A better understanding of the immune system of crops opens the way for reducing pesticide use in agriculture. New technologies such as Crispr can effectively boost disease resistant varieties.
More than ten millennia ago, the first farmers chose the best wild plants to preserve the seeds for the next growing season. They used experience and intuitively domesticated wild plants such as emmer wheat, spelled and later barley and linseed. Each year they selected the seeds, tubers and fruits with the best visible properties for their purpose, such as a high yield and healthy appearance. Those properties were the best choice for the user, ie humans, but not necessarily the best choice for the plant. The genetic variation of the selected plants has been depleted to such an extent that it has become difficult for the crops to be shaded by neighboring plants, Plant breeding: Art rooted in science.
Impoverishment through selection, enrichment through crossings
Professor Yuling Bai and her research team focus on breeding techniques to make crops such as tomatoes, potatoes or cucumbers more resilient again. The phase of genetic impoverishment ended when science entered plant breeding. Mendel’s theories have been rediscovered. The ‘art’ of breeding by non-professionals, based on experience, luck and intuition, is supported by professional science, genetics in particular, but also side sciences such as physiology, nematology and statistics. By crossing crops, due to Mendel’s laws of inheritance, the outcome in the next generation could be predicted. The newly developed varieties and varieties had new properties, such as disease resistance or a better taste. ”
What do you mean by the art of breeding plants? Here’s some explanation you need to find out.
Eternal plant-pathogen rivalry
Properties such as resistance to viruses, bacteria or stress factors such as drought lie in the genome of the crops. To discover resistance and to study the interaction with pathogens, such as bacteria and fungi, Prof. Bai’s group uses the resistance genes in the genome. But, she says, the resistance from R genes will not last forever. Pathogens can eventually break through the built-in resistance in the perpetual arms race of plant and pathogen, because the latter can also adapt, sometimes so quickly that plant breeders quickly run out of their limited supply of R genes. It sometimes only takes a pathogen one year to break through a resistance. Hence, genetic diversity in crops and in original wild forms are of crucial importance.
In addition to resistance genes, there is another group of genes that make a plant particularly attractive to intruders. “We speak of S genes, susceptibility genes : plant sensitivity genes . This is the main theme in our research. We are studying how we can switch off these S genes, so that germs can no longer use these plant genes to their advantage – causing disease. “
Circular agriculture from a plant breeding perspective
The starting point for circular or circular agriculture is healthy vegetable starting material such as seeds, bulbs and tubers. Resistances to diseases reduce the use of pesticides and thus prevent all or part of emissions and accumulation of harmful residues in the cycle. “This benefits soil life and soil fertility. The Dutch government wants to reduce the use of chemical crop protection products to zero by 2030. So there is an urgent need for resistant varieties. ”