西瓜枯萎病的研究进展及其防治

西瓜枯萎病作为一种重要的土传和种传病害,导致西瓜产量减少和品质降低。近年对该病害的研究较多,现对西瓜枯萎病的发病症状、发病条件、病害循环及其主要防治措施,特别是用于防治西瓜枯萎病的种子处理方法作一综述。     

西瓜内生细菌C18的内生定殖及对西瓜枯萎病的生防作用

西瓜枯萎病是西瓜的主要病害,寻找防治西瓜枯萎病安全有效的方法已成为生产中的重要课题。利用植物内生细菌防治植物病害特别是植物土传病害,已有较多的研究,但对于西瓜枯萎病的防治     

西瓜枯萎病防治途径

西瓜枯萎病防治途径郑高飞（中国农科院郑州果树所４５０００４）西瓜枯萎病是西瓜生产上的重要病害之一，堪称西瓜生产一大绝症。该病害是土传性病害，多发生在果实膨大期至采收前，发病后可使植株萎蔫或枯死。预防枯萎病主要有四条途径：一是轮作倒茬。轮作倒茬是生产上...     

西瓜品种抗枯萎病鉴定

西瓜枯萎病是一种顽固的土传真菌病害。病原菌Fusarium oxysporum广泛分布于病田0—60cm深的耕作层内,药剂防治难以奏效。和非葫芦科作物实行7—10年轮作的传统防治方法,在西瓜集中产区难以推行。培育抗病品种在生产上已引起重视,     

多粘类芽胞杆菌WY110对西瓜枯萎病的控制作用

西瓜枯萎病是由尖孢镰刀菌西瓜专化型引起的西瓜毁灭性土传病害,生产上主要采用药剂防治。由于病原菌的抗药性不断增强,利用拮抗菌对植物病害的生物防治越来越受到重视。目前,已有很多多粘类芽胞杆菌Paenibacillus polymyxa菌株用于植物病害的生物防治。     

实时荧光定量PCR检测土壤西瓜枯萎病菌体系的建立

正西瓜枯萎病是由尖孢镰刀菌西瓜专化型(Fusarium oxysporum f.sp.niveum,FON)引起的一种土传维管束病害,在各个时期均可发生,对西瓜产业构成严重威胁。该病具有传播途径多样、暴发快速、应急防治难等特点,因此及时准确监控土壤中的病原菌是防治西瓜枯萎病的关键。实时荧光定量PCR(quantitative real-time PCR,q PCR)技术能进行定量     

西瓜抗重茬剂1号防治西瓜枯萎病试验初报

西瓜抗重茬剂１号防治西瓜枯萎病试验初报孟凡香，王守宽，赵文学，王翠萍，林相璀（济南市植物检疫站，２５００２２）西瓜枯萎病是威胁西瓜生产的主要病害，生产上尚没有理想药剂。新近水利部北京水利研究所研制了一种防冶西瓜枯萎病的新药一西瓜抗重茬剂１号，我站应用...     

万寿菊杀菌素Ⅰ抗菌性及其对西瓜枯萎病菌作用机理的初步研究

西瓜枯萎病又称萎蔫病或蔓割病,是一种世界性瓜类土传病害。自1894年在美国南卡罗来纳州首次发现以来,目前几乎发生于世界各个西瓜产区,严重威胁着西瓜的安全生产,是西瓜的主要病害之一[1]。近几年来,由于西瓜种植面积不断扩大,造成轮作困难,致使枯萎病的危害也逐年加     

西瓜枯萎病的发生与防治

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。     

应用嫁接技术防治西瓜枯萎病

应用嫁接技术防治西瓜枯萎病陈宁承，陈安琪（桂林市蔬菜研究所）枯萎病是西瓜连作栽培中危害最严重的一种病害，采用轮作防病需经４～５年以上时间，在生产实践中难以推广。而应用嫁栽培技术将西瓜作接穗嫁接在抗枯萎病的瓠瓜、葫芦瓜等砧木上，进行换根栽培，则方法简而...     

LuxR家族调控因子 LuxR-2460 对西瓜嗜酸菌致病力及生物膜形成的调控

 LuxR家族的调控因子在革兰氏阴性细菌中起重要作用。对西瓜嗜酸菌一个LuxR家族的调控因子 LuxR-2460的调控作用进行研究。生物信息学分析表明该调控因子有2个保守结构域:N-末端为REC 结构域,C-末端为HTH 结构域。通过同源重组双交换的方法,构建了luxR-2460全基因缺失的突变株,该基因缺失突变株能够引起菌株致病力、运动能力及蹭行运动能力的下降及生物膜形成能力的增强。qRT-PCR 检测结果表明,该基因缺失导致鞭毛基因fliR在突变株中的表达量下调,影响病菌鞭毛的形成。说明luxR-2460基因对西瓜嗜酸菌的致病能力及相关因子具有重要调控作用,可以作为该病害防控的潜在靶标。     

Fusarium solani f. sp. cucurbitae race 1, a potential pathogen of grafted watermelon production in Spain*

A crown, root and fruit rot of squash (Cucurbita maxima and Cucurbita moschata) has been observed in eastern provinces of Spain over the past 4 years. Isolations from the crown of symptomatic plants and fruits yielded primarily a Fusarium solani that was identified as F. solani f. sp. cucurbitae race 1 on the basis of pathogenicity tests and disease symptoms in the field. In Spain, more than 90% of watermelon plants are grafted, using different Cucurbita hybrids (C. maxima × C. moschata) as rootstocks. In 1998, some grafted watermelon plants were first found to be affected by F. s. cucurbitae race 1. The purpose of this study was to evaluate the pathogenicity of this fungus on several rootstocks commonly used for grafting watermelon (Brava, Titan, Shintoza, RS‐841, TZ‐148 and TW‐1) in order to prevent a possible spread of this fungus that could cause serious economic losses in watermelon production. None of them proved to be resistant.     

携带eGFP的ZYMV侵染性克隆的构建及其侵染性

 小西葫芦黄花叶病毒(zucchini yellow mosaic virus,ZYMV)是瓜类作物主要病毒之一,严重威胁瓜类产业的可持续发展。本研究在ZYMV 甜瓜分离物CH-87侵染性克隆基础上,利用同源重组策略在NIb和CP编码序列之间插入了eGFP,命名为pXT1-ZYMV-eGFP。将pXT1-ZYMV-eGFP转化农杆菌并接种西瓜和甜瓜,结果发现pXT1-ZYMV-eGFP可以系统侵染西瓜和甜瓜,引起典型的花叶症状,在紫外灯下发病植株呈现绿色荧光。经摩擦接种证实,该克隆接种后所产生的病毒子代可以稳定的传播繁殖。研究表明携带eGFP的ZYMV侵染性克隆成功构建,可用于该病毒致病性及病毒与寄主互作的相关研究。     

3种瓜类枯萎病菌Fusarium oxysporum的分子检测

 Fusarium oxysporum is one of the most important phytopathogens and cause Fusarium wilt disease in cucumber, watermelon and melon, etc.In this study, a pair of species-specific primers Fc-1 and Fc-2 was synthesized based on differences in internal transcribed spacer sequences of Fusarium genus.With the primers, a specific 315 bp PCR product was amplified from five F.oxysporum isolates isolated from cucumber, watermelon and melon, infected cucumber and watermelon tissues, while no product was obtained from other fourteen fungi, healthy cucumber and watermelon tissues.The detection sensitivity is 100 fg for genomic DNA of F.oxysporum and 1 000 spores/g soil for the soil pathogens.In contrast, the nested PCR with two pairs of primers(ITS1/ITS4 and Fc-1/Fc-2) increased the sensitivity by 100-fold.In addition, one-step PCR could also detect F.oxysporum in symptomless cucumber root of 7 dpi(days post inoculation) and in infected cucumber and watermelon tissues at the early stage of disease development.Therefore, the developed PCR-based method enabled rapid, sensitive and reliable detection of F.oxysporum.It also provides the detection method for early monitoring and diagnosis of the pathogen as well as the plant disease management guidance.     

Aphid-borne viruses infecting cultivated watermelon and squash in Spain: Characterization of a variant of cucurbit aphid-borne yellows virus (CABYV)

Aphid-borne viruses are responsible for major cucurbit diseases and hamper the sustainability of crop production. Systematic monitoring can reveal the occurrence and distribution of these viruses, in addition to unadvertised viruses, facilitating the control of diseases. For three consecutive (2018–2020) seasons, the presence of aphid-borne viruses was monitored from a total of 292 samples of watermelon and squash plants that showed yellowing symptoms in three major cucurbit-producing areas (Castilla La-Mancha, Alicante, and Murcia) in Spain. We observed that cucurbit aphid-borne yellows virus (CABYV) was the most common virus found (29%) in the plants from both crops. Likewise, except for squash samples from Castilla La-Mancha and Alicante, watermelon mosaic virus (WMV) was also found (23%) with a relatively high frequency. Furthermore, we observed the exacerbation of bright yellowing symptoms in watermelon plants that was often accompanied by considerable fruit abortion. CABYV was the only causative agent for this new yellowing disease, and two infectious cDNA clones (one from watermelon, CABYV-LP63, and another from melon, CABYV-MEC12.1) were constructed to further compare and characterize this CABYV disease. Based on the full-length genome, both isolates were grouped phylogenetically together within the Mediterranean clade. However, the Koch's postulates tests were only successfully completed for the LP63 isolate, which also showed several amino acid changes and two potential recombination events, as compared to MEC12.1. Remarkably, the LP63 isolate caused more severe symptoms and showed higher RNA accumulation than MEC12.1 in five cucurbit plant species. These results suggest that a novel CABYV variant that causes severe yellowing symptoms may be causing outbreaks in cucurbit crops.     

控释尿素配比对西瓜生长、品质和土壤肥力的影响

采用田间试验,研究了混料试验中的单形重心设计在西瓜控释尿素与普通尿素配肥上的应用,测定了西瓜的生长状况和产量结构,进行了西瓜品质、土壤养分的分析,总结出了西瓜施用控释尿素的氪素利用率.结果表明,控释尿素配合施用可降低结瓜节位,增加地茎租度、蔓长,显著提高单瓜重,单施可增加西瓜的叶片数;控释尿素可提高西瓜的安全品质和营养品质.控释尿素土壤有机质的提高不明显,对全氮、碱解氮有显著提高,并具有明显的后效.U-D60-D90配合施用可显著提高氮素利用率,比普通尿素相对高98.58%,D60-D90比普通尿素相对高85.09%,U-D90比普通尿素相对高62.17%,在西瓜生产中可选用U-D60-D90、D60-D90两种方案施肥,既可提高西瓜产量又可提高品质.     

进境西瓜种子中西瓜细菌性果斑病菌的检测鉴定

由嗜酸菌属西瓜种(Acidovorax citrulli)引起的西瓜细菌性果斑病是西瓜等葫芦科作物上的一种极具毁灭性的病害,该病原细菌可以由种子携带传播。本研究通过直接研磨种子,用双抗体夹心酶联免疫吸附测定法(DAS-ELISA)和免疫捕捉聚合酶链式反应法(IC-PCR)对进境的西瓜种子进行检测,并且对PCR产物进一步克隆测序。结果表明,在DAS-ELISA产生阳性结果的样品中,IC-PCR结果也产生阳性。序列分析表明,该序列与已知的该病菌16S rRNA基因的相应序列具有100%同源性。因此,2006年这批来自台湾的西瓜种子携带有嗜酸菌属西瓜种(Acidovorax citrulli)。     

Molecular characterization and pathogenicity of binucleate Rhizoctonia AG-F associated to the watermelon vine decline in Italy

In recent years, watermelon (Citrullus lanatus) has been subjected to significant losses due to vine decline in Sicily (southern Italy). During a survey conducted in 2009, the predominant fungal species associated with root rot and vine decline were Rhizoctonia spp. The most isolates were characterized as binucleate Rhizoctonia AG-F through morphological observation, nuclear condition, anastomosis tests and sequence homology of rDNA-ITS. Occasionally, R. solani was found. The pathogenicity of binucleate Rhizoctonia and virulences of different isolates were tested in growth chamber on watermelon seedlings. All isolates were pathogenic on watermelon seedlings and showed statistically significant differences on the disease incidence and severity among them. To our knowledge, this is the first report worldwide of the occurrence of pathogenic binucleate Rhizoctonia responsible for root rot and associated with watermelon vine decline.     

土壤施加氧化钙对西瓜枯萎病的影响及其机理初探

为探明土壤撒施石灰对西瓜枯萎病发生的影响,本试验设计5个浓度剂量的氧化钙对连作西瓜5年的土壤进行消毒处理,通过栽培感病品种并调查植株生长情况、枯萎病发病率等指标,结合土壤中尖孢镰刀菌西瓜专化型1号小种病原菌孢子量和土壤pH的变化动态,以此评估土壤施加石灰防治西瓜枯萎病的效果,并利用不同浓度的钙对尖孢镰刀菌西瓜专化型菌丝生长和产孢量的影响进行防治机理的初步研究。试验结果表明,当土壤施加氧化钙后,西瓜发病率显著降低,各处理的相对防效分别为14%、57.8%、96.3%、94.7%、94.7%。在定植10d后,各处理均有促进植株生长发育的作用,其中1.34g/kg最显著。而随着氧化钙施加量的增加,土壤pH值也不断提高,30d趋于稳定。对土壤病原菌孢子数量检测表明:各处理土壤中病原菌数量均呈现显著降低的趋势。PDA平板生测结果表明,当钙离子浓度高于80mmol/L时,病原菌的生长及产孢量开始受到抑制,随着浓度的增加,抑制作用加强。土壤施加氧化钙不仅能改善土壤的酸化,还能有效防控西瓜枯萎病,其机理可能是土壤pH值的提高改变了土壤微环境,不利于病原菌侵染;施加的钙离子抑制了病原菌菌丝的生长及孢子的萌发。研究结果对揭示氧化钙防控西瓜枯萎病机制,具有一定的参考价值。