Transformation with rol genes from Agrobacterium rhizogenes as a strategy to breed compact ornamental plants with improved postharvest quality.

摘要

In Kalanchoe blossfeldiana, root inducing lines were regenerated from hairy roots produced by transformation with the natural occurring bacteria A. rhizogenes. Transformed plants (T₁) displayed distinct changes in plant morphology. A number of T₁-lines were analysed thoroughly in greenhouse trials. Several lines had a more compact growth habit and an increased number of lateral shoots. Time to flowering was delayed in most lines. However, for one line the flowering period was similar to the control plants. In ethylene free environment, transformants performed better than control plants and single flowers lasted longer. In response to exogenous ethylene, flowers of T₁-lines exhibited increased tolerance compared to control plants. Possible mechanisms behind the improved postharvest performance of plants transformed with rol genes are presently investigated. Crossings between T₁-lines and the cultivar 'Sarah' proved the heredity of the traits of interest, since dwarfism was also observed in the offspring. The presence of rol genes was proved in those F₁ progenies exhibiting dwarfism. The heredity of the traits will be further investigated. Selecting for a compact growing plant, without delayed flowering and improved postharvest performance will be of great value for further breeding programmes.