Advances and Challenges in Research on Spot Blotch of Wheat—A Major Threat in South Asia

ABSTRACT

Spot blotch caused by Bipolaris sorokiniana (teleomorph Cochliobolus sativus ) has become an increasingly important disease of wheat, particularly in regions characterized by warm, humid conditions and late‐sown crop environments. The disease is widely prevalent in the warm and humid wheat‐growing regions of South Asia, particularly across the Indo‐Gangetic Plains. Under favourable conditions, the disease may cause yield losses of about 50%, with an average loss of 15%–20%. With the continuously increasing global population, maintaining stable wheat production requires effective management of spot blotch, which has emerged as a major threat in several wheat‐growing regions. In this context, the present review summarizes key aspects of B. sorokiniana biology and provides an overview of its distribution, disease development, and associated impacts on wheat cultivation. This review also discusses epidemiological factors and challenges in disease prediction due to its complex symptoms. In addition, it provides insights into the wheat– B. sorokiniana pathosystem at the histological and molecular levels to better understand trophism. A range of strategies has been explored for managing spot blotch in wheat. These include the identification of quantitative trait loci (QTLs) associated with resistance, followed by their use in breeding programmes through marker‐assisted selection. Recent advances in genomics‐based tools and their potential to support more effective disease management in the future are discussed.