Micropropagated banana plants induced by gamma irradiation and resistant to the root-knot nematode reproduction
Keywords:Musa sp., micropropagation, gamma radiation, Meloidogyne incognita, free amino acids.
Micropropagation of banana plants has been used successfully in commerce. Banana plantation has a great interest in Egypt due to suitable climate. However, some problems might thwart the plantation progress like the root-knot nematode; Meloidogyne incognita infection which can affect acclimatization and plantation of in vitro plants. Thus, our investigation aimed to produce nematode resistant in vitro plants using gamma radiation (γ). Banana in vitro plantlets were exposed to gamma radiation at several doses then replanted in vitro. Sensitivity of banana plants to irradiation was determined. Acclimatized plants were infected with M. incognita in greenhouse to see their capability for tolerance. Results indicated that irradiated plants could manage the infection as they tolerated M. incognita infection when exposed to 10 Gy. This response was clear as plant length, leaf number, and leaf width, fresh and dry weight when compared to control. Irradiated plants affected nematode parameters as number of juveniles in soil, developmental stages, galls, and egg masses in banana roots. These were reduced gradually by increasing γ-doses up to 10 Gy. The highest reduction percentages of total nematode populations and build-up of root-knot nematode were also achieved by 10 Gy dose. Gamma irradiation and/or infection by nematode caused variations in leaf content as free amino acids, free proline, glycinebetaine, choline, phenolic compounds, and flavonoids.