大叶白蜡树锈病及其重寄生菌研究

 小叶白蜡树锈孢锈菌(Aecidium fraxinibungeanae Diet.)引起大叶白蜡树(Fraxinus chinensis var.rhynchophylla Hemsl)锈病为国内新记录。该锈病在我国重要白蜡产区乐山市严重发生,病株率和病叶率分别可达100%和56%,造成叶片病部坏死,病叶脱落,严重影响白蜡产量。大叶白蜡树锈病菌的重寄生菌(Tuberculina sp.)为国内外首次报道。该重寄生菌在乐山市及雅安市大叶白蜡树锈病菌上寄生很普遍,自然重寄生率达46.8%。重寄生菌寄生在大叶白蜡树锈菌春孢子器(锈子器)出口处,阻碍春孢子(锈孢子)的释放。本文还报道了大叶白蜡树锈病的危害、症状特点、病原形态特征及大叶白蜡树锈病菌的重寄生现象和重寄生菌形态特征。     

牛奶子锈病及其重寄生菌

2002年在四川省宝兴县蜂桶寨国家自然保护区和天全县喇叭河自然保护区牛奶子上发现了牛奶子锈病,经鉴定,该锈病为牛奶子春孢锈菌Aecidiumelaeagni-umbellatae Diet.其病株率100%、病叶率26%,叶片枯斑、脱落和削弱树势.在牛奶子锈病菌上采集到自然重寄生菌,经鉴定为Tuberculina sp.,该重寄生菌为国内外首次发现.重寄生菌寄生于牛奶子锈菌春孢子器出口处,阻碍春孢子的释放,具有潜在的生防应用价值.笔者对牛奶子锈病的症状特点、病原形态特征及牛奶子锈病菌的重寄生现象与重寄生菌的形态特征等进行了研究.     

长叶胡颓子锈病菌及其重寄生菌

长叶胡颓子是具有开发利用价值的野生植物资源。胡颓子春孢锈菌引起的长叶胡颓子锈病 ,使长叶胡颓子叶枯、落叶。长叶胡颓子锈病菌的重寄生菌Tuberculinasp .是长叶胡颓子锈病菌上的自然重寄生菌 ,为国内外首次报道。该重寄生菌寄生长叶胡颓子锈菌春孢子器处 ,阻碍春孢子的释放。本文报道了长叶胡颓子锈病的症状特点、病原形态特征及长叶胡颓子锈菌的重寄生现象及重寄生菌的形态特征     

梨胶锈菌重寄生菌对贴梗海棠锈病菌的寄生及控病作用

本文报道了梨胶锈菌的重寄生菌在贴梗海棠锈病菌上的寄生形态特征、侵入及控病作用。重寄生菌在贴梗海棠锈菌的性子器旁及性子器相对叶背发生重寄生现象。描述和测量了重寄生菌产孢结构的形态及大小。重寄生菌以分生孢子萌发形成芽管，经性子器口和锈子器口侵入（不能直接侵入），完成侵入所需最短时间为７个小时。潜育期８～９天。用重寄生菌孢子悬浮液，在性子器成熟时喷雾接种防治贴梗海棠锈病，重寄生率从５月初的３７．４％逐渐上升至７月中旬的９４．６％。     

梨胶锈菌的重寄生菌研究Ⅳ重寄生菌的越冬、传播及侵入

 本文报道了梨胶锈菌(Gymnosporangium asiaticum Miyabe ex Yamada)的重寄生菌(Tuberculina vinosa Sacc.)越冬、传播及侵入的研究结果。重寄生菌在自然条件下以分生孢子在其寄生部位越冬;经150天后,其孢子萌发率为29.5%;分生孢子随气流传播;孢子萌发形成芽管经性子器口和锈子器口侵入,不能直接侵入;完成侵入所需最短时间为10小时;在14~12℃下,潜育期为12~7天。在梨胶锈菌发生期,重寄生菌可发生多次再侵入。     

黄柏鞘锈菌重寄生菌研究初报

首次报导了重寄生菌寄生黄柏鞘锈菌(Coleosporium phellodendri Kom)的重寄生现象。重寄生菌寄生在黄柏鞘锈菌的夏孢子堆上,在不同的程度上阻碍了鞘锈菌夏孢子堆的发育和夏孢子的释放,寄生严重时甚至不能形成夏孢子。调查表明,黄柏鞘锈菌重寄生菌在7月底8月初开始发生,9月中下旬达到高峰,该重寄生菌在雅安周边县(区)的黄柏鞘锈菌上自然寄生很普遍,在一些黄柏林地,自然重寄生率高达100%,重寄生指数为60～90。经鉴定,黄柏鞘锈菌的重寄生菌为柱隔孢菌(Ramulariasp.)。     

小驳骨锈病的重寄生现象及重寄生菌鉴定(英文)

在小驳骨锈病的冬孢子堆上发现一种重寄生菌。被重寄生菌寄生的病斑表面可见到一层白色菌丝体。光学显微镜下发现,被寄生的柄锈菌菌丝和冬孢子断裂、变形和退色。18S rDNA PCR扩增及测序结果表明,重寄生菌为刀孢轮枝菌(Lecanicillium psalliotae),本文首次报道刀孢轮枝菌寄生柄锈菌。     

重寄生菌葡酒锈生座孢(Tuberculina vinosa)和白蜡锈生座孢(T.fraxinis)的寄生专化性

 用葡酒锈生座孢(Tuberculina vinosa)的孢子悬浮液,在贴梗海棠、木瓜、苹果和垂丝海棠锈病发生期,喷雾接种于叶面锈菌性子器处,7-12 d出现重寄生现象。表明葡酒锈生座孢除能在自然条件下寄生梨锈病菌外,在人为接种条件下,其寄主范围包括贴梗海棠锈病菌、木瓜锈病菌(Gymnosporangium asiaticum)、苹果锈病菌和垂丝海棠锈病菌(G.yamadai)。用葡酒锈生座孢和白蜡锈生座孢(T.fraxinis)在梨锈病菌和大叶白蜡锈病菌(Aecidium fraxinibungeanae)上交互接种,结果表明,两者不能交互寄生。研究T.vinosa和T.fraxinis的寄生专化性,对2种重寄生菌的应用及锈生座孢属(Tuberculina)种的鉴定具有意义。     

Tuberculina sp.,苹果锈病菌的一种重寄生菌

苹果锈病(Gymnosporangium yamadai)在我国大部分苹果产区均有发生，在一些地区发病严重。该病造成叶片枯斑，早期落叶，削弱树势，影响产量。该病长期采用化学农药或砍伐其转主寄主柏科植物进行防治，导致杀伤天敌，有益生物种类减少，果园生态群落结构恶化，果品中农药残留量增加。由于该锈菌同时在转主寄主柏科植物上寄生危害，也给药剂防治及防治效果带来不利影响。利用重寄生菌防治植物病害是生物防治的方法之一。植物锈菌的重寄生菌研究，国内外已有报道。但苹果锈病菌的自然重寄生菌尚未见报道。本文是苹果锈病菌的自然重寄生现象及重寄生菌的研究报道。     

梨胶锈菌的重寄生菌研究Ⅳ重寄生菌的越冬、传播及侵入

本文报道了梨胶锈菌（ＧｙｍｎｏｓｐｏｒａｎｇｉｕｍａｓｉａｔｉｃｕｍＭｉｙａｂｅｅｘＹａｍａｄａ）的重寄生菌（ＴｕｂｅｒｃｕｌｉｎａｖｉｎｏｓａＳａｃ．）越冬、传播及侵入的研究结果。重寄生菌在自然条件下以分生孢子在其寄生部位越冬；经１５０天后，其孢子萌发率为２９．５％；分生孢子随气流传播；孢子萌发形成芽管经性子器口和锈子器口侵入，不能直接侵入；完成侵入所需最短时间为１０小时；在１４～１２℃下，潜育期为１２～７天。在梨胶锈菌发生期，重寄生菌可发生多次再侵入     

The effects of rust and anthracnose on the photosynthetic competence of diseased bean leaves

ABSTRACT The effects of rust (caused by Uromyces appendiculatus) and anthracnose (caused by Colletotrichum lindemuthianum) and their interaction on the photosynthetic rates of healthy and diseased bean (Phaseolus vulgaris) leaves were determined by gas-exchange analysis, in plants with each disease, grown under controlled conditions. The equation P(x)/P(0) = (1 - x)() was used to relate relative photosynthetic rate (P(x)/P(0)) to proportional disease severity (x), where beta represents the ratio between virtual and visual lesion. The beta values obtained for rust were near one, indicating that the effect of the pathogen on the remaining green leaf area was minimal. The high values of beta obtained for anthracnose (8.46 and 12.18) indicated that the photosynthesis in the green area beyond the necrotic symptoms of anthracnose was severely impaired. The impact of anthracnose on bean leaf photosynthesis should be considered in assessments of the proportion of healthy tissue in diseased leaves. The accurate assessment of the healthy portion of the leaf could improve the use of concepts such as healthy leaf area duration and healthy leaf area absorption, which are valuable predictors of crop yield. The equation used to analyze the interaction between rust and anthracnose on the same leaf was P(z) = P(0) (1 - x)(x) x (1 - y)(y), where P(z) is the relative photosynthetic rate of any given leaf, P(0) is the maximum relative photosynthetic rate, x is anthracnose severity, y is rust severity, betax is the beta value for anthracnose in the presence of rust, and betay is the beta value for rust in the presence of anthracnose. From the resulting response surface, no interaction of the two diseases was observed. Dark respiration rate increased on diseased leaves compared with control leaves. The remaining green leaf area of leaves with both diseases was not a good source to estimate net photosynthetic rate because the effect of anthracnose extended far beyond the visual lesions, whereas the effect of rust on photosynthesis was essentially limited to the pustule plus halo.     

The assessment of infectious disease for brown rust (Puccinia hordei) of barley

The measurement of infectious disease (sporulating area), as opposed to the more conventional visually estimated total disease (sporulating area and chlorosis), was investigated for brown rust on spring barley. Visual estimates by four assessors of percentage leaf area occupied by uredinia overestimated the actual percentages by, on average, 8.7 times. It was concluded that better estimates of infectious disease came from uredinium densities (uredinium counts and measurements of leaf area).
The progress of uredinium density in crops was exponential up to the time when leaves senesced at the end of their development. Three-parameter exponential functions were fitted to epidemics on 26 different leaf layers in five crops grown in three years. It is suggested that the lack of sigmoid progress curves, as would be found with conventional total disease assessments, occurred because chlorosis was excluded from the assessment. Chlorosis, which can affect a large proportion of leaf area, has an upper limit which gives rise to the asymptotic form of conventional disease progress curves. Uredinium densities had skewed distributions and the variances were correlated with the mean values. These characteristics were rectified most effectively by cube-root transformation. An incidence-severity relationship between the percentage of diseased leaves in a sample and the mean cube-root transformed uredinium density was linear up to incidences of about 83%.     

Association of stomatal frequency and morphology in Lycopersicon species with resistance to Xanthomonas campestris pv. vesicatoria

Study of the stomata and leaf epidermis of eight Lycopersicon species has revealed a relationship between frequency of stomata, stomatal size and some morphological leaf characteristics, and resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vesicatoria. Significant correlations were found between the stomatal frequency in both adaxial and abaxial leaf epidermis and the number of bacterial lesions per leaf area ( r = 0.70 and 0.68, respectively) and the frequency of stomata in both adaxial and abaxial epidermis and disease incidence (percentage of diseased plants) ( r =0.87 and 0.80, respectively) for all the Lycopersicon species and one hybrid tested. A correlation was also found between disease incidence and number of bacterial lesions per leaf area ( r = 0.85). The length and width of stomata were correlated with frequency of stomata in adaxial and abaxial epidermis ( r = 0.85, 0.75, 0.89 and 0.90, respectively). The stomatal width was correlated with the number of bacterial lesions per cm² ( r =0.82; P = 0.0065). Scanning electron microscopic studies of the leaf surface and stomata indicated that other morphological features such as the raised stomatal complex in L. hirsutum and persistent, hydrophobic waxy coating of the epidermis in L. peruvianum may also be relevant in disease response.     

甘肃中部麦区小麦条锈病菌越夏调查及品种抗性变异监测结果初报*

2007-2009年,对甘肃省中部麦区小麦条锈病越夏情况进行调查,结果发现：条锈病菌在定西、临夏等中部麦区海拔1 718~2 350 m地带自生麦苗上可顺利越夏,病田率和病叶率分别为63.0%~80.0%和1.05%~5.80%,其越夏菌源量比陇南更大,是当地秋苗发病的初侵染源;秋苗病情调查结果表明,中部麦区秋苗病田率和病叶率均高于同期陇南麦区;品种抗性监测结果发现,34个供试品种（系）在中部麦区和陇南麦区的抗条锈性表现基本一致,部分品种发病程度重于陇南麦区。表明甘肃省定西、临夏等中部麦区已成为陇南小麦条锈病越夏区的重要组成部分。文中还对中部麦区越夏菌源的影响、作用及品种抗性变异因素等进行了讨论。     

甘肃省红豆草病原真菌鉴定及病害发生动态调查

为明确甘肃省红豆草的病害种类、发生动态和危害状况,采用病原物分离与培养、形态学及分子生物学鉴定和致病性测定确定红豆草病害种类,于2012—2013年在通渭、渭源、榆中和碌曲4县调查各病害的发病率以确定发生动态,观察病害田间发生特点并结合调查数据评价其重要性。结果表明,4县共发生真菌性病害12种,分别为大茎点霉叶斑病(病原为大茎点霉属真菌Macrophoma sp.)、壳针孢叶斑病(病原为歪头菜壳针孢Septoria orobina)、炭疽病(病原为白蜡树刺盘孢Colletotrichum spaethianum)、黑秆病(病原为红豆草壳二孢Ascochyta onobrychis、菠菜刺盘孢C.spinaciae和链格孢Alternaria alternata混合侵染)、壳二孢叶斑病、茎点霉叶斑病、尾孢叶斑病、柱格孢白斑病、匍柄霉叶斑病、链格孢黑斑病、锈病和白粉病,其中大茎点霉属真菌、白蜡树刺盘孢和菠菜刺盘孢在红豆草上首次发现;尾孢叶斑病和壳针孢叶斑病为甘肃新记录病害;大茎点霉叶斑病为世界新病害,仅于碌曲县发现。白粉病、锈病、链格孢黑斑病发生于红豆草生长后期,其它病害则始于6月;6—9月危害加重的为黑秆病和柱格孢白斑病,发病率最高达89.7%和96.0%;危害渐轻的为茎点霉叶斑病、壳二孢叶斑病和壳针孢叶斑病,发病率最高达88.7%、57.4%和45.1%。黑秆病和茎点霉叶斑病在甘肃省目前危害最重。     

落叶松褐锈病的研究1.夏孢子的发生及其形态鉴定

 落叶松褐锈病[Triphragmiopsis laricinum(Chou) Tai],是由落叶松拟三孢锈菌引起的一种叶锈病。现已知在黑龙江、吉林、辽宁三省的落叶松人工林内,均有不同程度的发生。发病率一般70~80%,重病区可达90%以上。病原菌能为害各种落叶松,以苗期和落叶松人工幼林较为严重。     

利用小种标记分析云南省两个县的小麦条锈菌群体

 小麦条锈病是由小麦条锈菌（Puccinia striiformis f.sp. tritici）引起的气流传播病害,在世界各主要麦区均有发生,也是我国小麦生产上危害最严重的病害之一。小麦条锈菌毒性变异频繁,易产生新毒性小种,导致小麦品种的抗病基因失效,引起小麦条锈病周期性流行。因此,了解小麦种植区的条锈菌群体结构组成及变异,对于制定更为有效的条锈病控制方法具有重要的意义。