Improved Postharvest Life and Ethylene Tolerance in Kalanchoe blossfeldiana Transformed with rol-Genes of Agrobacterium rhizogenes

Kalanchoe blossfeldiana is an important ornamental plant for the Danish horticultural industry. As alternative to chemical growth retardation, plants were transformed with rol-genes (root loci) from the natural occurring soil bacterium Agrobacterium rhizogenes. Apart from changes in morphology, the transformants exhibited clearly improved postharvest characteristics. Longevity and ethylene sensitivity of detached flowers and display quality of whole K. blossfeldiana plants varied among transformants, control and chemical growth retarded plants. The longevity of detached single flowers was defined as the stage where the flowers were 70% open. The longevity of the two transformed plant lines tested, Ri-line 306 and 331, was 32 and 34 days, respectively, whereas chemical growth retarded and control plants had a longevity of 28 and 26 days, respectively. In response to ethylene exposure, the flowers of the plants transformed with rol-genes exhibited tolerance while control and chemical growth regulated plants were sensitive.