Cloned plants: the future of seed breeding?

Raphael Mercier/Institut National de la Recherche Agronomique, V

[HYDERABAD] Seeds have been cloned for the first time, a move which could speed up crop breeding and one day allow farmers to produce their own high-yielding seed.

Most crop varieties are hybrids with a mixture of characteristics from genetically distinct parents. But their useful traits are not passed on to their seeds because sexual reproduction, which involves two parents, shuffles genes.

Now an international team of scientists has forced plants to produce seeds that are identical to themselves genetically (i.e. cloned), rather than containing a mix of genes from themselves and another parent.

The seeds have thus retained all the useful traits of their parent.

Imran Siddiqi, researcher at the Centre for Cellular and Molecular Biology, India, and one of the authors of the paper, published in Science last month(18 February), called this a "proof of principle" of what has long been only a theory.

The key to what they have done lies in the fact that some plants naturally reproduce asexually, by 'apomixis', where the offspring are identical to the parent. They have managed to make a plant that usually makes seeds sexually do so by this method instead.

Siddiqi said the process involved manipulating 2–4 genes that retain parental genetic material in a seed.

He told SciDev.Net that the process would make it possible to 'fix' desirable traits in crops without going through the several generations of cross breeding that are normally required.

"This is a real boost to the field of plant genomics as a whole," said Siddiqi. "But application is still a long way off."

The method creates clones in around a third of offspring in the model plant species Arabidopsis.

Commercial use would require at least 85–90 per cent of seeds to be successfully cloned, he said.

The publication has generated interest among plant scientists in India but they recognise that this is the first step on a long road.

P. B. Kirti, professor of plant sciences at the University of Hyderabad, told SciDev.Net that demonstrating that the method works for important crops would be a "huge challenge" and reaching field trials would take years of work and considerable financing.

"Getting good genetic material to work on and take this proof of concept further also poses its own challenges, particularly to scientists in developing countries," he added.

Siddiqi agreed: "To take this forward would certainly require a more concerted effort — a greater level of funding, a policy-level commitment and wider collaboration."

He said provisional patents have been filed for the process. "If and when application becomes a reality, the technology should remain accessible to public institutions." 

Link to full paper in Science