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

通过对Tricyrtis属多种转基因植株的鉴定，选择CHS基因被RNAi抑制的白花转基因植株和gaox基因过表达的矮化转基因植株作为选育材料，以矮化转基因植株为亲本，通过胚珠培养获得种间杂种。其中部分杂交品种不仅表现出矮化表型，而且与亲本相比具有新颖的花性状，表明利用转基因植物进行种间杂交在观赏植物改良中的可能性。另一方面，利用转基因植物的胚性愈伤组织培养，研究了诱导体细胞无性系变异和染色体加倍的方法。愈伤组织培养源植物的详细表征正在进行中。

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.