Study On The Insecticidal And Antifungal Activities Of Tetraena Mongolica Endemic To China

In this paper some kinds of crude extracts were produced in the way of cold-soaked process and Chinese traditional water-decoctum from Tetraena mongolica endemic to China. Different concentrations of these extracts were made to examine their bioactivities on many kinds of vegetable insect pests, plant pathogens and pine wood nematode. The results are as follows:1. Different concentration of extracts of Tetraena monogolica were selected for bioassay of action on Bursaphelenchus xylophilus(Bx) by the method of immersion. The results showed that, when concentration of the water extract was 10g·L^-1, the mortality rate of Bx was 100ï¼…in 24～72 hours; when concentration of the carbinol extract was 10g·L^-1, its corrected percent mortality was 95ï¼…in 72 hours. The nematicidal activities of acetone, petroleum ether, ethyl acetate extracts were weaker, with the same concentration, the mortality rates of Bx were less than 40ï¼…in 24～72 hours. The values of LC₅₀ water and carbinol were 1.18g·L^-1 and 2.43g·L^-1 against Bx after 24 hours, respectively. It indicated that the extracts of Tetraena monogolica contain some nematicidal thing, the water extract had strong nematicidal activity against Bx, and the activity of carbinol extract is second.2. The bioactivities of 6 kinds of extracts from Tetraena monogolica on 22 plant pathogenic fungi were examined in laboratory. Resaults showed that, when the mass-concentration of Tetraena mongolica Maxim extracts was 100g·L^-1, different extracts had complicated effect on different fungi tested. Some extracts had strong fungistasis effect on some species of fungi, some had a little fungistasis effect on some species, some had no effect on some species, while some had promotional effect on some species.3. The acetone extract had oviposition deterrent effects on Pieris rapae L. The acetone, water-decoctum extracts had effects of inhibiting oviposition on Plutella xylostella. The water-decoctum and acetone extracts also showed some antifeedant effects on Plutella xylostella.4. Tetraena mongolica, endemic to China, has important value of scientic research, controlling wind, fixing shifting sands, ornament and protection. Enhancing the study of its value and sustainable utilization is beneficial to the protection of it.