OF ALL the emerging technologies that could be used to improve the safety of
genetically modified crops, perhaps the most promising is one
that would let crops clone themselves, as many wild plants do already.
This phenomenon, called apomixis, could not only slam the door on accidental
gene transfer, it could also benefit farmers鈥攅specially the poorest
ones鈥攂ecause they could save seeds each year from the same elite plants
and replant them.
鈥淎pomixis is a winner from all perspectives,鈥� says Brian Johnson, an advisor
of the British government. 鈥淲e look at it as one of the ultimate genetic
isolation mechanisms.鈥�
Advertisement
Many of the best crop strains are hybrids. But because hybrids don鈥檛 keep all
their valuable traits when they breed
(see Diagram), farmers who want to grow
hybrid crops have to buy new seed each year.
The seeds produced by apomictic plants, however, are genetically identical to
the parent plant. Farmers would be set up for life if hybrid crops can be made
to reproduce apomictically. What鈥檚 more, it would even become practical to
tailor crops to suit local conditions.
In apomixis, the process that halves the number of chromosomes in a female
cell prior to fertilisation is bypassed. Instead, the egg retains its full set
of chromosomes and grows into a clone of the female parent.
Most apomictic plants neither accept pollen from other plants nor produce any
themselves. This means there鈥檇 be almost no risk of gene transfer if genetically
engineered plants reproduced this way.
The big challenge, however, is to transfer the apomixis trait to crop plants.
Efforts to create apomictic crops have been under way for decades, but
researchers may finally be getting close. 鈥淧eople say it will be cracked in the
next five years,鈥� says Johnson.
A team at the International Center for Maize and Wheat Improvement near
Mexico City, which has been working on an apomictic relative of maize called
Tripsacum, has recently found a gene that might be responsible for
apomixis. 鈥淚t鈥檚 called elongate, and we鈥檙e in the process of cloning
it,鈥� says Olivier Leblanc, the head of the research project.
Elsewhere, John Carman of Utah State University in Logan claims to have found
a way of introducing apomixis without genetic engineering. 鈥淥ur first target is
sorghum,鈥� says Arden Kelton of Apomyx, a company set up by the university to
commercialise the technology.
At a meeting in Bellagio in Italy in 1998, many of the apomixis pioneers
signed a declaration aimed at preventing multinationals from obstructing the
development of apomixis. But multinationals are already in on the act. Novartis
of Basle, Switzerland, for example, has a number of patents on the process.
A spokeswoman for the company says, however, that it won鈥檛 obstruct transfer
of the technology to poor farmers. 鈥淥ne of the goals of the programme is to
ensure these varieties are made available to subsistence farmers free of
charge,鈥� she says.