What does wheat, tulip, plum and algae have in common?
– somebody, somewhere is breeding them to be BETTER!
Plant breeding is an affectionate term used to describe genetic improvement in a plant. This may be for a plum tree to yield more, tastier plums or a tulip to have a yellow flower instead of a red one. Almost every single plant in cultivation be it for food, fibre or ornamentation (tulips and roses) has someone pushing it to be better.
Agriculture was the reason people settled 10,000 years ago, the ability to plant a crop and harvest food meant we no longer had to be nomadic to support ourselves. Ever since then people have made constant genetic improvements in the plants they cultivated. In the fertile crescent in modern day Syria and Afghanistan people begun to settle and cultivate wheat and barley, originally a wild grass they saw the potential for the tiny seeds as a food source. Thus began the genetic transformation of wheat and barley to what we have today. Way back then the process of plant breeding didn’t involve crossing two individuals to test the progeny, they relied on an understanding that if they planted the biggest best seeds from a harvest the following year they could continue to increase their food production (directional selection). This process didn’t change too much up until modern day where we know cross two individuals that we know are superior to the rest and hope for the best in the progeny…..albeit with a bit more sophistication.
Fun fact #1: Algae is being bred for the sustainable production of biofuel.
This process of planting the best seeds year in year out was the early method of breeding and was crucial in shaping some modern day favourites such as cabbage and broccoli which begun their transformation 3,000 years ago from what is believed to be the same ancestor. Isn’t it interesting to think that broccoli and cabbage originated from the same ancestor but are now so different thanks to plant breeding? Even almonds have been on the scene for 5,000 years with travelers munching away on them along the “silk road” all those years ago.
Plant breeding can be broken up into two broad categories; there is the classical breeding approach which loosely involves continuously harvesting and re-planting individuals that have desirable traits. Then there is the molecular breeding approach which encompasses a variety of different breeding strategies. Molecular breeding is a relatively new approach to breeding (last 50 years) where we do not rely solely on the observable traits of individuals but use genetic information for traits which are hard to measure or observe.
Molecular breeding is by far the most efficient approach to improving plant performance for whatever trait is being targeted. The simplest form of molecular breeding is marker assisted selection. This is initiated by ‘pre-breeding’ research which identifies tightly linked genetic markers to a gene of interest. This gene may for example contribute to higher yields in barley or an increase in scoville heat units for a chilli. After a tightly linked genetic marker has been identified and proven to represent the trait of interest than plant breeders can use them to make informed decisions bout which individuals to continue in the program and which individuals to ignore and subsequently remove. Marker assisted selection is fast becoming the norm in conventional plant breeding programs. Other molecular breeding approaches include CRISPR-Cas9 which is a recently developed approach to genome editing that has been labelled the new revolution in genetics. This new technology is even being used to bring back the Woolly Mammoth! The potential that a tool such as CRISPR-Cas9 has for plant breeding is almost boundless, already scientists are using it to develop peanuts that will be allergen free and mushrooms that will not brown.
Fun fact #2: Genetic modification is the process not the product. You can conventionally breed herbicide tolerance into a crop thus creating a conventionally bred variety or you can insert a herbicide tolerance gene to yield the same result that would by classified as a genetically modified organism. #frankenfood?
Looking to the future
Plant breeding is critical for sustainable food production. It is a process that can improve plant production on marginal lands, reduce input needs and improve the nutritional benefit of whatever it may be (bio-fortification). The days of classical breeding are almost behind us, molecular breeding and the use of new technologies such as CRISPR-Cas9 will become the norm for future plant breeding. This should not be met with much hesitation as it is necessary to feed a growing, hungry world sustainably. The area of arable land for broadacre crops in particular is decreasing as a result of salinity and drought and molecular plant breeding has the potential to slow or stop this relatively cheaply and quickly.
Pre-breeding strategies are going to become more important to plant breeders as the genetic information is often gathered by university research. What we will see is a big shift towards research institutions and plant breeders working together to develop new and improved plant varieties. As a pre-breeder myself I view this approach to be the most important for current plant breeding approaches because without the genetic information molecular breeding has nothing to function on. It has been stated that more food will have to be grown within the next 30 years than has been grown since the beginning of human civilization to meet future demand, and plant breeding is well placed to make sure we can meet this demand.
Fun fact #3: Since 2016 the United States Department of Agriculture has stated that crops bred using CRISPR-Cas9 technology will not be considered GMO and will not be governed by GMO regulation.