After decades of efforts, scientists have managed to modify a hybrid rice strain so that it passes on its favorable traits in its own seeds, according to ScienceDaily. By producing clones from its seeds, instead of requiring fertilization, the hybrids would allow farmers to replant seeds from their own plants instead of having to buy expensive new seeds each growing season.
Some wild plants, such as blackberries, have evolved the ability to self-replicate in a process called apomixis. But scientists have struggled to reproduce that process in commercial hybrids, which offer benefits like higher yields or resistance to pests and disease.
“It’s a very desirable goal that could change agriculture,” said Venkatesan Sundaresan, a University of California, Davis professor of plant biology who made the discovery, along with postdoctoral researcher Imtiyaz Khanday.
The researchers have now made a breakthrough toward that goal, with a hybrid strain of rice.
The researchers discovered that in fertilized plant eggs, the male version of genes called BBM1 or “Baby Boom 1,” spark the process of embryo formation in a seed. They used a genetic switch called a promoter that would allow a female version of the gene to perform the same function on its own.
But since a normal egg that had formed through the normal cell division process, meiosis, would have contained only half the necessary chromosomes, more changes were still necessary.
Using an approach developed by French National Institute for Agricultural Research plant geneticist and study coauthor Raphael Mercier, the team disabled genes necessary for meiosis, leading the rice to reproduce asexually through mitosis instead. Sundaresan and Khanday updated Mercier’s procedure, using CRISPR/Cas9 gene-editing to disable the genes.
In a type of japonica rice called Kitaake, the process succeeded in allowing about 30 percent of plants to produce viable seed clones with all the desirable hybrid genetic traits passed on. In turn, those seeds grew into plants that successfully produced clones, which themselves produced yet another generation of hybrid clones.
Sundaresan says the researchers will now work to make the process more efficient.
The development could help farmers, especially in developing countries, produce enough food for the world’s growing population. Hybrid plants can even offer properties that make them more resistant to climate change, which means the new process could play a crucial role in adapting food production to the extreme weather and higher temperatures that come with climate change.
The study was published in the journal Nature on Wednesday.