Studies On Epidemic Situation On Pine Wilt Disease And Biological Characteristics Of Monochamus Alternatus In Hunan

Pine wilt disease is the most serious forest diseases in China right now,it is through the Monochamus alternatus invasive pine,and it is one of the most devastating diseases which pine trees wither in a short time.Bursaphelenchus xylophilus were first identified in Japan in 1905 and in 1985 in China's Nanjing, Jiangsu,from then on,the disease has been found in China's 13 provinces,more than 100 counties(districts) in the incidence acreage of more than 8.7×10~4hm~2,this has aroused widespread concern and the whole society attach great regard to the issue.In this study,anchored in Hunan pine,the Bursaphelenchus xylophilus's major media-the biological characteristics of Monochamus alternatus in Hunan,the situation of pine infecting in Bursaphelenchus xylophilus's areas in spring,the number of pathogens in governance areas after treatment,the new district in the identification of pathogenic and rDNA sequences were studied.The major elements are following:The biological characteristics of Monochamus alternatus in Hunan.This study combining the method of field observation and keeping breed indoor.Results shows that Monochamus alternatus is one year happened a generation in most parts of Hunan,and 12.6%of the Chenzhou region which around the Guangdong is one year happened two generations,the incidence of pest is different in the state of the region in Hunan,The eclosion in forest was first discovered in Chenzhou Beihu borough on 26 April,the latest discovery is Yongding borough on 25 May,Shaoshan City on 2 May,Guzhang on 5 May,Yuanjiang City on 11 May.the earliest time of flourishing eclosion in forest is Chenzhou Beihu borough in five early in the second half to June, the later area is Yongding borough in mid-June;The number of Monochamus alternatus imago capture is relative with temperature,the maximum and minimum temperature,humidity and precipitation,the correlation coefficients were 0.017, -0.022,-0.103,-0.131;The favorite food for Monochamus alternatus in Hunan is pine tree,and the pine trees is also the suited for spawning and groove of Monochamus alternatus. The situation of withered branches infecting in Bursaphelenchus xylophilus's areas in spring.The investigate revealed that the in incidence of the Bursaphelenchus xylophilus disease,there is a certain percentage withered branches containing Bursaphelenchus xylophilus in spring:15.2%for about 10 years pine wood,38.5%for about 15 years pine,while 10.0%for about 20 years pine,fewer in more than the 22 years pine wood,the average ratio of Bursaphelenchus xylophilus in withered branches is about 21.2%.Another certain percentage of the dead branches contain nematodes or other nematodes,and most of the dead branches of pine wood contain other nematodes,and all the withered branches contain nematodes,without exception, are harmed by Monochamus alternatus.The number of pathogens in governance areas after treatment.Research shows that in Hunan governance,the ratio of Monochamus alternatus carrying nematodes was 22.0%in forest,adults of Monochamus alternatus carrying nematodes in mid-June with the largest amount,an average of 478 per individual;early May at least, an average of 331;late July average 380.In the room the ratio Monochamus alternatus carrying Bursaphelenchus xylophilus was 25.5%,Monochamus alternatus adults carrying nematodes in mid-June with the largest amount,an average of 625 per individual;At least late in July,an average of 358;early May the average 452.The number and ratio of Monochamus alternatus carrying nematodes are much less than the previous reports at home and abroad,this indicates that the treatment works through Hunan model in controlling the disease has been fairly satisfied with the results.The identification and analysis for pathogen of Bursaphelenchus xylophilus in Linxiang County.Identificating and confirming the suspicions Bursaphelenchus xylophilus rough morphological identification and real-time flourescent PCR methods in Hunan Linxiang,its rDNA sequence analysis showed that the occurrence of the epidemic in Hunan Linxiang is close to the Jiangsu Nantong region.