Effect of Chemotherapy and Thermotherapy on the Virus Incidence Reduction in Tissue-Cultured Ilocos White Garlic (Allium sativum L.)

Abstract

Garlic (Allium sativum L.), an important crop in the Philippines, suffers from viral infections that limit local production by reducing yield and bulb quality. Garlic is propagated vegetatively; hence, the planting material from the previous harvest is planted for the next planting season, thereby viral transmission from generation to generation is inevitable. To address this, the study evaluated the virus elimination effect of chemotherapy and thermotherapy with meristem culture in Ilocos White garlic.

This study tested two virus elimination treatments – chemotherapy at 10, 20, 30, and 40mg/l acyclovir – an antiviral drug, and thermotherapy at 50°C for 1, 1.5, and 2 hours. Five viruses, namely, OYDV, SLV, GCLV, LYSV, and Allexivirus, were molecularly detected through RNA extraction and RT-PCR.

Results showed Ilocos White garlic harvested from MMSU were infected with only LYSV and Allexivirus out of five viruses screened. Chemotherapy using acyclovir reduced LYSV by 75% using 10mg/l and Allexivirus by 100% using 20 to 40mg/l. Thermotherapy at 1 and 1.5 hours reduced LYSV by 66.67% and 75%, respectively, and Allexivirus by 100% for 1, 1.5, and 2 hours. These results showed that LYSV is more virulent than Allexivirus and more resistant to treatments.

The coordinated approach of meristem culture with chemotherapy using acyclovir at 20mg/l and thermotherapy at 50°C for 1 hour showed potential virus elimination and reduction ability. Further optimization and combinations of these methods are recommended to achieve consistent and significant virus elimination in garlic essential in sustaining the local garlic industry.