QUALITY IMPROVEMENT OF ORNAMENTAL PLANTS BY INTRODUCING DWARFISM INTO KALANCHOE BLOSSFELDIANA
Denmark is one of the leading countries in the production of potted ornamental plants. Around 85% of the production is exported, which is valued at EUR 267 million and this imposes a great demand on plant quality. One important qualitative criterion is that the plants should be compact; to satisfy this the plants are sprayed with chemical growth retardants. Their main problem is that they are hazardous to human health and the environment, and most likely will be banned in the near future. An alternate strategy to overcome such problems is to produce compact genotypes by inserting the rol-genes into the plants from the naturally occurring bacterium Agrobacterium rhizogenes. Leaf explants of Kalanchoe blossfeldiana were inoculated with a wild-type A. rhizogenes strain and transgenic hairy roots were induced at the site of infection due to the insertion of rol-genes. These transgenic roots were selected based on the hairy phenotypic characteristics without using any selectable marker. Plants regenerated in tissue culture from the transgenic root lines, called Ri-lines, were grown and evaluated in the greenhouse. PCR amplification confirmed the presence of T-DNA in six Ri-lines, and these lines were characterized under greenhouse conditions. The first set of results showed that the Ri-lines exhibit various degrees of the phenotypic characteristics. The internodes of the Ri-lines were clearly shorter giving a compact growth habit, and the inflorescences were denser compared to the control. These characteristics are useful in creating new genotypes in ornamental species, especially to create compact plants.
Christensen, B., Sriskandarajah , S., Müller, R. and Serek, M. (2012). QUALITY IMPROVEMENT OF ORNAMENTAL PLANTS BY INTRODUCING DWARFISM INTO KALANCHOE BLOSSFELDIANA. Acta Hortic. 941, 109-116
Agrobacterium rhizogenes, growth retardant, ornamentals, potted plants, rol-genes