F2群体接种鉴定抗性分析表明,川麦38对条锈病新小种的抗性受一对显性基因控制。将川麦38与含Yr13的德国小麦8661及源于硬粒小麦-节节麦人工合成种的3个抗病新品种(川麦42、川3736、复小穗小麦)杂交,分析川麦38与4个抗病品种的抗性基因等位性,结果发现抗×抗F2群体中均分离出一定比例的感病单株,表明川麦38与德国小麦(Yr13)、川麦42、川3736、复小穗小麦等的抗锈基因不等位,为不同的抗性基因。

小麦条锈病菌avrYr10/24/26/ch42突变体的毒性研究

自2005年起在四川省郫县病圃连续播种1．5hm^2抗病品种川麦42作为小麦条锈病菌新毒性突变捕获圃，周围感病品种上接种四川各地采集的小麦条锈病菌样品，2005—2008年川麦42反应型为0—2级。2009年川麦42乳熟后期突然普遍发病，反应型为3^-，将发病叶片分离的条锈病菌毒性突变体接种全国小麦条锈病菌生理小种鉴别寄主、含有已知抗条锈基因的小麦品种、近等基因系及四川小麦生产品种后，发现新毒性突变体对在目前在四川仍表现抗病的贵农22、川麦42、含有Yr10的近等基因系NILS12、Moro、含有Yr24的NILS16、以及合有Yr26的NILS17均具有毒性，新毒性突变体因而被命名为avrYr10／24／26／ch42；avrYr10／24／26／ch42突变体对含抗条锈基因Yr9的洛夫林13等不具毒性。avrYr10／24／26／ch42突变体的AFLP分析表明，其遗传相似度在0．94以上，因此可能来自于同一克隆。avrYr10／24／26／ch42突变体能够侵染39个四川小麦新品种中除资麦一号外的38个品种，能够引起四川大面积生产上83．26％田块种植的小麦发病。以上结果表明，建立捕获圃可以提前获得小麦条锈病菌新毒性突变，指导抗性品种选育和布局。

小偃6号抗条锈基因遗传分析及分子标记

用小麦条锈菌CY29-mut3、CY28、CY27和CY25分别接种小偃6号、铭贤169及其F2代各株系，在常温下（15～17℃）和高温下（20～22℃）进行了小偃6号抗条锈基因的遗传分析。结果发现，在常温下，小偃6号对4个条锈菌生理小种的抗病性均由1对显性核基因控制；在高温下，其抗病性由2对或3对基因控制，但其正反交的作用方式不同，抗锈性也可能与细胞质遗传有关；筛选到与抗条锈基因连锁的RAPD标记，分别命名为OPT17650、OPC111000。同时，具有长穗偃麦草血缘的小麦品种小偃22对OPC11进行了验证，明确了其在分子辅助育种中的价值。

2008年云南省小麦条锈菌生理小种变异监测

利用19个鉴别寄主对采自云南德宏、保山、大理、昆明、曲靖、昭通6个地州12个市(县)的小麦条锈病标样进行生理小种鉴定,结果明确的标样有72份,涵盖54个寄主品种。鉴定结果表明:云南小麦条锈菌群体结构复杂,小种类型丰富,本研究共监测到18个小种或致病类型,分别是条中17、条中18、条中21、洛10-6、条中31、条中32、Hybrid 46致病类群(Hy-5、Hy-6、Hy-7、Hy-8)、水源11致病类群(水-1、水-3、水-4、水-5、水-10、水-11、水-12、水-14)。其中,条中32处于首位,出现频率为44.44%,其次为水-14,出现频率为16.67%;处于第三位的是水-4,出现频率为5.56%;第四位是Hy-8和水-11,出现频率为4.17%;这几个小种为云南本年度优势小种,是当前抗条锈育种的主要对象。其它小种和致病类型出现频率都低于3%,为本年度次要小种。对7个抗条锈基因Yr1、Yr3、Yr3 b4 b、Yr6、Yr9、YrA、YrSu有毒力的毒性基因出现频率依次为93.01%、91.67%、55.56%、61.11%、77.78%、90.28%、93.06%,从其频率衡量,可认为这些基因已丧失抗性。