植物提取液对甜瓜枯萎病的抑菌活性及种子萌发的影响

Plant Extracts’Inhibition Effect on Muskmelon Fusarium Wilt and Influence on Germination Tests of Cucumis Melo Seeds

采用生长速率法测定了30种植物不同组织部位的乙醇提取液对甜瓜枯萎病菌(Fusarium oxysporum f.sp.melonis)的抑菌效果,其中合欢(Lycopersicon esculentum)叶、合欢枝、泽漆(Euphorbia helioscopia)全草和芹菜(Apium graveolens)茎叶等4种植物提取液对甜瓜枯萎病的抑制率分别为31.64%、41.82%、26.41%和30.81%,其他植物提取液均无明显抑菌效果。浓度试验表明,合欢枝提取液的抑菌活性高于合欢叶提取液;对抑菌效果最好的合欢枝乙醇提取物用石油醚、乙酸乙酯、水饱和正丁醇依次进行萃取,并对各萃取物进行抑菌活性测定,结果表明,有效活性成分存在于正丁醇相和水相中,两相萃取物对甜瓜枯萎病的抑制中浓度EC50分别为0.8202 mg.mL-1和0.8217 mg.mL-1。种子萌发试验结果表明,合欢枝正丁醇和水萃取物在浓度为1mg.mL-1时,对甜瓜种子的发芽势、发芽率、发芽指数和活力指数没有显著影响。抑菌谱试验发现,合欢枝萃取液对甜瓜灰霉病菌(Botrytis cinerea)、甜瓜叶枯病菌(Alternaria alternata)、西瓜菌核病菌(Sclerotinia sclerotiorum)、水稻恶苗病菌(Fusarium fujikuroi)和小麦赤霉病菌(Fusarium graminearum)等5种病原真菌都具有很好的抑菌效果。

By the mycelium growth inhibition methods, the inhibiting action of different tissue extracts of 30 plants were tested against Fusarium oxysporum f. sp. melonis. The results showed that the inhibiting rate of extracts from the leaves of Lycopersicon esculentum, the stems of L. esculentum, whole plant of Euphorbia helioscopia and the stems and leaves of Apium graveolen were respectively 31.6%, 41.8%, 26.4% and 30.8%, but the other plant extracts didn＇t have an obvious inhibition effect. Concentration tests showed that the extract from the stems of L. esculentum had better inhibition action of than from the leaves. The ethanol extract from the stems of L. esculentum, which had the better inhibition effect, was extracted respectively with petroleum ether, ethyl acetate and nbutyl alcohol. The mycelium growth inhibition tests showed that the active substance existed in n-butyl alcohol and water, and their EC50 were 0.8202 mg·mL^-1 and 0.8217 mg·mL^-1 The germination tests of eueumis melo seeds determined that the extracts of n-butyl alcohol and water from the stem of A. julibrissin had no influence on germination energy, germination rate, germination index and vigor index. In addition, Inhibition spectrum tests showed the extracts of n-butyl alcohol from the stem of A. julibrissin had good inhibition effect against 6 pathologic fungi such as F. oxysporum f. sp. meloni, Botrytis cinerea, Alternaria alternata, Sclerotinia sclerotiorum, Fusarium fujikuroi and Fusarium graminearum.