Scientists are working to develop apomictic varieties of crops that rely on self-cloning and can reproduce without the need for pollination.
In the world of agriculture, hybrid vigor is a well-known phenomenon. It involves crossing two strains of inbred parents to create seeds that produce high-yielding and resilient plants.
Hybrid varieties developed through traditional cross-pollination have boosted crop yields for various species by up to 50%, with rice, maize, and sorghum being particularly notable.
However, the process of producing hybrid seeds is expensive and labor-intensive, requiring helicopters to fly low and steady over rice fields, transferring pollen from one row of plants to another.
For decades, scientists have sought an easier and more powerful way to create hybrid seeds.
The solution may lie in apomixis, a phenomenon in which seeds develop and grow clonally, meaning they do not need pollination to be fertilized, according to a recent report by Science.
Although apomixis is commonly observed among hundreds of plant species, it has not been observed in key food crops.
First Instance of Synthetic Apomixis in a Crop
In 2019, an international team of scientists reported successfully engineering a line of rice plants that could reproduce clonally — the first synthetic apomixis in a crop.
There is now a burgeoning sense of excitement among scientists worldwide regarding the potential of the technology.
If researchers can genetically engineer crops to reproduce via apomixis, it would simplify and expedite the hybrid seed production process considerably.
Scientists could create the first hybrid generation using laborious traditional methods, but after that, the production of hybrid offspring would be much more straightforward.
It is worth noting, however, that the technology will take years before it can be accessed commercially.
“There’s still an awful lot that we don’t understand about how to make it efficient for agriculture,” said Peggy Ozias-Akins, a geneticist at the University of Georgia.
Scientists will also need to conduct extensive field testing to determine how hybrid varieties respond to different climate conditions.
Benefits of Apomixis in Plant Breeding
The potential benefits of apomixis in plant breeding are profound.
Apomixis technology promises to simplify and quicken the production of hybrid seeds, reduce costs for seed companies, and improve yields substantially.
It would also make hybrid crops more accessible to smallholder farmers in poorer countries, who may not have regular access to commercial hybrid seeds.
Furthermore, it could represent a significant breakthrough for agricultural researchers working on a variety of other crops.
In Australia, field trials have already commenced on sorghum that was genetically modified to produce haploid embryos and be parthenogenic.
Likewise, at least 10 groups in China are also working on apomictic varieties of cabbage, tomatoes, alfalfa, and other vegetable and forage crops, according to Kejian Wang, a geneticist at the China National Rice Research Institute.
Although apomixis technology shows great promise, there are concerns about resistance to it in some countries, particularly in Asia.
However, Jauhar Ali, head of the hybrid rice program at the International Rice Research Institute, said the resisting countries may change their stance as they realize the vast potential of the technology.
“Gene editing is slowly being accepted and many governments are understanding the importance of this tool for bringing benefits to agriculture.”
For now, hybrid seed production will continue to be a labor-intensive process, particularly where traditional cross-pollination methods are necessary.