Clonal fidelity of chrysanthemum regenerated from long term cultures

Morphological characteristics of flowers of long term regenerated chrysanthemum, cv. "White Spider", after ten years of micropropagation are investigated. Shoot cultures are established and maintained more than ten years by stem segment culture on MS medium supplemented with BAP and NAA (1.0, 0.1 mgL-1, respectively). Rooting of shoots (100 %) has done on MS medium without hormones and it was very successful after ten years, as well as, after two or eight years of micropropagation. Acclimation of rooted chrysanthemum plantlets at greenhouse conditions was excellent and after appropriate photoperiod "in vitro" plants flowered 90.3 % and have the same flower color, shape and size as mother plants. Flower color changes of "in vitro" plants are observed during another flowering cycle one year after acclimatization. Observed variations of chrysanthemum flowers could be attributed to epigenetic factors.Praćene su morfološke karakteristike cvetova regeneranata cv. "White Spider" posle deset godina gajenja u kulturi in vitro. Izdanci su umnožavani u kulturi segmenata stabla preko aksilarnih pupoljaka na MS podlozi sa α-naftilsirćetnom kiselinom i benzilaminopurinom (0,5 odnosno 1,0 mgL-1), . Praćeno je umnožavanje izdanaka u periodu od devetnaest pasaža (tri godine) kada je došlo do sukcesivnog smanjenja indeksa umnožavanja. Oživljavanje izdanaka je praćeno na MS podlozi bez hormona i bilo je podjednako uspešno posle dve, kao i posle osam i deset godina mikropropagacije. Oživljene biljke hrizantema su uspešno aklimatizovane na uslove staklenika (97 %). Nakon odgovarajućeg fotoperioda, 90,3 % biljaka je cvetalo i imale su identičnu boju cveta matičnim biljkama hrizantema. Promene u boji cveta su uočene kod "in vitro" biljaka u sledećem ciklusu cvetanja, tj. godinu dana posle aklimatizacije. Ove promene bi se mogle pripisati epigenetskim faktorima.nul