【作者】 李凌绪；

【导师】 林奇英；

【作者基本信息】 福建农林大学 ， 农药学， 2004， 硕士

【摘要】 本研究的目的是为了从海藻中获得天然抗病活性物质。本研究针对植物病毒、植物病原真菌和一些细菌进行了筛选。 采用半叶法对8种海藻粗提物的抗烟草花叶病毒(Tobacco mosaic virus,TMV)活性进行了测定。结果表明，在5％浓度下3种海藻的乙醇提取物对TMV的体外抑制率达到60％以上。采用不同极性的有机溶剂对抑制率在60％以上的海藻乙醇提取物进行萃取并分别测定其体外抑制病毒的活性，发现草叶马尾藻(Sargassum graminifolium)和铁钉菜(Ishige okamurai)对TMV具有体外抑制作用的成分大部分存在于低极性的石油醚萃取相和乙酸乙酯萃取相，萃余水层活性比较低，但羊栖菜(Sargassum fusiforme)对TMV具有体外抑制作用的成分大部分存在于水相中。各萃取相对TMV体外抑制作用在90％以上的有：铁钉菜石油醚萃取相91％、铁钉菜乙酸乙酯萃取相92.31％、羊栖菜水萃取相98.2％。叶圆片漂浮法测定表明，铁钉菜石油醚萃取物可以轻微抑制普通烟草体内TMV的复制。铁钉菜石油醚萃取相和乙酸乙酯萃取相喷施处理心叶烟，能起到一定的保护效果，枯斑抑制率分别为87.69％和91.54％。铁钉菜石油醚萃取物喷施处理可以轻微的抑制TMV侵染普通烟草，可以提升多酚氧化酶和过氧化物酶的活性。相对防效实验证实铁钉菜粗提物石油醚萃取相可能无法在生产中用作烟草花叶病防治剂。采用化学预试验、纸层析和薄层层析结合的方法初步确定铁钉菜石油醚萃取相中抗病毒活性物质为酚类物质。 以立枯丝核菌(Rhizoctonia solani)、香蕉炭疽菌(Gloeosporium musarum)、链格孢菌(Alternaria brassicae)、镰刀菌(Fusarium oxysporum f.sp.)、苹果干腐菌(Botryosphaeria dothidea)、苹果青霉菌(Penicilium expansum)、辣椒疫霉菌(Phytophthora capsici)、甜椒灰霉菌(Botrytis cinerea)为筛选靶标，采用生长速率法测定了8种海藻的抗植物病原真菌的活性。实验发现，孔石莼(Ulvapertusa)粗提物对链格孢菌，浒苔(Enteromorpha sp.)粗提物对甜椒灰霉菌，江蓠(Gracilaria verrucosa)粗提物对立枯丝核菌和甜椒狄霉菌、沙菜(Hypneasp.)粗提物对甜椒灰霉菌的菌丝生长抑制率都达到了40％以上。以香蕉炭疽菌、苹果干腐菌、玉米弯孢霉菌(Curvularia lunata)为筛选靶标，采用孢子萌发法福建农林大学硕卜学位论文测定了6种海藻的抗真菌活性。实验表明沙菜、江禽、娱蚁藻(G尹口tetouPia刀licina)粗提物对供试3种真菌的抱子萌发和羊栖菜粗提物对苹果青霉菌饱子的萌发都有70%以上的抑制率。其抑制作用主要表现为抱子不能萌发、芽管不能生长。从上述结果可以看出，几种海藻粗提物的抗真菌活性依次为:红藻>绿藻>褐藻。 以革兰氏阳性菌金黄色葡萄球菌(及即彻2口coccus aure“us)、枯草芽抱杆菌 (Bacillus、ubtilis)、蜡状芽饱杆菌(Bacillu、cereus):革兰氏阴性菌大肠杆菌 (Escherichia coli)、变形杆菌(尸勿teus sPecie，)、姜瘟病菌仔，‘封由monassozanaearum)、烟草野火菌(Pseudomonas圳i找gae pv.tabaei)为筛选靶标，采用抑菌圈法测定了7种海藻粗提物对病原细菌的活性。实验表明，沙菜、江篱、娱蛤藻的粗提物具有较强的广谱抗菌能力，褐藻对细菌的抑制能力相对红藻较弱。对沙菜粗提物进行了系统溶剂萃取，表明主要的抑菌物质分布在石油醚相和乙酸乙酷相。从实验结果看，海藻提取物对革兰氏阳性菌和阴性菌的抑制能力相近。更多还原

【Abstract】 The object of this research was to get some natural active substances from algae.The activities of algae on platn virus, plant pathogenic fungus, bacteria were screened.The anti-TMV activities in vitro were determined with ethanol extracts from 8 algae. The results indicated that ethanol extracts from 3 algae had more than 60% inhibiting rate on TMV. Ethanol extracts which inhibiting rates were more than 60% had been extracted by other organic solvent and their inhibiting rates on TMV had been determined. It was shown that the most of anti-TMV substance from Sargassum graminifolium and Ishige okamurai were in petroleum ether extracts and ethyl acetate extracts, fewness was in water extracts. But a majority of anti-TMV substance from Sargassum fusiforme was in water extracts. They were petroleum ether extracts from Ishige okamurai (91%), ethyl acetate extracts from Ishige okamurai (92.31%) and water extracts from Sargassum fusiforme (98.2%) . Petroleum ether extracts from Ishige okamurai and ethyl acetate extracts from Ishige okamurai could not distinctly inhibit multiplication of TMV in the discs of tobacco leaves. The inhibiting rates were 87.69% and 91.54% by spraying petroleum ether extracts from Ishige okamurai and ethyl acetate extracts from Ishige okamurai on Nicotiana glutinosa. The activity of peroxidase (POD) and Polyphenoloxidase (PPO) could be increased by spraying petroleum ether extracts from Ishige okamurai on N. tobacum cv K326. But petroleum ether extracts from Ishige okamurai could not protect tobacco against TMV. The chemical character of petroleum ether extracts from Ishige okamurai was detected by chemical preliminary pretest, paper chromatogram and thin layer chromatogram. It was a sort of phenolic compounds which could inhibit TMV in vitro.The inhibiting effects of the ethanol extracts from the 8 algae on hypha growth of Rhizoctonia solani, Gloeosporium musarum , Alternaria brassicae , Fusarium oxysporum f.sp., Botryosphaeria dothidea , Penicilium expansum , Phytophthoracapsici and Botrytis cinerea were determined. The inhibiting rates of ethanol extracts from Ulva pertusa on Alternaria brassicae is higher than 40%. The inhibiting rates of ethanol extracts of Enteromorpha sp. on Botrytis cinerea, ethanol extracts of Gracilaria verrucosa on Rhizoctonia solani and Botrytis cinerea, ethanol extracts of Hypnea sp. on Botrytis cinerea were also higher than 40%. The inhibiting effects of the ethanol extracts from the 6 algae on conidium germination of Colltotrichum higginsianum, Botryosphaeria dothidea, Curvularia lunata were determined. The ethanol extracts of Gracilaria verrucosa , Hypnea sp., Grateloupia filicina showed more than 70% inhibiting rates on conidium germination of all three-genus fungus. The ethanol extracts of Sargassum fusiforme showed more than 90% inhibiting rate on conidium germination of Botryosphaeria dothidea. The ethanol extracts had inhibiting effects on conidium germination and growth of hypha . The order of inhibiting rate from high to low was the red alga, the green alga, and the brown algae.The ethanol extracts from the 7 algae were tested for antibacterial activities. The result showed that the ethanol extracts from Gracilaria verrucosa, Hypnea sp., Grateloupia filicina had strong and universal inhibiting effects. It was shown that the most of antibacterial substance from Hypnea sp. were in petroleum ether extracts and ethyl acetate extracts. The inhibiting effects of G+ and G- were equal.更多还原