豌豆抗白粉病资源筛选及分子鉴定

由豌豆白粉菌引起的白粉病是豌豆生产上的重要病害,利用抗病品种是防治该病害最经济有效的方法。本研究在控制条件下苗期接种鉴定了396份豌豆资源对2个不同地理来源的豌豆白粉病菌分离物EPBJ和EPYN的抗性,用4个与豌豆抗白粉病基因er1连锁的SCAR标记对66份免疫或抗病资源进行标记基因型鉴定。结果表明,在鉴定的396份资源中,有101份资源表现免疫或抗病,其中对分离物EPBJ和EPYN免疫的资源分别为59份(14.9%)和60份(15.2%),对2个分离物均免疫的资源有54份(13.6%);在鉴定的82份中国资源中,有8份对2个分离物均表现免疫。分子标记将66份免疫或抗病资源鉴定为13个标记基因型,同一地理来源的抗性资源分属不同的标记基因型,其中8份来自中国云南的抗性资源分属7个标记基因型。研究表明,中国存在有效的豌豆白粉病抗源,抗性资源具有丰富的遗传多样性。     

四川豌豆种质资源白粉病抗性及分子鉴定

豌豆白粉病是由白粉菌（Erysiphe pisi D. C.）引起的豌豆最重要的病害之一,控制豌豆白粉病最经济有效且环保的方法是种植抗病品种。在温室条件下对400份豌豆种质资源进行白粉病抗性鉴定,同时利用7个与已知豌豆抗白粉病基因连锁的分子标记进行基因型鉴定。结果表明,在400份资源中,有8份表现免疫,3份表现抗病,5份表现抗感分离,其余384份均为感病;16份抗性资源中有10份来自于四川省中部不同纬度地区,其余6份为国外引进资源;7个分子标记将400份种质资源分为39个标记基因型,其中16份抗性资源分为7个标记基因型。上述抗性资源及其标记基因型可有效应用于豌豆白粉病抗性育种的研究中。     

Identification and characterization of sources of resistance to Erysiphe pisi Syd. in Pisum spp.

A collection of 67 accessions of Pisum species originating from different countries was screened in a glasshouse test for resistance to Erysiphe pisi. All Pisum fulvum accessions were completely resistant. Incomplete resistance was identified in some accessions of P. sativum subsp. sativum var. arvense and P. sativum subsp. elatius and abyssinicum. Microscopy revealed several distinct cellular mechanisms governing resistance. In P. fulvum, it was mainly due to a high frequency of cell death that occurred both as a rapid response to attempted infection and a delayed response that followed colony establishment. Cell death following colony establishment was also key to the incomplete resistance in some accessions of P. sativum subsp. sativum var. arvense. In addition, impaired spore germination, and to a lesser extent appressorium formation, contributed to pre‐penetration resistance in some accessions. In some cases, resistance also retarded colony growth, possibly through effects on haustorial development or function in cells that survived the attack. Thus, these wild pea accessions offer diverse resistances that could be introduced to cultivated peas to increase the efficacy of powdery mildew resistance.     

Possible New Genes for Resistance to Powdery Mildew, Septoria Glume Blotch and Leaf Rust of Wheat

An Ethiopian wheat collection consisting of 293 tetraploid and hexaploid entries was investigated for resistance to powdery mildew, Septoria glume blotch, and leaf rust with the aim of finding probable new genes for resistance to these diseases. Seedlings were screened with isolates of these diseases in the greenhouse or growth chamber. The material was also scored for field resistance to powdery mildew after the fifth leaf stale. The diversity of the reaction types to powdery mildew and Septoria glume blotch was estimated by the Shannon-Weaver diversity index. Thirty-nine entries (13%) of the collection were resistant to moderately resistant co the mildew isolates, 14S-77 and 46—77, that had: a combined virulence spectrum effective against nine identified genes for resistance to powdery mildew. One hundred and et till TV-tour entries (63 %) of the collection showed field resistance to mildew. One hundred and eighty-one entries (62 %) of the collection were at least moderately resistant in an aggressive isolate of Sartorial nodorum. Resistance to a race of leaf rust was detected in one hundred and sixty-eight entries or 58.% of the collection. Generally, resistance to these diseases is concentrated in Central and Southern Ethiopia. The different reaction types of the resistant entries to these diseases and the high estimates of diversity for reaction types indicated the presence of many different probable new genes and genetic backgrounds for resistance to these diseases.     

Resistance to powdery mildew in selections from Tunisian landraces of barley

Two-hundred and thirty-two accessions of barley landraces collected from Tunisia were screened for resistance to powdery mildew. A number of race-specific genes were detected using the detached leaf technique. Among the 232 accessions tested, 169 were susceptible to powdery mildew, 20 were resistant and 43 showed differential reactions to the three isolates of powdery mildew used. An attempt was made to determine the number of genes, the types of gene, the types of gene action and the gene loci in 20 resistant accessions. Three types of cross were made: (1) the accessions were crossed to the susceptible variety ‘Pallas’, (2) the accessions were crossed with ‘Pallas’ isolines, and (2) accessions with identical powdery mildew reaction patterns were intercrossed. Three isolates of Erysiphe graminis f. sp. hordei were used: Bzm-1, KM 18-75, R13C. A number of different resistance genes were detected among the 19 resistant accessions. Surprisingly, segregation indicating single genes only were detected with the isolates used. Some of these genes could be associated with loci already known. In 19 cases a dominant and in one a recessive mode of inheritance was detected. The recessive gene was not located at the mlo locus. This investigation represents the first systematic study of race-specific genes for powdery mildew resistance in Tunisian landraces. The newly identified sources of resistance may be used in many strategies of breeding for disease resistance.     

抗白粉病月季资源的田间筛选

筛选抗白粉病月季资源对月季栽培利用及抗病育种品种的选择有重要意义。对保存的来自国内外不同地区、不同类型的349份月季资源进行了田间筛选。供试品种病情分为高抗、抗病、中抗、感病、高感5个等级。供试品种对月季白粉病抗性表现比较分散。月季抗病资源182份,占供试品种的52.15%,其余167份均表现为感病,占47.85%,其中抗病资源中有13份表现为高抗,占供试品种的3.72%;349份资源中包括27份中国古老月季,其中有11份表现为抗病,占中国古老月季的40.74%。抗白粉病月季资源的筛选能够为月季栽培、育种亲本品种的选择提供参考。     

Resistance to powdery mildew in wild emmer (Triticum dicoccoides Körn.)

Summary Wild emmer from 73 collection sites, including 107 accessions from Israel, two from Lebanon and one from Turkey, were evaluated for resistance to powdery mildew in field nurseries in Israel and the Netherlands.The wild emmer entries displayed a diversity of responses to powdery mildew infection, ranging from high resistance to complete susceptibility. Most entries were resistant in at least one of the nurseries; several entries proved to be resistant in all the tests.Comparing the reactions of 47 wild emmer accessions tested in six nurseries, 11 markedly different patterns were discerned, indicating the probable presence of several different resistance genes.Genes for resistance to powdery mildew appear to be very common in wild emmer indigenous to Israel. Resistance was found in accessions from most collection sites, in all the geographic regions represented in the collection.The common occurrence of resistance and the apparent diversity of genotypes makes wild emmer a rich gene-pool for resistance to powdery mildew. Since genes for resistance to wheat pathogens can be quite readily transferred to cultivated wheat, wild emmer may be utilized as a valuable source of powdery mildew resistance in wheat breeding.     

Marker assisted selection (MAS) for developing powdery mildew resistant pea cultivars

In this contribution we review the state of the art for genetic resistance to powdery mildew, caused by Erysiphe pisi, in pea (Pisum sativum L.) and potential use of marker-assisted selection (MAS) for developing disease resistant cultivars. Powdery mildew is important in many production regions worldwide and reduces yield and crop quality when present in epidemic proportions. Although genetic resistance to powdery mildew is available (er1 and er2) and has been durable since its characterization in 1969, recently a new dominant gene (Er3) has been reported in Pisum fulvum, a wild relative of pea that is different from previously reported er1 and er2. The efficacy of these genes may be at risk from the point of view of new pathotypes and pathogens. Erysiphe trifolii has been reported that was not previously known as a pathogen of pea powdery mildew. A continued search for new and diverse resistant sources remains a priority in pea breeding and special emphasis should be paid to selection of resistance that will prolong durability of existing resistance genes. Marker assisted selection is a new emerging approach for target breeding that has been intensively employed especially in cereals and has recently got popularity among legume breeders. With the advancement of genomic research, especially related to quantitative traits loci, the MAS is potentially anticipated future technique for routine plant breeding that is scarce in legumes at present. In pea, various DNA markers have been reported linked to er1, er2 and Er3 at varying distances in different mapping populations that are currently being used in breeding programs. Currently MAS of single gene is the most powerful approach and successes have been witnessed. If single marker is not close enough to the gene of interest then two flanking markers are considerably utilized to improve the correct identification that is being successfully employed in MAS for powdery mildew resistance in pea.     

Search for novel genes for resistance to powdery mildew (Sphaerotheca fuliginae) in cucumber (Cucumis sativus)

Summary The current powdery mildew (Sphaerotheca fuligninea) resistant cucumber varieties suffer from leaf chlorosis during autumn, winter and early spring cultivation in the Netherlands. Therefore screening was carried out for novel powdery mildew resistance genes. From 177 accessions, derived from different sources, 108 accessions proved to be partially resistant to S. fuliginea. Crosses were made with 53 resistant accessions to distinguish the presence of novel genes. It is likely that the accessions C. sativus 2145, C. sativus LV 41, PI 188807, Vladivostokij, White and Yellow 1 have one or more recessive powdery mildew resistance genes, different from powdery mildew resistance genes of the line NPI, which was used for variety breeding. Powdery mildew resistance tests with S. fuliginea give similar results in different regions of the world.Abbreviations pmr powdery mildew resistance     

Screening the Spanish Barley Core Collection for disease resistance

The Spanish Barley Core Collection comprises 159 landrace-derived inbred lines and 16 cultivars adapted to Southern European conditions. The collection was screened for resistance to powdery mildew ( Blumeria graminis ), scald ( Rhynchosporium secalis ), leaf rust ( Puccinia hordei ), net blotch ( Pyrenophora teres f. teres ), Barley yellow dwarf virus (BYDV) and Barley mild mosaic virus (BaMMV). Resistance to powdery mildew was outstanding, with 58 lines presenting mean overall resistance, among them seven landrace-derived lines resistant to all seven isolates tested. About 26% of the Spanish lines were resistant to scald. Resistance to leaf rust and to net blotch was scarce, though a few accessions showed resistance levels as good as the checks. Thirteen accessions (12 Spanish) were totally resistant to BaMMV and c. 20% of accessions showed moderate tolerance to BYDV. Landrace-derived lines from the Mediterranean Coast and Southern regions of Spain were the most resistant to powdery mildew and leaf rust, but the most susceptible to viruses. Potential sources of resistance might be preserved in some accessions subjected to selective pressure in the region of origin.     

Powdery mildew resistance in barley landrace material. I. Screening for resistance

A total of 4,681 accessions of Hordeum vulgare landrace material from Ethiopia, East Mediterranean, Near East, Nepal and China were sown in the field and subjected to the natural powdery mildew epidemic in Denmark. Apparently resistant accessions were selected. Selfed progeny from them were retested and reselected in subsequent years at four locations in Denmark. Finally, 16 promising donors of resistance were retained. They were characterized in the field and tested in the seedling stage for reaction to up to 72 different isolates of the powdery mildew fungus. The absence of the corresponding virulences in the Danish airborne powdery mildew population was ascertained in five years. The resistances in the 16 donors are apparently mutually different and from known sources of powdery mildew resistance in barley. This revised version was published online in July 2006 with corrections to the Cover Date.     

Response to Mycosphaerella pinodes in a germplasm collection of Pisum spp

Little resistance against Mycosphaerella pinodes is available in pea. In this work 78 accessions of Pisum were screened for resistance to M. pinodes. Fourteen accessions showed a good level of resistance in seedlings under controlled conditions, and in mature plants in the field. The highest levels of resistance were found in P. fuivum, followed by P. sativum ssp. eiatius and P. sativum ssp. syriacum. Resistance of five selected accessions was effective against different isolates of M. pinodes originating from different countries. Resistant accessions reported in this paper have been successfully hybridized with field pea cultivars.     

河南小麦新育成品种(系)白粉病抗性鉴定与分子标记检测

利用华北地区流行的白粉菌菌株E09和E20,分别对河南省小麦新品种(系)区域和预备试验参试材料908份(2009—2013年度)和412份(2009—2012年度)进行苗期白粉病抗性鉴定,同时利用与Pm2、Pm4a、Pm8和Pm21基因连锁的分子标记检测相关抗病基因的分布。结果显示,抗E09的材料占21.9%(199/908),抗E20的材料占9.5%(39/412),同时抗E09和E20的材料仅占3.6%(15/412)。在908份供试材料中,580份含有1BL/1RS,占63.9%,含Pm8或新的1RS来源抗白粉病基因;另有2份材料含6AL/6VS来源广谱抗白粉病基因Pm21,8份可能携带Pm2,2份可能含有Pm4a;有6份材料可能含有多个抗白粉病基因。表明河南省近年育成的小麦新品种(系)依然含有对我国白粉菌菌系有效的抗白粉病基因,但抗源遗传基础较窄,部分已经或正在丧失抗性,应加快引进和利用新的多样化抗病基因资源。     

粗山羊草抗小麦白粉病基因遗传多样性的研究

粗山羊草(Ae.tauschii(Coss.)Schmal.)是普通小麦(T.aestivum L.)抗性改良的宝贵遗传资源。本研究对来自伊朗、前苏联等8个国家和地区的78份粗山羊草进行了小麦白粉病(powderymildew)混合菌种苗期接种鉴定,表现免疫或近免疫的有45份,占57.69％;用一套白粉病菌菌株(共16个)对原产地不同的11份粗山羊草分别进行苗期接种鉴定,结果表明除Y168表现感染外,其它10份材料表现出各自不同的抗性反应,只有来自伊朗的Y219、Y221、Y225和来自的苏联的Ae37能抗所有16个菌株,而没有感染的毒性菌株,说明它们可能含有新的不同于15个已知Pm基因的抗性基因。利用完全双列杂交对原产地不同的5份粗山羊草进行了苗期抗白粉病基因的遗传分析,出现3种不同的抗性基因类型,来自伊朗的3份材料表现单显性(PmA)或双显性(PmA、PmB)2种类型,而来自前苏联的2份材料表现出不同于前两种类型的另一种单显性(PmB)类型。从而为增加普通小麦抗白粉病基因的遗传多样性奠定了基础。     

Inheritance of the Powdery Mildew Resistance Mlk in Wheat

The inheritance of the Mlk powdery mildew resistance originating from ‘Heine 2174.50’ was analyzed by crossing the Mlk resistant cultivar ‘Ralle’× cv. ‘Amor’ (highly susceptible) and vice versa and by observing the reactions of F₁- and F₂-plants after inoculation with two different Mlk avirulent powdery mildew isolates. In all cases, a 3 (resistant): I (susceptible) segregation was found in F₂. The reactions of the F₂plants against the two powdery mildew isolates were identical in each case. Therefore, it is supposed that one dominant resistant gene is responsible for the resistant reactions against these two isolates. These results support the earlier assumption of Heun and Fischbeck (1987b) that the whole Mlk resistance pattern is controlled by a single gene.     

The resistance to leaf rust and powdery mildew of recombinant lines of barley (Hordeum vulgare L.) derived from H. vulgare × H. bulbosum crosses

A set of 23 recombinant lines (RLs) of barley ( Hordeum vulgare L.) derived from H. vulgare  ×  H. bulbosum L. crosses was inoculated with barley leaf rust ( Puccinia hordei ) and powdery mildew ( Blumeria graminis f.sp. hordei ) at the seedling stage to identify their levels and mechanisms of resistance. Eight RLs were studied further in glasshouse and field tests. All three barley parents ('Emir', 'Golden Promise' and 'Vada') were highly susceptible to powdery mildew and leaf rust isolates. Several RLs showed partial resistance expressed as high relative latency periods and low relative infection frequencies against leaf rust. This high level of partial resistance was due to a very high level of early aborting colonies without host cell necrosis. Several RLs showed hypersensitive resistance to some or all isolates. For powdery mildew, one RL was completely resistant to the CC1 isolate and had a hypersensitive resistance to the CO-02 isolate. Three RLs derived from 'Emir' were completely resistant to both powdery mildew isolates, and three more RLs tested in the field had higher levels of partial resistance than their parents. The results indicate that H. bulbosum contains major and minor gene(s) for resistance to leaf rust and powdery mildew that can be transferred to cultivated barley.     

Sources of resistance to broomrape (Orobanche crenata Forsk.) in narbon vetch

Little is known about the levels of resistance to Orobanche crenata available in narbon vetch. A germplasm collection of 200 accessions of narbon vetch (Vicia narbonensis L.) originating from different countries was screened for resistance to crenate broomrape under field conditions. Thirteen accessions were selected for more detailed screening under controlled conditions and for additional field testing. Resistance to O. crenata was manifested by lower germination of broomrape seeds, reduced emergence of Orobanche shoots and fewer root attachments per narbon vetch plant. Differences in pod yield among narbon vetch accessions were also found in response to Orobanche infestation. Finally, eight accessions were selected and identified as new sources of narbon vetch resistant to broomrape.     

Discovery,characterization and exploitation of Mlo powdery mildew resistance in barley

Summary Mlo resistance to barley powdery mildew is a relatively new kind of resistance. It was originally described in a powdery mildew resistant barley mutant in 1942 and has been mutagen-induced repeatedly since then. About 1970 it was also recognized in barley landraces collected in Ethiopia in the 1930s. It is unique in that 1) Mlo resistance does not conform to the gene-for-gene system; 2)mlo genes originating from different mutational events map as non-complementing recessive alleles in one locus; 3) all alleles confer the same phenotype, though with small quantitative differences; 4) it is effective against all isolates of the pathogen; and 5) the resistance is caused by rapid formation of large cell wall appositions at the encounter sites preventing penetration by the fungus. Powdery mildew isolates with elevated Mlo aggressiveness have been produced on barley in the laboratory, but have not been found in nature. Mlo resistance is considered very durable. The exploitation of Mlo resistance has been hampered by pleiotropic effects of themlo genes, vix. necrotic leaf spotting and reduced grain yield, but they have been overcome by recent breeding work. During the 1980s Mlo-resistant spring barley varieties have become cultivated extensively in several European countries, in 1990 on about 700,000 ha.     

Two powdery mildew resistance mutations induced by ENU in Pisum sativum L. affect the locus er1

The alkylating compounds and strong mutagens methylnitrosourea (MNU) and ethylnitrosourea (ENU) were used to widen the genetic variability of pea (Pisum sativum L.) via experimental mutagenesis. Amongst multiple mutations of agronomical interest, for the first time two mutations conferring broad-range resistance to powdery mildew (Erysiphe pisi Syd.) were induced in pea. Mutagenic treatments were carried out on seedlings using a technique that ensures very high mutagenic efficiency. Two-hour exposure of cv. Solara seedlings to chemical mutagens resulted in almost non noticeable lethality and sterility in the M1 generation and very high mutation rates: ~39% families with visible mutations in the M2 generation. The influence of the cell cycle phase on the process of mutagenesis was studied in cv. Frilene using a previously developed technique for synchronization of shoot apical meristem cells. The cell cycle phase at which cells were treated apparently did not influence the lethality and sterility in the M1 generation, while the visible mutation rate, assessed in the M2 generation, showed a clear cell cycle dependency. Seedlings treated at the G2 and M phases gave rise to progenies exhibiting the highest mutation rate, over 50% of M2 families with visible mutations. The powdery mildew resistant (PMR) mutant S(er1mut1) was induced by treatment of cv. Solara seedlings for 2 h with ENU, while the PMR mutant F(er1mut2) was induced by treatment of cv. Frilene seedlings with the same chemical mutagen for 1 h during the G2 phase of the cell cycle. The genetic analysis of the novel PMR mutant lines showed that both resistances are inherited as monogenic recessive traits. The performed genetic complementation analyses revealed that both mutations affect the same locus—er1, which determines most of the natural sources of PMR in pea. A project aiming at the isolation of the powdery mildew resistance mutated gene via map based cloning is currently under way.