Scientists from KeyGene, Wageningen University and Research and Japanese breeding company Takii are nearing a solution for breeding stronger crops faster with the discovery of the PAR gene which requires no pollination. Seed cuttings for lettuce, dandelion and sunflower have shown promising results.

What makes the PAR gene special, is that it is identical to the mother plant. The phenomenon, called apomixis, allows plants to produce offspring with the genetic combination of the mother plant.

The discovery is expected to lead to major innovations in plant breeding over the coming years.

“Plant breeders have been dreaming about apomixis in crops since the 1930s. In general, apomixis may result in faster and cheaper variety development, varieties adapted to local environments and serving niche markets,” Dr. Peter van Dijk, researcher at KeyGene, Wageningen University & Research (WUR) tells FoodIngredientsFirst.

Cuttings with a cultivation edge
Some wild plants, such as dandelions, can make seeds without pollination, developing directly from the egg cells of the mother plant. The process, known as apomixis ensures that the seedlings all have the same properties as the mother plant. 

The seeds are akin to cuttings, termed “cuttings-seeds” by WUR. These cuttings are faster to make, better to store and transport than regular ones. 

Apomixis is seen as the holy grail of agriculture. Apomictic plants produce “clonal” seeds from the mother plant, allowing superior combinations of the plant’s traits to be captured in one fell swoop. 

This can accelerate the breeding of crops, make seed production less costly and bring the advantages of hybrid breeding to many more of the world’s crop species.

“Apomixis in crops could be used as a universal plant breeding tool. It would affect many crops and many traits, especially very complex traits such as yield, flavor and taste,” explains van Dijk.

The KeyGene scientists started to unravel the genetics behind apomixis in the early-2000s. Before then apomixis could not be successfully introduced in plant breeding.The PAR gene is one-millionth the size of the total DNA of the dandelion.  

Plant breeders around the world have waited for this capability for decades, particularly its application for important or staple crops. If a breeder could replicate a lettuce plant, for example, that is resistant to disease, that has a good shelf-life and additional vitamins it would be a game-changer for that crop throughout the food system, from farm to fork. 

“Apomixis will make seed production cheaper because there is no need to make new F1 seeds by crosses each year again and again. 

F1 seeds refers to the selecive breeding of a plant by cross pollinating two different parent plants.

“This means that seed companies would have to develop new business models. In tuber propagated crops, like potato, apomictic seeds would reduce storage and shipping costs and virus transmission while still propagating clonally,” van Dijk outlines.

PAR gene to advance crop breeding
KeyGene, WUR, Takii, Plant and Food Research New Zealand and Lincoln University collaborated on research specific to the PAR gene, which was published innclick="updateothersitehits('Articlepage','External','OtherSitelink','KeyGene, WUR and Takii break new ground for crop modification','KeyGene, WUR and Takii break new ground for crop modification','325911','https://www.nature.com/articles/s41588-021-00984-y', 'article','KeyGene, WUR and Takii break new ground for crop modification')"> Nature Genetics.  

The researchers hope to use the discovery to develop crops more quickly that can better withstand diseases and climate change.

The PAR gene has been named from parthenogenesis, the process wher egg cells grow into plant embryos without fertilization of the egg cells. The gene is one-millionth of the total DNA of the dandelion. 

Parthenogenesis means “virgin birth”. Technically it means that the egg cell becomes an embryo without fertilization.

“Suppose an elite plant has many desirable traits. In that case, these will not be diluted in the progeny by less desirable traits from the father plant. The offspring will have the same good traits as the mother, irrespective of how genetically complex the traits are,” van Dijk explains. 

The discovery is the breakthrough the KeyGene research team has been working on for the last 15 years. It is expected to lead to major innovations in plant breeding in the coming years.

In other news, the UK will relax its policy on gene editing to help British farmers grow more pest-resistant, climate resistant and nutritious crops. 

The UK Department for Environment, Food and Rural Affairs, opened a consultation in January 2021 on genetic modification of food and gene editing.