Universitas Scientiarum (Sep 2008)
IN VITRO REGENERATION OF THREE CHRYSANTHEMUM (Dendrathema grandiflora) VARIETIES VIA ORGANOGENESIS AND SOMATIC EMBRYOGENESIS
Abstract
Chrysanthemum (Dendrathema grandiflora) has a high demand in the Colombian and international cut flower markets.Since commercial production of this ornamental species is strongly affected by fungal diseases such as chrysanthemumwhite rust (Puccinia horiana), high doses of fungicides are being used posing increased environmental and commercialcosts. Assessment of in vitro regeneration systems from leaf discs was a first step in developing a plant genetic transformationprotocol to obtain fungi-resistant plants. Leaf discs of White Albatross, Yellow Albatross, and Escapade varieties wereestablished in vitro on MS medium supplemented with NAA (0 - 4.83 μM) and BAP (0 - 13.32 μM) alone and incombination. Leaf discs were also cultured on MumB medium containing 2,4-D (0 - 4.52 μM) for 7, 14, and 21 days priorto their transferral to a 2,4-D free MumB medium. Regenerated shoots were individualized, rooted, and hardened. Resultsshow that MS with 4.83 μM NAA + 4.44 μM BAP and 4.83 μM NAA + 13.32 μM BAP induce organogenesis, and MumBwith 2.26 μM 2,4-D induces somatic embryogenesis on all three varieties, with exposition periods to 2,4-D of 14 days forWhite Albatross and 21 days for Yellow Albatross and Escapade. Shoot development from somatic embryos was observedin the three varieties when cultured on a 2,4-D free MumB medium. Spontaneous rooting was recorded in 85% of the shootsthus facilitating hardening and successful transfer to soil.
