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黄瓜枯萎病病株残茬对黄瓜的化感效应 总被引：1，自引：0，他引：1
采用生长速率法、孢子萌发法、胚根生长抑制法、电导率法等方法,研究不同发病程度的黄瓜残茬腐解物对黄瓜枯萎病菌菌丝生长和孢子萌发、黄瓜种子萌发、胚根生长、根部细胞膜通透性、苗期生长性状以及苗期枯萎病的影响.结果表明,黄瓜枯萎病发病越重,其残茬腐解物对黄瓜枯萎病菌孢子的促进作用越强,高浓度健株、轻病株和重病株残茬的产孢量分别比对照增加了27.29%、50.05%和44.88%;健株残茬可使黄瓜枯萎病病菌孢子萌发率提高15.91%～38.94%;不同浓度黄瓜残茬腐解液可影响黄瓜胚根生长,并减少须根6.15%～27.10%;重病株不同浓度残茬腐解液可使黄瓜幼苗细胞膜透性增加76.03%～89.96%;高浓度重病株残茬腐解物可使黄瓜出苗率降低53.15%,同时枯萎病病株率增加55.11%. 相似文献
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以4种野生抗病茄为试材,通过生长速率法和悬滴法测试了其根、茎、叶腐解物的乙醇提取液对茄子黄萎病菌菌丝生长和分生孢子萌发的室内抑制作用,并对室内抑菌效果较好的处理进行了盆栽防病试验。供试腐解物提取液对茄子黄萎病菌均具有一定抑制作用。其中,叶对菌丝生长的抑制率最高(>30%),抑制作用顺序为刚果茄>托鲁巴姆>CRP(刺茄)>赤茄,对孢子萌发的抑制效果较好的是刚果茄叶>CRP叶>刚果茄茎>赤茄叶>托鲁巴姆叶(>77%)。盆栽试验表明,除赤茄叶片腐解物外,其他3种野生茄叶片腐解物对茄子黄萎病均具有治疗效果;4种野生茄叶片腐解物对茄子黄萎病的预防效果均较好。 相似文献
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玉米秸秆腐解过程物质组成及胡敏酸的动态变化Ⅰ.物质组成的动态变化 总被引：3，自引：1，他引：3
采用恒温培养试验，利用植物化学组成系统分析法，对玉米秸秆腐解过程物质组成的动态变化进行了研究。结果表明，随腐解进行，腐解物中木质素、全氮以及灰分的含量逐渐增加；水溶性物质的含量在210d以前逐渐减小，210d以后也有所增加；苯醇溶性物质、纤维素和全碳的含量逐渐减小。腐解过程木质素、纤维素、全碳的总量均呈下降趋势，其分解率与腐解时间的关系可用指数方程来描述。同一腐解期，分解率的大小顺序是纤维素＞全碳＞木质素。腐解过程灰分的总量基本不变，全氮量略有减小。 相似文献
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以生长于新疆北部的实葶葱和入侵实葶葱种植地的小飞蓬作为供体植物，伴生植物菥蓂和马齿苋为受体材料，采用盆栽试验法研究不同分蘖株数实葶葱秸秆单一腐解以及不同分蘖株数实葶葱和小飞蓬秸秆室内混合腐解180 d后伴生植物的生长、生理变化及其对年生长结束后基质化学性质的影响。结果表明，单一腐解处理对菥蓂和马齿苋的根长、根体积和生物量积累分别表现出“低促高抑”和持续增强的抑制效果。混合腐解后，与单一腐解处理相比，同一低浓度下混合腐解处理对菥蓂的根长、根体积的促进作用分别消减了93%和61%，对地上部鲜、干质量的促进作用分别消减了30%、38%，对地下部鲜、干质量的促进作用分别消减了65%和90%，对马齿苋的根长和地下部鲜、干质量的抑制作用分别消减了60%、75%和49%，对根体积和地上部鲜、干质量则由抑制转变为促进作用。同一高浓度下混合腐解处理对菥蓂根体积的促进作用消减了77%，对地上部鲜、干质量和地下部鲜质量的抑制作用分别消减了37%、55%和31%，对马齿苋的根长、根体积、地上部干质量和地下部鲜质量的抑制作用分别消减了了21%、51%、14%和33%。实葶葱与小飞蓬混合腐解后产生的复合他感作用总体表现为拮抗效应。相关性分析显示复合腐解基质的化学性质比实葶葱单一腐解基质更利于伴生植物的生长。研究结果显示实葶葱腐解产生的他感作用能够抑制伴生植物的生长和生理活动，而小飞蓬的入侵可以缓解伴生植物受到的这种抑制作用，并影响改变实葶葱种植地的EC值和pH值，进一步影响入侵地的物种多样性和生态稳定性。 相似文献
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填闲作物腐解过程及其对后茬冬小麦产量的影响 总被引：1，自引：0，他引：1
研究了渭北旱塬地区不同填闲作物（长武怀豆（S）、黑麦草（R）及两者1∶1混合（M））翻压和氮肥水平（0、60、120 kg N·hm-2）双因素处理下,填闲作物的腐解规律、碳氮释放动态及对后茬冬小麦产量的影响,并对腐解速率与Olsen模型进行了拟合。结果表明：各填闲作物翻压后腐解规律及碳氮释放特征均表现为“前期快-中期慢-后期加快”,填闲作物腐解规律符合Olsen模型,在第276天各处理累积腐解率均达70%以上。在第0~35天,同一施氮处理下,累积腐解率和腐解速率均表现为S>M>R（P<0.05）;第35天,S、M和R各处理干物质累积腐解率分别达到61.9%、55.5%和47.5%;在0~35 d,施氮对S、M的腐解影响不显著,对R影响显著,35 d后氮肥效应逐渐减弱;填闲作物的腐解同时伴随其碳、氮的快速释放,在第21天,S、M和R碳氮残留率分别达到40%、50%和60%左右。平均来看,S的碳氮释放速率显著高于R,与M无显著差异。与裸地对照相比,翻压填闲作物能够显著提高后茬冬小麦产量,其籽粒产量增加10%~35% （P<0.05）,其中翻压长武怀豆低氮处理和混合翻压低氮处理效果最佳。 相似文献
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为了解绿肥毛叶苕子（Vicia Villosa L.）在青海高原地区对土壤的培肥效果以及为农作物提供养分情况,在田间利用尼龙网袋法,研究毛叶苕子腐解特性和氮磷钾等养分释放规律。结果表明:绿肥毛叶苕子在翻压后50 d内腐解速度较快,腐解率达38%,后期腐解速度缓慢,在取样结束后,累积腐解率为86.39%;整个腐解过程中氮磷钾养分释放速率表现为氮>钾>磷,氮和钾的养分释放趋势存在一致性,在52 d内快速释放,养分释放率分别为56.54%、74.27%,后期释放速率缓慢,在腐解结束时,其养分累积腐解率达91.31%、99.04%;磷的释放速率缓慢,且波动性较大,在腐解周期内磷素含量呈上升趋势,取样结束后,累积腐解率为75.71%。绿肥毛叶苕子的干物质累积腐解率、养分累积释放率与腐解时间的关系可以通过线性函数和对数函数拟合。预测本试验处理可为后茬作物地块提供氮素172.80 kg·hm-2、磷素10.93 kg·hm-2、钾素139.63 kg·hm-2。 相似文献
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为明确甜瓜黑点根腐病的发生和流行规律及有效防治方法,在不同培养基、碳源、氮源、温度、pH等培养条件下,测定甜瓜黑点根腐病菌的生物学特性及其对多种瓜类作物致病性,并采用菌丝生长速率法测定菌株对不同药剂的敏感性。结果表明,甜瓜黑点根腐病菌MC8菌丝生长的适宜培养基为马铃薯蔗糖培养基、燕麦粉琼脂和马铃薯葡萄糖琼脂培养基,马铃薯蔗糖培养基、燕麦粉琼脂和玉米琼脂粉这3种培养基可产生子囊壳;碳源和氮源对菌丝生长无明显促进作用,但乳糖可显著促进子囊壳产生,该发现为国内外首次报道;MC8菌丝生长的适宜pH为5～7,菌丝和子囊壳生长最适温度为30℃。致病力试验结果显示MC8菌株可侵染西瓜、甜瓜、南瓜和葫芦多种瓜类作物。咪酰胺和嘧菌酯在PDA上对瓜类黑点根腐病菌的菌丝生长有较好的抑制效果。 相似文献
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干旱荒漠条件下残茬分解特征和养分释放的研究 总被引：3，自引：1，他引：3
以大豆秆为材料研究了荒漠生态条件下残茬的腐解率、腐解物的有机C、N和K的含量、养分释放率和C/N比的变化。结果表明:残茬的累积腐解率和有机C的分解率随腐解时间的延长呈上升的趋势,0～1.5个月和1.5～3个月残茬腐解率分别达19.7%和18.5%,0～1.5个月和1.5～3个月残茬有机C的分解率均为19.2%;腐解残留物的有机C、N和K的含量存在不同的变化,有机C的含量变化不大,N的含量则是先逐渐上升,6个月后基本不变,K的含量前1.5个月迅速下降,1.5～3个月缓慢下降,然后基本不变;整个腐解过程是N的固定过程,N的释放量和释放率均为负值,K的释放集中在前1.5个月,释放率达75.8%;腐解残留物的C/N比先迅速下降,6个月后基本不变,最终为35.9。 相似文献
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为缓解连作甜瓜引起的连作障碍，在对河北省沧州市青县甜瓜连作区土壤障碍程度进行分析的基础上，通过室内盆栽和田间试验，研究了巨大芽孢杆菌Bacillus megaterium b1菌株与噁霉灵联用对连作甜瓜枯萎病的缓解效果及对甜瓜植株生长的影响，并初步分析了该地区土壤中微生物数量及群落结构变化。结果表明:采用11年连作甜瓜土壤培育南瓜和甜瓜，其幼苗根冠比及全株干重均显著低于1年土壤组；11年连作土壤中真菌数量最多，细菌和放线菌数量最少，镰刀菌属 (Fusarium) 相对丰度最高，是1年土壤的4.27倍，而1年土壤中芽孢杆菌属 (Bacillus) 相对丰度是11年土壤的2.65倍。噁霉灵和巨大芽孢杆菌b1菌株间不存在拮抗作用，二者对甜瓜枯萎菌 Fusarium oxysporum T2菌株的EC50值分别为10.82 mg/L和2.02 × 105 CFU/mL。室内分别采用巨大芽孢杆菌、噁霉灵单剂及二者联用处理连作11年土壤后培育甜瓜幼苗，结果表明:联用处理在开花结果期对甜瓜枯萎病的防效为42.85%，且甜瓜幼苗根冠比和全株干重均显著高于各单剂和空白对照处理。田间试验结果表明:巨大芽孢杆菌、噁霉灵单剂以及二者联用处理连作甜瓜土壤，对甜瓜枯萎病的防效分别为16.62%、100%和100%；各处理组甜瓜幼苗株高分别比空白对照提高11.19%、10.63%和16.03%；甜瓜增产率分别为20.35%、11.23%和26.15%；单株根系平均干重分别比空白对照提高40.63%、34.69%和64.38%，差异显著(P<0.05)。各处理组土壤中真菌数量降低，细菌和放线菌数量增加；镰刀菌属相对丰度分别比空白对照降低35.96%、59.55%和71.91%；芽孢杆菌属相对丰度分别比空白对照提高47.25%、3.52%和76.70%。研究表明:甜瓜连作存在明显的连作障碍，而巨大芽孢杆菌与噁霉灵联用能有效改善连作区土壤微生物群落结构，缓解连作障碍，减轻连作土壤甜瓜枯萎病的发生，促进甜瓜幼苗生长及提高甜瓜产量。 相似文献
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应用高通量测序技术对宁夏中卫地区不同连作年限硒砂瓜土壤细菌群落结构和多样性进行研究,旨在揭示不同连作年限对硒砂瓜土壤细菌群落结构的影响。结果表明:随着连作时间的增加,细菌多样性指数和丰富度指数逐渐增加。从5份不同连作年限硒砂瓜土壤样本中共获得39门、98纲和620属的细菌;优势门为放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria);随着连作时间的增加,放线菌门、酸酐菌门丰度先增加后降低,变形菌门丰度逐渐降低,绿弯菌门丰度呈先降低后增加又降低现象;优势纲分别为放线菌纲(Actinobacteria)、酸杆菌纲(Acidobacteria)、α-变形菌纲(Alphaproteobacteria)、芽单胞菌纲(Gmmatimonadetes)、杆菌纲(Bacilli)、热原体纲(Themomicrobia)、γ-变形菌纲(Gammaproteobacteria)、β-变形菌纲(Betaproteobacteria);优势目为norank_c_Acidobacteria、芽孢杆菌目(Bacillales)、芽单胞菌目(Gemmatimonadales)、根瘤菌目(Rhizobiales)。RDA分析表明,有机质、速效磷是硒砂瓜连作土壤细菌群落组成的主要影响因子。研究表明,引起硒砂瓜连作障碍发生主要因素不是由于土壤理化性质变化引起的,而是随着连作时间的增加,放线菌门、变形菌门、绿弯菌门、酸杆菌门、厚壁菌门等有益微生物丰度下降造成的。 相似文献
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Differences in the responses of melon accessions to fusarium root and stem rot and their colonization by Fusarium oxysporum f. sp. radicis‐cucumerinum 
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下载免费PDF全文 R. Cohen G. Orgil Y. Burger U. Saar M. Elkabetz Y. Tadmor M. Edelstein E. Belausov M. Maymon S. Freeman O. Yarden 《Plant pathology》2015,64(3):655-663
Fusarium root and stem rot caused by the fungus Fusarium oxysporum f. sp. radicis‐cucumerinum is a major disease in greenhouse cucumbers. Over the past decade, the disease has been documented in melon greenhouses in Greece, and recently it has been sporadically recorded in greenhouse melons in Israel. Variations in disease response were found among 41 melon accessions artificially inoculated with the pathogen: 10 accessions were highly susceptible (90–100% mortality), 23 exhibited an intermediate response (20–86%) and eight were resistant (0–4%). Two melon accessions – HEM (highly resistant) and TAD (partially resistant) – were crossed with the susceptible accession DUL. The responses of the three accessions and F1 crosses between the resistant and susceptible parents were evaluated. HEM contributed higher resistance to the F1 hybrid than TAD. Roots of susceptible and resistant accessions were 100 and 79% colonized, respectively, following artificial inoculation. However, only susceptible plants showed colonization of the upper plant tissues. Microscopic evaluation of cross sections taken from the crown region of the susceptible DUL revealed profuse fungal growth in the intercellular spaces of the parenchyma and in xylem vessels. In the resistant cultivar HEM, very little fungal growth was detected in the intercellular spaces of the parenchyma, and none in the xylem or any other vascular tissue. Finding resistant accessions may create an opportunity to study the genetics of resistance inheritance and to develop molecular markers that will facilitate breeding resistant melon cultivars. 相似文献
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南瓜蚜传黄化病毒(cucurbit aphid-borne yellows virus,CABYV)近年来发生普遍,严重威胁甜瓜的生产。前期构建了一个CABYV丝瓜分离物(CABYV-QY)的侵染性克隆,但其在甜瓜中的侵染率偏低,不宜用于甜瓜接种。本研究以CABYV甜瓜分离物CABYV-WS为研究对象,通过RT-PCR扩增、拼接获得全基因组序列,通过构建全长基因组cDNA克隆,分析其侵染性。结果显示,该分离物基因组全长为5682 nt,与CABYV-QY(MT943520)的核苷酸序列一致性为88.61%~100.00%,氨基酸为84.94%~100.00%。将cDNA克隆接种分析,发现所用的8个甜瓜品种均能被系统侵染并引起典型的黄化症状,侵染率为70%~100%。其中,甜瓜品种‘新密杂11号’和‘新密25号’感病性较强,接种CABYV后发病周期短且侵染率可达100%。CABYV侵染性克隆的成功构建有助于该病毒的分子致病性和寄主的抗病性等研究。 相似文献
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Maryam Mirtalebi Zia Banihashemi Celeste C. Linde 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(4):749-762
Fusarium wilt of melon caused by Fusarium oxysporum f. sp. melonis is a destructive fungal disease in melon growing regions. Isolates of F. oxysporum obtained from six major melon producing provinces in Iran, from melons and other hosts, were characterized based on pathogenicity to melon, vegetative compatibility groups (VCGs) and nuclear ribosomal DNA intergenic spacer (IGS) sequencing. Thirty-four of 41 isolates from Iran in this study were identified as race 1,2 which belonged to either VCG 0134 or an unassigned VCG, which based on IGS sequencing grouped with the VCG 0135 tester isolate. The seven remaining isolates were identified as nonpathogenic to melon belonging to two undescribed VCGs. Based on sequence analyses of the IGS region of Iranian and foreign isolates, nine lineages were identified, each including one VCG. The separation of VCGs into distinct lineages based on IGS sequences is mostly consistent with Repetitive extragenic palindromic PCR (Rep-PCR) results. Exceptions are VCGs 0130 and 0131, which could be differentiated with IGS sequences, but not with Rep-PCR. Different races from the USA, France and Iran associated with VCG 0134 grouped into one IGS lineage but could be differentiated with Rep-PCR, suggesting that this VCG is more diverse than previously thought. Given the long history of melon cultivation in Iran and the Rep-PCR diversity of isolates belonging to this VCG, it could be speculated that VCG 0134 perhaps evolved in Iran. 相似文献
17.
Spain produces 43 200 ha of melons with a considerable export to European markets. In the last 10 years, melon cultivation in Spain has decreased more than 40% due mainly to collapse of the vines caused by soil‐borne diseases. Serious economic losses have resulted. In order better to understand the aetiology of this disease, a survey of 217 melon fields throughout the melon production areas of Spain was conducted from 1987 to 1996 to analyse the fungal population associated with roots. In addition, the presence of melon necrotic spot carmovirus (MNSV) was studied in 93 fields. This virus is present mainly in southeastern Spain. The predominant fungal species isolated from 82.5% of sampled fields with symptoms of collapse was Acremonium cucurbitacearum. Roots affected by this fungus show corky brown areas soon after transplanting. Small secondary roots and root hairs become necrotic, although there is continuous production of new rootlets. This process continues until the late stages of the disease. As the fruits approach maturity, the entire plant wilts and dies. Other fungal species associated with melon collapse are: Monosporascus cannonballus (isolated from 29.5% of sampled fields), Macrophomina phaseolina (32.7%) and Rhizoctonia solani (31.8%). Of these, the incidence of M. cannonballus isolated from diseased melons has increased substantially over the past 10 years. Melon collapse in Spain is complex because several fungi capable of causing collapse of the vines are prevalent and often isolated from roots in the same field. In addition, other minor pathogens, such as Rhizopycnis vagum and Plectosporium tabacinum, are frequently isolated from symptomatic vines and may also contribute to the death of the plants. 相似文献
18.
The susceptibility of the Greek melon cvs Kokkini Banana, Thraki, Peplos and Amynteou to Verticillium dahliae and Fusarium oxysporum f. sp. melonis was tested, by inoculating seedlings of the four cultivars by root immersion in a Verticillium and Fusarium inoculum suspension for 1 h. After 35 days, disease incidence was estimated from a disease index calculated as the product of the'leaf symptom index'and'vascular discoloration index'of each plant. In addition, plant height, main stem diameter, above-ground fresh and dry weight and root fresh and dry weight were measured. The disease severity of verticillium and fusarium wilts on plants was estimated by the correlation coefficient ( r ) between the disease index and the other characteristics. Both fungi had a significant negative effect on all the measured characteristics independently of the tested cultivar. Finally, the four melon cultivars showed different degrees of susceptibility to Verticillium and Fusarium indicating that tolerant selections can be achieved. 相似文献
19.
尖孢镰刀菌黄瓜专化型(Fusarium oxysporum f. sp.cucumerinum,Foc)是引起黄瓜枯萎病的病原真菌,为了明确不同抗性黄瓜品种连作对枯萎病菌遗传分化的影响,本研究采用TEF1-α、H3基因片段对不同抗性黄瓜品种连作及对轮作后分离的枯萎病菌群体进行遗传分化分析。结果表明,感病品种连作及轮作后菌群分化程度较低(0.007ST<0.045);与种植抗病品种一茬后的菌群相比,连作三、五茬后的菌群均发生显著分化(FST> 0.050),其中连作三茬后的菌群遗传分化程度最高(FST> 0.300)。单倍型分析发现,抗、感病品种连作后部分菌株形成新的单倍型,且分离自抗病品种的病原菌群体分化产生的单倍型数量多于感病品种。主成分分析结果进一步证明,与感病品种连作及轮作相比,抗病品种连作后病原菌菌群呈现出更显著的菌群分化。综上所述,抗病品种连作能够加剧黄瓜枯萎病菌群体的遗传分化。 相似文献