A new strain of genetically modified geraniums that do not produce any pollen has been developed by Spanish researchers, leading to hopes that the risk of hay fever among scores of gardeners may now be a thing of past.
The resulting plants are completely harmless to allergy sufferers and pose no risk to natural varieties of the plant because they are sterile, researchers said.
As an added bonus, the new strain produces more brightly coloured flowers, has smaller flowers and leaves and is more compact, with a greater number of branches and leaves than a normal geranium.
They were also engineered to contain a gene that makes them live for longer than usual, with leaves of the new variety remaining green for almost four times longer than natural ones when detached from the plant and left in dark and wet conditions.
The researchers modified a type of bacteria to carry two genes which would delay ageing and block pollen production in the plants. The engineered DNA was injected into plant cells by the bacteria, where it became part of the genome.
"We introduced two new traits in pelargonium zonale, one to produce long-life plants and the other to produce male sterility," the Telegraph quoted researchers, from the Instituto de Biologia Molecular y Celular de Plantas in Spain, as writing.
"The use of engineered male sterility would be especially useful to eliminate pollen allergens and to produce environmentally friendly transgenic plants carrying new traits by preventing gene flow between the genetically modified ornamentals and related plant species," they added.
They concluded that the allergy-free plants, if made commercially available, would be "of interest both for consumers and producers".
The study has been published in the BMC Plant Biology journal.