防治柑桔青,绿霉病的新药剂筛选试验

防治柑桔青、绿霉病的新药剂筛选试验周小刚田承权李美玲高菡四川省农科院植保所,成都６１００６６）四川是我国重点柑桔产区之一,大量的鲜桔必须通过贮藏,来延长供应。但柑桔在贮藏期间,常遭受青、绿霉病菌的为害,造成严重损失。原使用的苯并咪唑类保鲜剂防腐效果已...     

甲基托布津和托布津防治柑桔青、绿霉病研究

柑桔青霉病(penicillium italium wehmer)、绿霉病(P.digiatum Sacc)是引起柑桔果实在贮、运期大量腐烂的严重病害。国内外对该病的发生规律及防治,均作过许多研究,并证明果实采收后使用肥皂水、硼砂液、氨气、邻苯基酚钠配合联苯、涕必灵等药剂,对防治柑桔青、绿霉病均有一定的效果。据报道,1971年日本新农药甲基托     

赣南脐橙绿霉病菌对常用杀菌剂抗性监测

 本文研究了来自赣南7个县的柑橘绿霉病菌(Penicillium digitatum)种群对该地区常用杀菌剂抑霉唑、咪鲜胺、甲基硫菌灵和百可得的抗性频率、抗性水平和对抑霉唑的抗性分子机制。结果表明:病菌对抑霉唑和咪鲜胺存在基本一致的抗性;2011和2012年病菌种群对抑霉唑和咪鲜胺的抗性频率分别为82%和90%,平均抗性倍数为51.5倍,抗性分子机制均属于IMZ-R3,即CYP51B基因启动子区发生199 bp插入的突变;病菌种群对甲基硫菌灵的抗性频率分别为82%和91%;病菌种群对百可得均表现敏感。本研究为采后柑橘病害防治药剂选择提供了科学的依据。     

浙江衢州地区柑橘绿霉病菌对抑霉唑和多菌灵的抗性水平及其分子机制

研究了采自浙江衢州地区,包括柯城区、衢江区和开化县12个贮藏库的70个柑橘绿霉病菌Penicillium digitatum菌株对抑霉唑和多菌灵的抗性频率、抗性水平及其抗性分子机制。结果表明:柯城区和衢江区的抑霉唑抗性菌株(最低抑制浓度MIC≥0.5 μg/mL)的比例分别为77.1%和62.5%,两地抗性菌株的平均EC50值分别为2.07±1.04 μg/mL和2.35±0.73 μg/mL,分别是当地敏感菌株EC50值的41.4和47.0倍;而采自开化县的菌株均对抑霉唑敏感(MIC≤0.1 μg/mL),平均EC50值为0.04±0.02 μg/mL。柯城区和衢江区的多菌灵抗性菌株(MIC≥10 μg/mL) 的比例分别为54.3%和54.2%,而开化县的抗性菌株比例仅为9.1%。即来自柯城和衢江两个柑橘主产区的绿霉病菌群体对抑霉唑和多菌灵的抗性频率均远高于非柑橘主产区的开化县群体,说明抗药性群体的形成与药剂使用历史有关。进一步研究发现,衢州地区柑橘绿霉病菌对抑霉唑的抗性均属于IMZ-R3型,即与抑霉唑靶标基因 CYP51B 启动子区的插入突变有关,而对多菌灵的抗性则与 β-微管蛋白基因的992位核苷酸点突变(T→A)导致对应的200位点的氨基酸突变(F→Y)有关。     

荔枝采后炭疽病的发生情况及对贮藏效果的影响

为了明确广东、海南荔枝采后主要病害及其发生和危害情况，从两省荔枝主产区取果，在常温贮藏条件下观察荔枝采后病害的发生情况，测定荔枝果皮上炭疽病菌潜伏侵染率及其对荔枝采后生理变化和贮藏效果的影响。结果表明：荔枝采收后在28℃下贮藏，炭疽病、霜疫病和酸腐病的发病率分别为95．3％、6．5％和8．2％。炭疽病在采后3—4天开始表现症状，7天后发病率为60．8％～100％，9天后发病率为83．1％～100％，该病害是引起荔枝采后腐烂的主要病害，其病原菌主要来自采前潜伏侵染。从幼果果皮上可分离出潜伏侵染的炭疽病菌，随着果实的生长，果皮上的潜伏侵染率不断上升，到采收时炭疽病菌潜伏侵染率达到90％左右。炭疽病菌潜伏侵染率较高的荔枝果实。其采后呼吸速率、乙烯释放量、果皮丙二醛含量均显著升高，褐变腐烂较快，贮藏效果较差，即使在采后用杀菌剂处理，防治效果也不明显。采收时荔枝果皮上炭疽病菌潜伏侵染率越低，贮藏效果越好。在荔枝果实生长期间喷雾2—3次杀菌剂可显著地降低炭疽病菌潜伏侵染率，减轻荔枝采收后炭疽病的发生严重程度，提高荔枝贮藏效果。     

培福朗对柑桔果实贮藏防腐试验

柑桔果实贮藏,由于受青霉病、绿霉病、蒂腐病等危害,贮藏时间缩短,烂果严重,损失甚大.为寻求较好的防腐保鲜药剂,延长贮藏保鲜期.1989年冬我们作了用培福朗防治柑桔果实贮藏病害的试验,现将其结果简述于下.     

柑桔保鲜期病害的防治

柑桔青霉病和绿霉病是柑桔果实贮藏保鲜运输期间最容易发生、危害最严重的真菌病害,会使果实大量腐烂,烂果率一般占10%～30%,严重的达50%以上,常造成不应有的经济损失.现将这2种病害的症状及防治措施介绍如下:     

嘧霉胺对采后柑橘绿霉病的防治效果

在实验室和贮藏库条件下,对嘧霉胺单剂、嘧霉胺与抑霉唑或嘧霉胺和咪鲜胺混剂防治柑橘绿霉病的效果进行了评价。室内实验结果表明:采用500或1 000 mg/L嘧霉胺单剂、500 mg/L嘧霉胺+500 mg/L抑霉唑或500 mg/L嘧霉胺+500 mg/L咪鲜胺混剂在接种后12~18 h进行浸果处理,对由抑霉唑抗性或敏感菌株引起的绿霉病均有显著的防治效果,防效超过94%;500或1 000 mg/L 的抑霉唑对敏感菌株的防效在93%以上,但对抗性菌株的防效低于70%。贮藏库防效试验结果表明:在具抑霉唑抗性菌系的贮藏库中,上述质量浓度的嘧霉胺单剂、嘧霉胺与抑霉唑、或嘧霉胺与咪鲜胺混剂对绿霉病的防治效果明显优于抑霉唑单剂;而在不具抗抑霉唑菌系贮藏库中的防效则与抑霉唑相当。由此认为:嘧霉胺可作为抑霉唑的替代药剂应用于柑橘的采后处理,其推荐使用质量浓度为500~1 000 mg/L,可单独使用,也可与抑霉唑或咪鲜胺混合使用。     

柑桔采后化学杀菌剂应用的进展

柑桔采后化学杀菌开始大规模应用是在本世纪２０年代末－３０年代初，因药性与抗性问题化学杀菌剂的种类不断更新，大致可分为联苯与ＳＯＰＰ，苯并咪唑类和抑唑３个时代。目前，世界各柑桔生产国广泛应用的是苯并咪唑，仲丁胺，抑霉唑，双胍盐等化学杀菌剂，其控制柑桔采后腐烂，减少损耗效果显著。     

抑霉唑防治高橙贮藏期病害效果试验

抑霉唑防治高橙贮藏期病害效果试验黄贤华（浙江玉环县植保站，３１７６００）高橙是一种优质、汁多、风味浓、营养价值高的水果。高橙贮藏期很长，并随贮藏期的延长，其风味愈来愈浓，但烂果亦逐渐增多。为减轻贮藏期的烂果损失，应用抑霉唑等５种药剂进行了贮藏期防腐试...     

海洋放线菌A3202的分离鉴定及其对柑橘采后病害的防效

为获得用于防治柑橘采后病害的海洋放线菌,以柑橘青霉病菌Penicillium italicum、柑橘绿霉病菌P.digitatum和柑橘炭疽病菌Colletotrichum gloeosporioides为指示菌,对分离到的25株海洋放线菌进行筛选。通过平板对峙法测定拮抗菌株的抑菌谱,并测定其发酵产物粗提物对柑橘果实采后病害的防效,根据形态特征、培养特征、生理生化特征及16S rDNA序列对其进行鉴定。结果表明,分离自鳞笠藤壶Tetraclita squamosa的菌株A3202对3种指示菌均具有强抑菌活性,对供试13种植物病原菌的菌丝生长具有不同程度的抑制作用,尤其对柑橘青霉病菌和柑橘绿霉病菌的抑制作用最强,抑菌带宽度分别可达2.33±0.05 cm和2.32±0.10 cm。该菌株800 mg/L粗提物溶液对接种后7 d的柑橘青霉病、柑橘绿霉病和柑橘炭疽病的相对防效均可达100%。初步鉴定该菌株为放线菌中的米修链霉菌Streptomyces misionensis。     

First report of whisker mold,a postharvest disease on citrus caused by <Emphasis Type="Italic">Penicillium ulaiense</Emphasis> (in Japan)

In March 2006, stored fruits of the medium-to-late-ripening citrus variety Shiranuhi ([Citrus unshiu × C. sinensis] × C. reticulata) were found to have a disease similar to blue mold. The fungus causing this disease differed distinctly from the well-known, blue mold agent, Penicillium italicum, because it formed whisker-like coremia measuring 1–8 mm. On the basis of the morphological characteristics and the phylogenetic analysis based on the nucleotide sequence of the β-tubulin gene, the fungus was identified as P. ulaiense. This is the first report of citrus whisker mold caused by P. ulaiense in Japan.     

Antifungal activity of sodium propylparaben alone or in combination with low doses of imazalil against Penicillium decay on citrus fruit

The performance of postharvest treatments with sodium propylparaben (SPP), alone or combined with low doses of the fungicide imazalil (IMZ), against citrus green (GM) and blue (BM) molds was evaluated on several citrus species and cultivars artificially inoculated with Penicillium digitatum and P. italicum, respectively, and incubated at 20 °C or cold-stored at 5 °C. Effectiveness of 100 mM SPP dips at 20 °C for 60 s was higher on oranges than on mandarins, with GM and BM incidence reductions of up to 60–90 % after 7 days at 20 °C. Irrespective of citrus cultivar and storage condition, SPP generally improved the curative action of 25 μl l^?1 IMZ to control Penicillium molds. In additional tests, 100 mM SPP dips at 20 °C for 60 s only prevented GM on ‘Valencia’ oranges inoculated 24 h after treatment when combined with IMZ. It can be concluded that postharvest SPP treatments show promise as an effective alternative to be considered in citrus postharvest disease control programs.     

Development of specific primers based on the genomes of <Emphasis Type="Italic">Penicillium</Emphasis> spp. for rapid detection of <Emphasis Type="Italic">Penicillium digitatum</Emphasis> among fungal isolates in citrus

Specific primers targeting Penicillium digitatum were developed based on fungal genes RPB1 and cmd, which are conserved among the genomes of Penicillium spp. The specific primers were designed based on the mutational sites in the homologous regions of the conserved genes. The results indicated that primer pairs RPB1–1 and cmd-3 were specific enough to distinguish Penicillium digitatum (N1) from Penicillium chrysogenum (Q), Penicillium italicum (A10) and Penicillium expansum (L) when the DNA samples were diluted 100-fold. To further verify the effectiveness and specificity of the two primer pairs RPB1–1 and cmd-3, 38 strains of fungal isolates from sources related to citrus were detected using both primer pairs, and 14 candidate P. digitatum strains were identified. Then, the fourteen candidate P. digitatum strains were further identified as P. digitatum by morphological and molecular methods, which confirmed the detection accuracy and reliability of the specific primer pairs RPB1–1 and cmd-3 as molecular markers of P. digitatum. This work may significantly facilitate the rapid identification of P. digitatum in the citrus industry.     

Application of <Emphasis Type="Italic">Pantoea agglomerans</Emphasis> CPA-2 in combination with heated sodium bicarbonate solutions to control the major postharvest diseases affecting citrus fruit at several mediterranean locations

We determined the potential of using a formulated product based on Pantoea agglomerans CPA-2, either alone or in combination with heated sodium bicarbonate (SBC) solutions, to control the major postharvest diseases affecting citrus crops in the Mediterranean region. Treatments applied either individually or in combination were tested in semi-commercial and commercial trials carried out with oranges and mandarins from the Algarve, Andalusia and Catalonia. Firstly, several formulations of the biocontrol agents were tested in laboratory trials; one of them, a freeze-dried formulation of P. agglomerans strain CPA-2 called FD10-3, was chosen for combined with SBC. This formulation, applied at 2 × 10⁸cfu ml⁻¹ and the SBC treatment, applied at 3% 50°C for 20–40 s, demonstrated that it was possible to reduce decay development in laboratory trials. Semi-commercial applications of FD10-3 and 3% SBC solution at 50°C for 40 s showed excellent control of decay in unwounded mandarins and oranges artificially inoculated with both Penicillium digitatum and P. italicum. No rind injuries or residues attributable to hot water or SBC were observed on treated fruits. Combined treatment provided better control than the two treatments applied separately. Commercial trials demonstrated an important reduction in natural decay with the treatment of SBC 3% at 50°C for 40 s. Furthermore, bacterial-product formulation treatment significantly reduced the percentage of infected fruit and in some cases this reduction was equal to chemical treatments. Even so, no improvement in efficacy was observed with the combination of FD10-3 and SBC in the commercial test. We also assessed the ability of FD10-3 to grow at the wound site in oranges, whether alone or in the presence of SBC, and also its compatibility with standard citrus packinghouse practices.     

21种药用植物提取物对柑橘青霉病抑菌作用的筛选及白薇醇提物对脐橙青霉病的防治效果

为开发研制新型植物源柑橘保鲜剂,以抑菌圈直径为指标,利用牛津杯法筛选出对柑橘采后意大利青霉有良好抑制作用的21种中草药的醇提物,并对白薇醇提物防治脐橙青霉病的效果进行了评价。结果表明:白薇、零陵香、鸦胆子、藏青果、白药子5种中草药乙醇提取物对意大利青霉均有较好的抑制效果,抑制圈直径达26 mm以上,其中白薇醇提物抑菌活性最佳,抑制圈直径可达38.39 mm,最小抑菌浓度和最小杀菌浓度分别为3.13 mg/m L和6.25 mg/m L,且抑菌效果与对照药剂1 000倍咪鲜胺无显著差异。25 mg/m L白薇醇提物处理脐橙7 d后,对脐橙青霉病的防治效果达35.93%,与1 000倍咪鲜胺的防治效果相当(36.37%);白薇醇提物处理后可抑制意大利青霉菌菌丝生长,导致菌丝肿胀、膨大、畸形、细胞膜透性增加、细胞内含物外渗;还可诱导脐橙体内过氧化物酶活性下降,而苯丙氨酸解氨酶和几丁质酶活性上升。表明白薇醇提物对脐橙采后青霉病具有较好的防治效果,可进一步开发为植物源柑橘保鲜剂。     

Control of Citrus Green and Blue Molds with Garlic Extracts

Water and ethanol extracts of garlic cloves were applied to artificially inoculated citrus fruits to test their efficacy in the control of Penicillium digitatum and P. italicum, the cause of citrus green and blue mold respectively. Extracts were tested either alone, or in combination with vegetable (sunflower) cooking oil or fruit wax at the rate of (0.1% v/v), using two orange cultivars (Valencia and Shamouti), and grapefruit. Treated fruits were stored at 10±1 °C, and 90–95% relative humidity for 30 days. All concentrations of extracts were more effective than the water control in inhibiting the growth and development of both pathogens, but were not as effective as the fungicide treatment (imazalil 500 ppm + quazatine 1000 ppm). A remarkable increase in the activity of garlic extracts was observed when extracts were mixed with oil. Consequently, the treatment comprising 1% extract plus oil was as effective (100% control) as the fungicide treatment in controlling both green and blue molds on Valencia oranges.     

Control of<Emphasis Type="Italic">Penicillium digitatum</Emphasis> on citrus fruit using two plant extracts and study of their mode of action

Extracts from two plants from Ethiopia,Withania somnifera andAcacia seyal, were evaluated for their potential as natural biopesticides and to study their mode of action. Methanolic extracts of these plants were testedin vivo on citrus fruit for their efficacy to controlPenicillium digitatum when applied on wounded or unwounded fruit surfaces. Relative to the control, 70% and 75% of wound — inoculated fruit did not develop decay symptoms for up to 21 days of storage at 25°C and >85% r.h. An increase in cell wall-bound phenolics was evident in wounded fruit treated with plant extracts and inoculated with a spore suspension ofP. digitatum. Scanning electron microscopy revealed deposition of crystalline plant material sticking to the pathogen and around the wound site. The application of the plant extracts increased the epiphytic background total microbial population but decreased diversity. http://www.phytoparasitica.org posting May 7, 2007.     

Control of postharvest green mould of citrus by haliscosamine isolated from Haliclona viscosa sponge

The aim of this study was to evaluate the antifungal activity of haliscosamine isolated from Haliclona viscosa sea sponge from the Moroccan Atlantic coast against Penicillium digitatum, the causal agent of citrus green mould. The in vitro antifungal activity of haliscosamine, determined using the agar disc‐diffusion method, showed that haliscosamine and DESOGERME SP VEGETAUX^® (reference product) have fungicidal activity with inhibition diameters of 19 and 18 mm, respectively. Haliscosamine and a positive control (DESOGERME SP VEGETAUX^®) were tested in vivo in comparison with a negative control on orange fruits in normal storage conditions. This test showed that after four weeks of storage, the rate of decay of citrus fruits treated with haliscosamine or DESOGERME does not exceed 14%, whereas in the negative control the decay rate is 77%. The results of in vitro and in vivo tests indicate that haliscosamine and DESOGERME SP VEGETAUX^® have an important antifungal potential against P. digitatum and that haliscosamine (a natural product) may represent an alternative to the use of chemical fungicides.     

Effects of imazalil on sterol composition of sensitive and DMI-resistant isolates of Penicillium italicum

Imazalil differentially inhibited dry weight increase of 10-hour-old germlings of wild-type and DMI-resistant isolates ofPenicillium italicum in liquid malt cultures. EC₅₀ values ranged from 0.005 to 0.27 g ml^–1. In all isolates ergosterol constituted the major sterol (over 95% of total sterols) in the absence of the fungicide. Therefore, DMI-resistance cannot be associated to a deficiency of the C-14 demethylation enzyme in the ergosterol biosynthetic pathway. Imazalil treatment at concentrations around EC₅₀ values for inhibition of mycelial growth resulted in a decrease in ergosterol content and a simultaneous increase in 24-methylene-24,25-dihydrolanosterol content in all isolates. A correlation existed between the imazalil concentration necessary to induce such changes in sterol composition and the EC₅₀ values for inhibition of mycelial growth of the different isolates. The reason for the differential effects of imazalil on sterol composition in the variousP. italicum isolates may be due to decreased accumulation of the fungicide in the mycelium and to other yet non-identified mechanisms of resistance.Imazalil remt differentieel de toename in drooggewicht van 10-uur-oude gekiemde sporen van wild-type en DMI-resistente isolaten vanPenicillium italicum in vloeistofcultures van moutextract. De EC₅₀ waarden voor groei van de verschillende isolaten lopen uiteen van 0,005 tot 0,27 g ml^–1. In afwezigheid van het fungicide is in alle isolaten ergosterol het belangrijkste sterol (meer dan 95% van het totaal). DMI-resistentie kan daarom niet in verband staan met deficiëntie van het C-14 demethyleringsenzym in de ergosterol biosynthese. Imazalilbehandeling van mycelium bij concentraties rond de EC₅₀ waarde voor groeiremming, resulteerde bij alle isolaten in een afname van het ergosterolgehalte en een gelijktijdige toename van het gehalte aan 24-methyleen-24,25-dihydrolanosterol. Er bestaat dus een nauwe correlatie tussen de imazalilconcentratie die noodzakelijk is om vergelijkbare veranderingen in sterolsamenstelling te induceren en de EC₅₀ waarde voor remming van myceliumgroei van de verschillende isolaten. De differentiële effecten van imazalil op de sterolsamenstelling van de verschillendeP. italicum isolaten kunnen worden veroorzaakt door verminderde accumulatie van het fungicide in het mycelium en door andere, nog niet geïdentificeerde resistentiemechanismen.