茶皂素和噻菌灵混配对沙糖橘采后青绿霉菌的防治效果及品质的影响

为明确茶皂素和噻菌灵混配对柑橘青霉和绿霉病菌的抑制作用,采用菌丝生长速率法和共毒系数法测定了茶皂素、噻菌灵及其混剂对柑橘青霉和绿霉病菌的室内毒力以及增效比率(SR),同时测定了茶皂素与噻菌灵混剂对沙糖橘采后青绿霉菌的防治效果及其对贮藏品质的影响.结果表明,茶皂素与噻菌灵配比为8:2时对柑橘青霉和绿霉病菌具有显著的防治效...     

利用ITS核酸序列分析鉴定海洋青霉菌

1材料与方法 1．1菌株试验鉴定的青霉菌由海洋一所分离保存,见表 1.1．2培养基固体培养基：马铃薯葡萄糖琼脂培养基（PDA）,马铃薯浸汁1000ml,葡萄糖20g,琼脂20g。液体培养基：为该实验室改良,马铃薯浸汁200ml,蛋白胨2g,酵母粉1g,葡萄糖15g,NaCl30g,MgCl2·6H2O2．0g,KCl0．4g,FePO40．01g,蒸馏水1000ml。     

费菜黄酮对柑橘意大利青霉菌抑制作用的研究

为研究费菜黄酮对意大利青霉的抑菌效果并揭示其抑菌机制,本试验采用损伤接种法接种意大利青霉至柑橘,观察0、0.3、0.6、1.2 mg·mL^-1费菜黄酮对柑橘青霉病的控制效果,探究其对意大利青霉细胞膜通透性、细胞成分释放、菌丝表面结构、菌丝丙二醛(MDA)和过氧化氢(H₂O₂)含量等指标的影响。结果表明,费菜黄酮能够显著抑制菌丝生长,1.75 mg·mL^-1浓度下的抑制率为75.82%,7.00 mg·mL^-1 浓度下的抑制率达到100%。经费菜黄酮处理后,意大利青霉细胞膜通透性显著增加,糖类等胞内物质释放至细胞外;扫描电镜显示菌丝体结构遭到破坏,菌丝体表面出现褶皱、塌陷;同时引起H₂O₂和MDA含量增加;柑橘果实的发病率和病斑直径减小。本研究结果为天然杀菌剂的研制以及抑菌机制的后续研究提供了一定的理论依据。     

辣木叶黄酮对采后金桔青霉病的防治及机理研究

为考察辣木叶黄酮对采后金桔青霉病的防治效果,以意大利青霉菌为试验菌种,采用体外平板接菌试验和体内损伤接种试验研究辣木叶黄酮对金桔果实采后青霉病的抑制效果及其抑制机理。结果表明,辣木叶黄酮对意大利青霉菌具有良好的抑菌活性,其最小抑菌浓度(MIC)及最小杀菌浓度(MFC)分别为4.00和8.00 mg·mL^-1。扫描电镜(SEM)和透射电镜(TEM)结果表明,辣木叶黄酮会引起意大利青霉菌菌丝体的扭曲,明显改变青霉菌菌丝的形态,而胞内超微结构显示辣木叶黄酮会破坏其膜结构和细胞器,导致胞内内容物外流,胞内空洞化,进而引起菌体死亡;损伤接种结果表明,辣木叶黄酮处理可显著降低金桔的病斑直径并保持金桔硬度(P<0.05),同时提高苯丙氨酸解氨酶(PAL)和几丁质酶相关防御酶的活性,使果胶酶保持较低的活性,增强果实的抗病性。本研究结果对辣木叶黄酮在柑橘类水果采后贮藏保鲜的应用具有重要意义。     

Chemical composition and phytotoxic activity of the volatile oil of invasive Xanthium italicum Moretti from Xinjiang, China

Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the environment to affect other plants' growth.This phenomenon was further studied by evaluating the phytotoxic effects of X.italicum essential oil against two dicot plants,amaranth(Amaranthus mangostanus L.)and lettuce(Lectuca sativa L.),and two monocot plants,wheat(Triticum aestivum Linn)and ryegrass(Lolium multiforum),and analyzing the chemical composition of the oil.Among the 4 test species,amaranth was the most sensitive plant,0.5μl/mL essential oil application resulted in a 50% reduction on root elongation,and 2.5 μl/mL essential oil almost completely inhibited its seedling growth.Wheat was the least sensitive species,whose root growth was reduced to 36% of control by 5 μl/mL essential oil.The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass.Compared to a commercial herbicide-Harness,X.italicum oil exhibited stronger phytotoxicity on amaranth,lettuce and wheat,but weaker activity on ryegrass.The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X.italicum Moretti was analyzed by GC/MS.Thirty two compounds were identified,representing 94.89% of total oil,which was found to be rich in monoterpene hydrocarbons(60.71%).The main constituents of the oil were limonene(51.61%),germacrene B(6.98%),δ-cadinol(5.94%),β-pinene(5.23%),α-caryophyllene(5.1%)and bornyl acetate(3.15%).Bioassay revealed the dominant constituent-limonene,was unlikely the responsible phytotoxic compound due to its low biological activity;rather,there might be other oil constituent(s)that either act alone,or work together,and possibly assisted by synergistic effect,to display the phytotoxic activity.Our results suggested that X.italicum might produce allelopathic VOCs to facilitate its invasion success.This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X.italicum Moretti from China.     

拮抗细菌对部分水果产后病原真菌的抑制及防腐作用

研究了桔抗细菌即地衣芽孢杆菌(Bacillus licheniformis)W10和多粘类芽孢杆菌(Paenibacilluspolymyxa)W3、Y2对苹果轮纹病菌、柑桔炭疽病菌和柑桔青霉病菌的抑制作用。结果表明,拮抗细菌对病菌菌丝生长、产孢和芽管伸长均有显著的抑制作用,其中W10菌株抑菌作用最强。显微镜观察显示,车抗细菌可引起病菌菌丝异常,即菌丝扭曲,菌丝细胞畸形,菌丝颜色变淡,菌丝断裂离解等。离体果实接种试验表明,菌株W10能明显推迟水果发病,降低果腐率,抑制病斑扩展。     

500g/L抑霉唑乳油对柑橘青霉和绿霉病菌的抑制作用与防治效果

试验结果表明,5 0 0 g/L抑霉唑乳油对柑橘青霉病菌和绿霉病菌的抑制中浓度(EC50)分别为0.0136mg/kg和0.0129mg/kg。用400~800mg/kg的抑霉唑药液浸果1m in,捞起晾干,装箱入库常温贮藏,药后60d,对柑橘青霉、绿霉病的防效达93.11%~96.48%,极显著高于70%甲基硫菌灵用600mg/kg处理的防效(84.30%),且对贮藏期的柑橘没有药害,对果实的色泽和口味没有明显的影响。     

和厚朴酚对水果采后致腐真菌的抑制作用

以和厚朴酚标准品为试材,测定其对引起采后水果腐烂的青霉菌(Penicililum expansum)和链格孢菌(Al-ternaria alternata)的抑菌活性.结果表明,和厚朴酚对供试青霉菌(P.expansum)茵丝与孢子萌发均有较强的抑制作用;对链格孢菌(A.alternata)菌丝也有较强的抑制作用,但对链格孢菌(A.alternata)孢子萌发没有显著的抑制作用.     

Prochloraz采后处理对苹果贮藏期病害的控制

经Prochloraz处理对苹果采后青霉病(penicilium expansum)的抑制效果进行了研究.结果表明,Prochloraz对P.expansum具有明显的抑制作用,浸泡处理可明显地降低损伤接种P.expansum的病斑直径,其中以500 mg/LProchloraz在40℃浸泡处理对降低损伤接种P.expansum的病斑直径效果最佳;不同处理时间对病斑直径也有一定的影响,以500mg/L Prochloraz处理2min的抑制效果最佳.     

高压静电场对桔青霉菌的萌发率与产孢量的影响

采用不同的预处理方法，利用匀强高压静电场的不同场强，研究了高压静电场、处理时间、预萌发时间对桔青霉菌的萌发率、产孢量的作用效果。结果表明：场强对青霉菌的萌发率的作用效果极显著，场强不同，作用效果不同。随着处理时间的增加，桔青霉菌的萌发率有下降的趋势。对萌发一定时间的孢子悬液处理，其萌发率与对照相比没有明显的差别。