核桃枝枯病小新壳梭孢巢式PCR检测方法的建立

近年来,小新壳梭孢Neofusicoccum parvum导致的核桃枝枯病屡有报道,该病防治困难,发病率高,是核桃的一种灾难性病害。为建立N.parvum的快速、灵敏的分子检测体系,根据N.parvum的几丁质合酶1基因(CHS1)及其前后100bp序列,分别设计了两对特异性引物CT-WK3-S/CT-WK3-A和CT-N-S/CT-N-A,建立了N.parvum的巢式PCR检测方法。结果表明,建立的体系可以从不同来源的5个N.parvum菌株中特异性地扩增出97bp的目的条带,灵敏度达30fg/μL,是常规PCR的10倍,而从其近缘种葡萄座腔菌属Botryosphaeriasp.的病原菌及其他供试菌株均未扩增出任何条带。以感染N.parvum的核桃组织总DNA为模板进行检测,可以在发病早期检测出N.parvum的存在。本研究建立的巢式PCR体系可以为核桃枝枯病的田间检测提供思路。     

防治葡萄溃疡病的杀菌剂筛选与评价

采用菌丝生长速率法和孢子萌发法测定了7种杀菌剂对可可毛色二孢CSS-01s的室内生物活性,筛选出3种抑制效果较好的杀菌剂;通过对离体葡萄绿枝条及盆栽葡萄幼苗新梢进行人工接种病原菌,进一步评价杀菌剂的防治效果。结果表明,7种杀菌剂对可可毛色二孢菌丝生长和孢子萌发表现出不同的抑制活性,其中戊唑醇、氯氟醚菌唑、啶酰菌胺和氟啶胺对菌丝生长的抑制作用较强,EC₅₀分别为0.116、0.137、0.109μg/mL和0.119μg/mL;戊唑醇、氯氟醚菌唑、氟啶胺对孢子萌发的抑制作用较强,EC₅₀分别为0.420、0.595μg/mL和1.885μg/mL。CSS-01s接种离体葡萄绿枝条试验中,戊唑醇100、200 mg/L,氯氟醚菌唑100、300 mg/L和氟啶胺100、200 mg/L的防治效果无显著差异,在57.81%～65.31%;CSS-01s接种葡萄幼苗新梢试验中,氟啶胺200 mg/L的防治效果最好,为77.56%,与氟啶胺100 mg/L、氯氟醚菌唑100、300 mg/L和戊唑醇200 mg/L之间无显著差异,但显著高于戊唑醇100...     

苹果轮纹病瘤组织形态研究

苹果轮纹病[Botryosphaeria dothidea(M oug.)Ces.et De Not.]是富士苹果的主要病害,该病在环渤海湾和黄河故道苹果产区已严重影响苹果生产。据2008年调查,国内苹果枝干轮纹病总体发病率达77.6%[1],因轮纹病一般年份苹果果实损失20%~30%,严重年份损失70%以上[2]。目前,对于苹     

Evaluation of fungicides for the management of Botryosphaeria dieback diseases of grapevines

BACKGROUND: A range of botryosphaeriaceous species can cause dieback and cankers in grapevines; however, different species most commonly affect the grapevines in different grape‐growing regions and countries. They infect through wounds and sporulate on woody stems and green shoots throughout the year, so wound protection is the recommended control strategy. This research evaluated fungicides for their ability to reduce mycelial growth and conidial germination of three botryosphaeriaceous species and to protect pruning wounds against infection. RESULTS: In vitro experiments showed that nine out of 16 tested fungicides were effective at reducing mycelial growth and/or conidial germination of three isolates each of Neofusicoccum australe, N. luteum and Diplodia mutila. The species differed in their response to the fungicides, although N. luteum was usually the least sensitive. When nine selected fungicides were sprayed on cane pruning wounds on potted and field grapevines and subsequently inoculated with N. luteum conidia, some effectively protected them from infection. The most effective fungicides were flusilazole, carbendazim, tebuconazole, thiophanate‐methyl and mancozeb, as they prevented the inoculated pathogen from infecting healthy wood in 100, 93, 87, 83 and 80% of field vines, respectively. CONCLUSION: This research has demonstrated that fungicides applied after winter pruning can protect vines from infection by conidia of three botryosphaeriaceous species. Copyright © 2012 Society of Chemical Industry     

北京葡萄溃疡病病原菌Lasiodiplodia citricola的鉴定和生物学特性初探

Botryosphaeria dieback is one of the important grapevine trunk diseases in the world. In this study, two grapevine trunk disease samples were collected from two grape vineyards in Miyun District of Beijing, where grapevine trunk disease was very severe. The potential pathogens were isolated, purified and identified. Meanwhile this study conducted to evaluate the pathogenicity by Koch’s Postulate, and the effects of temperature and light on the growth of pathogens. According to morphological characteristics and a multi-gene phylogenetic analysis with sequences of ITS, EF-1α and TUB, four isolates were identified as Lasiodiplodia citricola, which was the causal organism of grapevine Botryosphaeria dieback. Moreover, the pathogen was able to grow between 10-40 ℃. The optimum temperature for mycelial growth was 30 ℃, and it grew rapidly under full light. This is the first report of grapevine Botryosphaeria dieback disease on grapes caused by L. citricola in China.     

葡萄座腔菌对引进大规格色叶观赏乔木的为害及其治理

葡萄座腔菌溃疡病是世界林木的重要病害.对北美枫香、莲香树、北美红栎等3种引进的大规格色叶观赏乔木为害严重.甚至死亡.在调查了感病乔木溃疡病在上海的发生严重情况的基础上,描述了其发病的主要症状,分析了为害严重的原因,并进行了初步治理.     

核桃枝枯病病原菌鉴定及其生物学特性

In May 2018,a new shoot dieback disease was found in several walnut orchards in Rizhao,Shandong Province.The fungal pathogen was obtained on PDA plate from diseased walnut shoots using a tissue isolation method.The purified fungal isolates formed white to grey colonies on PDA plate and three single spore isolates SDWa1-SDWa3 were obtained.Based on morphological characteristics and analysis of rDNA internal transcribed spacer (ITS),calmodulin (CAL),translation elongation factor 1-α (TEF1) and β-tubulin (TUB) sequences,the fungal isolates were identified as Diaporthe nobilis,a new pathogen on walnut.The test of Koch's rule confirmed that D.nobilis was the pathogen of walnut shoot dieback.To determine optimal growing conditions for the pathogen,its biological characteristics test was conducted.The results showed that the optimal growth temperature and pH value were at 25℃ and pH 5-9,respectively.The optimum carbon source was glucose,and favourable nitrogen source was peptone.     

核桃枝枯病病原菌鉴定及其生物学特性

In May 2018,a new shoot dieback disease was found in several walnut orchards in Rizhao,Shandong Province.The fungal pathogen was obtained on PDA plate from diseased walnut shoots using a tissue isolation method.The purified fungal isolates formed white to grey colonies on PDA plate and three single spore isolates SDWa1-SDWa3 were obtained.Based on morphological characteristics and analysis of rDNA internal transcribed spacer (ITS),calmodulin (CAL),translation elongation factor 1-α (TEF1) and β-tubulin (TUB) sequences,the fungal isolates were identified as Diaporthe nobilis,a new pathogen on walnut.The test of Koch's rule confirmed that D.nobilis was the pathogen of walnut shoot dieback.To determine optimal growing conditions for the pathogen,its biological characteristics test was conducted.The results showed that the optimal growth temperature and pH value were at 25℃ and pH 5-9,respectively.The optimum carbon source was glucose,and favourable nitrogen source was peptone.     

矮化核桃枝枯病病原菌的形态与分子鉴定

为了明确河南省洛阳地区核桃枝条一种新病害的病原种类,对采自田间的典型症状枝条进行了常规组织分离,对单孢菌株进行了形态鉴定、rDNA ITS序列分析及致病性测定。结果表明,病原菌在PDA培养基上菌落初为白色,随着色素的积累,由中心向边缘变为灰绿色,再变成墨绿色,最终全部变成黑色;气生菌丝棉絮毛状,菌落边缘不整齐,近圆形或不规则形。分生孢子器散生或聚生,呈黑色小粒状,分生孢子器球形或近球形,深褐色,具孔口;分生孢子梗短缺,无色,杆状,末端产生分生孢子;分生孢子梭形、纺锤形,无色,无隔,基部钝圆,顶部稍尖,单孢(24.5～29.0)μm×(4.8～7.5)μm。离体枝条接种结果表明,该菌能侵染核桃枝条引起与田间相同的症状。据此将分离物鉴定为葡萄座腔菌Botryosphaeria dothidea。     

Potential susceptibility of Australian native plant species to branch dieback and bole canker diseases caused by Phytophthora ramorum

Susceptibility to branch dieback caused by Phytophthora ramorum was tested using a detached branch assay for 66 Australian native plant species sourced from established gardens and arboreta in California. Six of these species were further tested for their susceptibility to bole cankers caused by P. ramorum using a sealed log assay. Isopogon formosus and Eucalyptus denticulata were identified as potentially highly susceptible Australian branch dieback hosts. Thirteen potentially tolerant Australian host species included Banksia attenuata, B. marginata, E. haemastoma, E. regnans, Pittosporum undulatum and Billardiera heterophylla. Eucalyptus regnans was identified as a potentially highly susceptible bole canker host, while E. diversicolor and E. viminalis were considered potentially tolerant species to bole cankers caused by P. ramorum. Phytophthora ramorum was able to infect all 66 species, as confirmed by reisolation. These results extend the known potential host range for P. ramorum, confirm it as a possible threat to Australian plant industries and ecosystems and highlight additional associated hosts that are important in the global horticultural trade, native forests and plantation forestry.     

Aetiology of branch dieback,panicle and shoot blight of pistachio associated with fungal trunk pathogens in southern Spain

Pistachio represents an emerging nut crop across the Mediterranean basin. In Spain, pistachio has been traditionally cultivated in marginal-dry areas with unfavourable climatic conditions for plant diseases. Consequently, little attention has been given to research on pistachio diseases until recently. Symptoms of branch dieback and cankers, and shoot and panicle blight have been recently observed in commercial pistachio orchards across southern Spain. In this study, 10 commercial pistachio orchards showing disease symptoms were surveyed between 2017 and 2018. Botryosphaeriaceae fungi were consistently isolated from affected shoots, among other fungal families with minor relevance. Representative isolates of each family were characterized based on colony and conidial morphology, optimum growth temperature, and the comparison of DNA sequence data (ITS, LSU, EF, TUB2, and ACT genomic regions). Detached and attached shoots, and attached panicles of pistachio cv. Kerman were inoculated with mycelial plugs or conidial suspensions to demonstrate the pathogenicity of the selected isolates. Botryosphaeria dothidea, Lasiodiplodia pseudotheobromae, Neofusicoccum mediterraneum, N. parvum, Diaporthe neotheicola, Diaporthe sp., Eutypa lata, Eutypa sp., Cytospora sp., and Phaeoacremonium minimum were identified. P. minimum had the highest optimum growth temperature (29.6 °C) and Cytospora sp. the lowest (21–22 °C). Botryosphaeriaceae isolates showed the largest lesions on inoculated shoots, with L. pseudotheobromae being the most aggressive, followed by Neofusicoccum species. Panicles inoculated with N. mediterraneum showed blight symptoms and canker formation 6 weeks after inoculation, without significant differences in aggressiveness between isolates. This work reports relevant information about this emerging disease in the novel Spanish pistachio-growing areas.     

Twig and stem blight of cotton caused by Botryodiplodia theobromae

A twig and stem blight of cotton ( Gossypium hirsutum ) was observed in Tamil Nadu, India in 1977. The causal organism was isolated in pure culture and identified as Botryodiplodia theobromae , a first record of this species causing twig and stem blight on cotton. Typical fruit rot symptoms were produced on several inoculated fruits but not Citrus sp., Punica granatum or Achras sapota.     

李树流胶病病原特性及发病规律研究

李树流胶病在福建李主产区普遍发生 ,其病原菌为葡萄座腔菌 [Botryosphaeria dothidea (Moung .ex Fr.)Ces.et de Not.]。该病是单病程病害 ,病原最适培养基为PDA ,温度 25～30℃ ,pH6～7,黑光灯照射有利分生孢子产生。 2月下旬开始释放分生孢子 ,5月旬雨量 30mm时出现高峰。病菌的分生孢子随雨水传播 ,通过皮孔、伤口侵入当年生枝梢 ,潜育期 3～5个月 ,10月为发病盛期     

Eutypa canker and dieback of almonds

Eutypa canker and dieback of almonds was first recorded in commercial plantations in Greece in mid-1980 and confirmed as due to the ascomycetous fungus Eutypa lata. The disease manifests itself by the formation of cankers at the point of the junction of the branches and the trunk and is associated with pruning wounds made by the growers in order to confront the'non-infectious bud failure'disorder or to remove unwanted limbs close to the crotch. Pathogenicity tests made on young trees of cv. Texas with different isolates originated from grapevine, almond, apricot and pear showed significant differences in virulence. Pathogenicity tests carried out on 20 different almond cultivars gave a significant indication of the existence of tolerant and susceptible cultivars.     

Reduction of cavity spot and root dieback in carrots by fungicide applications

Metalaxyl greatly reduced the incidences of root dieback and cavity spot in carrots in field and pot experiments, and in spray tests in growers' fields. Propamocarb and fosetyl-Al also greatly reduced cavity spot in a pot experiment. No significant effects were attributable to aldicarb, benomyl, iprodione or a micronutrient compound containing Fe, Mn, Cu, Zn, Co, B and Mo.     

Canker and die-back of Eucalyptus in South Africa caused by Botryosphaeria dothidea

Die-back and canker of several Eucalyptus species and clones were observed during a survey of the most important forestry areas of South Africa. Disease was often associated with extreme environmental conditions such as drought, hot winds and frost. Botryosphaeria dothidea , which is well known as a cause of canker and die-back of Eucalyptus in other countries, was consistently isolated from symptomatic trees. Artificial inoculations of Eucalyptus nitens resulted in lesion development, confirming the pathogenicity of 5. dothidea to Eucalyptus in South Africa. This is the first report of this disease in South Africa.