Application of terahertz spectroscopic technology in identification of pine wood nematode disease

In this paper, we present methods to identify harmful Bursaphelenchus xylophilus (Bx) nematode and harmless Bursaphelenchus mucronatus (Bm) nematode, both of them living in the pine wood. We employ the terahertz (THz) spectroscopic technology to distinguish the Bx and Bm nematodes, i.e., terahertz domain spectroscopy (TDS) and Fourier transform infrared spectroscopy (FTIR). We measure the transmission characteristics of the deoxyribose nucleic acid (DNA) of the Bx and the Bm samples, and their corresponding polymerase chain reaction (PCR) amplification segments of the DNA molecules by the THz-TDS and the FTIR techniques. The refractive index measured by the TDS and the absorbance obtained by broadband FTIR measurement demonstrate that the Bm-DNA has a large difference from the other three samples, suggesting THz spectroscopic technology is a useful technique to identify the Bx and the Bm pine wood nematodes.