Genetic analysis of enhanced-axillary-branching-derived Eucalyptus tereticornis Smith and E. camaldulensis Dehn. plants

Abstract

In a culture method for enhanced axillary branching functional plants of Eucalyptus tereticornis and E. camaldulensis are efficiently regenerated. To assess the genetic integrity among the regenerants, we employed multiple analytical tools including cytochemical and molecular assays. The 2C DNA amounts were estimated in the meristematic zones of root and shoot tips of 250 micropropagated plants, collected at various cycles of tissue culture from multiplication to field transfer, and compared to the corresponding mother plants. The culture conditions did not induce amplification or deletion of DNA sequences, nor were there drastic change(s) in chromosome number, since all the micropropagated plants of E. tereticornis (1.2 pg) and E. camaldulensis (1.4 pg) maintained the same DNA amounts as the mother plant. Total DNA of 46 micropropagated and mother plants digested with eight restriction enzymes and hybridized to 13 nuclear, mitochondrial, and synthetic oligonucleotide DNA probes yielded 82 bands. Hybridization patterns indicated that the variation observed was minor. To further confirm the genetic fidelity, 12 arbitrary 10-base primers and six synthetic oligonucleotide sequences, successfully used to amplify genomic DNA from in vivo and in vitro materials, produced 133 fragments that were monomorphic across the plants tested. The present results demonstrate that enhanced-axillary-branching culture of mature trees could be utilized commercially for mass clonal propagation of these two important Eucalyptus species that have been recalcitrant to vegetative propagation. The results also provide novel insights into the genetic differences between E. tereticornis and E. camaldulensis.

RETRACTED ARTICLE: Plant regeneration in Chlorophytum borivilianum Sant. et Fernand. from embryogenic callus and cell suspension culture and assessment of genetic fidelity of plants derived through somatic embryogenesis

“…Long term multiplication may lead to somaclonal or epigenetic variations in the micropropagated plants questioning the fidelity of their clonal nature (Cecchini et al 1992;Rani and Raina 1998). Therefore, it is important to first establish the suitability of the micropropagation protocol developed with respect to the production of genetically identical and stable plants.…”

ASSESSMENT OF GENETIC STABILITY OF MICROPROPAGATED Eucalyptus globulus Labill HYBRID CLONES BY MEANS OF FLOW CYTOMETRY AND MICROSATELLITES MARKERS

“…The findings agree with the fact that the micropropagation through axillary bud proliferation is one of the safest methods for the production of genetically identical plants to the mother plant. There are several works in literature which obtained similar results (Rani and Raina, 1998;Martins et al, 2004;Renau-Morata et al, 2005;Joshi and Dhawan, 2007;Borchetia et al, 2009;Brito et al, 2010;Nayak et al, 2011;Leva and Petruccelli, 2012).…”

“…In a wide variety of plant species, aneuploidy and/ or changes in ploidy level has been considered the major changes that occur as the somaclonal variation (Rani and Raina, 1998). According Endemann et al (2001), polyploidization is result of prolonged in vitro culture, unfavorable in vitro conditions, or the action of substances which affect metabolism, growth and development of plant.…”

“…Tremblay et al (1999) noted that the occurrence of somaclonal variation was strongly influenced by genotype in two species of Picea. Although, specifically for Eucalyptus, this has low vulnerability to phenotypic changes in the number and ploidy due to in vitro culture, biochemicals action or stress (Rani and Raina, 1998).…”

“…has been previously reported in the literature, published studies did not assessed in detail the genetic stability of in vitro subcultured plants by axillary bud proliferation for long periods of time, except only the work of Rani and Raina (1998).…”