| At present, most studies about essential oils are concentrated on its insecticidal activity, and less studies identifying the active constituents in the essential oil has been made. In this paper, the constituents of essential oil of constituentⅠ,constituentⅡ,constituentⅢ,constituentⅣ,constituentⅤwere identified by modern analyzing means, contact activity, fumigant activity and repellent activity of these constituents have been investigated, and five active constituents in this essential oil were identified at last. The main results are as follows:1. Choose constituentⅠ,constituentⅡ,constituentⅢ,constituentⅣ,constituentⅤchecked by GC-MS in the AA oil as test monomer constituents.2. Topical application was employed for contact toxicity studies of the AA oil and five constituents on adults of Trubolium castanium, the results showed that AA oil and constituents have fine contact toxicity, and the LD50 and LD95 of AA oil were 0.053μl/mg and 0.24μl/mg body weight of adult insect, and the LD50 of constituentⅡand constituentⅢwere both 0.05μl/mg body weight of adult insect, which was lower than AA oil. The sequence of LD95 was constituentⅡ= constituentⅣ< constituentⅤ< constituentⅠ< constituentⅢ=AA oil.3. AA oik constituentⅠ,constituentⅡ,constituentⅢ,constituentⅣ,and constituentⅤhave a strong repellency effect on adults of Trubolium castanium. At a dose of 0.168μl/cm2, the percentage repellency of AA oil and constituentⅢwere of 96.6% and 89.9%, the repellency class wasⅤ. The percentage repellency of rest four constituents constituentⅠ,constituentⅡ,constituentⅣ,constituentⅤwere 90%,93.3%,93.3%,99.9% at a dose of 0.84μl/cm2, the respective repellency class wasⅤ.4. The fumigant activity of AA oil and five constituents to adults of Sitophilus zeamais by filter paper method in a sealed cylinder was investigated. The mortality of Sitophilus zeamais was increasing with the increasing of fumigant concentration and fumigant time. At a dose of 0.42μl/cm2 and 1.68μl/cm2 of AA oil and 24h and 96h exposure period conditions, the mortality of Sitophilus zeamais were 10%,75% and 61.5%,100% respectively. The mortality of Sitophilus zeamais was zero at a dose of 0.63μl/cm2 of constituentⅣand 24h exposure time, the mortality increased to 85% after 96h exposure time, and under 1.47μl/cm2 and 1.89μl/cm2, the mortality was 100%. AA oil on adults of Sitophilus zeamais has a very good fumigant activity, the LC50 of AA oil exposed 24 hours was about 3.19μl/cm2, which was the lowest in all essential oil and constituents. The lowest LC95 was constituentⅡ1.98μl/cm2.The sequence LC95 was: constituentⅠ＞constituent Ⅲ＞constituentⅤ＞AA oil＞constituentⅣ＞constituentⅡ.5. AA oil inhibited the larval development in Trubolium castanium fumigated by essential oil. It indicated that the larval survival, pupal survival and eclosion ratio were decreased with the increasing concentration of AA oil, and were of 65.5%, 35.5% and 1.7% at a dose of 1.68μl/cm2, respecively.6. AA oil has advantages of comprehensive antimicrobial spectrum and good inhibition. It has some inhibition effect on all tested pathogenic fungi and bacterium. Especially, AA oil inhibited growth of Phytophthora parasitica and Sclerotinia sclerotiorum completely, and also CoIletotrichum capsici, CoIIetotrichum nicotianae and Gtoeosporium fructigenum effectively. The AA oil can significant inhibit the growth of three kinds of bacterium for test.7. AA oil and its constituents have some effect on acetylcholinesterase (AchE) of Sitophilus zeamais adults after different fumigant time. The AchE of Sitophilus zeamais was activationed exposed in AA oil. The inhibition ratio were 60%, 91%, 90% after 12h, 24h, 36h exposure in the fumigant activity of constituentⅤ. After 12h exposure of constituentⅣ, the AchE droped to 0.81 U/mgprot, inhibition ratio was about 70%. In summaries, analysis by gas chromatography-mass spectrometry led to 25 constituents from AA oil of, and identified 5 kinds of constituents constituentⅠ, constituentⅡ, constituentⅢ, constituentⅣ, constituentⅤwere active constituents by biossays. |
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