Study On The Early Diagnosis Technology Of Pine Wilt Disease

Pine wilt disease is a devastating forest disease and has very serious harm to the Pine forest. It has spreaded fast, the prevention and treatment is extremely difficult. Monitoring and early warning of pine wilt disease is an important measure. Study and application of the early diagnosis technology of pine wilt disease is the main methods and means to the disease. The thesis is a preliminary study from spectroscopy, chemical ecology and molecular biology three aspects on the early diagnosis of pine wilt disease. The results are as follows.1. The green and near-infrared reflectance spectral curves can indicate the pine disease severity. Pine needles reflectance reduces with the deepening of the disease severity significantly. The near-infrared band indicates better. The reflectance around760nm can be used as reference values to distinguish between artificial inoculated Pinus thunbergii and healthy pine trees and other reasons withered pine.The changes of spectral parameters such as red edge position blue shift, green peak height and red band depth decreases, red edge slope to reduce can reflect well the disease situation of pine. Chlorophyll content of pine needles reduces with the deepening of the disease severity. Analysis of variance showed that the reflectance at760nm wavelength between PWD early and other types of victims pine has significant differences. Spectral characteristic parameters and chlorophyll content showed a significant correlation. Dynamic changes of the red edge can be clearly reflects the changes of chlorophyll content of the pine susceptible stage. In the early susceptible difficult to see from the appearance of symptoms of the tree, according to the different band reflectance spectral curves or spectral characteristic parameters of the disease situation, we can provide data for early detection of the pine wilt disease.2. Using sampling tubes contain chemical information substances could specifically detect the pine wood nematode in the incidence of late of pine wilt disease. And the detection result is well.3. The improved nematode DNA extraction method and specific primers Pxl, Px2PCR amplification, can accurately separate Bursaphelenchus xylophilus and Bursaphelenchus mucronatus. The method is easy to operate and has good detection results. It can be used for rapid molecular diagnosis of the pine wood nematode.The pine wood nematode derived from the four cities of Shandong Province belonging to three different groups. They existed population differences and parts of had closer phylogenetic relationship with pine wood nematode in Japan and Portugal, and had distant phylogenetic relationship with pine wood nematode in Canada, the United States, Mexico. This can be a preliminary judge that the pine wood nematode of Shandong Province maybe come from Japan. Systematic relationship is needed more locations and the numbers and variety of molecular marker technology to deep research.