小桐子枝叶提取物对植物病原真菌的生物活性

Bioactivity of Extracts from Jatropha curcas L. Branches and Leaves Against Plant Pathogenic Fungi

采用菌丝生长抑制法,测定了小桐子枝叶6种不同溶剂提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌和辣椒疫霉菌的抑制作用,从中筛选出抑制作用最强的粗提物进行进一步的活性组分分离和抑菌活性测定。结果表明小桐子枝叶的乙醇提取物对4种植物病原菌抑制活性最高,在浓度为0.8g·L-1时,小桐子枝叶的乙醇提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌、辣椒疫霉菌菌丝生长抑制率分别为:87.1%、90.3%、86.4%、77.9%,其抗菌活性与农药世高均无显著差异;在小桐子枝叶乙醇提取物的不同溶剂萃取物对稻瘟病菌和烟草疫霉病菌进行生物活性追踪测试中发现,石油醚和水萃取物都具有较好的活性,当浓度为0.8g·L-1时,石油醚和水萃取物对两种病菌抑制率都达50%以上。表明小桐子枝叶含有丰富的抗植物病原真菌活性物质,且主要存在于小桐子枝叶乙醇提取物的石油醚相和水相中。

The inhibitory effects of crude extracts from Jatropha curcas L. branches and leaves using six different solvents were tested against Fusarium graminearum,Pyricularia oryae Cav.,Phytophthora nicotianae Breda de Haan. and Phytophthora capsici Leon,using mycelium growth inhibition method. Then active component separation and bioactivity assay were conducted on the crude extracts with the highest bioactivity. The results showed that the most active extracts from J.curcas L. branches and leaves against four plant pathogenic fungi was alcohol extracts,the inhibition rate to the mycelial radial growth of four plant pathogenic fungi was 87.1%,90.3%,86.4% and 77.9% when concentration was 0.8g·L-1,there was no obvious difference when comparing to 10% difenoconazole. In the bioassays of alcohol crude extracts by partitively extracting of five different solvents against Pyricularia oryae Cav. and Phytophthora nicotianae Breda de Haan. We found that the antifungal activity of petroleum ether and water fractions were all higher,the inhibition rate to the mycelial radial growth of two plant pathogenic fungi were all higher than 50% at concentration of 0.8g·L^-1. It is suggested that the branches and leaves of J.curcas L. contain abundant substances with antifungal activity,the active components with the inhibitory effect on plant pathogenic fungi mainly exit in petroleum ether and water fractions of alcohol extracts from J.curcas L. branches and leaves.