Efficacy of virus elimination from in vitro-cultured sand pear (Pyrus pyrifolia) by chemotherapy combined with thermotherapy

In vitro plants of sand pear (Pyrus pyrifolia cv. Jinshui no. 2), which were infected by Apple chlorotic leaf spot virus (ACLSV) and Apple stem grooving virus (ASGV), were treated by chemotherapy with ribavirin, thermotherapy at 35 ± 0.5 °C and the combined application of both methods. Results showed that chemotherapy with ribavirin at 15–25 μg/ml for 5–30 days could enhance the growth and proliferation of in vitro pear plants. Chemotherapy combined with thermotherapy could greatly improve the efficiency of virus eradication as it was compared with the separated application of both methods. A high virus eradication efficiency of 100% was achieved by chemotherapy of ribavirin at 25 μg/ml combined with thermotherapy at 35 °C for 40 days, followed by culturing of 0.5–1 mm long meristem-tips. The efficacy of ribavirin for the elimination of both ASGV and ACLSV had no significant difference.

► In vitro pears were treated by thermotherapy, chemotherapy, and their combination.
► Increased ribavirin and prolonged treatment duration could improve the eradication efficacy.
► High virus eradication efficacy was achieved by ribavirin at 25 μg/ml combined with 35 °C for 40 days.