植物提取液对水稻潜根线虫的抑杀作用

测定了采自云南的6种植物的24种提取物对水稻潜根线虫的生物活性，以黄花菊甲醇提取物的杀线虫活性为最高，夹竹桃其次。从植物不同部位提取的植物提取液，其杀线虫活性也存在差异，72 h后，线虫在夹竹桃花、叶、皮提取液中死亡率分别为85.45%、73.15%、40.56%，在紫茎泽兰花、新叶、陈叶、茎秆提取液中死亡率依次为69.92%、37.76%、32.56%、27.64%。夹竹桃（叶）、紫茎泽兰全株、青蒿等植物甲醇提取液用无菌水稀释2.5倍、5倍、10倍、20倍、40倍后，48 h后夹竹桃稀释2.5倍活性最高，达到82.16%，稀释10倍以上活性降低。夹竹桃、紫茎泽兰、青蒿三种植物叶片水提取液经太阳光照射6 h后，线虫死亡率分别从原来的74.1%、21.5%、7.91%提高到100%、35.6%、24.5%，表明光照处理可增强植物提取液的杀线虫活性。

Inhibition and Nematocidal Effect of Plant Extracts on Hirschmanniella spp.

The bioactivity of 24 extracts from 6 species plants in Yunnan province in China against Hirschmanniella spp.was reported.Results showed that the methanol extract from Tithonia spp.possessed the strongest nematocidal activity,followed by that from Nerium indium.There was distinctive differences in the nematicidal efficacy among various extracts from the different parts of the same plant,after 72 hours'treatment,the exact from the flower,leaf and skin of Nerium indium had nematocidal rate of 85.45%,73.15%,40.56%,respectively;the nematocidal rate of flower,new leaf,old leaf,and stem water extracts of Eupatorium adenophorum was 69.92%,37.76%,32.56%,27.64%,respectively.The methanol extracts of Nerium indium leaf,Eupatorium adenophorum were diluted to 2.5 times,5 times,10 times,20 times and 40 times by water,after 48h,the extract of Nerium indium leaf diluted to 2.5 times had the strongest activity,the extract diluted to more than 10 times had weak activity.After the leaf extracts of Nerium indium,Eupatorium adenophorum and Artemisia apiacea were shined for six hours by the sun light,their nematicidal activities were strengthened obviously.