61份大麦种质资源对蠕孢菌叶斑病的抗性鉴定

麦根腐平脐蠕孢菌[Bipolaris sorokiniana(Sacc.)Shoemaker]引起的叶斑病是大麦上重要的病害叶部之一,在世界各大麦主要种植区均能造成严重的经济损失。本研究利用3个致病力不同的蠕孢叶斑病菌株Z 12010、Z 12014和Z 13010分别对来源于中国及国外引进的61份大麦种质资源进行苗期抗蠕孢菌叶斑病鉴定,田间接种Z 12014菌株进行成株期抗病性鉴定。在所鉴定的大麦种质中未发现在苗期或成株期对叶斑病免疫的材料。苗期抗叶斑病分析发现,品种之间对3个菌株的抗性存在明显差异,Varunda、Legacy、Tradition、09GW-01、09GW-07、08PJ-36、09PJ-39、垦啤麦7号、垦啤麦10号、驻大麦3号、S-4和中饲麦1号等12份材料对3个菌株表现为中抗至高抗反应型。7份材料成株期抗Z 12014菌株,其中Legacy、蒙啤麦3号、09PJ-39、垦啤麦9号、垦啤麦11号和龙啤麦3号等6份材料具有全生育期抗性特点,品种10-3苗期对菌株Z 12014感病,而成株期抗该菌株。     

大麦种质对叶斑病的抗性鉴定与评价

 由麦根腐平脐蠕胞菌引起的叶斑病在世界各大麦种植区均有发生,严重影响大麦的产量和品质。选育和应用抗性品种是防控该病害最有效的策略,然而可利用的抗源非常有限。在本研究中对中国233份具有代表性的大麦种质资源进行成株期抗叶斑病田间人工接种鉴定,发现只有垦啤麦5号等10份材料对3个供试菌株都表现抗病,仅占供试材料的4.3%。另外对37份国内外重要的叶斑病抗源材料进行苗期及成株期抗叶斑病鉴定,结果显示成株期抗叶斑病材料所占比例为41%~46%,苗期抗性材料所占比例为50%~64%,其中ND17293等11份材料在苗期和成株期对3个菌株均表现为抗病,可作为抗源继续加以利用;基于上述鉴定结果,进一步分析发现供试大麦苗期对三个菌株的抗病比例均高于成株期抗病比例,说明大麦在不同生育期对叶斑病的抗性存在较大差异。另外发现大麦对B. sorokiniana不同致病类型的抗性也存在明显的专化性。     

玉米弯孢菌叶斑病的初步研究简报

经作者分离接种鉴定,确认近年北京郊区和河北省的一些玉米产区发生的叶斑病为玉米弯孢菌叶斑病。病原菌是Ｃｕｒｖｕｌａｒｉａｌｕｎａｔａ。发生此病玉米可减产２０％～６０％,且有逐年加重的趋势。经人工接种鉴定不同品种（系）抗性不同,Ｍｏ１７、黄早四、丹３４０、４７８、５００３和Ｅ２８等骨干自交系均为感病类型（３～４级）。西玉３号、京早１０号不同生育期抗性不同,以３～４叶期为抗病类型（０．５级）、７～８叶期、１０叶期和抽雄期为中抗型（２级）,１３叶期为感病型（３～４级）     

外引玉米种质对3种玉米叶斑病的抗性鉴定与评价

2012-2013年,应用田间人工接种的方法对引进的165份国外玉米种质进行了玉米大斑病、灰斑病、弯孢菌叶斑病等3种病害同步抗性鉴定与评价,结果表明:引进的国外玉米种质对3种玉米叶斑病的抗性表现均存在差异,表现抗病的种质较少,大部分种质表现感病或高度感病;抗性种质均以中抗为主,表明国外玉米种质对3种叶斑病的抗病能力较低。筛选出一批单抗性种质和兼抗2种或3种叶斑病的多抗性种质37份,为抗病育种提供了重要基础材料。     

57份小麦微核心种质白粉病抗性评价

为筛选对小麦白粉病具良好抗性的种质资源,本研究采用人工接种感病的方法,评价了57份小麦微核心种质材料的苗期与成株期抗性.结果 表明,育成品种复壮30和兴义4号在苗期与成株期均表现为免疫或近免疫,具有优良的全生育期抗性.农家品种酱麦与猪屎麦和育成品种会宁10号、甘麦8号与日喀则8号5个品种在苗期表现为高感或中感,成株期则...     

外源化学物质对玉米抗弯孢菌叶斑病的诱导作用

测定了9种外源化学物质对玉米抗弯孢菌叶斑病的诱导作用,它们的诱导效果为9.8%～49.6%。其中,水杨酸的诱导效果最好为49.6%,核黄素、草酸、维生素K3和磷酸氢二钾也表现出较强的诱导能力,诱导效果分别为38.8%、41.5%、27.2%、37.8%;比较了玉米品种间和不同生育期的诱导效果,品种间的诱导效果有一定的差异,但差异不显著。不同玉米生育期的诱导效果以苗期最好,拔节期其次,最差的是成株期。对两种化学物质组合使用研究发现,有些具有协同作用,有些则有抑制作用。     

菜豆种质资源对枯萎病抗性鉴定

菜豆种质资源对枯萎病抗性鉴定王素（北京中国农科院蔬菜花卉研究所１０００８１）菜豆枯萎病Ｆｕｓａｒｉｕｍｏｘｙｓｐｏｒｕｍｆ．ｓｐ．ｐｈａｓｅｏｌｉ是菜豆生产上的重要病害,在适宜的发病年份和地区,给菜豆生产带来较大的影响。为了尽快找到抗源和简便的鉴定方...     

玉米弯孢菌叶斑病研究

 玉米弯孢菌叶斑病是近年来北京、河北、河南、山东、辽宁、吉林等北方玉米产区新发生的重要病害之一。其主要病原菌为弯孢菌Curvularia lunata(Walk) Boed.,局部地区同时存在Curvularia inaequalis(Shear) Boed.,但以前者为主要。弯孢菌C.lunata生长适温为28~32℃,对pH适应范围广。玉米叶片浸汁可以促进分生孢子的萌发和芽管的生长。干燥条件下,病原菌在植株病残体上可以安全越冬,成为次年田间的初侵染源。病菌分生孢子形态为多态型,但单孢分离后代仍保持孢子的多态型,致病性无变化。病菌不同菌株间致病力有差异,强致病力菌株存在于北京及周边地区。人工接种鉴定120份玉米品种(组合)、自交系,材料间存在明显的抗性差异,抗性较好材料有农大108、中玉5号、高油115等及自交系CN95、CN165等。品种抗病性随植株生长而递减。苗期抗性较好,13叶期极为感病,因此弯孢菌叶斑病属于成株期病害。     

橡胶狗尾草平脐蠕孢叶斑病病原菌鉴定及生物学特性研究

为明确采自西双版纳景洪地区疑似橡胶麻点病的病原菌,采用组织分离法进行病原菌分离,活体接种法进行致病性测定,通过形态学观察结合rDNA-ITS和GAPDH两个核苷酸片段序列分析,将病原菌确定为狗尾草平脐蠕孢Bipolaris setariae。通过单因子变量试验,对病原菌进行生物学特性研究,结果表明：菌丝生长最适温度为30℃,最适pH为7～8,最适培养基为PDA,菌丝致死温度为53℃,10 min。该病原菌能有效利用多种碳源和氮源,碳源以可溶性淀粉利用率最高,最适氮源为蛋白胨。24 h黑暗条件下培养更有利于菌丝生长。分生孢子萌发的最适温度为28～35℃,最适pH为7～8,28℃黑暗培养2 h后萌发率达到最大,为95.5%,分生孢子致死温度为60℃,10 min。     

玉米麦根腐平脐蠕孢叶斑病的发生与病原鉴定

在河北省春播玉米WN2000和山东省夏播普通玉米上发现一种叶斑病,其病斑圆形或椭圆形,中心灰白色,边缘褐色,有黄褐色褪绿圈,糯玉米WN2000病斑较大,(3~10)mm×(3~5)mm;普通玉米病斑较小,(1~2)mm×(2~3)mm。通过病原菌分离培养、致病性测定、形态特征观察及r DNA-ITS和1,3,8-三羟基萘还原酶基因(3HNR)序列分析,证明两种大小病斑是由同一种病原菌—麦根腐平脐蠕孢(Bipolaris sorokiniana)引起。田间调查结果表明,在山东省夏播玉米各品种苗期叶片上均有不同程度的发病,发病率最高的为冠玉6号,病株率52%,最低的为五岳88,病株率2%;鲜食玉米仅在河北春播玉米WN2000上发生,发病率为32%。麦根腐平脐蠕孢侵染不同玉米品种产生两种大小不同的病斑在国内外尚属首次报道。     

Genetic variation of Pyrenophora teres f. teres isolates in Western Australia and emergence of a Cyp51A fungicide resistance mutation

Genome-wide, unlinked, simple sequence repeat markers were used to examine genetic variation and relationships within Pyrenophora teres f. teres, a common pathogen of barley, in Western Australia. Despite the region's geographic isolation, the isolates showed relatively high allelic variation compared to similar studies, averaging 7.11 alleles per locus. Principal component, Bayesian clustering and distance differentiation parameters provided evidence for both regional genotypic subdivision together with juxtaposing of isolates possessing different genetic backgrounds. Genotyping of fungicide resistant Cyp51A isolates indicated a single mutation event occurred followed by recombination and long-distance regional dispersal over hundreds of kilometres. Selection of recently emergent favourable alleles such as the Cyp51A mutation and a cultivar virulence may provide an explanation, at least in part, for juxtaposed genotypes. Factors affecting genotypic composition and the movement of new genotypes are discussed in the context of grower practices and pathogen epidemiology, together with the implications for resistance breeding.     

薏苡叶枯病和叶斑病调查与病原鉴定

对福建省龙岩市新罗区薏苡叶部病害进行了调查。用组织分离法,PSA平板培养经纯化后作病原鉴定,在其上发现了两种病害:薏苡叶斑病为一种新病害,病原鉴定为薏苡尾孢(Cercospora sp.);薏苡叶枯病为福建省首次记录,其病原为薏苡平脐蠕孢(Bipolaris coicis)。     

大麦苗期抗旱性鉴定及评价

为了了解20份大麦(Hordeum vulgare L.)种质材料抗旱性差异,采用温室模拟干旱胁迫-复水法,对其苗期的相对含水量、相对电导率、叶绿素含量、丙二醛含量、超氧化物歧化酶和株高等8个抗旱指标进行测定,利用相关分析、聚类分析研究了各项指标与种质材料抗旱性关系,综合评价其抗旱性。结果显示：叶片相对含水量与株高呈显著正相关,其余各指标间没有显著的相关性;以采用欧式距离法综合分析结果为依据,可将20份种质材料划分为3个抗旱等级,相对抗旱包括陇麦1号、新引D5、Z126V004W、新引D9、PREJTGE、SCARLETT、Z02751407、韭崎12号、Z127U016V、MAURITIA,中等抗旱包括 J13-80、新引D7、PASADENA、NCF-TIPPLE、甘啤6号,相对敏感包括黑引瑞、Z200V017W、新啤12号、BEATRIX、Z204V021W。     

Sources of inoculum and reappearance of spot blotch of wheat in rice–wheat cropping

A study was undertaken to examine the main source of inoculum of Bipolaris sorokiniana responsible for its reappearance in rice–wheat cropping regions of eastern India. Soil samples were collected at monthly intervals during April–October in the years 2000 and 2001 from fields having rice–wheat cropping. Bipolaris sorokiniana conidia were isolated and their viability was found to decline sharply with the onset of flooding in the month of August. In contrast to 82% in April, viability was 4% and <1% in August and September, respectively. Viable conidia were multiplied in the laboratory and inoculated on to susceptible cv. Sonalika under controlled conditions for test of pathogenicity. Appearance of symptoms typical to spot blotch were recorded after 7 days. Twenty-two different species (weeds and grasses) normally found to be associated with rice–wheat fields were tested for the presence of B. sorokiniana to evaluate their possible role as alternative hosts. Only three species, i.e. Setaria glauca, Echinochloa colonum and Pennisetum typhoids, were found to naturally harbour B. sorokiniana. Isolates from these hosts were tested for pathogenicity and also for their possible spread to wheat. When reisolated from these hosts, the pathogen did not infect wheat. Seeds of 25 different wheat genotypes were tested for B. sorokiniana infection. All genotypes were infected and the incidence of infection varied from 26% to 86%. Five isolates of wheat and one isolate from each of the three species (S. glauca, E. colonum and P. typhoids) were subjected to RAPD analysis. Two broad clusters were formed, suggesting that the wheat isolates were different from the isolates originating from other hosts. The results indicate that seeds are the most important source of inoculum for the reappearance of spot blotch of wheat in rice-wheat cropping systems in eastern India.     

几种甘蓝型油菜幼苗抗旱性特征的比较研究

以EV1、EV2、EV3、EV4、EV5、EV66个抗旱性不同的油菜品种为试验材料,通过不同浓度PEG-6000渗透溶液模拟干旱胁迫处理,研究油菜幼苗的抗旱指数、根长、苗高和根冠比等性状变化,探索在大田环境条件下的苗期生长特征。结果表明,水分胁迫下EV2的抗旱指数最大,EV6的抗旱指数最小;不同浓度PEG胁迫下,各品种差异显著,EV1、EV2、和EV3的根长、苗高和根冠比较大,而EV5和EV6的表现较差。在大田油菜五叶期时,EV2的冠层覆盖面积最大,与其它品种之间存在极显著性差异;总生物量以EV2、EV3和EV1较大,根系干重以EV2较大,而且三者之间存在显著相关性;与抗旱指数进行通径分析,冠层覆盖面积对抗旱性的直接通径系数最大,达到0．5975。冠层覆盖面积的大小反映了早期活力的强弱,早期活力强,相应的品种抗旱指数高,抗旱性强。     

Development of an international standard set of barley differential genotypes for Pyrenophora teres f. teres

International comparison of virulence profiles of Pyrenophora teres f . teres (Ptt), the cause of barley net blotch, is seriously restricted by inconsistencies in differential testers used among researchers. This paper reports an attempt to develop an appropriate set of differentials to standardize characterization of Ptt populations globally. Fourteen barley genotypes (Canadian Lake Shore (CLS), Harbin, c-8755, c-20019, Manchurian, Tifang, CI 9825, CI 5791, CI 9819, Beecher, CI 9214, Skiff, Prior and Corvette) were selected from among genotypes previously used as Ptt differentials. Three cultivars (Pirkka, Haruna Nijo and Harrington) were included to identify a universally susceptible control. Genotypes were inoculated with approximately 1000 Ptt isolates from Russia, Europe, Australia and Canada. The mean reaction frequency of genotypes ranged from highly resistant (CI 9819, CI 5791, c-8755 and CI 9825) to highly susceptible (Harrington, Haruna Nijo and Pirkka). The best differential abilities were demonstrated by Harbin, CLS, c-20019, Manchurian and Prior. Application of cluster analyses identified genotypes with similar reaction patterns, which supported a reduction of genotypes in the set. When combined with an algorithm comparing the ability of individual genotypes to discriminate among Ptt isolates, a further reduction of genotypes was justified. A new, concise set of barley genotypes for differentiating virulences in Ptt was formulated. It is proposed that these genotypes be adopted as the standard, international differential set to characterize and identify the virulence properties of Ptt populations across environments. The new Ptt differential set consists of the genotypes c-8755, c-20019, CI 5791, CI 9825, CLS, Harbin, Prior, Skiff and Harrington.     

Associations between fungal and abiotic leaf spotting and the presence of mlo alleles in barley

The hypothesis that the increased use of the powdery mildew-resistance gene mlo has caused the increase in spotting diseases of barley over the past 20 years was tested in field trials. Near-isogenic lines with alleles of the Mlo gene for susceptibility or resistance to mildew in two parental backgrounds were trialled at four sites in Scotland and two in Ireland that were prone to spotting diseases, over 3 consecutive years. Mildew was controlled by sprays with quinoxyfen. Disease levels were low in the trials, the two most important diseases being scald caused by Rhynchosporium secalis and ramularia leaf spot caused by Ramularia collo-cygni . There were high levels of abiotic spotting. Lines with mutant mlo alleles consistently developed less Rh. secalis and Ra. collo-cygni , but more abiotic spots. This study indicates that the mlo mildew-resistance gene has not alone been responsible for the rise in spotting diseases over the past 20 years. Possible reasons for the rise are discussed, including the interaction of the mlo gene with the environment.