Assessment of blue light treatments on citrus postharvest diseases

作者：Liao Hui Ling; Alferez Fernando; Burns Jacqueline K^*

来源：Postharvest Biology and Technology, 2013, 81: 81-88.

DOI：10.1016/j.postharvbio.2013.02.019

• Decay
• Irradiance
• Octanal
• Penicillium
• Phomopsis
• Tangerine

Exposure of mature 'Fallglo' tangerine fruit to blue light with a photon fluence rate 40 mu mol m(-2) s(-1) reduced symptom development of blue mold (Penicillium italicum), green mold (Penicillium digitatum), and stem end rot (Phomopsis citri) postharvest decays. Direct exposure to blue light was required to reduce decay caused by Penicillium. Blue light (40 mu mol m(-2) s(-1)) reduced in vitro fungal growth of P. italicum and P. citri. The growth of P. digitatum was more tolerant to blue light, however, the activity of fungal polygalacturonase was reduced by blue light at the intensity of 40 mu mol m(-2) s(-1). Gas chromatography-mass spectrometry analysis identified 29 chemical constituents in flavedo oil; blue light induced only octanal accumulation. Application of octanal suppressed growth of P. italicum, P. digitatum, and P. citri in vitro. Treatment of fruit with octanal at 5 mM or 50 mM suppressed symptom development caused by Penicillium and P. citri, but discolored the peel. Inhibition of postharvest decays by blue light may be due to a combination of inhibition of fungal growth and induction of defensive responses in the host.

• 出版日期2013-7