Plant disease resistance

Resistance breeding in cereals

In Chawade Lab, our research focus lies on studying the resistance mechanisms underlying disease resistance and developing genetic markers for breeding, developing protocols for large scale germplasm evaluation in breeding programs. We work in close collaboration with breeders and stakeholders in Sweden, Nordic and Baltic countries, Bangladesh and Zambia.


In wheat we are working on diseases Septoria tritici blotch and Fusarium head blight


In barley we are working on diseases scald, net blotch and powdery mildew

Resistance Breeding for STB and FHB in Wheat

Septoria tritci blotch (STB), Fusarium Head Blight (FHB) and yellow rust are the most important foliar diseases of winter wheat in Europe and specifically in Sweden. In the year 2013 and 2014, almost 80% of the winter wheat grown in Southern Sweden was infected by STB which is a significant increase from previous years. Yield loss in susceptible varieties could be up to 50% and 20-30% in the resistant varieties. Furthermore, Septoria has developed resistance to multiple fungicides and has thus put a tremendous pressure on the research community to develop STB resistant winter wheat. Improvement in the resistance is slow due to very few genetic markers and difficulties in phenotyping for STB resistance in wheat. 

Apart from lowered yield and reduced grain quality, the biggest concern with FHB is the accumulation of mycotoxins in the infected grains. Mycotoxins are secondary metabolites produced by Fusarium upon infection. FHB resistance is a quantitative trait controlled by multiple genes, making it difficult to determine resistance mechanisms and breed resistant cultivars. Major QTLs explain only a small part of the total variance.

Research Outcome from Chawade Lab
  • Characterized local virulent isolates for STB and FHB
  • Developed protocols for disease screening under controlled conditions
  • Hundreds of breeding and genebank winter wheat germplasm evaluated for FHB and STB using our developed protocols
  • Developed genetic markers for STB and FHB
  • All results provided to the breeding company Lantmännen, Sweden
  • Germplasm, markers and protocols being used in the breeding program
  • All breeding markers, protocols and identified germplasm published in peer-reviewed papers. Please visit Dr. Aakash Chawade’s  google scholar.

Resistance breeding for Wheat blast disease

Wheat blast (WB) caused by the fungal pathogen Magnaporthe oryzae pathotype Triticum (MoT) has become a significant threat to wheat production in warm and humid areas. WB was first discovered in Brazil in 1985 and then gradually spread to the neighbouring countries, causing yield losses in a range of 10 to 100%. In February 2016, the first intercontinental observation of WB beyond South America was recorded in Bangladesh (Asia). Recently, the disease was observed in the continent of Africa, Zambia, for the first time on wheat grown in experimental plots and farmers’ fields. WB transboundary jump to South Asia and then Sub-Saharan Africa originated from South America threatens food security and farmers’ income. Zambia, located at the crossroads of Central, Southern and East Africa, is particularly a unique country in terms of importing and exporting (to neighbouring countries) wheat within a year that increases the possibility of wheat blast spread. The fast-spreading and fast-acting nature of the pathogen makes it one of the most horrendous wheat pathogens, and a collaborative inaction to mitigate this disease will definitely lead to its spreading to other Asian and African countries, threatening inhabitants’ food and income security.

Dr. Aakash Chawade has two ongoing projects on wheat blast with research focus on

  • Germplasm evaluation and development of genetic markers
  • Creating awareness through workshops, farmer’s field school and mass media.
  • Development of Early Warning System (EWS) based on climatic favourability, surveillance, and monitoring of WB incidence and crop stage in Zambia and neighbouring countries.
  • Characterizing MoT isolates from Bangladesh and Zambia.
  • Capacity development and dissemination of the results to researchers, farmers and other stakeholders.

Resistance Breeding in Barley

The yield loss due to fungal diseases in barley can vary depending on factors such as the severity of the infection, the stage of crop development when the disease strikes, environmental conditions, and the effectiveness of disease management practices. However, fungal diseases collectively can cause significant yield reductions in barley production. For instance, diseases like scald, powdery mildew, net blotch, spot blotch, Fusarium head blight (scab), and leaf rust can all lead to yield losses ranging from 10% to 50% or even higher under severe conditions.

We have recently identified several genebank accessions with higher resistance to scald disease. The markers for scald and the protocol for evaluation is being transferred to the barley breeding program. Other ongoing projects are on powdery mildew and net blotch diseases.