不同浓度苦参提取物对蔬菜病原菌的抑菌活性

采用生长速率法和悬滴法室内测试了不同浓度苦参提取物对葱菌核菌、番茄早疫菌、菜豆根腐菌、辣椒枯萎菌、黄瓜枯萎菌、茄子黄萎菌等6种蔬菜病原菌的抑菌活性。结果表明:苦参提取物对供试病菌菌丝生长和孢子萌发均有很强的抑制作用。在供试质量浓度10mg/mL时,对辣椒枯萎菌、葱菌核菌、菜豆根腐菌、黄瓜枯萎菌菌丝生长的抑制率均在61%以上;在供试质量浓度30mg/mL时,对辣椒枯萎菌、菜豆根腐菌、黄瓜枯萎菌、番茄早疫菌的抑制率均在70%以上,对葱菌核菌的抑制率达81.61%。试验表明,随着苦参提取液浓度的升高对供试菌孢子萌发抑制作用增强。在供试质量浓度30mg/mL时,孢子萌发抑制率均在77.04%以上。     

不同提取条件对葡萄叶提取物抑制两种病原菌活性的影响

以黄瓜枯萎病菌和辣椒枯萎病菌作为供试菌种,采用生长速率法对葡萄叶不同溶剂提取物和不同提取方法提取物的抑菌活性进行测定。结果表明,葡萄叶不同溶剂提取物对供试菌种均表现出抗菌效果,并筛选出最佳提取溶剂是95%的乙醇,而最佳提取条件是提取温度40 ℃、提取时间和方式是超声波提取30 min,提取料液比1∶8(g/mL)。     

茜草等25种中药材对5种植物病原真菌的抑制活性

以苹果腐烂病菌、苹果轮纹病菌、棉花枯萎病菌、柑橘炭疽病菌与白菜黑斑病菌为供试菌,采用生长速率法测定25种中药材甲醇粗提物的抑菌活性。结果表明,在浓度为5.0mg/mL时,大部分中药材的甲醇粗提物对至少一种植物病原真菌都表现出不同程度的抑制活性,其中知母、青蒿、细辛与白鲜皮对3种供试植物病原菌的抑制率大于75%,而茜草与姜黄对4种供试植物病原菌的抑制率均在80%以上,具有广泛的抑菌谱。进一步采用系统溶剂法得到的茜草不同溶剂萃取物中,水饱和正丁醇相抑菌活性明显优于石油醚及乙酸乙酯相,表明茜草抑菌活性成分主要为中等及大极性化合物。     

不同时期嫁接感染甘薯病毒病害SPVD对甘薯产量的影响

以苹果腐烂病菌、苹果轮纹病菌、棉花枯萎病菌、柑橘炭疽病菌与白菜黑斑病菌为供试菌,采用生长速率法测定25种中药材甲醇粗提物的抑菌活性。结果表明,在浓度为5．0 mg／mL 时,大部分中药材的甲醇粗提物对至少一种植物病原真菌都表现出不同程度的抑制活性,其中知母、青蒿、细辛与白鲜皮对3种供试植物病原菌的抑制率大于75％,而茜草与姜黄对4种供试植物病原菌的抑制率均在80％以上,具有广泛的抑菌谱。进一步采用系统溶剂法得到的茜草不同溶剂萃取物中,水饱和正丁醇相抑菌活性明显优于石油醚及乙酸乙酯相,表明茜草抑菌活性成分主要为中等及大极性化合物。     

10种N-取代氨基香豆素的合成及生物活性

基于结构拼接思想,设计合成了10个N-取代氨基香豆素类化合物,并测定了其抑菌及除草活性。6-硝基香豆素经Fe/NH4Cl还原得6-氨基香豆素,再与不同醛缩合得Schiff碱,最后经硼氢化钠还原制得10个N-取代氨基香豆素类化合物(4a~4J),其中9个未见文献报道,其结构均经红外光谱、核磁共振氢谱和质谱确认。抑菌活性测试结果表明,所有化合物对苹果腐烂病菌Valsa mali、葡萄白腐病菌Coniothyrium diplodiella、棉花枯萎病菌Fusarium oxysporium和柑橘炭疽病菌Citrusanthrax bacteria均有一定抑制作用,其中 4e 的抑菌活性最强,对苹果腐烂病菌和柑橘炭疽病菌的EC50值分别为7.53和12.93 mg/L,对其余2种植物病原菌的EC50值均小于25 mg/L;化合物 4f 次之,对苹果腐烂病菌和葡萄白腐病菌的EC50值均约为11 mg/L。除草活性测试结果表明,除 4f 外,所有目标化合物均有一定除草作用,其中 4c 的活性最强,100 mg/L下对反枝苋Amaranthus retroflexus种子根、茎生长的抑制率均为99%。     

肉桂精油对4种重要果蔬病原真菌的生物活性研究

为进一步明确肉桂精油的农用抑菌活性,采用菌丝生长速率法、孢子萌发法和活体组织法系统测试了其对番茄灰霉病菌、苹果青霉病菌、番茄茎枯病菌和黄瓜镰刀菌4种重要果蔬病原真菌的抑菌活性。结果表明,肉桂精油对番茄灰霉病菌的抑制效果较好。离体活性测试中,肉桂精油对4种供试菌菌丝生长的抑制中浓度（EC50）分别为272.17、324.78、316.24、326.95 mg/L;对4种供试菌孢子萌发的EC50分别为196.01、273.52、390.44、311.23 mg/L。果实针刺法试验结果表明,在10 g/L处理剂量下,肉桂精油对番茄灰霉病的治疗作用和保护作用分别为64.16%和34.90%（3 d）,保护作用与对照药剂1 g/L腐霉利无显著差异。     

黄瓜炭疽病菌代谢物中抑菌活性成分研究

采用大孔吸附树脂提取和硅胶柱层析分离技术,从黄瓜炭疽病菌Colletotrichum orbiculare代谢物中获得一个抗真菌化合物,采用高分辨质谱、核磁共振波谱和红外光谱等技术鉴定了其化学结构,并评价了其对番茄灰霉病菌、西瓜枯萎病菌、烟草赤星病菌、苹果炭疽病菌和玉米弯孢病菌的孢子萌发和菌丝生长的抑制作用。结果表明:该化合物为间二羟基苯甲酸大环内酯类抗生素——根赤壳菌素;其对所有供试真菌的孢子萌发均未表现出明显的抑制活性,但对番茄灰霉病菌Botrytis cinerea的菌丝生长表现出很强的抑制作用。     

两种新型琥珀酸脱氢酶抑制剂的抑菌活性比较

采用菌丝生长速率法、孢子萌发法和幼苗法比较了吡唑萘菌胺和氟吡菌酰胺对23种病原菌的毒力。结果表明,吡唑萘菌胺对黄瓜褐斑病菌、黄瓜炭疽病菌、辣椒炭疽病菌、番茄早疫病菌、苹果斑点病菌、辣椒疫霉病菌、马铃薯晚疫病菌、番茄灰霉病菌、番茄菌核病菌、水稻稻瘟病菌和苹果轮纹病菌菌丝生长均有较高的抑制活性,其EC50值为0.10~9.52μg/mL,EC90值为1.87~62.23μg/mL。吡唑萘菌胺对花生白绢病菌、苹果腐烂病菌、棉花黄萎病菌、棉花立枯病菌和镰刀菌属病原菌的抑制活性均高于氟吡菌酰胺,而氟吡菌酰胺却对黄瓜褐斑病菌、番茄早疫病菌、苹果斑点病菌、番茄灰霉病菌、番茄菌核病菌和苹果褐斑病菌具有较高的抑制活性,其EC50值为0.39~3.98μg/mL,与吡唑萘菌胺相当。吡唑萘菌胺对玉米丝黑穗、花生冠腐病菌和番茄灰霉病菌的孢子有较高的毒力,其EC50值分别为0.002 9、0.07和1.38μg/mL。氟吡菌酰胺仅对花生冠腐病菌、番茄灰霉病菌的孢子有较高的活性,且它与吡唑萘菌胺活性相当。吡唑萘菌胺和氟吡菌酰胺对黄瓜白粉病菌均有较高的毒力,EC50值分别为0.04、0.05μg/mL。因此,吡唑萘菌胺比氟吡菌酰胺更加广谱,且抑菌活性相当或更高。     

瑞香狼毒根提取物对植物病原真菌的抑菌效果研究

用乙醇温浸法提取瑞香狼毒根的活性物质,对11种常见植物病害的病原菌,采用生长速率法进行抑菌活性测定。结果表明,乙醇提取液中存在抑菌活性物质,对油菜菌核病菌、辣椒疫病菌、番茄早疫病菌、草莓灰霉病菌的抑制效果较好,对其他几种病菌也表现出一定的抑制作用。     

18种中药提取物对植物病原菌的抑制作用

以18种中药丙酮提取物为材料,测定了其对几种病菌的生物活性。结果表明：在供试质量浓度为0.05g/mL时,公丁香、八角茴香、姜黄、川芎提取物对所有供试菌菌丝生长抑制作用的抑制率均在60%以上,其中公丁香提取物抑菌活性最好,对所有供试菌的抑制率均为100%;黄岑、羌活、知母、当归提取物抑菌活性次之,对其中4种供试菌的抑菌活性均大于60%;青木香、白术、地榆、萆薢提取物的抑菌活性也较好,对其中2～3种供试菌的抑菌活性均大于60%。在供试质量浓度为0.1g/mL时,公丁香、八角茴香和黄岑提取物能强烈抑制棉花枯萎病菌的孢子萌发抑制作用,抑制率均为100%;川芎、羌活和知母提取物对棉花枯萎病菌的孢子萌发抑制作用显著,抑制率均在90%以上;防己、莪术和白术提取物对孢子萌发抑制活性次之,抑制率均在70%以上。公丁香、八角茴香、川芎、姜黄、黄岑、羌活、知母和当归等8种中药作为植物源杀菌剂值得进一步研究。     

Studies on the therapeutic effects of pectolytic enzyme inhibitors

A few polyphenols (tannic acid and digallic acid), anthraquinone derivatives (rufianic acid and quinalizarin), and detergents (an alkylaryl sulfonate) proved to be especially effective inhibitors of pectolytic and cellulolytic enzymes of four phytopathogenic fungi. Some of these substances prevented the infection of tomato leaves withAlternaria solani. It appears, however, that inhibition of the germination of conidia was the crucial effect rather than inhibition of the enzymes. Alkylaryl sulfonate and rufianic acid were able to reduce the maceration of bean hypocotyls byRhizoctonia solani. Rufianic acid also counteracted tomato wilt, caused byFusarium oxysporum f.lycopersici, especially in the case of postinfectional application. On the other hand preinfectional rather than postinfectional application of rufianic acid had effect onVerticillium wilt of tomato.In one case, viz.Fusarium wilt, the mode of action of rufianic acid was investigated in greater detail. The presence of this substance could be demonstrated in the exudates of healthy and infected plants after application to the roots. The pectolytic and cellulolytic activity of the exudates and the pectinmethylesterase activity of stem extracts of infected, rufianic acid treated plants were reduced, as well as the quantity of mycelium in the stems. Possibly other mechanisms are also involved in the mode of action of rufianic acid.The prospects of using pectolytic enzyme inhibitors for the therapy of plant diseases are discussed.     

OS-诱抗剂诱导植物抗病性的作用探讨

用PDA培养基平板法测定了0.4%OS-诱抗剂水剂对水稻纹枯病菌、小麦纹枯病菌、油菜菌核病菌、辣椒立枯病菌、瓜类绵腐病菌、黄瓜枯萎病菌的生物活性,其EC₅₀值分别为34.56、59.33、33.17、85.92、91.91、122.87μg/mL,OS-诱抗剂对水稻纹枯病、油菜菌核病较好。高效液相色谱分析表明,经OS-诱抗剂处理后的植物提取液中酚类物质的种类和含量相对于对照有明显的变化,说明OS-诱抗剂对植物的防病作用可能是促使植物体内产生了酚类抗病物质。     

Inhibitory and stimulatory effects of essential oils and individual monoterpenoids on growth and sporulation of four soil-borne fungal isolates of Aspergillus terreus, Fusarium oxysporum, Penicillium expansum, and Verticillium dahliae

The effect of essential oils and individual monoterpenoids on soil-borne fungi, in pure and mixed cultures, in growth media and in the soil environment, was investigated. Essential oils were extracted from lavender (Lavandula stoechas), oregano (Origanum vulgare subsp. hirtum), sage (Salvia fruticosa) and spearmint (Mentha spicata). The monoterpenoids tested were fenchone, carvacrol, 1,8-cineole, carvone, α-pinene and terpinen-4-ol. Their effect was examined on growth and sporulation of Aspergillus terreus, Fusarium oxysporum, Penicillium expansum and Verticillium dahliae isolated from an organic cultivation of tomato. All tested essential oils and individual monoterpenoids inhibited mycelial growth in all fungi and conidial production in most fungi. The strongest inhibitory activity on mycelial growth was exhibited by oregano and spearmint oils and by carvacrol and carvone, respectively their main constituents. The inhibitory activity was clearly fungistatic in A. terreus and F. oxysporum but fungicidal in V. dahliae. On sporulation, clearly stimulatory effects were observed alongside inhibitory ones. Conidial production was always promoted by α-pinene in P. expansum and by sage oil in F. oxysporum. At certain dosages it was promoted by cineole and carvone in F. oxysporum, and by lavender oil in A. terreus and V. dahliae. Experiments with carvone and carvacrol against mixed fungal cultures in a soil environment showed that V. dahliae was the most sensitive and A. terreus the most tolerant of the four fungi. Our results demonstrate strong but divergent effects and selectivity of action of the lower terpenoids on fungal strains that can become serious pests of tomato. Of special importance is the complete inhibition of growth and conidial production of V. dahliae, a pathogen otherwise very resistant to chemical control.     

一株生防内生真菌的分离筛选、鉴定及抑菌特性

为获取优良植物病害生防菌,以交链孢菌Alternaria tenuis Ness和尖镰孢菌Fusarium oxysporum Schlecht为指示菌,采用平板对峙培养法、抑菌圈法和菌落直径法对健康龙柏鳞叶小枝中分离的4株优势内生真菌进行了筛选评价,并结合形态学观察及ITS序列分析对筛选出的生防内生真菌进行了鉴定。结果表明,对峙培养发现1菌株对交链孢菌和尖镰孢菌均具有较好的抑制作用,抑菌率分别为52.05%和48.65%,标记其为LB-1;LB-1菌株与指示菌对峙培养的菌落交界面处,2种指示菌的菌丝均出现了消解、断裂,而LB-1的菌丝则生长正常。未灭菌LB-1菌株发酵液对交链孢菌和尖镰孢菌产生的抑菌圈直径分别为14.1 mm和13.7 mm,抑菌率分别为47.89%和48.72%;灭菌LB-1菌株发酵液对交链孢菌和尖镰孢菌的抑菌圈直径分别为15.3 mm和15.0 mm,抑菌率分别为5.96%和33.90%,指示菌在生长过程中菌丝溶解现象明显。经鉴定,LB-1菌株为毛壳菌属Chaetomium中的近缘毛壳菌C.subaffine,是一种极具生防潜力的内生真菌,其抑菌特性可能通过溶菌作用实现。     

几种药用植物杀菌活性的初步研究

以茄链格孢（Alternaria solani）、尖孢镰刀菌（Fusarium oxysporum）、茄病镰刀菌（F. solani）、出芽短梗霉（Aureobasidium pullulans）、灰葡萄孢（Botrytis cinerea）为供试真菌,用生长速率法和孢子萌发法对8种药用植物提取物的离体活性进行测定。结果表明：在生药质量浓度为0.1 g/mL时,党参和黄芩对5种供试菌菌丝的抑制率达78%以上,苦参和地黄对5 种供试菌菌丝的抑制率达65%,苦参、党参和黄芩对5 种供试菌的孢子萌发抑制率大于70%。尤其是党参、黄芩和苦参的提取液对5 种供试菌的菌丝生长和孢子萌发抑制率均大于65%,值得进一步研究开发。     

野生酸枣内生细菌筛选、鉴定及其抑菌活性测定

为广泛开发植物内生菌资源,采用组织分离法从野生酸枣的根、茎、叶和果实中进行生防菌的分离和筛选,通过平板对峙法和发酵液法测定了所得菌株对8种植物病原菌的活性,并利用生物学和分子学方法对所得菌株进行了鉴定。结果显示,从野生酸枣的根、茎、叶和果实中共分离得到76株内生细菌;通过对所有菌株进行初筛和复筛,最终得到8株拮抗作用较强的菌株,菌株SZG-23、SZG-1、SZY-13和SZS-3对梨黑斑病菌Alternaria kikuchiana和黄瓜枯萎病菌Fusarium oxysporum f.sp.cucumerinum的抑制作用较强,抑制率均分别高于82.5%和71.1%,其中菌株SZG-23的抑制率最高,达90.3%和72.4%。菌株SZG-23发酵液对8种植物病原菌生长均有一定的抑制作用,其中对梨黑斑病菌和番茄灰霉病菌Bortytis cinerea的抑制作用最好,抑制率分别达92.2%和90.5%。菌株SZG-23的抗利福平突变菌株能在酸枣幼苗中定殖和移动。结合形态观察、生理生化特征及16S r DNA同源性分析将菌株SZG-23鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens,16S r DNA序列在Gen Bank中登录号为KF483660。     

Screening for Antifungal Potential of Plant Extracts of Fifteen Plant Species Against Four Pathogenic Fungi Species

The antifungal activity of fifteen wild plant species grown in the Al-Qassim region, Saudi Arabia, was investigated against the fungi species Fusarium solani, Botrytis cinerea, Alternaria alternata and Stemphylium botryosum at concentrations of 10, 20, 40 and 80?g/L. The inhibitory effect of test extracts varied among examined fungi, and Fusarium solani exhibited the least sensitivity compared to other fungi species. Antifungal activity of the tested extracts was proportional to the applied dose. Extracts of Lactuca virosa, Neurada procumbens, Ochradenus baccatus and Cyperus conglomerates showed relatively low inhibition effects on the fungi species. The most effective plants were Pulicaria undulata, Artemisia monosperma, Prosopis juliflora, Withania somnifera and Rumex vesicarius. At 80?g/L, extracts of these plant species reduced mycelial growth of Botrytis cinerea by 16.5–32.2%, of Fusarium solani by 11.1–27.9%, of Alternaria alternaae by 26.9–63.5% and of Stemphylium botryosum by 22–40%. The methanolic extract of the most effective plant species was further fractioned with hexane, methylene chloride and ethyl acetate. The obtained fractions varied in their effects on mycelial growth of the four tested fungi. Using the same fraction resulted in different inhibition effects on mycelial growth of all tested fungi. The antifungal activity of each crude extract tended to be distributed among its three fractions, probably because the bioactive components were also distributed among the fractions.     

Effect of ammonium/nitrate ratio in nutrient solution on control of Fusarium wilt of tomato by Trichoderma asperellum T34

The behaviour of Fusarium oxysporum f.sp. lycopersici (Fol) and the effectiveness of the microbial control agent Trichoderma asperellum strain T34 were examined in hydroponically grown tomato plants under five ammonium/nitrate ratios. The results showed that disease severity was reduced by the action of T34 under increasing concentrations of ammonia. Furthermore, rhizosphere F. oxysporum populations decreased with T34 application. The presence of T34 augmented leaf nitrogen concentration in treatments infested with Fol. In addition, T34 application reduced iron concentration in tomato leaves at high ammonium/nitrate ratios and reduced the severity of Fusarium wilt at high iron and nitrogen leaf concentrations.     

地肤子提取物对苹果树腐烂病菌的抑制作用及对其菌体结构和功能的影响

为开发新型安全高效的植物源苹果树腐烂病防治剂,采用菌丝生长速率法测定中草药地肤子乙醇提取物及各层析流分L1～L9对苹果树腐烂病菌Valsa mali的抑制作用,同时通过室内常规分析方法观测流分L7对该菌菌丝形态结构、细胞膜通透性及物质吸收和代谢的影响。结果表明,地肤子乙醇粗提物浓度为2 mg/mL时对苹果树腐烂病菌具有较强的离体抑制活性,处理后96 h的抑菌率达到92.16%。分别用石油醚、氯仿、正丁醇萃取醇提物,石油醚萃取物对苹果树腐烂病菌的抑制效果最为明显,其EC_(50)为0.07 mg/mL;在石油醚萃取物通过硅胶柱层析分离得到的9种流分中,流分L7对苹果树腐烂病菌的抑制作用显著,离体抑菌率高达96.73%;且在流分L7处理下,病菌菌丝体出现肿胀、膨大或畸形等现象,细胞膜通透性增大,可溶性蛋白、还原糖以及丙酮酸的含量随流分L7浓度的升高而持续降低,当浓度为100μg/mL时,菌丝体可溶性蛋白、还原糖及丙酮酸的含量分别降低70.78%、71.74%和78.68%。表明在离体培养条件下地肤子乙醇提取物能明显抑制苹果树腐烂病菌的生长,并对菌丝体细胞膜结构和功能稳定性产生显著影响,具有进一步开发为新型植物源苹果树腐烂病防治剂的潜力。