A new interspecififi c hybrid of Torenia obtained through ovule culture

Torenia is one of the most popular summer bedding plants in Japan. Commercially available hybrids are assumed to be interspecific hybrids derived from T. fournieri , T. concolor , and T. baillonii . Use of new Torenia species is required to producenovel fl ower types of interspecifi c hybrids. Three species from Thailand, T. bicolor , T. hirsutissima , and T. siamensis , wereselected and crossed with T. fournieri , T. concolor , and T. baillonii . The chromosome number of six Torenia species variedfrom 2n = 16 to 2n = 34. Mature seeds were obtained from only 3 of 30 reciprocal cross combinations: T. fournieri × T. bicolor ,T. fournieri × T. baillonii , and T. bicolor × T. baillonii . Ovule culture was applied to overcome the interspecifi c crossing barrierof Torenia , ovule culture was applied. Swollen ovules (250) were taken from pods at 10 days after crossing and cultured onMS medium. Progenies were obtained in 14 cross combinations, through ovule culture. This is the fi rst interspecifi c Toreniahybrid obtained using T. bicolor , T. hirsutissima , and T. siamensis. The hybridity of all the obtained plants was confi rmedusing PCR–RFLP analysis of rDNA. The obtained hybrids showed intermediate morphological characteristics and pigmentationof fl oral organs between parents. This study shows that ovule culture is a powerful tool for overcoming the crossingbarrier in interspecifi c crosses in Torenia. KCI Citation Count: 0