TRANSFORMATION OF AFRICAN VIOLET (SAINTPAULIA IONANTHA) WITH GLUCANASECHITINASE GENES USING AGROBACTERIUM TUMEFACIENS

African violet (Saintpaulia ionantha H. Wendland) is one of the most important ornamental plants used in indoor decoration, gardening and landscaping. These plants are attacked by Fusarium oxysporum, Phytophthora sp., and Pythium sps which cause crown rot and by Botrytis sp. which causes botrytis blight. The present work was envisaged to incorporate the genes producing chitinase and glucanase which impart resistance to these diseases. Transgenic African violets were produced via Agrobacterium tumefaciens-mediated transformation. To start with regeneration protocols were standardised through multiple shoot bud production from leaf and petiole explants using growth regulators BAP and NAA. BAP at 2.5 mgl^-1 and NAA at 1 mgl^-1 gave the highest number of shoot buds (40) in leaf explants. In petiole explants, BAP at 0.5 mgl^-1 and NAA at 0.1 mgl^-1 gave the maximum number of shoot buds (22). Rooting of these shoot buds was found to be maximum with NAA at 2 mgl^-1. Leaf explants were inoculated with the strain LBA4404 of Agrobacterium tumefaciens harbouring the binary pBINAR carrying Glucanase-chitinase genes and nptII selectable marker. Regenerants obtained on the selection media containing kanamycin (70 mgl^-1) and cefotaxime (800 mgl^-1) were excised and rooted on media containing NAA. Integration of the transgenes in the plant genome was confirmed by PCR analysis and Southern hybridzation. Mean glucanase activity in the transgenic plants was 44220 mu ml^-1 while that in control plants it was 27060 mu ml^-1 . The crude protein extracts of transformed plants showed zones of inhibition when tested on Fusarium oxysporum and Pythium while control plants did not show any such antifungal activity.

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