Effects of Explant Type, Culture Media and Picloram and Dicamba Growth Regulators on Induction and Proliferation of Somatic Embryos in Eucalyptus Grandis X E. Urophylla1

Abstract

The objective of the present study was to test the effects of explant type, auxin concentrations, culture media, and auxin concentrations on the induction and proliferation of somatic embryos of Eucalyptus grandis x E. urophylla. Seeds and cotyledons were used as explants and inoculated in culture media containing 1.13, 2.26, 3.39 and 4.52 µM dicamba or 4.14, 10.35, 20.71 and 31.06 µM picloram. Embryogenic calli induced in the picloram treatments were used as explants and inoculated in semisolid or liquid media containing 4.14, 10.35, 20.71 and 31.06 µM picloram and keeping the origin of the embryogenic callus (seeds or cotyledons) and the concentration of picloram in those who were in the induction phase. Statistical, descriptive and anatomical analyses were performed. Induction of somatic pro-embryos into the juvenile plant material of Eucalyptus grandis x E. urophylla was performed using seeds or cotyledons as the source of explants, with the addition of dicamba and picloram as growth regulators. The use of cotyledons as a source of explants and the concentration of 4.1 µM picloram added to the culture media resulted in a higher induction of somatic pro-embryos. Proliferation of secondary somatic embryos was achieved using liquid medium added with picloram.

Embryogenic potential of the callus of gabirobeira, Campomanesia adamantium (Cambess) O. Berg

“…Most studies have indicated that calli are achieved primarily through the use of 2,4-D (Bajpai, Kalim, Chandra, & Kamle, 2016;Fehér, 2015;Rocha et al, 2016;Winkelmann et al, 2015), including in the induction of calogenesis in Campomanesia rufa leaf explants (Sant'Ana, Paiva, Reis, Silva, & Silva, 2018), which was not found in the present study. Satisfactory results have been achieved using picloram for embryogenic callus induction in Eucalyptus grandis x E. urophylla (Moura et al, 2017) and Acca sellowiana (Cangahuala-Inocente, Caprestano, & Pierre, 2007), both from the same family, Myrtaceae, as gabiroba.…”

“…During this phase, cytological monitoring is necessary to identify cells that have embryogenic characteristics and to document abnormal formation of somatic embryos during plant regeneration (Gomes, Bartos, & Scherwinski-Pereira, 2017;Oliveira et al, 2017). Such cytological analyses have been used repeatedly for some species of the Myrtaceae family with the aim of describing the sequences of morphogenetic events involved in the development and formation of somatic embryos (Correia & Canhoto, 2010;Moura et al, 2017;Pescador, Kerbauy, Viviani, & Kraus, 2008;Pinto, Silva, Neves, Araújo, & Santos, 2010).…”

AUXIN PULSE IN THE INDUCTION OF SOMATIC EMBRYOS OF Eucalyptus

“…In some non-woody species, callus oxidation causes absence of the embryogenic process and death of the explant (Takamori et al, 2015). However, in some other species, woody or otherwise, the oxidation of callogenic tissue preceding or concomitant to the formation of somatic embryos can be observed, as in the somatic embryogenesis of Eucalyptus grandis x E. urophylla (Moura et al, 2017), Vitis (Martínez et al, 2015) and Mondia whitei (Baskaran et al, 2015). Oxidation may occur when the excised explant produces secondary metabolites when in contact with the culture medium, producing a brownish color in the tissue.…”

Somatic embryos from Phalaenopsis classic Spotted Pink (Orchidaceae) protocorms

“…In the sense, somatic embryogenesis is a method used in the production of new embryos from pre-existing somatic embryos. Embryogenic callus systems are highly regenerable and can generate large numbers of propagules and hold for long periods (MOURA et al, 2017).…”

“…Factors such as ontogenetic age of maternal tissue, hormonal levels, type of culture medium used, among others, interfere with the various stages of somatic embryo formation (MOURA et al, 2017). However, the selection of suitable types and sources of explant are critical factors for obtaining a successful culture in somatic embryogenesis system (FENG & CHEN, 2014).…”