Microplants production of Eucalyptus cloeziana from indirect organogenesis

Abstract

Few studies have focused on the in vitro multiplication methods for Eucalyptus cloeziana. In this work we developed an indirect organogenesis protocol to obtain micropropagated plants. The interactions of plant growth regulators in juvenile tissues were evaluated. Hypocotyl, cotyledon and root tissues obtained from in vitro germinated seedlings were subjected to combinations of α-naphthaleneacetic acid (NAA), thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D). In vitro callogenesis, adventitious bud induction, shoot elongation, and ex vitro survival and rooting were evaluated. Callogenic structures were observed in all evaluated tissues. Morphogenic characteristics related to the meristematic center was observed. The tissues that presented the callus mass were subcultured in a regeneration culture medium supplemented with 1.0 mg L-1 of 6-benzylaminopurine (BAP). Only hypocotyl and cotyledon induced adventitious bud and shoot elongation. Hypocotyl subjected to 2.0 mg L-1 TDZ had the highest number of elongated shoots. The two tissues (i.e., hypocotyl and cotyledon) combined with thidiazuron were characterized by the ex vitro survival of microcuttings and by adventitious rooting. Results confirmed tissue culture efficiency for microplants production by indirect organogenesis from hypocotyl and cotyledon cultivated with TDZ, and its implementation can be an alternative for forest tree breeding programs of E. cloeziana.

In Vitro Multiplication of Eucalyptus pilularis and Eucalyptus grandis x E. urophylla (Urograndis Eucalypt): Effect of Light Quality in Temporary Immersion Bioreactor

“…Blake and their hybrids (i.e., E. grandis x E. urophylla, also known as urograndis eucalypt) is becoming increasingly important for forest improvement. Reports are available regarding the early phases of in vitro introduction (Avelar et al, 2020;Molinari et al, 2021), bud multiplication (Máximo et al, 2018;Carvalho et al, 2019;Souza et al, 2020a), shoot elongation (Souza et al, 2020b;Zorz et al, 2020), rooting and acclimatization of microplants (Souza et al, 2019;Miranda et al, 2020). Tissue rejuvenation/reinvigoration can be optimized through asexual propagation, which provides higher levels of clonal productivity and adventitious rooting (Wendling et al, 2014;Brondani et al, 2018;Abiri et al, 2020;Souza et al, 2022).…”

Effect of light intensity and seal type on the in vitro elongation and adventitious rooting of Eucalyptus grandis × E. urophylla

“…The hybridation of Eucalyptus grandis × Eucalyptus urophylla (i.e., the hybrid is known as urograndis eucalypt) has provided excellent results in terms of wood quality and growth, in addition to better soil and climate adaptation and easier vegetative propagation (Carrillo et al 2018). In this context, different ways to improve the production Keywords: clonal propagation, micropropagation, luminosity; LED, porous membranes for obtaining shoots for rooting and for acclimatisation of microcuttings (Souza et al 2020b;Zorz et al 2020), performed both in the ex vitro (Brondani et al 2018;Li et al 2019) and in vitro conditions (Miranda et al 2020;Molinari et al 2020).…”