From wild species to ornamental crops: a never-ending story

The plant ornamental industry is characterized by the enormous amounts of products, it is even difficult to try to classify them as everything is commercialized: stems, leaves, flowers, fruits and whole plants. Products are bred for every purpose and for every region of the world. However, every product has initially started in the same way, from a wild species. Ornamental plant breeding does not differ much from other crops, except for one particular thing, diversity, which is the most valuable characteristic while breeding ornamental crops. There is a general path for the generation of new ornamental cultivars, which includes several steps that must be considered. These steps are: i) parental selection, ii) chromosome analyses, iii) crossing, iv) pollen tube growth, v) embryo growth, vi) fertile plants, and finally vii) selection of new cultivar. However, pre- or post-fertilization barriers might be present in between some steps, and biotechnological tools are often needed to overcome these problems. Some of these tools are: somatic hybridization, cut-style pollination, in vitro pollination, mentor pollen, embryo rescue, chromosome doubling and backcrossing. Which and how many tools should be used will vary regarding the species involved in the generation of a new cultivar. One of the most important factors for breeding is a wide genetic base, the wider this is, the higher amount of variation that could be achieved at the beginning of a breeding program, which will ease the selection of new characteristics in novel cultivars. In this work some examples of breeding new ornamental cultivars from wild species will be given, and the methods to obtain the final products will be depicted.