Studies On Migration Of Bursaphlenchus Xylophilus And The Extracts From Medium Cultured With Botrytis Cinerea And It's Inducing Activity To B. Xylophilus

The present Bursaphelenchus xylophilus (Bx) rapid detecting tube prepared by our lab can induce the Bx from the pine trees. To study the inducing mechanism, in this paper, we designed a new way to study the influence of different factors on the Bursaphelenchus xylophilus migration behavior based on the sterile sand tray and agar flat as the migration matrixes. We also separated different extracts from the medium cultured with Botrytis Cinerea by filter paper method and studied the extracts on inducing activity to Bursaphelenchus xylophilus. The main results are listed as follows.First, the sick wood has a strong inducing force to the Bx. The inducing effect decreases after high pressure sterilization but the difference isn't obvious which means the effective inducing substance isn't removed entirely by the high pressure. This result is different from the presumption that the inducing substance is the volatility substance. The inducing force of Botrytis cinerea toward Bx is stable while the pine skin lixivium hasn't obvious inducing effect.Second, Bursaphelenchus xylophilus has obvious tendency to different strains (Botrytis cinerea >Pestalotia >Microzyme >Contrast), which means the Bursaphelenchus xylophilus presents more tendency to Botrytis cinerea. The attracting efficiency difference gets more obvious when we prolong the depositing time accompanying with the accumulative available metabolic products getting more. Furthermore, agar concentration has significant influence on the migration behavior, which means the migration and free selection ability of Bursaphelenchus xylophilus increase with agar concentration decreasing.Finally, we investigated the active components which could attract the Bursaphelenchus xylophilus from the Botrytis Cinerea extracts by different separation methods. Results showed that active substances mainly existed in extracellular organic phase (ethyl acetate phase) which might be ethanol soluble compounds. With the separation continuing step by step, the attraction efficiency decreased. Based on the results above, we could draw the conclusion that the inducing activity depended on the synergistic action of these extracts.