Acclimatization of secondary somatic embryos derived plants of Eucalyptus globulus Labill.: an ultrastructural approach

Abstract

This paper reports the complete process from secondary emblings (SE-derived plants) regeneration to acclimatization of Eucalyptus globulus and describes histocytological changes that occur in leaves from in vitro to ex vitro acclimatization for a 3-month period. After elongation, plants were transferred to pots with sterilized peat:perlite and acclimatized in a phytotron, with progressive reduction of RH and increase of light intensity. Histocytological analyses were performed in fixed material using light microscopy and ultrastructural changes followed by electron microscopy (SEM and TEM). The protocol used allowed the successful acclimatization of the emblings. Plants looked morphologically normal and FCM screening revealed no ploidy or DNA content abnormalities. Histocytological analyses showed significant changes along time, mostly in stomata shape and aperture, starch reserves, chloroplast morphology and mesophyll differentiation. This is the first report concerning emblings acclimatization to ex vitro conditions in Eucalyptus. It was clearly demonstrated that during acclimatization emblings suffered profound changes in leaf morphology in order to successfully adapt to ex vitro conditions.

Physiological and biochemical parameters influencing ex vitro establishment of the in vitro regenerants of Albizia lebbeck (L.) Benth.: an important soil reclaiming plantation tree

“…Generally, water stress and photoinhibition promotes the production of reactive oxygen species (ROS) and in consequence of oxidative stress during the acclimatization of plants to ex vitro conditions (Pinto et al 2011). ROS being inevitable byproducts of aerobic metabolism cause lipid peroxidation, protein degradation, damage of DNA; therefore, their production and removal must be controlled (Batkova et al 2008).…”

Acclimatization of micropropagated plantlets induces an antioxidative burst: a case study with Ulmus minor Mill.

“…During in vitro conditions, plants grow under specific climatic conditions of high relative humidity, low CO 2 concentration and low light intensity in a culture medium with a large concentration of sugar. These special conditions result in a formation of plants with abnormal morphology, anatomy and physiology (Pospíšilová et al 1999, Hazarica 2006, Estrada-Luna et al 2001, Pinto et al 2011. During the transfer to ex vitro conditions, in vitro plants are exposed to light intensities higher than those used under in vitro conditions, resulting usually in photoinhibition (Carvalho and Amâncio 2002a, Ali et al 2005, Osório et al 2010).…”

Photosynthetic parameters of Ulmus minor plantlets affected by irradiance during acclimatization

“…Nowadays, improvement programs can be found for Eucalyptus species (e.g. Pinto et al 2008Pinto et al , 2011, Pinus and Picea species (Park 2002), and Olea maderensis (Brito et al 2009). However, for the largescale acclimatization of micropropagated species, processes that are particularly sensitive during this stage (e.g.…”