玫瑰黄链霉菌代谢产物诱导烟草抗病研究

为探索烟草灰霉病绿色防控新方法,通过试验明确了玫瑰黄链霉菌Men-myco-93-63活性代谢产物RM诱导烟草幼苗产生抗病性的适宜方式与浓度,并检测了经其处理后烟草叶片中防御酶（SOD、POD、PAL）的活性和防御相关物质（丙二醛、木质素）的含量。结果表明,RM能诱导烟苗对灰霉病的抗性,诱抗效果为51.67%,显著高于对照苯并噻二唑,最佳诱抗方式为喷雾处理,最佳诱抗浓度为80 mg/L。施用RM后,烟叶防御相关酶SOD、POD活性稳定提高,PAL活性前2 d逐渐提高,之后降低,但均高于清水对照;木质素含量增加,丙二醛含量降低。在烟草灰霉病绿色防控方面,RM具有良好的应用潜力。     

枯草芽孢杆菌PTS-394诱导番茄对灰霉病的系统抗性

本文研究了枯草芽孢杆菌PTS-394对番茄的防御相关酶活性、抗病信号转导通路的标志基因表达的诱导情况和诱导抗病性对灰霉病的防治效果。结果显示,菌株PTS-394灌根番茄后,在24~72 h内番茄顶端叶片中PAL、PPO、POX、LOX的活性都有不同程度的持续增加,且72 h时达到最高峰值,随后在96 h下降,与对照相比差异显著;此外,番茄抗病信号通路节点基因NPR1和水杨酸(SA)信号通路激发的防卫基因PR-1a,在24~72 h得到了显著持续高表达。以上结果表明,利用菌株PTS-394灌根番茄后,能够诱导植株产生系统抗病性。菌株PTS-394灌根番茄后48 h,离体叶片挑战接种番茄灰霉菌,结果显示,菌株PTS-394处理的番茄叶片病斑面积仅为对照处理的50%,防控效果达47.1%;温室盆栽试验显示,菌株PTS-394处理后对番茄灰霉的防治效果为58.2%。综上所述,枯草芽孢杆菌PTS-394灌根番茄后,可以触发番茄植株系统性的抗病性,增强植株免疫能力。     

玫瑰黄链霉菌Men-myco-93-63诱抗粗蛋白对黄瓜的诱抗作用

玫瑰黄链霉菌Strempomyces roseoflavus Men-myco-93-63是分离自马铃薯疮痂病自然衰退土壤中的一株拮抗链霉菌,该菌株及其代谢产物对多种重要的植物病原菌都具有较强的抑制作用,为了探明该生防菌产生的诱抗粗蛋白对黄瓜抗病性的诱导作用,采用离体叶片接种的方法,发现诱抗粗蛋白诱导黄瓜叶片灰霉病发病直径显著小于对照;经组织染色法和紫外分光光度计法测定,发现诱抗粗蛋白可以诱导黄瓜叶片中活性氧（ROS）的积累和超氧化物歧化酶（SOD）、过氧化物酶（POD）和多酚氧化酶（PPO）等抗病相关酶活性的显著提高;通过实时荧光定量PCR（qRT-PCR）测定,发现诱抗粗蛋白还可以诱导黄瓜叶片中PR-1a、PR-3、PR-9和NPR1等抗病相关基因表达的上调,试验结果表明Men-myco-93-63产生的诱抗粗蛋白能够诱导黄瓜抗病性的提升。     

解淀粉芽孢杆菌LJ1诱导黄瓜抗白粉病的研究

解淀粉芽孢杆菌LJ1是从土壤中分离得到的一株对黄瓜白粉病具有较好防效的生防细菌。田间试验发现,用LJ1发酵上清100倍稀释液喷施黄瓜幼苗,在施药后14 d时其对黄瓜白粉病的防效可达83.45%。为研究LJ1防治病害的作用机制,用LJ1发酵上清100倍稀释液喷施黄瓜幼苗,测定黄瓜叶片中的超氧化物歧化酶(SOD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)等与诱导抗病性相关的酶活性和信号分子水杨酸含量的变化,并检测了苗期根围土壤中真菌的动态。结果显示,经过LJ1发酵液处理后3种酶的活性和水杨酸的含量在不同时间点均有一个骤增的过程,其活性显著高于对照,并且7 d后土壤中的可培养真菌数量急剧减少。说明LJ1发酵液中有诱导黄瓜产生抗病性的物质,并且诱导后分泌的抗性物质对真菌具有广谱性。     

玫瑰黄链霉菌对黄瓜根结线虫乙酰胆碱酯酶活性的影响

玫瑰黄链霉菌Men-myco-93-63是从马铃薯疮痂病自然衰退土壤中筛选出的对多种重要植物病原菌具有较强抑制作用的拮抗链霉菌。前期研究表明,该生防菌及其发酵液对蔬菜根结线虫具有较好的防治作用。为研究玫瑰黄链霉菌抑制根结线虫的作用机制,利用发酵液浸没法,检测了Men-myco-93-63代谢产物对根结线虫乙酰胆碱酯酶活性的影响。结果表明,Men-myco-93-63发酵液能够有效地抑制黄瓜根结线虫乙酰胆碱酯酶的活性,在36 h时抑制率最高,达到88.82%,之后抑制作用缓慢减弱,但72h时抑制作用仍可达47.32%。说明Men-myco-93-63发酵液能有效抑制根结线虫乙酰胆碱酯酶活性,且抑制作用持续时间长。     

病原菌诱导后黄瓜叶片中脂氧合酶活性与茉莉酸积累的关系

通过酶活性测定和高效液相色谱分析,研究经病原菌诱导后黄瓜叶片中脂氧合酶(LOX)活性与茉莉酸(JA)积累量的关系。结果表明,黄瓜经褐斑菌诱导后,叶片中茉莉酸(JA)大量积累,同时脂氧合酶(LOX)活性上升,接种叶片的上位叶中LOX活性和JA含量于诱导接种褐斑菌12h后开始升高,并于诱导接种24h后达到峰值,接种叶片的下位叶中LOX活性和JA含量在诱导接种12h后变化不大,但在24h后显著升高,并于48h达到峰值,此后逐渐平稳下降。相关分析表明,LOX与JA呈显著正相关,相关系数r为0.92。同时通过喷施脂氧合酶抑制剂(NDGA)和添加茉莉酸的试验证实LOX是JA合成的关键酶。     

SA诱导拟南芥对灰霉病的抗性与木质素含量的关系

对拟南芥植株喷施水杨酸后,接种灰霉病菌(Botrytis cinerea),观察植物对病原物反应的变化。结果表明:喷施水杨酸可以降低拟南芥灰霉病的发生率。在平板培养中,水杨酸对灰霉菌分生孢子的萌发及菌丝的生长均无明显抑制作用,因此认为水杨酸处理后发病率的下降是由于水杨酸处理提高了植物的抗病性,且诱导抗性的持久期在10 d以上。观察中还发现在拟南芥叶片上喷施SA或接种灰霉菌都会使叶片PAL和POD活性上升,进而引起木质素的积累,两者在积累量上和时间程度上具较好的一致性,说明水杨酸诱导拟南芥抗灰霉病的过程中,通过PAL和POD活性的提高进而引起木质素含量的增加,可能是诱导拟南芥产生抗性的机制之一。     

茉莉酸对PR-1、PR-2、PR-5和Ta-JA2基因 表达以及小麦白粉病抗性的诱导

 为了探索小麦抗白粉病分子机理,明确茉莉酸对小麦白粉病抗性的诱导作用、对植物抗病性标志基因PR-1、PR-2、PR-5和本实验室克隆的1个新基因Ta-JA2的激活作用,以及抗病性变化与基因表达变化之间的相关性,本研究以感白粉病的小麦品种“中国春”、“濮麦9号” 和“周麦18”为材料,用茉莉酸甲酯（methyl jasmonate,MeJA）喷洒小麦幼苗叶片进行诱导,通过离体叶段培养法接种白粉菌（Blumeria graminis f. sp. tritici,Bgt）进行抗性鉴定;用实时定量PCR技术检测小麦叶片中PR-1、PR-2、PR-5和Ta-JA2基因的表达变化。结果表明MeJA处理可以显著提高“中国春”、“濮麦9号”和“周麦18”对白粉菌的抗病水平。茉莉酸处理显著激活了PR-1、PR-2、PR-5和Ta-JA2的转录。茉莉酸诱导的抗病性提高与抗病标志基因PR-1、PR-2、PR-5及Ta-JA2的表达增强呈正相关。植物激素茉莉酸是小麦抗白粉病反应的信号分子。     

哈茨木霉对接种尖孢镰刀茵后黄瓜根系次生代谢物的影响

采用室内筛选与田间试验相结合的方法,对哈茨木霉抑制黄瓜枯萎病菌的拮抗机制进行了研究.对峙培养结果显示木霉菌和病原菌之间形成了较明显的抑菌圈,其中菌株TN对枯萎病菌抑制作用较强.接种木霉菌植株显著提高了植株中肉桂醇脱氢酶（CAD）、多酚氧化酶（PPO）、愈创木酚过氧化物酶（G-POD）、咖啡酸过氧化物酶（CA-POD）和绿原酸过氧化物酶（CGA-POD）的活性及总酚、类黄酮、木质素的含量.接种木霉菌可诱导根系次生代谢相关基因的上调表达,C4H、CAD、CCOMT、G6PDH、PAL和PR-1的表达量分别为对照的 5.64、5.31、4.28、15.33、7.36 和 6.45 倍.表明木霉菌诱导的黄瓜根部对枯萎病的抗性与植物次生代谢密切相关.     

草地贪夜蛾取食诱导玉米叶片转录组分析

为阐明玉米响应草地贪夜蛾Spodoptera frugiperda取食胁迫防御反应的分子机制,利用RNAseq技术对草地贪夜蛾取食的玉米叶片进行转录组测序分析,并对抗虫代谢产物生物合成途径中的基因进行筛选鉴定。结果显示,与未接虫对照相比,草地贪夜蛾取食18 h导致玉米叶片中有1 645个基因差异表达(log2|处理/对照|1且FDR0.05),其中上调表达基因有1 352个,下调表达基因有293个。茉莉酸、水杨酸、乙烯等植物激素生物合成与信号转导途径相关基因大多上调表达,其中44个茉莉酸途径相关基因全部上调表达,说明该途径在玉米响应草地贪夜蛾取食诱导的防御反应中发挥着核心作用,其它激素生物合成与信号转导途径发挥协同作用。玉米重要抗虫次生代谢物苯并噁唑嗪酮类生物合成相关基因中有9个基因上调表达;15个萜烯挥发物生物合成相关差异表达基因中有14个上调表达,包括8个萜烯合成酶基因和1个CYP基因CYP92C5。表明草地贪夜蛾取食会诱导玉米复杂的植物激素途径和基因调控机制,激活以次级抗虫代谢物合成为主的防御反应。     

Epidemiology and simulation of population development of Sitobion avenae in winter wheat

The epidemiology ofSitobion avenae and its natural enemies in winter wheat was studied in 1975, 1976 and 1977. Immigration was important until the end of flowering. The alate immigrants had apterous offspring. These became the driving force in population growth. Their offspring were mostly alatae which usually left the field. A model of the epidemic was developed. Quantitative relations between the aphids and their environment were obtained from literature or established in laboratory trials. The model simulated population development and population composition from the beginning of June till the population peak at the end of June or early in July. Because quantitative data on relations between aphids and their natural enemies and pathogens are scarce, and since the knowledge on wing formation is still limited, the population collapse could not be predicted. In the future, prognosis over a period of three weeks seems possible.Samenvatting De toenemende betekenis van graanbladluizen (vooralSitobion avenae) gepaard gaande met een sterke toename van het gebruik van insecticiden op granen maakte verbetering van de prognose over het schadelijk optreden wenselijk. Door gedetailleerde tellingen in het veld (Fig. 1–7) werden gegevens verkregen over het verloop van de epidemie en het optreden van natuurlijke vijanden in 1975, 1976 en 1977.Een immigratieperiode tot in de bloei kon worden vastgesteld. Daarna lijkt de aantrekkelijkheid van het gewas voor alate luizen te verminderen. De alate immigranten krijgen aptere nakomelingen. Deze vormen de stuwende kracht van de populatiegroei. De nakomelingen van apteren zijn merendeels alaat. Zij verlaten het gewas.Een model van de populatieontwikkeling gedurende de epidemie werd opgesteld. De relatiediagrammen Fig. 9 en 10 laten groei en ontwikkeling vanS. avenae en een predator (Syrphus corollae) zien. Kwantificering van de betrekkingen werd mogelijk door literatuurgegevens en laboratoriumexperimenten.Met het model kon de populatieontwikkeling vanS. avenae vanaf begin juni tot aan de populatiepiek in 1975, 1976 en 1977 vrij goed worden gesimuleerd (Fig. 12). Ook de populatieopbouw kon worden gesimuleerd (Fig. 14). De teruggang van de populatiedichtheid blijkt moeilijker te voorspellen door het ontbreken van gegevens over natuurlijke vijanden.Het lijkt waarschijnlijk dat in de toekomst met het model een prognose over de piek van de bladluispopulatie circa 3 weken tevoren mogelijk zal zijn.     

Tumours of Begonia and some other ornamentals,induced by Corynebacterium fascians

In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten.     

Nematicidal Activity of Chrysanthemum coronarium

Organic amendments and green manure are potential alternatives to the harmful chemical control means currently used against plant-parasitic nematodes. In this work, Chrysanthemum coronarium was applied to the soil as a green manure to control the root-knot nematodes Meloidogyne incognita and M. javanica. Chrysanthemum coronarium significantly reduced nematode infection of tomato roots and improved plant-top fresh weight, both in the greenhouse and in microplots. Other green manures, derived from Anthemis pseudocotula, wild chickpea (Cicer pinnatifidum), Geranium spp. and wheat, were not as effective as C. coronarium. Chrysanthemum coronarium, retained its nematicidal activity even when applied as a dried material. Only mature C. coronarium plants, in their flowering stage, exhibited nematode control activity, but the green plant parts were more effective than the flowers. An aqueous extract of C. coronarium exhibited in vitro, nematostatic activity towards M. incognita and M. javanica second-stage juveniles and inhibited their hatching from eggs and egg-masses; its nematostatic activity was expressed also against other phytonematode species such as Heterodera avenae and Pratylenchus mediterraneus, but did not affect the beneficial entomopathogenic nematode Steinernema feltiae.     

Inactivation of soil-borne plant pathogens during small-scale composting of crop residues

Samples of heavily infested crop residues were incorporated in static compost heaps (2.5–4.6 m³) of the Indore type. Temperature increased to 50–70°C within 6 days depending on the type of crop residues used and the location within the heap. The heat phase (>40 °C) lasted 2–3 weeks and was followed by a c. 5-months maturation phase (<40 °c).=" among=" the=" 17=" pathogens=" tested,=">Olpidium brassicae and one of the four formae speciales ofFusarium oxysporum that were tested survived composting, but also their inoculum was greatly reduced.Survival during specific phases of composting was studied by incorporation and retrieval of samples at various stages of the process.F. oxysporum f. sp.melonis was completely inactivated andO. brassicae andPlasmodiophora brassicae were almost completely inactivated during the short heat phase. The three pathogens survived the long-lasting maturation phase without loss of viability. Heat evolved during composting was found to be the most important factor involved with sanitation of crop residues. The possible involvement of fungitoxic conversion products and microbial antagonism is discussed.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

浅黄恩蚜小蜂和丽蚜小蜂对温室白粉虱的寄生潜能分析

浅黄恩蚜小蜂Encarsia sophia GiraultDodd和丽蚜小蜂Encarsia formosa Gahan是防治粉虱类害虫的优势寄生蜂,通过生命表技术方法分析了2种寄生蜂对温室白粉虱Trialeurodes vaporariorum(Westwood)的防治潜能。结果表明,丽蚜小蜂在羽化第3天和第10天出现2次寄生高峰,占其总寄生量的13.7%和8.0%,在2次高峰之间逐日寄生粉虱数量比较平稳,单雌逐日平均产雌数保持在10.6~13.4头,10 d后寄生量呈明显的下降趋势;而浅黄恩蚜小蜂羽化10 d内逐日寄生粉虱量变化不大,单雌逐日产雌数稳定在4.2~5.4头,羽化14 d后寄生量呈明显下降趋势。丽蚜小蜂和浅黄恩蚜小蜂的R0、T、rm、λ值分别为171.5、18.0、0.2854、1.3303和61.6、16.2、0.2544、1.2897;粉虱若虫充足时,丽蚜小蜂平均单雌寄生若虫数是浅黄恩蚜小蜂的2.7倍,而后者平均单雌取食若虫数为60.6头,明显高于前者42.7头,总的来看,丽蚜小蜂通过寄生和取食杀死粉虱总量220.8头,明显高于浅黄恩蚜小蜂的127.9头。表明在应用寄生蜂防治温室白粉虱时,单独释放丽蚜小蜂比浅黄恩蚜小蜂显示出更好的防治潜能。     

Aetiology and causal agents of mango sudden decline disease in the Sultanate of Oman

Mango sudden decline is a recently introduced, economically serious disease in Oman. Affected mango trees have wilting symptoms that usually begin on one side and later spread to involve the entire tree. Trees exude amber-coloured gum from the bark of their trunks or branches and vascular tissues are discoloured. Having entered Oman in the recent past, survey data is presented that shows the disease to have spread throughout the northern part of the country. Evidence is presented that the vascular wilt pathogen Ceratocystis fimbriata causes mango sudden decline disease in Oman, possibly in concert with Lasiodiplodia theobromae and the recently described Ceratocystis omanensis. Isolates of these fungi from affected trees, cause infection and can be recovered from inoculated seedlings. Bark beetles (Hypocryphalus mangiferae) are shown to carry C. fimbriata and L. theobromae and are presumably responsible for transmitting both pathogens to healthy mango trees. Acting as a wounding agent and vector, the bark beetle is likely to have assisted the rapid spread of the disease across Oman.     

Identification and pathogenicity of Pythium species causing damping-off of kidney bean

Five Pythium species (Pythium irregulare, P. mamillatum, P. myriotylum, P. spinosum and P. ultimum var. ultimum) were isolated from the hypocotyls and roots of kidney bean plants with damping-off from a commercial field and from experimental plots that have undergone either continuous cropping with kidney bean or rotational cropping with arable crops. In inoculation tests, all five Pythium species were pathogenic to kidney bean. This is the first report of damping-off of kidney bean caused by Pythium species; we named this disease damping-off of kidney bean. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB291811, AB291944 and AB291945.     

Pathogenic fungi involved in root rot of peas in the Netherlands and their physiological specialization

Research on root rot pathogens of peas in the Netherlands has confirmed the prevalence ofFusarium solani, F. oxysporum, Pythium spp.,Mycosphaerella pinodes andPhoma medicaginis var.pinodella. Aphanomyces euteiches andThielaviopsis basicola were identified for the first time as pea pathogens in the Netherlands. Other pathogens such asRhizoctonia solani andCylindrocarpon destructans were also found on diseased parts of roots. F. solani existed in different degrees of pathogenicity, and was sometimes highly specific to pea, dwarf bean of field bean, depending on the cropping history of the field.A. euteiches was specific to peas, whereasT. basicola showed some degree of physiological specialization.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.