Plants Grown from Seed Clones
Published in The California Aggie (theaggie.org) on March 2, 2011
Photo and Story by Hudson Lofchie
A recent breakthrough in plant cloning techniques at UC Davis could help farmers grow tastier food. Scientists are developing a way to make plants produce perfect clones of themselves.
A current challenge in hybrid plant agriculture is getting future generations to retain favorable traits like fruit size or sweetness. Seeds from hybrids may contain different combinations of genes and will therefore produce offspring that contain different traits than their parents, the same way that humans are a mix of their mothers and fathers. When offspring are exact clones of their parents, it is known as true breeding.
In nature, there are certain plants that naturally create clone offspring through a process called apomixis. In apomixis, plants create seeds without fertilization. These seeds are exact clones of the mother plant.
A new method developed by UC Davis plant scientists and international collaborators from India and France will induce plants – that do not normally make clones – to produce seeds that are exact clones of the parent plant. This study was published on Feb. 18 in the journal Science.
The process that the researchers are going through is essentially an effort to artificially induce apomixis.
“We made mutations and altered genes in a commonly used laboratory plant. [The mutations] were induced with chemicals or by introducing new genetic material into the plant,” said Simon Chan, assistant professor of plant biology at UC Davis and one of the authors of the study.
“The advantage of our strategy is that the processes we have manipulated are found in every plant: chromosome inheritance during cell division and meiosis,” Chan said.
This means that once the method is perfected, it can be applied to any plant, including those that are important for agriculture. Once plants like corn and wheat can be grown from perfect clones, the growing process will be more efficient.
Chan collaborated with researchers Imran Siddiq, from the Center for Cell and Molecular Biology in Hyderabad, India, and Raphael Mercier from the National Institute for Agricultural Research in Versailles, France. The international, interdisciplinary collaboration brought together experts from a wide range of related and complementary areas of study.
Ravi Maruthachalam, a post-doctoral research fellow in Chan’s lab, was originally part of Siddiq’s team in India before coming to study and research at UC Davis. Maruthachalam comes from a farming family in southern India, where his family grows coconuts. His farming background, combined with a master’s in agriculture and a specialization in plant breeding and genetics, makes him a true expert in the field.
The cloning breakthrough did not come without challenges. An early step in the cloning process still requires crossing two parent plants, and the process of crossing is tricky and time consuming.
“We need to generate a system which upon self-pollination gives rise to clones. It may take some time to make it perfect,” said Maruthachalam. “[So far], only one-third of the progeny were clones of the mother plant. To obtain full benefits, we need to improve the efficiency to 100 percent.”
Another challenge was coordinating all of the experiments across three labs in three different countries.
The genetically modified crops that farmers grow are often unable to reproduce. This means that each season, farmers must buy new seeds from companies like Monsanto, who hold patents on many genetically modified crops. The UC Davis research project could give farmers an alternative to these patented strains.
“If it becomes a reality, then it will save time and effort needed to generate hybrid seeds,” said Maruthachalam. “Farmers can save seeds from the desired hybrid and can propagate them indefinitely.”