Electrotherapy, thermotherapy, chemotherapy, and cryotherapy to regenerate Prunus armeniaca L. free of ACLSV, ApMV, and TRSV

Abstract

Abstract In the present study, in vitro regenerated shoot tips of three apricot cultivars namely ˈQaysiˈ, ˈShamsˈ and ˈOrdubadˈ, already infected with Apple chlorotic leaf spot Trichovirus (ACLSV), Apple mosaic Ilarvirus (ApMV), and Tobacco ring spot Nepovirus (TRSV), were exposed to electrotherapy (0, 30, 40, 50, and 100 mA), thermotherapy (38°C for 7 days), chemotherapy (ribavirin at 0, 25, 50, 75, and 100 mg L− 1), or droplet-vitrification cryotherapy (40 min at 0°C prior to -20°C and − 80°C for 10 and 15 min, respectively) to achieve virus-free plants. Although electrotherapy with current intensities more than 40 mA led to drastic decrease in explants' viability, a 40–60% virus removal rate was noticed depending on the type of virus and the variety tested. Amongst various shoot tip sizes exicised, 1.0–2.0 mm explants exhibited by far more survival (60–80%) and virus eradication rate (90–100%) following thermotherapy. The explants' survival and proliferation rates also decreased with increment of ribivirin concentration in the culture medium as compared to the untreated cultures. The rate of virus elimination, however, inclined by 75–100% upon exposure to 25 mg L− 1 ribavirin. According to our results, production of virus-free regenerants would be feasible in Prunus armeniaca L. providing proper therapeutic methods are adopted as regards the type of infecting virus and the host variety.