Application of IBA on in vitro and ex vitro rooting microcutting of Lavandula angustifolia Miller

Abstract

Rooting in vitroincreases the cost of production of plants for the micropropagation of plants, because plants need another phase of development, and the use of culture medium plus growth regulators, burdening the process. The ex vitrorooting for reducing the difficulties associated with survival the acclimatization and reduce production costs. The aim was to promote the in vitroand ex vitrorooting of micropropagated microcuttings of Lavandula angustifolia. Rooting in vitropromoted with concentrations of the IBA 0, 0.5, 1.0 and 2.0 μM were applied. Concentrations of 0, 2.5, 5.0 and 10.0 mM of IBA were applied on 2.0 cm and 4.0 cm in length microcuttings. With the application of IBA microcuttings in vitrodecreased the number of roots,root length and rooting percentage. The better result obtained was 47.3% rooting with the control. 4.0 cm microcutting under effect of 5.0 mM IBA recorded the highest percentage of rooting and survival of ex vitromicrocutting. Analyses showed anatomical connection between the adventitious roots and the vascular system of the microcuttings, not being observed the formation of callus. It was concluded that the ex vitrorooting of microcutting of L. angustifoliais more efficient than in vitrorooting, producing a higher rooting percentage (85%) and survival (80%) using microcutting of 4.0 cm, treated with
5.0 mM IBA