Chapter 15 - Karnal bunt (Tilletia indica) in wheat

Abstract

Climate change and regional variability of climate have always been effective in agriculture system, crops, and plant pathogen and food security. Pathogens are substantially capable of generating, recombining, and selecting combinations of variants in pathogenicity and aggressiveness traits as well. However, the relationships between pathogens and crops are complicated and uncertain concerning climate change. In the case of specific pathogens, both temporal and spatial synchronies are necessary for the survival of pathogens because the infection can occur during particular host growth stages and climatic conditions. For the past few decades, pest and disease management played a significant role in doubling food production, but pathogens have still a harmful effect on 10%–16% of the global harvest. Pathologists should work with economists and sociologists for the best understanding to control plant diseases and improve food security under climate change. Tilletia indica, the causal agent of Karnal bunt, is a significant disease in international wheat trade. Although Karnal bunt has a regional distribution, it reduces grain quality and therefore appears in quarantine lists in many countries. Infection arises from the infected seed or soil at an early stage of wheat growth. Bunted grain smells stinky owing to the presence of the volatile compound, namely triethylamine. Therefore, it causes losses in the quality of grain and grain products by discoloring and emitting an unpleasant odor. Although the infection losses are not higher from 0.3% to 0.5% of the overall harvest in the epidemic incidence, substantial losses caused by T. indica influences mainly export markets (seed and food) due to high cost of quarantine precautions and treatments of the infected grain. Because of quarantine precautions costs, control and treatment of the infected grain. Although the loss of the commercial product caused by Karnal bunt is low, it is a threat to international wheat trade. Besides, the temperature and humidity requirements vary according to the other wheat smuts. Therefore, it has the potential to be affected by climate change. In this chapter, we focus on climatic characteristics for the completion of the life cycle and the thresholds of inoculum of T. indica, the potential economic impact of food security, and effect of climate change on T. indica.