食用菌细菌性病害及防治

一、细菌性斑点病,又叫细菌性褐斑病,主要危害蘑菇和平菇。１．发病症状局限于菌盖上,菌盖初期出现水渍状小斑点,渐渐变成黄褐色并扩大成小斑,不规则,凹陷,凹陷处呈棕褐色。湿度大时,凹斑内有粘稠的菌液,当病斑干后,菌盖往往开裂。２．病原该病由托拉斯假单胞杆...     

双孢蘑菇镰刀菌病害的研究

半裸镰刀菌(Fusarium semitectum Brek .&Rav .)是双孢蘑菇稻田栽培中的一种新的病原菌。本文报道了该病原菌的形态特征、致病症状以及温度、pH对菌丝体生长的影响 ,克霉灵、甲醛、硫酸铜等药物在室内和田间可有效地杀灭病原菌     

双孢蘑菇病原菌点枝顶孢菌和半裸镰刀菌的鉴定和药剂防治试验

分离鉴定结果显示,点枝顶孢菌和半裸镰刀菌是双孢蘑菇稻田栽培中的2种病原菌。试验表明,腐霉利、甲醛、硫酸铜等药物在室内和田间可有效杀灭病原菌。     

桑细菌性枯萎病病原菌的分离鉴定与全基因组序列分析

为明确华南蚕区桑树细菌性枯萎病主要病原菌的种类,本研究从广西、广东等地桑园采集了多份桑树细菌性枯萎病病样,采用分离培养、形态学鉴定和分子生物学鉴定的方法,对病原菌进行了分离鉴定,并通过药敏试验分析病原菌的耐药性。结果表明,结合柯赫氏法则,将分离到的桑枯萎病病原菌鉴定为产酸克雷伯氏菌Klebsiella oxytoca,编号AKKL-001(菌种保藏号GDMCC No.1.1602)。该病原菌属革兰氏阴性菌,基因组全长6 149 586 bp,含有5 792个基因,GC含量55.80%;药敏试验结果表明,病原菌对氨苄西林、头孢唑啉、头孢呋辛、头孢噻吩、链霉素、麦迪霉素等抗生素具有耐受性。本研究报道了桑细菌性枯萎病病样上分离的产酸克雷伯氏菌,为桑细菌性枯萎病病原菌的研究提供理论依据,全基因组测序的结果为桑细菌性枯萎病的相关致病机制研究奠定了基础。     

基于刃天青微平板法测定交链格孢菌橘致病型对戊唑醇和苯醚甲环唑的敏感性

由交链格孢菌橘致病型(Alternaria alternata tangerine pathotype)引起的柑橘链格孢褐斑病(Alternaria brown spot,ABS)是柑橘上的主要病害,目前主要采用杀菌剂防治。本研究以采自中国各柑橘链格孢褐斑病发生区的54个交链格孢菌橘致病型菌株为供试群体,采用刃天青微平板法测定了病原菌孢子萌发和菌丝生长对戊唑醇和苯醚甲环唑的敏感性。结果表明:刃天青微平板法最佳体系中的培养基为完全培养基(CM),刃天青终浓度为40 μmol/L,孢子浓度为105个/mL。戊唑醇和苯醚甲环唑的有效抑制中浓度(EC50)范围分别为0.304~0.885 μg/mL和0.367~0.873 μg/mL,平均值分别为0.562和0.609 μg/mL。正态分布检测结果显示:这2种药剂抑制交链格孢菌橘致病型群体的EC50值均符合正态分布,因此认为所得EC50值可作为病原菌对戊唑醇和苯醚甲环唑的敏感性基线。本研究结果可为田间防治褐斑病和监测交链格孢菌对戊唑醇和苯醚甲环唑的抗药性奠定基础。     

蘑菇枯萎病病原菌分离与鉴定

我国近年蘑菇栽培面积不断扩大,但蘑菇生产主要在农村,绝大多数生产者没有经过专业培训,生产比较粗放.病虫害危害严重,发生严重时可致蘑菇产量损失80%以上,甚至绝收.蘑菇枯萎病、褐斑病、褐腐病已成为秋冬春蘑菇栽培的主要病害.笔者对广西横县蘑菇枯萎病的病原菌进行了分离鉴定,认为镰刀菌是蘑菇枯萎病的病原菌.     

双孢蘑菇顶枝孢霉病害的生物学特性和药剂筛选

在双孢蘑菇上发现一种新的病原菌:点枝顶孢菌(Acremonium strictum W.)。该菌侵染双孢蘑菇的子实体,形成不规则的褐色斑块,大小为(2-15)mm×(3-20)mm,病斑凹陷于菌肉或穿过菌肉组织直至菌褶,深达2-13 mmo病斑干枯不腐烂,俗你黑疤病或褐疤病。通过人工接菌观察了病害症状、发病规律、培养特性、形态特征,以及温度、pH对菌丝体生长和孢子萌发的影响。经室内外药剂筛选试验,明确克霉灵、甲醛、硫酸铜和石灰水可有效杀灭该病菌。     

寡雄腐霉对多喙茎点霉的抑制作用及其机制

寡雄腐霉Pythium oligandrum Drechsler能够在多种重要农作物根围定殖、拮抗或寄生16个属中的20多种真菌和其它卵菌[1],除双孢蘑菇Agaricus bis-porus外,其余均为重要的植物病原菌.     

青枯雷尔氏菌Ⅲ型分泌系统hrcN基因的功能分析

hrcN是植物病原菌Ⅲ型分泌系统基因（T3SS）的结构基因之一,对病原菌的致病力有重要影响。本研究克隆青枯雷尔氏菌CBM613的hrcN基因并作生物信息学分析,结果显示该基因长度为1320 bp,共编码439个氨基酸,预测HrcN蛋白无信号肽,无跨膜区域,整体呈弱亲水性,该蛋白为ATP酶,定位于细胞内膜和细胞质。基因敲除结果显示,菌株CBM613的hrcN突变体与野生型菌株在富营养培养基上的生长速率差异不明显,而在贫营养培养基上前者的生长速率显著快于后者。敲除hrcN基因后,青枯雷尔氏菌的运动能力无明显变化,生物被膜形成能力显著降低。以敲除突变型和野生型青枯雷尔氏菌株接种番茄,与后者相比,前者的致病力下降,病情指数降低,病程延长,但并未完全丧失致病力,表明hrcN基因是青枯雷尔氏菌致病性相关的重要基因。本研究为进一步探索青枯雷尔氏菌致病机制及防治具有重要意义。     

小麦黑点病的病原菌及其致病力研究

小麦黑点病在河南省主要麦区发生比较普遍,其病原菌以细交链孢菌为主,发生频率为７６．３％,其次是极细交链孢菌和麦根腐离蠕孢菌,其发生频率分别为１４．１％和７．０％,其它病原菌仅为２．８％。３种病原菌所致黑胚率、产生的症状和病粒的严重度均有明显的差异。Ｂ．ｓｏｒｏｋｉｎｉａｎａ的致病力最强,Ａ．ｔｅｎｕｉｓｓｉｍａ在我国也是较强的致病菌。作者分析了病原菌存在地区性差异的原因,首次发现穗蚜为害能加重小麦     

Evaluation of oyster mushroom strains for resistance to Pseudomonas tolaasii by inoculation in spawned substrates

Bacterial brown blotch disease, caused by Pseudomonas tolaasii, has been one of the most serious bacterial diseases of the oyster mushroom. Resistance to disease has been a priority in breeding programs for the oyster mushroom. In this study, a set of 37 Pleurotus ostreatus strains was tested for resistance to the pathogen P. tolaasii by two methods, with inoculations on pileus and spawned substrate under controlled environmental conditions. The results showed that the protocol with inoculation on spawned substrate was sensitive and adequate for testing resistance of oyster mushroom to brown blotch disease. According to the disease severity of fruiting bodies with inoculation on spawned substrates, strain ACCC50618 was resistant; ACCC50236 was moderate resistant; and the others were susceptible to the pathogen P. tolaasii (ACCC 01267). However, it was difficult to differentiate the resistance of P. ostreatus strains to P. tolaasii by inoculation on the pileus. This is the first report about resistance evaluation of P. ostreatus to brown blotch disease.     

Control of dry bubble disease (Lecanicillium fungicola) in button mushroom (Agaricus bisporus) by spent mushroom substrate tea

Dry bubble (caused by Lecanicillium fungicola) is a widespread disease of button mushroom. The objective of the experiments was to determine the efficacy of compost teas made from spent mushroom substrate (SMS) as a biocontrol method against the disease. All SMS teas produced in this study significantly inhibited (100 %) the in vitro mycelial growth of L. fungicola, whereas the fungicide prochloraz at 50 ppm inhibited growth by 91 %. The in vivo effectiveness of two SMS aerated teas, one with mineral soil (MS) and the other with peat (TPT), was evaluated in two mushroom cropping trials inoculated with L. fungicola. The results demonstrated that the most effective treatments were those with TPT applied close to harvest and/or those with the greatest number of applications. The most efficacious treatments were TPT treatments (reducing disease by 34 to 73 % in the two trials, compared to the inoculated control). In contrast, prochloraz reduced disease by 7 % and 4 % in the two trials, compared to the control. These results suggest that dry bubble disease can be controlled by the use of spent mushroom substrate teas.     

Immunity of strains of Agaricus bitorquis to mushroom virus disease

Agaricus bitorquis, a species originally found in nature, produces snowwhite, tasty and well storable fruiting bodies on the common mushroom substrate. Several strains of this species were tested for susceptibility to mushroom virus, viz, the original wild isolatesA. bitorquis Nos 1, 2, 4 and 6, and the selection and breeding products ‘Somycel 2.017’, Horst B30, Horst B6, Horst K26 and Horst K32. Inoculum consisted of either mycelium or spores from virus-infected mushrooms (A. bisporus), or both. Trays withA. bisporus were always inoculated simultaneously to check the infectivity of the inoculum. UnlikeA. bisporus, the strains ofA. bitorquis tested did not show symptoms of virus disease after inoculation. Their fruiting bodies did not present mushroom virus particles, either in extracted cell-free preparations, or in ultrathin sections of the tissue. Yields ofA. bitorquis were not decreased by inoculation. The efficacy of the inoculation technique is discussed. The recent commercial availability of immune mushroom strains was a relief to Dutch mushroom growers, who found the disease difficult to eradicate by sanitary measures only.     

应用实时荧光定量RT-PCR检测几种食用菌蛋白抗烟草花叶病毒的活性

根据烟草花叶病毒(Tobacco mosaic virus,TMV)外壳蛋白(CP)RNA的特异性序列设计TaqMan荧光探针及其引物,利用实时荧光定量RT-PCR检测食用菌蛋白抗TMV的活性。经食用菌蛋白处理后,TMV病毒汁液中TMV的RNA浓度下降了22.02%~87.93%,传统生物学测定的食用菌蛋白抗TMV的平均枯斑抑制率为10.88%～83.97%;相关性分析表明,实时荧光定量RT-PCR测定的病毒RNA浓度的下降与传统生物学方法测定的平均枯斑抑制率之间呈正相关(r=0.818 8),具有较好的一致性。利用实时荧光定量RT-PCR检测蛋白抗烟草花叶病毒活性的方法,具有特异性好、快速、简便、重复性高的特点,适合于蛋白抗烟草花叶病毒活性的痕量快速高效检测。     

Insecticide granules in mushroom culture

In laboratory tests, chlorfenvinphos granules were distributed in various ways in mushroom casing (a peat/chalk mixture) to relate efficiency of mixing to effectiveness against larvae of Lycoriella auripila. Amounts giving complete control when thoroughly mixed, killed only 40% when “clumped”. Whenever untreated patches were provided, some larvae survived. Pulverising granules, however, improved control in thorough mixes. By using fluorescent granules it was found that insecticide incorporation in mushroom compost was very irregular after mixing in a spawning machine. At best, only half the compost was acceptably treated; that is, it received between a half and double the intended dose.     

Control of the mushroom phorid fly, Megaselia halterata (Wood), with plant extracts

BACKGROUND: The most serious insect pest problems affecting the cultivation of mushroom [Agaricus bisporus (Lange) Imbach] in Turkey are mushroom flies (sciarids, cecids and phorids). Mushroom phorid fly, Megaselia halterata (Wood), is the most common insect pest species during April‐October. The aim of this study was to evaluate the potential for eight botanical materials (two commercial neem‐based products and six hot‐water plant extracts) to control M. halterata populations in three successive growing periods. RESULTS: Treatment efficacy was evaluated by assessing adult emergence and sporophore damage rates compared with that of a standard insecticide, chlorpyrifos‐ethyl (positive control). All plant extracts caused significant reductions in the mean number of emerging adults and sporophore damage rates compared with the water‐treated control (negative control). Reduction in adult emergence in both neem treatments, Neemazal and Greeneem oil, was greater than that in the positive control. While Neemazal and Origanum onites L. extract had significantly lower sporophore damage rates than the positive control, there were no significant differences between the chlorpyrifos‐ethyl, Greeneem oil and Pimpinella anisum L. extract treatments. CONCLUSION: The results suggest that both neem products and hot‐water extracts of O. onites and P. anisum may be potential alternatives to conventional pesticides for the control of mushroom phorid fly. Copyright © 2008 Society of Chemical Industry     

Suppression of bacterial wilt of tomato by soil amendment with mushroom compost containing <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> IUMC7

Bacillus amyloliquefaciens IUMC7 and its culture supernatant, which we previously found to suppress Fusarium wilt, were found here to have antimicrobial activity against Ralstonia solanacearum. In in vivo experiments, mushroom compost inoculated with IUMC7 significantly reduced disease severity in tomato plants over that in control soils. The R. solanacearum population decreased in soil inoculated with IUMC7. A TLC–bioautography assay showed that one of the antimicrobial substances produced by IUMC7 is likely an iturin-like lipopeptide. These results suggest that these antimicrobial compounds are responsible for disease suppression and that mushroom compost containing IUMC7 has potential as a biocontrol product.     

Persistence of the fungicides thiabendazole, carbendazim and prochloraz-Mn in mushroom casing soil

The persistence of the fungicides thiabendazole, carbendazim and prochloraz-Mn in mushroom casing soil was determined following their application at rates commonly used in the UK mushroom industry. Following drench applications, the concentration of all active ingredients was always higher in the top half of the casing soil layer than in with the bottom half. When carbendazim and prochloraz-Mn were applied using half the recommended volume of water per unit area, there was a tendency for carbendazim concentrations to be even higher in the top half of the casing soil, compared with the standard treatment, while concentrations of prochloraz-Mn were similar, irrespective of the volume of water used. Carbendazim and prochloraz-Mn concentrations in the top half of the casing layer decreased to < or = 13 mg kg(-1) by day 28/29, following different applications, whereas the thiabendazole concentration was consistently high during the course of the crop, being < or = 83 mg kg(-1) at day 31. Fungicides that do not persist at high concentrations in mushroom casing soil for the duration of the crop may not give good control of mushroom pathogens, particularly if the fungicide concentration falls to a level which is close to the EC50 value.     

Differentiation of Trichoderma taxa associated with mushroom production

A major epidemic of green mould in mushroom compost in Northern Ireland lasting for 6 months was caused by a single taxon of Trichoderma harzianum (Th2). This has continued to be the principal taxon causing losses in Ireland over a 9-year period. A separate taxon, Th4 , is responsible for a more recent epidemic in North America. Cultural methods are described which aid rapid differentiation of four distinct taxa of T. harzianum and five other species from the mushroom environment. After developing a standard cultural method, isolates were grouped visually by features such as growth rate at 27°C, amount of aerial mycelium, and the effect of light on sporulation form and timing. Most of these groups of isolates had significantly different growth rate ratios from each other at 27°C/17°C. Furthermore isolates within groups which had been separated by culture features alone were closely homologous as regards their microscopic morphological features such as phialides and phialospores. Two factors underlining the importance of using a standard cultural method in aiding identification were that culture morphology was shown to vary widely on different media and spore size was found to vary significantly with incubation temperature. Some difficulties are discussed concerning differentiation of Trichoderma spp. using classical microscopic features alone.