Eucalyptus nitens plant regeneration from seedling explants through direct adventitious shoot bud formation.

PAULA G. AYALA; ELSA A. BRUGNOLI; CLAUDIA V. LUNA; ANA M. GONZÁLEZ; RAÚL PEZZUTTI; PEDRO A. SANSBERRO

TREES-STRUCTURE AND FUNCTION

SPRINGER

Lugar: Berlin; Año: 2019 vol. 33 p. 1667 - 1678

0931-1890

Hypocotyls, cotyledons, andexpanded leaves of Eucalyptus nitenswere cultured in Murashige and Skoog (MS) medium containing naphthalene aceticacid or indole-3-acetic acid (IAA) and 6-benzyl adenine (BA). The mosteffective treatment for shoot bud formation, 0.5 μM IAA and 2.5 μM BA, was used in additional experiments. After30 days of culture, the highest rate of regeneration (40 ± 5.8%) and themaximum number of buds differentiated per hypocotyl explant (10.3 ± 4) wereobtained when explants were subjected to darkness for the first 10 daysand then transferred to light-emitting diode lights mimicking daylight for20 days of incubation. Histological examination confirmed direct shootregeneration of E. nitens. For shoot growth, half-strength MSplus 0.09 M sucrose under forced ventilation yielded elongated shootsafter 1 month. After 12 weeks from the onset of an experiment, 40 ±11.5% of elongated shoots produced 5.3 ± 0.8 roots after pretreatment withindole-3-butyric acid aqueous solution and culture on basal medium withoutplant growth regulators under a temporary immersion system. Inter simplesequence repeat (ISSR) marker analysis revealed the genetic uniformity amongthe in vitro raised plants, demonstrating the reliability of theprocedure.