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西瓜枯委病是一种常见的土传的毁灭性病害,随着西瓜逐年连作和重茬,该病发生日趋严重。1999年九江市庐山区西瓜病害大发生,其中枯萎病占总发病的面积51.8%,给瓜农造成巨大的损失。为此,笔者对该病的防治技术进行了调查研究,综合其他学者的意见,现提出如下防治意见。 相似文献
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西瓜枯萎病(WatermelonfusariumWilt)又叫西瓜“死秧”。是蔚县西瓜生产的一大重要病害 ,一旦发病 ,轻者减产30% ,重者减产50% ,甚至绝收。近10年来 ,由于西瓜种植面积不断扩大 ,而且轮作倒茬困难 ,致使西瓜枯萎病连年发生且愈来愈重 ,直接威胁着西瓜生产 ,严重影响其产量和质量。一、发生特点西瓜枯萎病是一种土传病害 ,一般在座果期开始发病。1.叶片症状。发病初期叶片从后向前逐渐萎蔫 ,似缺水状 ,中午最明显 ,但早晚可恢复 ,3~6天后 ,整株叶片枯萎下垂不能复原。2.茎部症状。茎蔓部缢缩 ,有的病部… 相似文献
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为明确西瓜生产中一种幼苗新病害的病原菌种类,分离纯化获得菌株XG1601,并测定其致病性,利用形态学特征和rDNA ITS序列分析技术明确了该病原菌的分类地位,研究了不同杀菌剂及干热处理西瓜种子对该病害的防治效果。结果显示,结合形态特征及rDNA ITS序列技术分析最终确定菌株XG1601为尖孢镰刀菌Fusarium oxysporum f. sp. niveum。该病原菌为种子传带,引起西瓜种传枯萎病,西瓜种子种皮和种胚的带菌率分别为5.4%和1.7%,在温室中播种30 d左右,幼苗的发病率可达35.7%~41.1%。种子处理对该病害的防治试验结果显示,6.25%精甲霜灵?咯菌腈悬浮种衣剂和2.5%咯菌腈悬浮种衣剂包衣种子对病害的防治效果分别为67.0%和68.6%,80℃干热处理种子72~96 h的防治效果均为100.0%,且对处理种子的发芽势、出苗率和鲜重均无不利影响。说明80℃干热处理种子72~96 h对西瓜种传枯萎病的防治效果最好。 相似文献
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Adalberto C. Café-Filho Gil R. Santos Francisco F. Laranjeira 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):473-482
The effect of the distance of initial inoculum on the intensity of watermelon gummy stem blight, caused by Didymella bryoniae, was studied in a naturally-infected rainfed commercial field. The shorter the distance from the focus, the sooner was disease
onset and the earlier maximum disease levels were achieved. Maximum disease incidences were reached earlier than maximum severities,
but eventually destructive levels were observed for both disease incidence and severity. Disease progressed at similar rates,
irrespective of the radial distance from the focus. A detailed study of the disease temporal progress was conducted in inoculated
rainfed experimental fields with commercial genotypes Crimson Sweet (susceptible, S) and Riviera (moderately resistant, R).
The Gompertz model best described the disease progress curves, and estimated apparent infection rates were 0.049 and 0.020
respectively for S and R genotypes. In addition, spatial pattern studies were conducted during the dry season in overhead
irrigated experimental plots, inoculated with point-source foci. Disease intensity gradients were better explained by the
Exponential model than by the Power Law model. Gummy stem blight distribution was classified as aggregated by the Ordinary
Runs procedure. Two different spatial autocorrelation methods (2DCorr and LCOR) revealed strong short distance spatial dependencies.
Long distance positive correlations between quadrats were observed along with periods of higher progress rates. The dynamic
patterns of the epidemics of gummy stem blight in watermelon described here are consistent with epidemics of polycyclic diseases
with splash-dispersed spores. 相似文献
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西瓜品种资源对枯萎病和蔓枯病的抗性鉴定 总被引:3,自引:0,他引:3
采用室内苗期人工接种鉴定方法,对国内外引进和育成的78份西瓜品种资源进行了枯萎病和蔓枯病的人工接种双重抗性鉴定,筛选出Smokylee、 Summit、 Sugarlee、Calhoun Gray、 Dixielee、TexaW5、 Conqueror等9份高抗枯萎病的单抗种质,及AU Sweet Scarlet、 AU Jubilant、 AU Producer、W6 9、W23 18和W23 47 为中抗蔓枯病兼抗枯萎病的双抗种质,并对双抗种质材料的主要农艺性状进行了考察。 相似文献
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Yonas Kefialew Sanju Kunwar Dawit Abate Amare Ayalew James Colee Laura Ritchie Stephen M. Olson Mathews L. Paret 《Journal of General Plant Pathology》2018,84(4):284-295
This study evaluated the direct antifungal activity of tiadinil [N-(3-chloro-4-methylphenyl)-4-methyl-1,2,3-thiadiazole-5-carboxamide], a systemic acquired resistance (SAR) inducer and two formulations of thymol (thymol I and thymol II) against Stagonosporopsis citrulli, the causal agent of gummy stem blight (GSB) disease of watermelon. Tiadinil, thymol I and thymol II completely inhibited the mycelial growth of S. citrulli in vitro at ≥?100 ppm. Conidial germination and germ tube elongation were completely inhibited by tiadinil at ≥?2000 ppm and by thymol-based formulations at ≥?100 ppm. A single foliar application of tiadinil at ≥?10 ppm or a single application of thymol I and II at ≥?1 ppm, 48 h before or after pathogen inoculation, significantly reduced disease severity of watermelon seedlings inoculated with 105/ml conidial suspension of S. citrulli, compared to respective nontreated controls. Plants treated with foliar application of tiadinil at ≥?1000 ppm before pathogen inoculation had significantly lower disease severity than plants that received an equivalent drench application. The efficacy of foliar application of tiadinil was affected by concentration and frequency of application. The study suggests direct antifungal activity of tiadinil, indicating a new mode of action of tiadinil against GSB disease of watermelon. The study also demonstrated direct antifungal action of thymol, a formulated active compound of essential oils, against S. citrulli and GSB disease of watermelon. 相似文献
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Development of late blight of potatoes caused by Phytophthora infestans (US 8 fungal genotype, A2 mating type) was monitored in two Russet Norkotah commercial fields at Fort Fairfield in 1996 and Duncan Farm in 1997. Experimental plots representing various disease treatments (low, moderate, high and random late blight severity levels) were established in two fields in 1996. In 1997, only low and high disease treatments were established. The application of fungicides for late blight control was conducted in both years. Late blight incidence and severity were assessed in each plot of each treatment. Components of late blight disease development, tuber blight incidence and tuber yields were determined from each plot. Progress of late blight disease was rapid in 1996 but not in 1997. During the 1996 cropping season, mean disease incidence and severity in the random disease treatment plots were 84 and 21% respectively within 10 days of disease detection. In 1997, low levels of late blight severity were detected in the field plots. Average numbers of late blight leaf and stem lesions on infected plant and fungal sporangia on the diseased leaf were not significantly affected by disease treatment. Late blight foliar severity significantly affected potato tuber yields. Lowest tuber yield was obtained in plots with high disease levels and highest yields were recorded in plots with low late blight severity in 1996. Late blight severity was significantly correlated with tuber yield but not with per cent tuber blight. 相似文献
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棉花烂铃病的发生、品种抗病性及主要病原菌致病力分析 总被引:2,自引:0,他引:2
2011~2013年,调查了我国黄河和长江流域6省70县(市)200块棉田和不同栽培模式下棉花烂铃病发生情况,田间试验评价了棉花品种对烂铃病的抗性,采用离体棉铃人工接种方法分析了棉铃烂铃主要病原菌的致病力分化情况。结果表明:(1)所有调查的棉田均有棉花烂铃病发生,其中,棉铃疫病在各地发生最为普遍而且严重,仍属于我国黄河和长江流域棉区的最主要的棉花烂铃病,其病原菌为苎麻疫霉(Phytophthora boehmeriae)。(2)与春棉直播模式相比,3种套种模式均能显著减少棉花烂铃病的发生,其中麦-棉-西瓜12∶2∶1种植模式的防效最好,减少烂铃72.96%。(3)河北、山东和河南3省审定的50个棉花品种对棉花烂铃病的抗性存在显著差异,其中邯7860、邯棉103、锦科178、百棉1号和郑农棉4号5个品种对棉花烂铃病表现了较好的抗性,单株烂铃低于3.0个。(4)苎麻疫霉在棉铃上的致病力存在显著分化。 相似文献
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西瓜蔓枯病分子诊断技术研究 总被引:2,自引:0,他引:2
本文测定西瓜上的西瓜蔓枯病菌(Didymella bryoniae)、西瓜炭疽病菌(Colletotrichum orbiculare)及西瓜枯萎病菌(Fusarium oxysporum f. sp. niveum)的rDNA的ITS序列,比对近缘种及西瓜上不同病菌的ITS序列同源性,设计出特异性上游引物XM-2和下游引物XM-R2。经过对XM-2/XM-R2引物的PCR扩增条件的优化,可以扩增出一条344bp的西瓜蔓枯病菌特异性DNA条带。上述方法可以检测到pg以上的蔓枯病菌基因组DNA,并且可以准确扩增出西瓜蔓枯病自然病样中特异性的DNA片段。本文建立了一项西瓜蔓枯病分子检测技术,该方法准确、快速、可靠,可用于西瓜蔓枯病田间的快速诊断。 相似文献
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近年来,甘肃省白银市靖远县的一些砂田西瓜中出现了严重的叶疫病,严重田块病株率超过70%。2018年7月,从靖远县高湾乡罹病西瓜叶片上分离得到拟多隔孢属Stagonosporopsis真菌,病叶检出率达100%。采用离体叶片和植株接种法评价单孢分离菌株XG-3对西瓜和甜瓜的致病性,所有接种处理在24 h内均发病显症而对照未发病,其中发病叶片原接种菌的检出率为100%。菌株XG-3在PDA和OA平板培养基上20和25 ℃培养20 d,未见产孢。在自然感病的西瓜叶片上观察到少量分生孢子器,在人工接种发病的西瓜和甜瓜茎、叶上产生大量分生孢子器和分生孢子:分生孢子器球形至亚球形,大小为(82.4~243.3) μm×(82.4~188.4)μm,分生孢子器具1~2个孔口,孔口直径15.7~27.5 μm;分生孢子无色,0~3个隔膜,杆状、柱状、长椭圆形、花生形及不规则形,直或稍弯曲,分隔处不缢缩或缢缩,大小为(5.2~28.3)μm×(2.2~6.0)μm,分生孢子形态和大小依基质和环境条件的不同而有较大差异。BLASTn分析结果显示,菌株XG-3(GenBank登录号:MW282128)的rDNA-ITS序列与瓜拟多隔孢Sta. cucurbitacearum分离物287ITS(GenBank登录号:AY293804.1)的序列相似性达99.80%。在基于rDNA-ITS构建的系统发育树中,菌株XG-3与Sta. cucurbitacearum聚为一组,与西瓜拟多隔孢Sta. citrulli和木瓜拟多隔孢Sta. caricae区分开来。依据病菌形态学和分子生物学特征,将菌株XG-3鉴定为瓜拟多隔孢Sta. cucurbitacearum [Basionym: Sphaeria cucurbitacearum]。 相似文献
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解淀粉芽胞杆菌YU-1对水稻纹枯病的防治作用 总被引:1,自引:0,他引:1
本文旨在筛选对水稻纹枯病有生防作用的菌株,并初步探索其生防作用机理。收集水稻、甘蓝、黄瓜等不同植物根际土壤,采用稀释分离和对峙培养法筛选对水稻纹枯病菌Rhizoctonia solani Kühn有抑菌作用的菌株;通过离体接种防效、盆栽防效、抑菌谱、对水稻纹枯病菌菌核萌发及形成的抑制作用等方面评价其生防潜力,并对生防菌株进行鉴定。结果表明,从采集的37份根际土壤中共分离获得细菌297株,其中4株对纹枯病菌具有较好的拮抗作用,菌株YU-1对水稻纹枯病菌菌丝生长的抑制率达89.8%;对西瓜枯萎病菌、草莓灰霉病菌、番茄早疫病菌、油菜菌核病菌、小麦赤霉病菌菌丝生长的抑制率均在85%以上;对水稻纹枯病的离体和盆栽防效分别为73.1%和66.3%;对水稻纹枯病菌菌核萌发的抑菌率在92%以上;经生理生化和分子鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens。由此可看出,菌株YU-1对水稻纹枯病的防治具有较强的应用价值,具有进一步开发成生物农药的潜力。 相似文献