Combination of stem-disc dome culture and thermotherapy to eliminate Allexiviruses and Onion yellow dwarf virus from garlic (Allium sativum cv. Hamedan)

Abstract

Onion yellow dwarf virus (OYDV) and Garlic viruses (GarVs) A–D belonging to the genera Potyvirus and Allexivirus, respectively, cause serious disease problems and yield losses in garlic (Allium sativum L.). Possibility of obtaining virus-free garlic using stem-disc dome (SDD) culture and its combination with thermotherapy (36 °C for 4 and 5 weeks) were studied. Duplex reverse transcriptase-polymerase chain reaction was used for detecting these viruses. Results showed that the efficiency of viral elimination is depended on viral type, applied methods and duration of thermotherapy. For SDD culture, an overall average efficiency of virus-free plant production was 61 and 77% for GarVs and OYDV, respectively. Thermotherapy combined with SDD culture had a deleterious effect on OYDV elimination. For GarVs, it was more effective than SDD culture by itself and a high GarVs elimination of 75% was achieved by thermotherapy for four weeks of treatment. The efficiency of GarVs elimination (90%) was improved as treatment duration prolonged for five weeks.

Keywords:

• Allium sativum
• duplex RT-PCR
• OYDV
• GarVs

Acknowledgements

The authors gratefully acknowledge Dr Asghar Mirzaei, Miss Vida Nasrolahi and plant pathology department at Bu-Ali Sina University, Hamedan, Iran for technical assistance.