Beans are an important staple for many people in Africa and Latin America.
However, pests and diseases severely reduce bean yields, such as the dreaded
angular leaf spot disease which can cause yield losses of up to 80 percent.
Researchers from ETH Zurich and the International Center for Tropical
Agriculture (CIAT) worked to investigate the resistance of beans to angular
leaf spot disease. Michelle Nay from the ETH group gathered 316 different
bean varieties from CIAT's repository. These varieties showed
characteristics suitable for breeding resistance to the fungus that causes
angular leaf spot disease. Nay also created a high-resolution genetic
profile for each of the 316 bean types based on variations in their DNA, and
identified which markers occurred only in the disease-resistant beans. She
then used these markers to predict which progeny would be resistant to which
pathotypes in a given country, and which ones would be susceptible to
Bruno Studer, Professor of Molecular Plant Breeding at ETH said their method
speeds bean breeding as the genetic test makes it possible to predict a
plant's resistance without the need for laborious field trials. "This is a
huge help in bean breeding and great news for people who rely heavily on
beans as a staple of their diet," Studer says.