Identifif ication of Embellisia allii Causing Skin Blotch on Garlic Bulbs Imported from The People's Republic of China and Controlling by Ozonated water

Abstract

The study of skin blotch pathogen of garlic bulb imported from The People’s Republic of China was carried out at Chiangsaen Plant Quarantine Station, Chiang Rai Province during January-August 2016. Symptom of skin blotch was detected in 15 of 187 samples of imported garlic bulbs. Embellisia allii was isolated as a key pathogen caused skin blotch symptom in all 15 defected samples using morphological and molecular characteristics. The molecular characteristic was investigated by a PCR and run with gel electrophoresis. The results showed that fungal DNA of 15 isolates were consisted of 315 base pairs. Obtained base sequence was compared to the Genbank database. It was found that skin blotch fungi from garlic base shared the same E. allii for 100 % identity. The E. allii is quarantine pest in Thailand, therefore control of E. allii must be concerned. Application of ozonated water at 1 g/h for 30, 45 and 60 min could reduce the spores germination of E. allii after 24 h of incubation at 0.75, 0 and 0% respectively. Moreover, application of ozonated water at 1 g/h for 30 min was completely inhibited skin blotch disease in garlic blub.