Connel red obels veislės devirusavimas in vitro

Abstract

The chlorotic leaf spot virus of apple trees was completely eliminated from the microshoots of Connel Red by growing them for 7 days on the MS medium with 20 smf 50 mg l-1 ribavirin concentration additive, or by applying chemotherapy (10–50 mg l-1 ribavirin) in combination with thermotherapy (39 ºC). The best virus elimination results were obtained after growing Connel Red microshoots for 7 days in the temperature of 21 °C on the MS nutrient medium with 20 mg l-1 ribavirin additive. In this variant, the shoots remained most viable and the apple chlorotic leaf spot virus was eliminated. The aim of the study is to eliminate viruses from the microshoots of the Connel Red apple tree variety by applying the chemotherapy and thermotherapy methods. The tests were carried out in the garden plant genetics and biotechnology laboratory of the Horticulture Institute (LAAMC SDI). For the virus research, leaves of the Connel Red apple tree variety were collected in the garden of genetic resources of the Horticulture Institute of the Lithuanian Research Centre for Agriculture and Forestry, and analysed using the PGR method. The apple chlorotic leaf spot virus – ACLSV – was detected in the Connel Red apple tree variety. The Connel Red apple tree variety was introduced to the in vitro system. Chemotherapy and thermotherapy methods were applied for the virus elimination. Chemotherapy was performed by planting the tips of the apple tree microshoots on the MS medium (strawberry propagation) + 0.75 mg/l BAP + 30 g sucrose + 7 g plant agar, pH 5.8, with different concentrations of ribavirin 10, 20, 30, 40 and 50 mg/l-1. The plants were kept in the cultivation room for one week (temperature 21°C, photoperiod 16/8 h), and those subject to chemotherapy and thermotherapy were additionally grown for 7 days at the temperature of 39 °C. After the virus elimination, microshoots were propagated in vitro and counted and replanted after 30 and 60 days. In 60 days the microshoots were checked for viruses using the PGR meth-od. It was found that with the combined application of chemotherapy and thermotherapy on Connel Red microshoots had more negative effects on their vitality, rather than with thermotherapy alone. The most negative effects were obtained using 30 mg l-1 ribavirin in the MS nutrient medium for virus elimination.