Selecting Nematicides And Synergism Of Antibiotics To Nematicide To Bursaphelenchus Xylophilus

To use a new bioassay method selects pesticides to Bursaphelenchus xylophilus and promoting the effect of antibiotics to pesticides to Bursaphelenchus xylophilus. The main result are as follows:l.A new bioassay way designed to Bursaphelenchus xylophilus was studied. The blocks with the dia of 3cm and thickness of 0.5cm was adopted. The testing showed that blocks containing 40-60% water, with 300 pine wood nematodes being inoculated per block, 8-day darkness cultivation under the temperature of 25 degrees Celsius was the optimum condition. Nematodes in the block were isolated and counted. Statistical analysis showed the toxicity of nematicides. The condition adopted in the new way was similar to that of the field trees and the effect of the false death of Bursaphelenchus xylophilus existing in other ways could be avoided.2.It was the first report to study the effect of α-T against Bursaphelenchus xylophilus .The result showed that a-T is strong toxic agent of Bursaphelenchus xylophilus,. 10-4g/mL α-T killed all Bursaphelenchus xylophilus in six hours. Under the illumination intensity of 450 Lux, EC50 of α-T was measured as 1.48 10-6 g/mL. The illumination intensity affected the effect of α-T against Bursaphelenchus xylophilus. The testing pine trees got good protection against pine wilt disease at the dosage 10-4 g/g of a-T in the field test.3. It was the first report to study the effect of albendazole and L-imidazole against Bursaphelenchus xylophilus and the result showed they were strong toxic against Bursaphelenchus xylophilus. It was studied farther the toxicity of antibiotics(amikacia sulfate and streptomycin sulfate) and aloperine against Bursaphelenchus xylophilus. The result showed: for albendazole: EC50=3.6 10-5g/g; for L-imidazole: EC50=2.8 10-5g/g; for the antibiotics(amikacia sulfate and streptomycin sulfate): EC50=1.45 10-4g/g; for aloperine: EC50=5.02 10-5g/g. Among the tested 17 amines, the toxicity of dimethyl yellow against Bursaphelenchus xylophilus was the strongest. The death rate of Bursaphelenchus xylophilus was 50% with 10-5g/g dimethyl yellow.4. When certain antibiotics (amikacia sulfate and streptomycin sulfate) were mixed with certain nematicides such as aloperine and alberdazole, synergism between the antibiotics and the nematicides was srong . SR of the aloperine and the antibiotics was 6.34; SR of the albendazole and the antibiotics was 1.7. In the field tests, it was found that the effects of the mixtures were stronger than the single component in the mixture to Bursaphelenchus xylophilus. Synergetic effect of the mixture of 1 0-4g/g aloperine and 10-4g/g antibiotics(amikacia sulfate and streptomycin sulfate), and that of 2 10-5g/g albendazile and 10-5g/g aloperine and 10-4Vg antibiotics (amikacia sulfate and streptomycin sulfate) to Bursaphelenchus xylophilus were the best. The result offer a experiment evidence for the hypothesis that the pine wilt disease was a disease complex involving the nematodes and bacteria and provide a new way to provent pine wilt disease.