ThePartnership no. 14

Technology helps breeding move forward Technology Plant breeding has existed for centuries and the traditional techniques still form the foundation of the process. Yet the field has really taken off in recent decades. Increased knowledge and new techniques have a major impact on the development of vegetable varieties. Techniques that allow us to measure characteristics quickly and develop good varieties. If you want to compete in plant breeding at a professional level in today’s world, then high-tech laboratories are essential. The breeder still plays a leading role in the development process towards new varieties, but lab technicians provide the required input to speed up the process and make it more efficient. It is now commonplace to accelerate the breeding process by three or four generations. From 10, to 100, to 1000 “Not so long ago, we would have about ten plant characteristics on which we could test a hybrid,” explains Manager Molecular Markers Mike Heimerikx. “That soon become one hundred and we are now well on our way to a thousand.” These are marker tests that allow the scientists to analyse the plant material for a certain characteristic. Will the sweet pepper turn red or yellow on the plant? Will the tomato be round or plum-shaped? These characteristics of a plant are known long before the first fruit appears on the plant. And the number of characteristics of a plant that scientists can analyse is only increasing. Switching between breeding and labs With the increased knowledge and available techniques, the role of the laboratories has increased strongly. It is striking to note how the disciplines have merged towards each other in recent years. No doubt the Biotech Breeders had a hand in this. “Biotech Breeders are the link between the breeding process and the various laboratories,” explains Biotech Breeder Cucumber Karin van Langen. “The breeders hear from the Sales department what the needs of a certain market are. Or the breeder contacts the market himself. Either way, the market determines the direction and the breeders translate this wish into specific characteristics in their cross-breeding schemes. They then ask us to perform plant analyses, which they can use to set up the schedules as efficiently as possible and accelerate the plant selection.” Gathering momentum It sounds simple, but nothing is further from the truth. First, the scientists need to track down where a certain characteristic is located on the DNA and – considering the size of DNA – that is a complicated and lengthy process. And in the case of a disease resistance or fruit colour, this is still a ‘simple’ characteristic that corresponds to a single gene in the DNA. In reality, a series of genes often determines these characteristics. This does not make the research any easier. Heimerikx: “After testing for certain characteristics, we can also use thousands of markers per plant to ‘map’ the DNA. Markers are like flags on the DNA which allow us to compare the progeny of a cross to the parent. These markers provide essential information for plant breeders to make choices in the selection process. We have been using these techniques for a number of years and the speed at which we can unravel (parts of) the DNA is increasing all the time. As a result, this technique has really gathered momentum. And the train keeps moving faster. 10,000 tests, 50,000 tests, why not map all the DNA? The possibilities seem endless.” DNA package Imagine that you have a fantastic variety, but it is lacking a certain characteristic, for example a certain flavour structure. We know from previous research that the structure that we are looking for in the DNA consists of a specific series of data points. The breeder then crosses the original variety with the plant that has this flavour structure as a characteristic. The DNA of the progeny is then studied. Van Langen: “I then inform the lab that I am looking for a plant that is as similar as possible to that one plant, but that a specific ‘DNA package’ needs to be identical to that of the other plant. We are effectively looking for a specific ‘fingerprint’.” 26 | The Partnership The Partnership | 27