薇甘菊挥发油的化感潜力

外来植物薇甘菊 (MikaniamicranthaKunth .)已成为华南地区重要的杂草 ,其挥发油对植物、真菌和细菌均具有生物活性 ,对植物和水稻稻瘟病菌的抑制活性尤其显著 .随着薇甘菊挥发油浓度 (2 0 0、4 0 0、80 0、16 0 0mg·L-1)的增加 ,6种受试植物幼苗的生长随之明显减弱 .薇甘菊挥发油 (2 5 0 0 g·hm-2 )土壤处理 ,受试的 6种植物鲜重明显减少 ,出苗时间推迟 1～ 2d .薇甘菊挥发油在中等浓度 (40 0mg·L-1)时 ,对水稻稻瘟病菌的抑制作用最强 ,抑菌率为 5 3.38%;对香蕉枯萎病菌的抑制作用次之 ,抑菌率为2 8.6 6 %;对长春花疫病菌的抑制作用最弱 ,抑菌率为 18.6 9%.

Allelopathic potential of volatile oil from Mikania micrantha

Mikania micrantha, an exotic plant species, is an important weed in south China. The volatile oil of the weed species had significant biological activities on plants and their pathogens, particularly Pyricularia grisea. The results showed that the seeding growth of 6 plant species decreased obviously when exposed to increasing concentration (200, 400, 800, 1600 mg.L-1) of the volatile oil. The fresh weight of all test plants decreased, and the emergence of all test plants delayed for 1-2 days under soil treatment (2500 g.hm-2). The inhibitory effect of volatile oil of M. micrantha at its medium concentration was the most strong on Pyricularia grisea; secondary on Fusarium oxysporum; but weak on Phytophthora nicotianae. The inhibitory rate was 53.38%, 28.66% and 18.69% for the three plant pathogens, respectively.