The originator of the GM orange petunia believes GM ornamentals may be widespread in the supply chain because of the way breeders borrow competitors' material - and because, outside the EU, GM is becoming more acceptable to the public.
In a December 1987 Nature paper, a team led by plant geneticist Peter Meyer, then with the Max Planck Institute for Plant Breeding Research in Cologne, Germany, but now at University of Leeds, showed that inserting a maize gene into a petunia enabled it to produce the pigment pelargonidin (a characteristic orange colour).
Almost three decades after Meyer’s pioneering work, following the first interception of unauthorised GM ornamentals in popular bedding plant the petunia, thousands of plants are now having to be thrown away in Europe and the US after the experimental gene Meyer produced found its way into breeding programmes.
The orange GM petunia has reached as far afield as New Zealand, and other colours are now being reported as GM.
The issue does not look like going away, as many in the industry hope, because the genes have got into other plants that breeders have worked on over the past couple of decades. Volmary’s Wayne Eady says reaction has been "blown out of proportion"; WD Smith & Son’s Mike Smith adds "the plants won’t be here next year so that is the end of it – hopefully", while Woodlark Nursery’s Colin Edwards hopes the headline-making findings were "a storm in a teacup".
Breeders such as Volmary and Dummen are compensating or replacing thrown away plants, and Smith said publicity over the controversial GM issue had not damaged petunia sales, apart from ones that were thrown away. Some might still lose money if they have planted them in mixed baskets for instance and have had to undo their work.
While UK agency APHA continues investigations, it has yet to release new information on GM petunias since Finnish authorities revealed they were in the supply chain in late April.
In the US, the US Department of Agriculture’s Animal and Plant Health Inspection Services (APHIS) says as well as orange, red and purple coloured flowers have been imported into the US from Africa, Asia, Central America, Europe, South America, Australia, Israel and Mexico.
"APHIS is working in close cooperation with breeders and growers represented by the American Seed Trade Association (ASTA) and AmericanHort to ensure the implicated GE petunia varieties are withdrawn from distribution. Several distributors have already voluntarily removed GE petunias from distribution and destroyed them in accordance with APHIS guidance."
The 30,000 petunias Meyer’s team planted in a trial were the first transgenic plants released into the field in Germany.
S&G Seeds, an affiliate of the Dutch seed company Zaadunie, licensed the technology, developing an orange commercial petunia by 1995. Rogers NK, also collaborating with Zaadunie, gained clearance from US regulators for an orange petunia field trial in Florida.
Biotech conglomerate Sandoz, which owned Zaadunie when the GM petunia was first developed, merged to form Novartis in 1996, which then joined its agribusiness with AstraZeneca’s in 2000 to form Syngenta.
It is not yet known how the GM petunias entered the supply chain. It is possible it had been around for a decade before Finnish biologist Teemu Teeri picked some orange petunias in Helsinki.
"Breeders in Europe and the US have thrown away thousands of plants across more than 20 varieties that are illegal for sale because they are unlicensed", says Meyer.
Meyer says the transgenic plants he produced had orange flowers but were not suitable to be marketed because the flowers were too small and the transgene could be silenced, but S&G improved colour intensity and stability.
He says the spread happened because "it is common practice for breeders to use material, including plants from competitors, to breed new varieties. I assume that breeders have used orange petunia lines to produce new varieties, probably without even realising that they were including a transgenic line in their breeding programmes".
Meyer says GM ornamentals could become more widespread. Only GM carnations from Suntory, bred with unusual colours, are now authorised in Europe: "GM technologies are now widely accepted across the world with the exception of most EU countries. I therefore assume that in the future some new ornamental varieties will include traits induced via GM technologies, especially those that help the plants to cope with biotic and abiotic stress, and that produce new shapes, colour or other features."
He says now that the genie is out of the bottle he would not exclude GM plants becoming more widespread "considering that it appears to be common practice for breeders to use foreign material".
But he says the genome editing tool CRISPR/Cas technology only induces small mutations or modification that will be very difficult to identify.
It would make sense to assess new ornamentals and crops, not on the basis of whether they are a GM line or if they are derived from a GM line, but on a plant's characteristics.
"It does not make sense to assess which technology has been used to produce a plant as this says nothing about the features of the plant – this seems to be as useless as assessing the quality of a book on the basis of whether it was written on a typewriter or on a computer."