白粉寄生孢生物学特性及其生防应用研究进展

白粉寄生孢Ampelomyces quisqualis是寄生在白粉菌上的一种重寄生菌,作为白粉菌的生防因子,一直受到人们普遍关注。本文从白粉寄生孢的生物学形态、分类、寄主范围、最佳生长条件、分离鉴定以及生防效果和应用前景等方面进行论述,提出了目前白粉寄生孢研究中存在的一些问题以及今后的研究重点,并对白粉寄生孢的生防效果及应用前景进行讨论。     

重寄生菌白粉寄生孢的致病性研究

 在离体条件下,选择了6种白粉菌和49个白粉寄生孢(Ampelomyces quisqualis)菌株进行致病性测定,结果表明,白粉寄生孢菌株之间存在致病性分化且差异极显著,致病性分化主要与寄主真菌和寄主植物有关,而与地理来源相关性不大。研究同时表明,白粉寄生孢有一定的寄生专化性。     

桑里白粉病菌重寄生真菌的分离与鉴定

为了解桑里白粉病菌的重寄生真菌种类,通过分离和寄生性验证,获得2个桑里白粉病菌重寄生真菌菌株HP8和HP9,这两个菌株寄生闭囊壳后,子囊及子囊孢子溃解.菌株HP8菌落绿色,菌丝体无色至褐色,菌丝有隔膜,分生孢子梗结节状膨大,分生孢子椭圆形、单胞、褐色或无色,ITS序列(MT463536)与尖孢枝孢Cladosporiu...     

白粉菌重寄生菌的分离鉴定及其生防效果初评

从新疆石河子地区3种花卉上采集的150份白粉病株样本中分离出白粉菌重寄生真菌,对代表性菌株进行形态特征观察与ITS-rDNA序列分析：分离物的分生孢子器深棕色,多聚生,大小为（40.66～82.92）μm×（34.65～63.05）μm;分生孢子单胞、无色,两端含油球,大小为（3.88～5.67）μm×（2.19～2.75）μm;菌株的ITS-rDNA序列与Ampelomyces quisqualis序列的同源性达94%～100%,由此将其鉴定为白粉寄生孢（A. quisqualis）。测定该菌对荷兰菊白粉病菌的重寄生效能及控病效果,发现供试的12个菌株均可寄生于荷兰菊白粉病菌上,平均重寄生指数为26.21;菌株As-81和Rh-60对白粉病的防效较好,分别为46.62%和46.15%。     

白粉寄生孢不同菌株对控制黄瓜和苹果自粉病病菌的试验研究

为了筛选出更好的能控制白粉病病菌的白粉寄生孢生防菌株,将白粉寄生孢不同菌株对黄瓜白粉病病菌和苹果白粉病病菌分别进行了生防测定.结果显示,白粉寄生孢不同菌株对白粉病病菌的寄生效果和控制作用各异.在白粉寄生孢的不同菌株中,AQ40、AQ9、AQ117对控制温室黄瓜白粉病具有较好的效果,而AQGA-22、AQ13、AQB15-20对控制苹果白粉病的效果较好.表明这些菌株对黄瓜白粉病和苹果白粉病具有一定的选择性和较好的生防应用潜力.     

白粉寄生孢寄生黄瓜白粉菌的特性研究

采用白粉寄生孢（Ampelomyces quisqualis Ces.AQ）接种离体条件下赛璐酚上黄瓜白粉菌［Sphaerotheca fuliginea (Schlecht)Poll.］和活体条件下黄瓜白粉菌后,通过棉兰染色和显微观察分析,初步明确了白粉寄生孢的侵染寄生过程。白粉寄生孢分生孢子产生芽管可入侵黄瓜白粉菌的分生孢子、菌丝、分生孢子梗;有时黄瓜白粉菌串生的分生孢子、分生孢子梗可被2~3条白粉寄生孢的菌丝寄生,随着寄生过程的进一步发展,黄瓜白粉菌的分生孢子梗基部膨大成无色的椭圆形或球形,其上逐渐产生由黄色至褐色的白粉寄生孢的分生孢子器,器内含有大量的分生孢子。     

凤仙花白粉寄生孢的生物学特性

对凤仙花白粉寄生孢生物学特性研究表明：凤仙花白粉寄生孢生长温度为10～30℃，pH值为5～10；最适生长及产孢温度为20℃，pH值为7。有利于菌落生长的碳、氮源分别为葡萄糖、乳糖和蛋白胨；乳糖和牛肉膏最适于其产孢。光照对菌落生长及孢子产生有明显促进作用。以乳糖作为碳源，牛肉膏作为氮源的察氏培养基有利于孢子的产生。     

大麦白粉病菌遗传学研究进展

大麦白粉病是由布氏白粉菌属大麦专化型活体寄生菌Blumeria graminis f.sp.hordei（Bgh）引起的真菌病害,在全球大麦种植区普遍发生,危害日趋严重。大麦白粉病菌与寄主之间存在着“基因对基因”的关系,分化为不同的生理小种或致病型。由于病原菌基因突变、重组和流动以及寄主的选择作用,大麦Bgh种群毒性、致病型频率和分布不断发生变化。随着分子生物学技术飞速发展,应用分子标记已对30多个Bgh无毒基因位点进行了连锁作图分析,已克隆了Bgh无毒基因AVRk1和AVRa10,Bgh全基因组测序现已完成。文章综述了大麦白粉病菌的侵染循环、遗传分化及其无毒基因的定位、克隆和致病机制研究进展,并探讨了基于病原菌毒性进化和基因组解码信息获得持久控制大麦白粉病的有效手段。     

聚孢霉属真菌研究进展、应用现状及展望

聚孢霉属真菌是一类具有丰富形态学和生态学特征的生物类群,广泛分布于多种环境条件中,尤其是在土壤中。聚孢霉属真菌有着巨大的生防潜力,可通过拮抗、重寄生、促生以及诱导植物抗性等多种机制防控植物病害,因而受到广泛关注。本文概述了聚孢霉属真菌的系统分类学进展,并对聚孢霉-植物病原菌以及聚孢霉-植物寄主之间的互作机制进行了综述。随后对聚孢霉的应用现状进行了总结,并对其应用前景进行了展望。从聚孢霉属真菌中挖掘具有优良生防特性的菌株,将推动其在农业应用上的商品化。     

橡胶树白粉病菌分子检测技术的建立

根据橡胶树白粉菌(Oidium heveae Steinm.)基因组中的特有保守序列OHS,设计两对特异性引物OHF1/OHR1和OHF2/OHR2。以不同地区收集的6份O.heveae(OH1~OH6)和橡胶树胶孢炭疽病菌(Colletotrichum gloeosporioides Penz.)等5种非靶标病原菌及健康橡胶树叶片基因组DNA为模板,建立了橡胶树白粉菌PCR及nested-PCR分子检测技术,并验证了检测体系的特异性和灵敏度。结果表明,引物OHF1/OHR1和OHF2/OHR2对橡胶树白粉菌均具有较高的特异性和灵敏度。其中引物OHF2/OHR2能检测到10pg/μL的橡胶树白粉菌DNA,而以OHF1/OHR1和OHF2/OHR2组合进行nested-PCR,其最低DNA检测浓度达到0.01fg/μL。人工接种试验中,当孢子接种量为2×10~3个/叶时,PCR和nested-PCR检测体系可分别在接种4d和24h后检测到目的条带。表明nested-PCR对在叶片组织中处于潜育期的橡胶树白粉菌的检测更有效,可为橡胶树白粉菌的检测提供一种简便而准确的检测方法。     

山西省小麦新品种抗白粉病鉴定及其利用

１９９１～１９９４年采用人工接种和自然诱发相结合的方法对８７１份小麦新品种（品系）进行苗期和成株期抗白粉性鉴定，筛选出中麦２号、农大０１５、京４１１、京８３７、吉华６号、晋麦３０号、鲁麦１４、晋麦３２、冀麦３０等９份农艺性状突出，抗病性好的品种（系）。这些材料抗病性稳定，有的已供育种部门作杂交亲本利用，有的已大面积推广应用。     

中国的葡萄孢分类之二:一新种和五个已知种

 本文报道葡萄孢属一新种:拟葱腐葡萄孢Botrytis acladiopsis X.Y.Wang,L.X.Zhang et Z.Y.Zhang sp.nov.和5个已知种B.convoluta Drayt.,B.fabae Sard.,B.gladiolorum Timm.,B.paeoniae Oud.和B.perlargonii Roed。标本和菌种均保存于云南农业大学植病研究所真菌标本室(MHYAU)。     

Exploration and Exploitation Strategies of Powdery Mildew on Barley Cultivars with Different Levels of Nutrients

The mass fractal dimension (MFD) of colonies of mildew (Erysiphe graminis f.sp. hordei) growing on barley was calculated as a measure of their spatial structure. Despite the elongated shape of the colonies imposed by the leaf cellular structure, the MFD remained constant with scale. The mildew MFD differed on different cultivars of barley, and was greater on leaves produced under higher nutrient level indicating a physiological component. Lower MFD values correspond with the thin spreading growth associated with exploration strategies and higher values correspond to the denser, more branched structure associated with exploitation of the substrate. Cultivars showing exploration strategies induced by resistance expression responded to increased nutrient levels more than those expressing little resistance such as Golden Promise.     

Evidence for an Osmotic Mechanism in the Control of Powdery Mildew Disease of Wheat by Foliar-applied Potassium Chloride

The mechanism by which foliar application of potassium chloride solution reduces symptoms of powdery mildew disease (Erysiphe graminis f.sp. tritici) of wheat was investigated. The hypothesis that potassium chloride reduces mildew by an osmotic effect on spore germination was tested in three glasshouse experiments. Either potassium chloride solution or the osmoticum polyethylene glycol 200 was sprayed on wheat at the three- or four-leaf stage. The plants were inoculated with spores and spore germination and leaf area affected by mildew were assessed. Leaf water potential was determined as a measure of the osmotic effect of the treatments. Spore germination and leaf area affected by mildew were related to leaf water potential using regression analysis in groups on the data averaged over the three experiments. Both spore germination on the leaf and leaf area affected by mildew were reduced as leaf water potential decreased. There was no difference between potassium chloride or polyethylene glycol in the relationship between spore germination and leaf water potential, but polyethylene glycol was slightly less effective at reducing mildew symptoms at any given leaf water potential. The results are compatible with the hypothesis that potassium chloride reduces symptoms of powdery mildew by an osmotic effect on spore germination.     

Occurrence of New Powdery Mildew on Greenhouse Tomato Cultivars

During a year-round survey on the occurrence of powdery mildew on greenhouse-cultivated tomato plants, the disease was most severe in June and July. All tomato plants (45 commercial cultivars and 11 breeding lines) tested were infected with the pathogen but had different degrees of susceptibility. The pathogen was epiphytic and produced white, round pustules mainly on leaves of tomato plants. The pathogen produced conidia singly on conidiophores and forked appressoria on inoculated tomato leaves and seemed to be an Oidium sp. of Erysiphe polygoni type. Received 18 December 2000/ Accepted in revised form 22 July 2001     

A New Race of Spinach Downy Mildew in Japan

A new race of spinach downy mildew caused by Peronospora effusa occurred in Fukui, Japan. The fungus was capable of affecting spinach cultivars resistant to races 1, 2, 3 and 4, but not some other cultivars. Thus, the fungus had different pathogenicity from race 3 and race 4 of the pathogen and was considered to be a new race of spinach downy mildew in Japan. Received 26 April 2001/ Accepted in revised form 17 August 2001     

泽泻白斑病防治药剂筛选及药材安全风险评价

通过对防治泽泻白斑病常用化学农药和生物农药的防治效果及其在药材中的残留进行分析,筛选出泽泻生态防治的最佳药剂,为泽泻绿色、可持续生产和建立生态种植基地提供依据。结果表明：施药2次后春雷霉素防效最好,三唑酮、波尔多液和多抗霉素次之;本试验用量下,采收时药材中已无春雷霉素残留,三唑酮和波尔多液仍有少量残留;三唑酮安全期较长,波尔多液残留难以降解,两种化学农药长期使用易对药材和环境造成影响,存在安全风险。综合防效和残留分析结果,春雷霉素防效好且降解快,是泽泻生产可安全使用的药剂,具有较好的推广应用价值。     

植物白粉病的化学防治进展

对植物白粉病的化学防治历史和发展进行了综述 ,同时介绍了一些重要的药剂及其作用机制 ,并讨论了白粉病化学防治中存在的问题。     

Characterization of Botryosphaeriaceae from plantation‐grown Eucalyptus species in South China

The Botryosphaeriaceae is a species‐rich family that includes pathogens of a wide variety of trees, including Eucalyptus species. Symptoms typical of infection by the Botryosphaeriaceae have recently been observed in Eucalyptus plantations in South China. The aim of this study was to identify the Botryosphaeriaceae associated with these symptoms. Isolates were collected from branch cankers and senescent twigs of different Eucalyptus spp. All isolates resembling Botryosphaeriaceae were separated into groups based on conidial morphology. Initial identifications were made using PCR‐RFLP fingerprinting, by digesting the ITS region of the rDNA operon with the restriction enzymes CfoI and KspI. Furthermore, to distinguish isolates in the Neofusicoccum parvum/N. ribis complex, a locus (BotF15) previously shown to define these species, was amplified and restricted with CfoI. Selected isolates were then identified using comparisons of DNA sequence data for the ITS rDNA and translation elongation factor 1‐alpha (TEF‐1α) gene regions. Based on anamorph morphology and DNA sequence comparisons, five species were identified: Lasiodiplodia pseudotheobromae, L. theobromae, Neofusicoccum parvum, N. ribis sensu lato and one undescribed taxon, for which the name Fusicoccum fabicercianum sp. nov. is provided. Isolates of all species gave rise to lesions on the stems of an E. grandis clone in a glasshouse inoculation trial and on the stems of five Eucalyptus genotypes inoculated in the field, where L. pseudotheobromae and L. theobromae were most pathogenic. The five Eucalyptus genotypes differed in their susceptibility to the Botryosphaeriaceae species suggesting that breeding and selection offers opportunity for disease avoidance in the future.