Development of a new cultivar production system using transgenic plants in ornamental plants

通过对Tricyrtis spp.各种转基因植株的鉴定，筛选出CHS基因RNAi抑制产生的白花转基因植株和GA2ox基因过表达产生的矮秆转基因植株作为育种材料。以矮秆转基因植株为亲本，通过胚珠培养产生种间杂种。其中一些杂交种不仅表现出转基因植株的矮化表型，而且与亲本相比还表现出新的花型特征，这表明利用转基因植株进行种间杂交在观赏植物改良中是可能的。另一方面，利用转基因植株的胚性愈伤组织培养，还检测了体细胞无性系变异的诱导和染色体加倍。愈伤组织培养衍生植物的详细特征目前正在进行中。

White-flowered transgenic plants resulted from RNAi suppression of the CHS gene and dwarf transgenic plants resulted from overexpression of the GA2ox gene were selected as breeding materials through characterization of various transgenic plants of Tricyrtis spp. Interspecific hybrids were produced via ovule culture when dwarf transgenic plants were used as parents. Some of these hybrids showed not only dwarf phenotypes due to the transgene but also novel flower characteristics compared with the parents, indicating the possibility of interspecific hybridization using transgenic plants in the improvement programs of ornamental plants. On the other hand, induction of somaclonal variants and chromosome doubling were also examined by using embryogenic callus cultures of transgenic plants. Detailed characterization of callus culture-derived plants are now in progress.