|Beans are a recommended part of a healthy diet, and globally, tons of beans are exported and consumed by people / Photo by: Seksak Kerdkanno via 123RF|
Beans are a recommended part of a healthy diet, and globally, tons of beans are exported and consumed by people. However, this healthy food option is susceptible to different types of diseases. So, researchers developed and implemented a method to make beans more resistant to diseases to help livelihood and food security.
Researchers at the École Polytechnique Fédérale de Zurich or ETH Zurich, a science, technology, engineering, and mathematics university in Switzerland, created a breeding method to make disease-resistant beans. Their method could help the livelihood of regions ailing from severely reduced bean yields. They published the results in the journal Frontiers in Plant Science.
New Breeding Method Could Pave the Way for More Bean Yields
For people in Africa and Latin America, beans are very important because of two things. First, they are like the meat of the poor because people can get protein and minerals from them. Second, beans are a source of income for individuals with skills in gardening and farming. As more people around the world incorporate beans in their diet, a huge opportunity is given to bean farmers in different regions
Unfortunately, planting beans can come with major challenges including diseases that often result in very low yields. One of the diseases that terrorize bean yields is the angular leaf spot disease, a fungal infection of crops that can result in up to 80 percent of yield loss. This is particularly dreadful among bean farmers in Africa. Since they do not have the luxury to use chemicals to protect their beans, the infection can cripple their livelihood and potential source of food.
|Unfortunately, planting beans can come with major challenges including diseases that often result in very low yields / Photo by: Kostic Dusan via 123RF|
Researchers at ETH put their attention into this problem and focused on what could be done . They investigated the potential resistance of multiple beans to the aforementioned disease. Their efforts led them to an approach to enable the resistance of bean varieties in other beans, which are prone to the affliction. Also, their approach has been designed for rapid breeding to make it a practical tool in bean-producing regions.
The team was able to develop the method using genome analyses of beans that showed the resistance. Genetic profiles from the analyses pinpointed cross-breeding varieties that would produce natively resistant beans for farming.
Collecting and Cultivating the Bean Varieties
Michelle Nay, the first author of the study, gathered as many bean seeds as possible from the seed repository of CIAT, the International Center for Tropical Agriculture. Nay was able to collect 316 different bean varieties, all of which showed characteristics possible for breeding resistance. After that, they planted the beans in Colombia and Uganda in the field and greenhouses.
Planting the beans was intended to find out how the varieties would react to different pathotypes in each region. Then, they analyzed the genetic basis of the varieties' resistance to the angular leaf spot disease. Nay even created a high-resolution genetic profile of the 316 bean varieties using the variations of their genetic markers. These genetic markers were later applied to predict the progeny with resistance to the disease in each region, and which one would be more prone to it.
While the advanced breeding process is still ongoing, the design of the process hastened the search of resistant varieties. Bruno Studer, an author of the study, said that crossbreeding before is more involved in testing each plant for resistance. But the genetic test allows the prediction of resistance without the arduous field trials.
Once the results from the genetic tests are final, the genetic profile can hit two major elements in bean farming. It can help farmers in bean-producing regions deal with the fungal infection more effectively. It can eliminate, as well, the need for fungicide and pesticides, which can poison the soil and its microbial biodiversity.
|Planting the beans was intended to find out how the varieties would react to different pathotypes in each region / Photo by: Supot Suebwongsa via 123RF|
About Angular Leaf Spot Disease
According to the Ministry of Agriculture, Food, and Rural Affairs, a government ministry in Ontario, Canada, the angular leaf spot or ALS is caused by the fungus Phaeoisariopsis griseola. It is an infection considered serious in bean farmlands.
In Ontario, the fungus has been observed with a massive impact of up to 80 percent on yield loss in just one field of Roma beans in 2000. While in Brazil, the disease was initially treated as a minor threat but now, it has become a major threat in the dry bean economy of the country. Worldwide, ALS has been reported in over 70 countries, including Mexico and the US. These places confirmed ALS in different beans, including lima, scarlet runner, tepary, and even peas.
The fungus influences the yield of the beans due to the reduction in photosynthetic area. As the invasive microbe occupies more areas of the leaves, the plant cannot maximize its photosynthesis potential required for greater yields. Aside from infecting the leaves, the fungus can spread on the pods that effectively reduce quality. Full-blown ALS infection can result in yield losses of between 10 and 50 percent in the northern US while up to 80 percent in tropical and subtropical regions.