Ploidy level determination within the context of in vitro breeding

Abstract

Variations in genome size and chromosome complement of species provide very useful information for biosystematic studies, and also because they influence a range of ecological characteristics. They are also of utmost importance for breeding, especially when in vitro biotechnology tools are used and the need arises to assess the trueness-to-type of regenerated plants. Thus, protocols have existed for a long time for chromosome counting, and more recently also for the determination of the relative nuclear DNA content and genome size. It has also been shown that these latter traits are strongly correlated to regeneration competence and, more generally, to developmental processes in plants. This article will briefly review such approaches from a methodological and breeding-oriented viewpoint.

Micropropagation of Viola uliginosa (Violaceae) for endangered species conservation and for somaclonal variation-enhanced cyclotide biosynthesis

“…Molecular markers can identify gene polymorphism and are useful for exploring polyploid (mainly allopolyploid) genomes in plants, but identifying autopolyploids (produced via somaclonal variation in culture) by these methods is problematic (Aversano et al 2012). The value of flow cytometry technique for somaclone genome size assessment has been demonstrated by a number of authors (e.g., Bairu et al 2011;Ochatt et al 2011). In our study, *24 % of the regenerants from direct and indirect organogensis (on MS media supplemented with TDZ, 2 mg l -1 KIN ?…”

“…Somaclonal variation induced by culture conditions limits the use of in vitro micropropagation, as it leads to changes in nuclear and cytoplasmic genomes and causes genetic differentiation of regenerated plants (D'Amato 1991; Larkin and Scowcroft 1981; Lee and Phillips 1988;Neelakandan and Wang 2012;Rodriguez-Enriquez et al 2011;Vazquez 2001;Wang and Wang 2012). Confirmation of the genetic identity with maternal material, and the genome size and reproductive normality of regenerated plants, is required before reintroduction (Nybom et al 2014;Ochatt et al 2011;Singh et al 2013;Thiem et al 2013;Thiem and Sliwinska 2003). Molecular markers are valuable tools for detecting the sequence variation of closely related genomes such as those between source plants and somaclones regenerated through tissue culture.…”

“…Molecular marker systems-random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR), simple sequence repeat (SSR), amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP)-each having its advantages and limitations, are used to estimate somaclonal variation in tissue culture (Bairu et al 2011;Nybom et al 2014;Rewers et al 2012;Singh et al 2013). Flow cytometry for somaclone genome size assessment can be used to complement molecular marker analyses (Bairu et al 2011;Ochatt et al 2011;Rewers et al 2012).…”

Pré-seleção de poliploides por métodos foliares em acessos de bananeira

“…Contudo, esta técnica é morosa e demanda operadores qualificados, além de reduzir o número de amostras e não fornecer imagens representativas de uma população heterogênea de células (Dolezel et al, 2007;Ochatt et al, 2011). Neste contexto, o desenvolvimento da citometria de fluxo fez com que o teste de ploidia pudesse ser realizado de forma muito mais rápida, o que permitiu a realização de estudos com análise de grande número de plantas, com diferentes tipos de camadas de tecido e de células analisados (Leus et al, 2009).…”

Review Article: ISTR, a Retrotransposons-Based Marker to Assess Plant Genome Variability with Special Emphasis in the Genera <i>Zea</i> and <i>Agave</i>

“…At this time, transformation and transposon-induced changes are new ways of mutation [5][6][7][8]; transformation and somatic hybridization are new ways of recombination [9]. Techniques like embryo rescue and in vitro pollination have permitted hybridizations till now impossible [10,11]. Molecular data offer important information to understand and assess relationships between cultivated and wild plants, makes evident the differences among phenotypes and make visible the changes in gene sequences and the proteins that they encoded.…”