O-Hyeon Kwon

FT-transgenic spray-type Chrysanthemum (Dendranthema grandiflorum Kitamura) showing early-flowering

Abstract The flowering locus T (FT) gene, of which expression will be controlled at high temperature by heat shock promoter (it printed as to HS pro FT) , was introduced into spray-type chrysanthemum ( Dendranthema grandiflorum (Ramat.) Kitamura) 2 cultivars (‘Pink PangPang’ and ‘Pink Pride’ by co-cultivation with Agrobacterium tumefaciens strain C58C1 harboring pCAMBIA2300 containing the HS pro FT gene. After leaf segments of the 2 cultivars were infected with the A. tumafaciens with C58C1 as explants, shoots were regenerated from the explants cultured on the 1 st selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 10 mg/L kanamycin + 0.7% plant agar, pH 5.8). The shoots were transferred into the 2 nd selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 20 mg/L kanamycin + 0.7% plant agar, pH 5.8). One hundred seventeen plantlets from ‘Pink PangPang’ and 5 ones from ‘Pink Pride’ were confirmed as transformants by PCR analysis. Twenty six of the transformants and non-transformants were acclimatized and established well in a green house. Eights of 26 transgenic lines showed flower bud 1.7~10 days earlier than non- transgenic plants, and 24 of them flowered 1~6 days earlier than non- transgenic plants. The shape and color of flower of all