Comperative Observation On Esophageal Glands And Their Secretory Granules In Bursaphelenchus Xylophilus And B.Mucronatus By Tem

Pine wood nematode (Bursaphelenchus xylophilus) is a kind of parasitic nematode that can cause serious pine wilt disease. Now, pathogenesis of pine wood nematode wasn't clear, maybe the esophageal glands play an important role in the process of pathogen. In this experiment the structure and morphology of esophageal glands and secretary granules (SG) have been observed and compared by TEM, also cellulase have been examined in esophageal glands in order to compare the morphologic difference between B. xylophilus and B. mucronatus.Ultrastructural observations of the esophageal glands of B. xylophilus and B. mucronatus revealed that they have the same structure of esophageal glands. The level of esophageal glands activity was observed in juveniles and adult stage. The result indicated that they have the same changes between B. xylophilus and B. mucronatus. Subventral glands, which were actively synthesizing SG in juveniles, appeared to become inactive in adult stage. Furthermore, SG of subventral gland in adult stage were much less than in juveniles. The dorsal gland, on the other hand, began to enlarge and actively synthesize SG in adult stage. Esophageal glands in pine wood nematode had the same changes with plant nematode. These results indicated that esophageal glands had different functions in different life stage.Observation on SG of esophageal glands Indicated that there were the same kind of granules in two species which were named as type I granule and type II granule. Type I granule is electron-dense spherical vesicles with clearlyboundary; and type II granule is low density with larger size than former. Two type of granules in esophageal glands indicated that these SG had different function.LSD-Test showed secretary granule changed in the process of life stage both in B. xylophilus and B. mucronatus. Type I granule and type II granule had significantly difference between Juveniles and adult stage of Nanhei (B. xylophilus), but no difference was observed on secretary granules between female and male; In Hangjiu (B. mucronatus), type I granule had remarkable difference between juveniles and adult stage., but type II granule appeared no difference in different life stage. Two type of SG in Fl (B. mucronatus) had no changes in its life stage.The comparison of SG indicated that SG were different between B. xylophilus and B. mucronatus . Type I granule had no difference in juveniles but had obvious difference in adult stage between B. xylophilus and B. mucronatus; On the contrary , type II granule had difference in juveniles and had no difference in adult stage between Nanhei and Hangjiu. These results showed that SG of B. xylophilus might play an important role hi pathogenesis. However type II granule of Nanhei was different from that of Fl in adult stage. In addition, comparison indicated that SG of Fl was larger than that of others; these results indicated Fl were different with populations of B. mucronatus onphylogeny.Cellulose was compared between B. xylophilus and B. mucronatus. The result indicated that cellulase was found in two species pinewood nematode ,which located in type II granule appeared spherical granule with high electron density . Cellulase has no morphologic difference in two species, but in different stage the shape and location of cellulase had some changes. In juveniles cellulase located in the edge of SG with larger size than which in adult stage. But in adultstage cellulose dispersed or located in the center of type II secretary granule. The observation stated that there are the same changes of cellulase in different stage between B. xylophilus and B. mucronatus. It can be infer that cellulase may have no key function in pathogenesis.