Effect of rootstock and age of seedling on success of in vitro shoot tip grafting in Kinnow mandarin

The in vitro shoot tip grafting (STG) is a method employed for production of virus-free plants. The present investigation was carried out to study the effect of rootstock and age of seedling on success of in vitro shoot tip grafting in Kinnow mandarin. Four citrus rootstocks, viz., sour orange (Citrus aurantium L.), Carrizo citrange [Citrus sinensis (L.) Osbeck x Poncirus trifoliata (L.) Raf.], rough lemon (Citrus jambhiri Lush.) and Cleopatra mandarin (Citrus reshni Hort. ex. Tan.) were selected for present study. The maximum STG success was observed in Carrizo citrange on 12-day-old seedlings. STG on rough lemon rootstock took minimum number of days for bud sprout followed by Carrizo citrange. The highest number of leaves per graft was recorded on 12-day-old Carrizo citrange seedlings followed by rough lemon. The highest scion shoot length was observed on 12-day-old seedlings of Carrizo citrange followed by that of 16-day-old rough lemon seedlings. The maximum number of roots per graft was produced in Carrizo citrange. The highest per cent transplanting success of STG plantlets was observed on Carrizo citrange followed by rough lemon. It was observed that the Carrizo citrange was found best for most of STG parameters, viz. per cent STG success, number of leaves per graft, scion shoot length, number of roots per graft, stock root length and transplanting success.