IN VITRO STUDIES ON MICROGRAFTING TECHNIQUE IN TWO CULTIVARS OF CITRUS TO PRODUCE VIRUS FREE PLANTS

Abstract This study was carried out to assess the potential use and applicability of micrografting technique for the development of virus free nursery in citrus. Some techniques that tend to increase the grafting success were employed. MS media added with 3%, 5% and 7% sugar was used in combination with two grafting methods e.g., inverted-T incision and surface placement in Kinnow mandarin and Succari sweet orange. The grafting was carried out under aseptic conditions by using15 days old etiolated seedlings of rough lemon. Shoot tips (1-2 mm) and 3-leaf primordia (0.3-0.5 mm) were taken from the fresh shoot flushes and grafted in vitro. Higher grafting success of 34.7% was recorded with inverted-T incision than surface placement which gave 26.7% successful micrografts. A total of 21% successful micrografts were achieved at 3% sugar level which increased significantly to 33% with increase in sugar level to 5% in both cultivars. Overall, Kinnow mandarin showed relatively better response in combination with inverted-T incision and produced 33.3% successful micrografts. Succari sweet orange responded maximum with surface placement method and yielded 30.7% successful micrografts