Biotech Bouquet in the Works
By Jan Suszkiw
July 14, 1999
Sturdier breeds of lily, gladiolus and
other cut-flowers may come from the greenhouse of Kathryn Kamo and her
colleagues in a Beltsville, Md., laboratory operated by the
Agricultural Research Service, the
U.S. Department of Agricultures chief
Using biotechnology, the scientists are seeking to do what conventional
breeding has not achieved: produce commercial cultivars with resistance to
viruses that menace the nations $15 billion floriculture industry. One is
the cucumber mosaic virus (CMV), a disease-causing pathogen that aphids spread
to flower crops while probing for sap.
Spraying insecticide is one recourse. But the practice can be costly and
harmful to beneficial bugs. As an alternative, Kamos team genetically
engineered 30 strains of gladiolus with built-in defenses. About 250 of the
plants are growing in a greenhouse at the
Arboretums Floral and Nursery Crops Research Lab in Beltsville.
Operated by ARS, the arboretum itself is located in Washington, D.C.
The gladioli, now in full bloom in Beltsville, are resplendent in yellow and
pink flowers. But soon, theyll be artificially infected with CMV so
scientists can check for signs of resistance or susceptibility. Virus-induced
streaking in petals, brown spotting in leaves, and other unsightly symptoms can
diminish a cut-flowers aesthetic value, according to Kamo, a plant
She is particularly anxious to test the gladiolis durability, since
theyre the first ornamental bulb crop to be engineered with a gene
gun. The device has enabled scientists to fire bits of genetic material,
called viral DNA, into cells grown from the bulbs of the gladiolus cultivars
Peter Pears and Jenny Lee. From the cells, scientists
grew whole plants.
This summers greenhouse studies will help show whether two viral coat
proteins and an enzyme in the plants will foil CMVs ability to replicate
and cause disease. The trick for scientists is perfecting an inoculation
technique that leaves little doubt of disease resistance. From there, it would
be up to commercial florists to develop the gladiolis into new varieties.
Scientific contact: Kathryn Kamo, ARS
Floral and Nursery
Crops Research Lab, Beltsville, Md., (301) 504 5350, fax (301) 504-5096,