Bipolaris sorokiniana associated with common root rot in Azerbaijan and Kazakhstan

Abstract

Wheat (Triticum spp.) is the third most important crop in terms of global production, with an average annual production of almost 219 million ha and yielding 760.9 million tons, after maize and rice. However, A complex of fungi attacking the crown and root tissues of wheat causes a serious problem and significant yield reductions in wheat. Although most prevailing species in this complex can change yearly and regionally in dryland winter wheat production areas, Bipolaris sorokiniana Shoemaker (teleomorph: Cochliobolus sativus) is one of the dominant species and causes spot blotch and common root rot (CRR) on wheat plants, especially in winter wheat varieties. Comprehensive surveys were conducted to identify B. sorokiniana associated with CRR of wheat throughout the main wheat-growing areas of Azerbaijan and Kazakhstan in 2017 and 2019, respectively. As a result of the classification of species based on morphological and molecular tools, 96 and 547 isolates were identified as B. sorokiniana for Azerbaijan and Kazakhstan, respectively. All surveyed regions for these countries were contaminated with this pathogen. Some representative isolates of B. sorokiniana were tested for their ability to cause disease and produced moderate disease severities on cultivar Seri 82 (Triticum aestivum, bread wheat). The percent incidence of B. sorokiniana isolates in all isolates was 15.2% for Azerbaijan, whereas, for Kazakhstan, B. sorokiniana was the most frequently recovered species in the three regions surveyed, with an isolated frequency of 44.80%. The results of the current study provide crucial and helpful information to improve disease management strategies against CRR of wheat in these countries.