Molecular and pathogenic characterization of Cochliobolus anamorphs associated with common root rot of wheat in Azerbaijan

Abstract

Genetic variation among the Azerbaijani isolates of anamorphs of Cochliobolus spp., the causal agents of common root rot of wheat, was evaluated using pathogenicity assessments, sequence analyses of the internal transcribed spacer (ITS) region and glyceraldehyde-3-phosphate dehydrogenase (GPDH) gene, as well as inter-simple sequence repeat (ISSR) and inter-primer binding site (iPBS) markers. Twenty-eight isolates used in this study were obtained from diseased wheat plants in cereal growing regions of Azerbaijan in 2017. Bipolaris sorokiniana, Curvularia spicifera, and Curvularia inaequalis were identified. Bipolaris sorokiniana isolates were the most virulent on wheat seedlings, followed by isolates of C. spicifera and C. inaequalis. Phylogenetic analyses of a combined dataset of the ITS and GPDH regions grouped the isolates into three clusters, each of which contained isolates of one species. The dendrogram derived from the unweighted pair-grouped method by arithmetic average (UPGMA) cluster analyses based on the data of ISSR and iPBS markers divided the isolates into three clusters in concordance to their taxonomic grouping at species level, but without correlation to their geographic origins. Population structure of isolates was estimated based on Bayesian modelling, and this showed three populations (K = 3) supporting the separation of isolates in the dendrogram with the greatest mean value of Ln likelihood (-893,8). Utilization of the markers either separately or together produced a high level of polymorphism at interspecies level, which allowed for the separation of species. Although both marker systems had similar discrimination power to reveal genetic differences among the species, ISSR markers were more informative for eliciting intraspecies polymorphisms within B. sorokiniana and C. spicifera isolates. This is the first study on genetic diversity and population structure of anamorphic stages of Cochliobolus associated with common root rot of wheat using iPBS markers.

Occurrence of Spot Blotch in Spring Barley Caused by Bipolaris sorokiniana Shoem. in South-Eastern Kazakhstan

“…e conidium sizes of the B. sorokiniana in barley examined in this study were consistent with that description from Sivanesan [18] and showed similar results to those obtained in previous studies by Samuels and Sivanesan [25], Agrios [2], and Özer et al [5,6].…”

“…The conidium sizes of the B. sorokiniana in barley examined in this study were consistent with that description from Sivanesan [ 18 ] and showed similar results to those obtained in previous studies by Samuels and Sivanesan [ 25 ], Agrios [ 2 ], and Özer et al [ 5 , 6 ]. The conidium characteristics were useful criteria for the discrimination of B. sorokiniana isolates from other isolates due to their morphological similarities [ 5 , 6 , 25 ].…”

“…Recent studies devoted to studying B. sorokiniana in cereal diseases were carried out to reveal the population structure of leaf pathogens of spring wheat in Northern Kazakhstan [ 11 ] and the host compatibility of barley varieties to the pathogens of leaf spotting based on the artificial infectious background [ 6 ]. Most recently, the International Maize and Wheat Improvement Center (CIMMYT) conducted two intensive surveys on soilborne diseases in cereals in main cereal-growing areas in Kazakhstan [ 5 , 12 ].…”

“…Cochliobolus sativus Drechsler ex Dastur, anamorph Bipolaris sorokiniana (Sacc.) Shoemaker is a fungus in the Ascomycota division and one of the most important soilborne pathogens that causes root rot and spot blotch diseases in cereal crops, including wheat, barley, and triticale [2][3][4][5][6]. B. sorokiniana has wide geographic and host ranges [2,3].…”

Fungal Pathogens Associated with Crown and Root Rot of Wheat in Central, Eastern, and Southeastern Kazakhstan

“…sorokiniana . These findings imply that the distribution of individual species appears to be related to their adaptation to specific environments [ 16 , 72 , 73 ].…”