Investigation on Pathogenic Factors of Tobacco Root-Knot Nematode Disease in Gengma County,Yunnan Province

Tobacco root-knot nematode disease has caused severe damage in Geng- ma County, Yunnan Province. In order to identify the pathogenic factors of the tobac- co root-knot nematode disease in this county, the pathogenic nematodes, hosts and environment of tobacco fields in Mengsa, Hepai and Sipaishan 3 main tobacco-grow- ing towns in Gengma County were investigated and analyzed based on the local re- lated field survey on tobacco root-knot nematode disease in this county in 2012. The results showed the incidence and severity of the tobacco root-knot nematode disease were all higher than those of previous years. dominant pathogens of the tobacco root-knot The species identification showed the nematode disease were Meloidogyne arenaria and M. javanica in Gengma County. The lacking of disease-resistant culti- vars, poor management and climatic anomaly were the main causes of the tobacco root-knot nematode disease in Gengma. According to the occurrence characteristics of the disease, the agricultural prevention-based control measures were proposed.

Identification of sympatric bat species by the echolocation calls

One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species(Rhinolophus ferrumequinum,Myotis formosus,Myotis ikonnikovi,Myotis daubentoni and Murina leucogaster)were recorded(by ultrasonic bat detector(D980))in Zhi’an village of Jilin Province,China.According to the frequency-time spectra,these calls were categorized into two types:FM/CF(constant frequency)/FM(R.ferrumequinum)and FM(frequency modulated)(M.formosus,M.ikonnikovi,M.daubentoni and M.leucogaster).Sonograms of the calls of R.ferrumequinum could easily be distinguished from those of the other four species.For the calls of the remaining four species,six echolocation call parameters,including starting frequency,ending frequency,peak frequency duration,longest inter-pulse interval and shortest inter-pulse interval,were examined by stepwise discriminant analysis.The results show that 84.1%of calls were correctly classified,which indicates that these parameters of echolocation calls play an important role in identifying bat species.These parameters can be used to test the accuracy of general predictions based on bats’morphology in the same forest and can provide essential information for assessing patterns of bat habitat use.