大麦品种对白粉病抗病性鉴定及抗源筛选

通过田间初筛和病圃复筛,对6515份国内外大麦品种进行了白粉病抗性鉴定。重点材料结合苗期、分蘖期鉴定和异地鉴定,筛选出免疫或高抗材料52份,慢白粉病抗性材料59份,并发现具有Mla、Mla6单基因和Mla Mlat、Mla Mlh Mlp多基因组合的国外已知抗病基因品种,在浙江舟山和福建莆田表现抗病。统计分析表明,二棱大麦抗病性较多棱大麦强;抗病品种发病较感病品种迟;抗性材料大多来自国外,英、德、瑞典、叙利亚、澳大利亚、墨西哥等国品种,筛出率较高。     

Effect of early infection on pathotype frequencies in barley powdery mildew (Blumeria graminis f.sp. hordei) populations in field plots

A field experiment with barley powdery mildew ( Blumeria graminis f.sp. hordei ) was designed in order to study how the time of arrival of inoculum in the field influenced pathotype frequencies in the resulting populations. Three isolates belonging to pathotypes that were absent or rare in the local aerial inoculum were used to inoculate field plots of winter barley cv. Plaisant. Two successive inoculations with different combinations of the three isolates were performed with an approximately two-generation delay, and frequencies of inoculated pathotypes were assessed four and nine generations after the first inoculation. Pathotypes of the first inoculated isolates generally persisted throughout the period of sampling; this is described as an 'early arrival' effect. During the epidemics the inoculated isolates were not replaced by isolates from the natural airborne inoculum. Pathotype frequencies depended mainly on the time of arrival of inoculum in the plot, but frequencies also depended on the isolate that had been inoculated. The most frequent isolate, GL1, belonged to the clonal lineage dominant in powdery mildew populations on winter barley in the north of France. These results confirmed that the composition of a powdery mildew population in a field is largely determined by the composition of the initial inoculum.     

Comparison of resistance-inducing abilities of virulent and avirulent races of Erysiphe graminis f.sp. hordei and a race of Erysiphe graminis f.sp. tritici in barley

Resistance to powdery mildew was induced in barley by preinoculation with virulent and avirulent races of barley powdery mildew ( Erysiphe graminis f.sp. hordei ), and with a race of wheat powdery mildew ( E. graminis f.sp. tritici ). Four inducer densities were tested in 13 different induction periods between 1 and 24 h. Generally, the resistance induced by barley powdery mildew increased up to 10-12 h of induction and was maintained in longer induction periods. The inducing abilities of virulent and avirulent races could not be distinguished up to 10-12 h of induction, after which the inducing ability of avirulent races increased significantly in relation to virulent races. Wheat powdery mildew was able to induce more resistance than barley powdery mildew in induction periods up to 8 h. In a single inoculation procedure the number of haustoria developing from virulent barley powdery mildew decreased as inoculum density increased. The effect was ascribed to induction of resistance. This reduction of infection efficiency in the compatible interaction was compared to induced resistance. However, the inoculum density needed for 50% resistance induction in the double inoculation procedure was approximately 40 times higher than the inoculum density needed for 50% reduction in infection efficiency in the single inoculation procedure.     

大麦白粉菌种群毒性监测及抗性材料鉴定

2005和2006年从我国冬大麦区采集和分离大麦白粉菌单胞菌株729个,利用Pallas近等基因系进行致病型鉴定和群体毒性频率分析.同时,利用分离得到的不同致病型菌株,通过抗谱分析的方法鉴定了328份大麦品种(系)的白粉病抗性和抗病基因.结果显示:大麦白粉菌群体对抗病基因Mlal Mla(A12)、Mla3、Mla6 Mla14、Mla7 Mla(No3)、Mla7 Ml(Lg2)、Mla9 Mlk、Mla9、Mlal3 MlaRu3、Mlpl、Mlg(Cp)和mlo5的毒性频率为0;对Mla12 MlaEm2、Mla7 Mlk、Mlat Mla8、Mla10MlaDu2和Mlk1的毒性频率很低,分别为0.1%、0.4%、0.9%、2.8%和4.2%.两年共鉴定出不同的致病型21个,致病型000、001和003在两个年度皆为优势致病型.所鉴定的328份材料绝大多数感病,仅37份抗病材料,能明确推导出抗白粉病基因的品种(品系)很少,这些品种(品系)含有的抗白粉病基因为Mr(Bw)Mla8、Mlg、Mira Mla8、Mla9 Mla1、Mla Mla(A12)和mlo5.     

Virulence structure of the <Emphasis Type="Italic">Blumeria graminis</Emphasis> DC.f. sp. <Emphasis Type="Italic">avenae</Emphasis> populations occurring in Poland across 2010–2013

The aim of the present study was to determine the virulence structure of powdery mildew of oats (Blumeria graminis DC.f. sp. avena) in Poland in the years 2010–2013. For this purpose, powdery mildew isolates were collected from three experimental stations in Poland. To assess the virulence of the isolates, eight oat varieties with different responses to the pathogen were used. The results showed that a significant proportion of powdery mildew isolates found in Poland overcame the resistance genes of varieties Bruno (Pm6), Jumbo (Pm1) and Mostyn (Pm3). In contrast, lines Av1860 (Pm4), Am27 (Pm5) and Cc3678 (Pm2) were completely resistant to all pathogen isolates involved in the experiment. Changes constantly occurring in the powdery mildew population perfectly reflect diversity indexes, which were the smallest in the first year of observation, where in the following years these parameters were significantly higher. It is worth noting that the presence of powdery mildew is seasonal and local, which is reflected in the prevalence of the disease in a defined area of the country.     

Powdery mildew resistance in selections from moroccan barley landraces

Thirty barley landraces collected from Morocco in 1985 and 1989, and held in the Polish Gene Bank, IHAR, Radzików, Poland, were screened for resistance to powdery mildew. Fifteen tested landraces (50%) showed powdery mildew resistance reactions and 24 single plant lines were selected. Eighteen lines originating from 13 landraces were tested with 17 isolates of powdery mildew and another six lines originating from six landraces were tested with 23; the isolates were chosen according to their virulence spectra observed on the ‘Pallas’ isolines differential set. Three lines (E 1090-2-2, E 1110-3-2 and E 1077-1-1) showed resistance to all powdery mildew virulence genes prevalent in Europe. In 21 lines, unknown genes alone or in combination with specific ones were detected. Five different resistance alleles(Mlat, Mlal, Mla3, Mlg andMl(CP)) were postulated to be present in the tested lines, alone or in combination:Mlat was postulated to be present in nine (~38%) lines;Mlg andMl(CP) in two lines, andMla1 andMla3 in one tested line each. The use of newly identified sources of resistance in barley breeding as a means of controlling powdery mildew is discussed.     

小豆白粉病菌的鉴定与小豆品种抗白粉病评价

为明确小豆白粉病病原菌的种类以及小豆种质资源对白粉病的抗性,采用形态学和系统发育学方法对近年来在北京市发生的小豆白粉病病原菌种类进行鉴定,并采用室内苗期人工接种法评价小豆常见栽培品种（系）对白粉病的抗性。结果表明,从北京市采集的感白粉病小豆病样中培养获得病原菌BJ1,该菌能在小豆叶片和茎上产生明显的白色粉斑,分生孢子梗直立,不分枝,分生孢子单细胞,成链状着生于分生孢子梗上,呈椭圆形或卵圆形。通过rDNA-ITS序列系统发育分析,小豆白粉病菌BJ1被鉴定为白粉菌目白粉菌科的苍耳叉丝单囊壳Podosphaera xanthii。室内苗期人工接种条件下,19个供试小豆品种（系）接种小豆白粉病菌BJ1后均可发病,其中9个审定品种均表现为中度感病或高度感病,10个优良品系发病略轻。     

Utility of defeated resistance genes to powdery mildew,Erysiphe graminis f. sp. hordei,in spring barley variety mixtures

In 1980 and 1981 experiments have been performed to study the utility of defeated resistance genes to powdery mildew in spring barley variety mixtures. For this purpose the epidemic development of powdery mildew in pure stands and mixtures of four spring barley varieties was monitored. In three varieties the resistance was overcome several years ago. One variety is still resistant. Changes in frequencies of corresponding virulence genes were also studied.It was found that the variety mixtures slowed down the mildew epidemic only at the beginning of the season. Some reduction was lost later on since the pure stands reached their saturation level of infection at an earlier date than the more healthy mixtures. The level of reduction of infection depended on the composition of the mixtures and the number of components. Two-way mixtures appeared to be very risky due to the high frequency of corresponding combinations of virulence genes in the pathogen. Furthermore, two-way mixtures appeared to be unable to reduce the infection rate sufficiently when the infection pressure was high.In 1981 the frequencies of combinations of corresponding virulence genes increased very much in the Diva-Mazurka mixture but declined in the pure stands of both varieties.On the basis of these results it is concluded that the utility of defeated resistance genes involved in this study is very limited.The low number and the irregular distribution of the Dutch spring barley varieties over the different resistance groups prohibit the use of variety mixtures in the Netherlands.Samenvatting In 1980 en 1981 is onderzoek verricht over de bruikbaarheid van doorbroken resistentiegenen tegen meeldauw,Erysiphe graminis f. sp.hordei, in zomergerstrassenmengsels. Daartoe werd de epidemieontwikkeling in monocultures en mengsels van vier zomergerstrassen bestudeerd. Van drie rassen is de resistentie reeds verscheidene jaren doorbroken. Eén ras is nog resistent. De frequenties van compatibele meeldauwvirulentiegenen werden eveneens bepaald.Het bleek dat in vergelijking met de monocultures in de rassenmengsels de meeldauwepidemie alleen in het begin van het seizoen werd afgeremd. Later in het seizoen ging weer enige reductie in aantasting van de mengsels verloren doordat in de monocultures de aantasting eerder het verzadigingspunt bereikte dan in de minder aangetaste mengsels. De mate waarin de aantasting gereduceerd werd was afhankelijk van de aard en het aantal componenten in het mengsel. Twee-componentenmengsels bleken vrij riskant te zijn vanwege de aanwezigheid van combinaties van corresponderende virulentiegenen in de meeldauwpopulatie. Verder bleken tweecomponentenmengsels niet in staat de infectiesnelheid afdoende af te remmen wanneer de infectiedruk hoog werd.De frequentie van combinaties van corresponderende virulentiegenen nam sterk toe in het Diva-Mazurka-mengsel doch nam af in de monocultures van deze beide rassen.Gezien de verkregen resultaten lijkt de bruikbaarheid van de in dit onderzoek betrokken doorbroken resistentiegenen erg beperkt. Het geringe aantal zomergerstrassen op de rassenlijst en de ongelijke verdeling over de te onderscheiden resistentiegroepen belemmeren de toepassing van rassenmengsels in de Nederlandse akkerbouw.     

The Hordeum vulgare subsp. spontaneum–Blumeria graminis f. sp. hordei pathosystem: its position in resistance research and breeding applications

Barley (Hordeum vulgare L.) is an important cereal crop and powdery mildew, caused by Blumeria graminis f. sp. hordei, is one of the most serious diseases that occurs on barley throughout the world. In the Middle East, which is the centre of diversity for barley and its pathogens, the wild barley–powdery mildew pathosystem co-evolves resulting in many specific resistances in the host as well as corresponding virulences in the pathogen. Many specific resistances have been used in European breeding programmes and a centre of pathogen diversity has arisen also especially in central Europe. This short review briefly summarizes the use of host resistances derived from wild barley and land races including the durable resistance gene mlo. The use of powdery mildew pathogenicity for studying new and unknown specific resistances and for identifying resistances in commercial varieties is described. However, highly heterogeneous wild barley is also characterized as a valuable source of minor genes for powdery mildew resistance. These might be exploited by barley breeders especially for winter barley improvement where the non-specific resistance gene mlo cannot be used.     

小麦抗白粉病品种的基因分析与归类研究

 研究出用抗谱及抗谱的近似,分析小麦抗白粉病品种的基因与归类的方法,测试了152个小麦抗白粉病品种,归类出15个类群,共120个品种,分析了类群主效抗病基因,并根据测试结果分析提出,为聚合主效抗病基因,进行复合杂交,在选取抗病亲本对上,要掌握毒性频率低,抗谱上互补,抗病基因非等位三项基本原则,才能取得预期成效。抗谱、近似分析法快速,准确,能同时测量大量品种、获得较多可靠信息,适用于基因对基因专化性病害抗病品种的基因分析与归类。     

Components of partial resistance to Erysiphe graminis in spring barley

The development of powdery mildew on seven spring barley varieties lacking effective major resistance factors was compared in a small-plot field trial. Differences were observed at later growth stages indicating partial resistance in some varieties. Latent period and sporulation capacity were examined on the fifth or sixth leaf of these varieties plus several known to be susceptible, using plants raised under spore-free conditions. Latent period was extended in most partially resistant varieties compared with susceptible controls, more so at 5°C than at 10°C. Cumulative total spore production per colony over the 16-day sporulation period differed markedly between varieties, the most resistant yielding one-third as many spores as the susceptible controls. There was evidence that these resistance components were correlated with each other and with previous estimates of infection frequency. The significance of this finding, in relation to selection for improved levels of partial resistance, is discussed.     

Sporenverteilung des Echten Mehltaus im Hopfen ausgehend von Infektionsherden und Abhängigkeit vom Vegetationsstadium

In order to assess the potential of infection of hop powdery mildew it is important to know the spore dissemination coming from different sources. Overwintering via cleitothecia is not provable in experiments. So wild hops, not correctly cleared cultural hops and non-cultivation hops are potential carriers of powdery mildew which is overwintering via mycel. In 2007 we found a source which has infected an area of about 30?ha cultural hops. By the observation of infections in these hop gardens we found that half of the amount of conidia is in a distance of 9,55?m away from the source. In a smaller dimension we counted the amount of conidia around one single plant in a commercial hop garden by a special spore trap. In the single plant the amount of spores is lower than outside, while it is decreasing in a higher distance from the single plant. Analysing the micro spore dissemination in a single plant there was a big diversity of the amount of spores because of the complex architecture of the hop plants. Further studies showed that the susceptibility of hop is much higher in May than later in the year. Thus, statistically a lower amount of conidia is needed for one complete infection. However, a lower amount of conidia can easily be transported for long distances by wind. As a result a source of powdery mildew in a long distance from the cultural hops is a serious danger for the commercial hop gardens early in the year. Later each source of conidia looses its influence nearly completely.     

甘肃南部小麦白粉菌群体的毒性及多基因片段分析

 为了解甘肃小麦白粉病菌的毒性变化动态及其群体遗传结构,利用毒性监测及多基因家系法,对采自甘肃省大陇南地区陇南、天水两市的49个小麦白粉菌的单孢子堆分离物进行群体遗传结构研究。毒性监测结果显示:供试菌株对抗病基因Pm12、Pm16、Pm18、Pm21的毒性频率均低于10%,表明上述抗病基因可以在育种和生产中继续使用;近些年定名的抗病基因Pm23、Pm25、Pm30、Pm34、Pm35的毒性频率为35%～95%,并在陇南、天水两市间存在差异,说明这些基因的利用需要慎重;对Pm4b的毒性频率已大幅度上升;在相似系数为0.752时,除11号菌株之外,其余聚为四类。选择AOX、EFA、PKA、PPA、TUB五个基因片段对供试菌株的多基因家系分析表明:基因序列聚为两类,病菌在陇南、天水两市间及各县市间存在传播。甘肃省大陇南地区病菌毒性多态性较高;白粉菌在各地区间存在交流的同时,也存在一定的独立进化。     

2011—2014年河南省小麦白粉菌群体毒性结构分析

<正>小麦白粉病是小麦生产上的重要病害,在我国各主要麦区均有发生。上世纪70年代后期以来,随着小麦矮秆品种的推广、水肥条件的改善和小麦白粉病单一抗源的利用,再加上小麦白粉菌生理小种高度变异等因素的影响,导致小麦白粉病的发病面积和危害程度维持在一个较高的水平。国际上普遍采用的是基于小麦     

Racial diversity and complexity in regional populations of Erysiphe graminis f.sp. hordei in France over a 5-year period

The evolution of race patterns in three French regional populations of the barley powdery mildew pathogen Erysiphe graminis f.sp. hordei over a 5-year period showed rapid adaptation to newly introduced host resistance genes. In all three regions, the main change consisted of the replacement of initially abundant races by pathotypes differing markedly from them by their virulence gene combinations. This explained the increase in diversity during the first 3 years of the survey, when the second group of pathotypes became more common in the populations, and its subsequent decrease due to the decline of the first group of races. The mean number of virulence genes per isolate did not vary noticeably over time in the three populations, remaining at about four out of 12 genes tested. However, the distribution of the isolates into virulence complexity classes was greatly modified, fitting a binomial distribution by the end of the study, although significant deviations were apparent in the first 2 years (1986 and 1987). The data indicate that selection, migration and recombination are the most important factors shaping race structure and evolution in powdery mildew populations, and that mutation is of limited significance. No convincing evidence was obtained for the existence of stabilizing selection sensu Vanderplank as the mechanism limiting virulence complexity. Implications regarding spatial and temporal deployment of race-specific resistance genes to control powdery mildew are discussed.     

小麦白粉病菌生理小种的鉴定与病菌毒性的监测

１９９１～１９９４年小麦白粉病菌生理小种鉴定的结果表明,１１,１５号小种这几年的优势小种,３１５号小种有上升的趋势,用毒性频率分析的方法对所获数据进行分析表明,Ｖ１,Ｖ３,Ｖ５及Ｖ８等毒性的当前白粉菌群体中已基本固定（毒性频率接近１００％）,小麦白粉菌对Ｐｍ４ａ的毒性频率呈较快的上升趋势,说明Ｐｍ４ａ基因的使用应该审慎,白粉菌对Ｐｍ２１为目前最有效的抗白粉病基因,对北京,西南及江浙三地区小区白粉菌     

A rapid method of counting spores of fungal pathogens by infra-red reflectance analysis

A method of counting freshly harvested spores of powdery mildew ( Erysiphe graminis f.sp. hordei ), yellow rust ( Puccinia striiformis ) and brown rust ( P. hordei ) of barley as well as brown rust ( P. recondita ) of wheat, using infra-red reflectance spectrophotometry was investigated. A Neotec 6350 Research Composition Analyser was used to scan spore samples on glass-fibre filter disks in the near infra-red region of the spectrum (1100–2500 nm) and the amount of energy reflected at 1400 different wavelengths recorded. Three wavelengths (1900, 2252 and 2308 nm) that together gave the best multiple correlation with spore populations counted on a haemocytometer slide were selected. Partial regression coefficients for each fungal species were derived by relating reflectance energy values to direct spore counts. Utilizing these and the energy reflected at the three selected wavelengths, it was possible to count spore samples with high precision. Correlations >0.9 between numbers estimated by the instrument and those obtained using a haemocytometer slide (within the range 0–30000 spores) were achieved with all the fungi examined. Application of the technique to smaller, fixed-filter instruments as a routine method of counting spores is discussed.     

2009—2010年河南省小麦白粉菌群体毒性及其遗传多样性分析

利用40个鉴别寄主对河南省5个小麦产区的44个单孢子堆纯化分离的小麦白粉病菌进行毒性鉴定分析,并采用多基因家系法进行了遗传多样性分析。结果显示,供试群体对Pm8、Pm1、Pm3a、Pm3b、Pm3c、Pm3f、Pm3e、Pm5、Pm6、Pm7、Pm17、Pm19、Pm34等抗病基因的毒性频率分别达到90%以上,已不能再作为抗源利用;对Pm12、Pm16、Pm21、Pm18、Pm2、Pm2＋6、Pm2＋MLD、Pm5（Mli）、Pm23、Pm30、Pm4a等基因的毒性频率低于15%,仍可以在抗病育种中加以利用;河南省的小麦白粉病菌存在地理之间的差异,同时病菌在地区之间有自西南向东北/东方向的传播。表明省内群体中存在着丰富的遗传多样性。     

采用孢子萌发法测定化合物对黄瓜白粉病菌的生物活性

接种黄瓜白粉菌后16 h的黄瓜叶片用透明胶带在子叶表面粘孢子取样的平均发芽率与用台盼蓝染色后在光学显微镜下调查的发芽率分别为83.7%和85.0%,t测验无显著差异,表明透明胶带取样的发芽率可以代表黄瓜叶片上白粉病菌孢子的发芽率。采用孢子萌发法和叶碟法分别测定了醚菌酯、植物源活性组分大黄素甲醚(P3D)对8个黄瓜白粉菌菌株的EC₅₀。统计结果表明:采用两种方法测定醚菌酯P、3D对黄瓜白粉菌的EC₅₀的相关系数的平方值分别为0.880、.99,表明两种方法的测定结果有很强的相关性;采用该孢子萌发法可评价化合物对植物专性寄生病菌如白粉菌孢子萌发的生物活性。     

Spatial aggregation of pathotypes of barley powdery mildew

Aggregation in the distribution of pathotypes of Erysiphe graminis f.sp. hordei , the barley powdery mildew pathogen, was investigated in field plots of 'Golden Promise', 'Proctor' and 'Tyra'. 'Golden Promise' and 'Proctor' have no effective mildew resistance alleles, whereas 'Tyra' has Mla1 , which was only effective against a proportion of the mildew population. Isolates of mildew were sampled according to a grid sampling scheme and their virulence spectra ascertained in order to group them according to pathotype. The populations were very diverse, and evidence for aggregation (quantified using join counts) was found only in the 'Tyra' plots, at distances of up to 1m. This aggregation was reduced in a subsequent sample. The results are consistent with a model in which mildew epidemics are started by a large number of initial infections, which then form diffuse, overlapping aggregations of clones. These aggregations then become more diffuse, so that the amount of aggregation reduces with time. The greater amount of aggregation seen in the 'Tyra' plots might have been caused by there being less initial inoculum with virulence towards that cultivar.