HE Zhi-yao;Liu HaiLi;Wu QiuJuan;Xin Zhou;Gang Liu;Qian Dong;Fan Y

Center of Experiment, Yunnan University, Kunming 650091, China;Center of Experiment, Yunnan University, Kunming 650091, China.

a1;a2;leaf;normal;fistular;63

[Objective] Fourier transform infrared spectroscopy was used to study fistular onion(Allium fistulosum) and garlic(Allium sativum) rust leaves,so as to explore the application potential of mid-infrared spectroscopy in the diagnosis of crop disease.[Method] The normal green leaves and rust leaves of fistular onion and garlic were tested using fourier transform infrared spectroscopy,and their spectral differences were analyzed.[Result] The infrared spectra of green leaves of fistular onion and garlic are mainly composed of the vibrational bands of polysaccharides,protein and ester.Normal and rust leaves exhibited differences in the fingerprint interval of 1 800-900 cm-1,in which the band at 1 640 cm-1 in the spectrum of fistular onion rust leaf became stronger,and the band at 1 103 cm-1 was not obvious compared with the spectrum of normal leaf.The absorbance ratios A1 640/A1 063,A1 640/A1 736,A1 640/A2 924,and A1 063/A2 924 of onion rust leaf were larger than the corresponding ratios A1 638/A1 059,A1 738/A1 638,A2 921/A1 638,and A2 921/A1 059 in the spectrum of normal leaf.The band of polysaccharides at 1 056 cm-1 in the spectrum of garlic normal leaf was the strongest in fingerprint area,while the band at 1 634 cm-1 in the spectrum of garlic rust leaf was the strongest in that area.The absorbance ratios A1 634/A1 069,A1 634/A1 099,A1 409/A2 923,and A1 634/A1 737 of garlic rust leaf were larger than the corresponding ratios A1 627/A1 056,A1 627/A1 104,A1 411/A2 920 and A1 627/A1 740 of normal leaves.While the ratios A1 634/A2 923,A1 069/A2 923,and A1 737/A2 923 of garlic rust leaf were less than the corresponding values of A1 627/A2 920,A1 056/A2 920,and A1 740/A2 920 of normal leaf.[Conclusion] Rust leaf and normal leaf could be distinguished according to the differences in infrared spectra,and infrared spectroscopy could be developed as the detection method for crop diseases.