In vitro plant regeneration of Alnus acuminata H.B.K. ssp. acuminata and its root nodulation by Frankia

Abstract

A procedure for in vitro plant regeneration of Alnus acuminata from epicotyls with cotyledonary buds was developed using different media formulations with different growth regulators and carbon sources. The development of multiple buds on explants at the initiation step was obtained with MS at 1/2 strength with either 1 or 2 lM of BAP but not without it. Multiplication gave up to 15 elongating shoots by explant, the best medium being MS supplemented with vitamins from B5 medium, 1 lM of BAP and 87 mM sucrose. Rooting of about 88% occurred in the medium MS with 83 mM sucrose and 1 lM IBA. Alnus acuminata did not developed well on WPM. Roots of in vitro propagated plants were nodulated by Alnus-infective Frankia. The root nodules show a typical alder root nodule anatomy and differentiation pattern and effectively fixed nitrogen. Rhamnaceae-infective Frankia did not nodulate in vitro cultivated Alnus acuminata suggesting that symbiotic recognition was not altered by in vitro regeneration of the plant.