The population structure and sex ratios of Bursaphelenchus xylophilus under α-pinene stress

Abstract

Pine wood nematode (PWN), Bursaphelenchus xylophilus, is a serious pathogen of pines throughout the world. Previous work indicated that different concentrations of α-pinene could affect nematode reproduction, however the mechanism of that influence is not clear. In order to examine the reproductive strategies of PWN in response to the stress of the volatile material α-pinene, we investigated different aspects of population changes of B. xylophilus under two concentrations of α-pinene. The results show that a high concentration (214.5 mg ml⁻¹) promoted population growth while a low concentration (56.33 mg ml⁻¹) decreased the population. Population structure was analyzed and it was found that a high concentration of α-pinene decreased the percentage of adults but increased the percentages of larvae and eggs. Furthermore, from the results of an evaluation of sex ratios (female/male), it was determined that a high concentration could elevate sex ratios but a low concentration decreased ratios sharply. These results suggest that the PWN could regulate its population by changing sex ratios under stress of α-pinene. This study has provided a theoretical basis for the prevention and control of pine wilt disease caused by the pine wood nematode.

Keywords

Pine wood nematode / α-Pinene / Population structure / Sex ratios

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